Port Moresby Power System Survey - Report
December 2011
1
Table of Contents 1
Introduction
1.1
Summary
1.1
Geographical Location
1.1
PNG Economy
1.1
Land
1.5
Climate Conditions
1.6
Seismic Risk
2
Electricity Industry
2.1
National Energy Policy
2.2
PNG Power Limited
2.3
Private Sector Participation
2.4
The Independent Consumer and Competition Commission (ICCC)
2.5
The Independent Public Business Corporation – (IBPC)
3.
PNG Electricity Market
3.1
Electricity Tariffs
3.2
Customers
3.3
Load Demand
3.4
Load Forecast
4
Port Moresby Power Generation
4.1
Laloki Hydroelectric Scheme
4.2
Moitaka Thermal Power Station
4.3
Kanudi Thermal Power Stations
4.4
Generation – Long-term Development Program
4.5
Generation Reliability
4.6
Power System Losses
6
Generation - Conclusions and Recommendations
7
Transmission - Conclusions and Recommendations
2
List of Appendices
Appendix 1
Port Moresby – Generation transmission and water flow diagram
Appendix 2
Survey of the status of equipment in outgoing bays of power stations and sub-stations (66, 33, 22, 11 kV switchgear)
Appendix 3
Hydro Generation Equipment - Summary
Appendix 4
Thermal Generation Equipment - Summary
Appendix 5
Generation Unit Inspection Report
Appendix 6
Survey of the generation sites and sub-stations in the Port Moresby supply area
3
1. Introduction
1.1 Summary The Independent Public Business Corporation (IPBC) of Papua New Guinea, in pursuit of its interest in improving the performance of the power supply system in Port Moresby, invited The LR Group (LR) to undertake a Survey of the Port Moresby power system and to put a proposal for an IPP as part of a structured strategy in pursuing IPBC’s requirements. To facilitate IPBC requirements, IPBC and LR executed a Memorandum of Agreement (MOA) to enable LR to commence the Survey of the Port Moresby power system. The LR team comprised power system engineers from within the LR Group, the Israel Electric Corporation (IEC) as well as Innovative Agro Industry Ltd (IAI), a PNG subsidiary of the LR Group . Under the provisions of an MOA entered into by IPBC and the LR Group, the LR Group and the Israel Electric corp. (IEC) surveyed the Port Moresby Power System.
The Survey has been prepared based on information presented at meetings with PNG Power (PPL), management and staff, site visits at all hydro and thermal generation stations and substations, and partial survey of the transmission lines in the vicinity of Port Moresby, as well as interviews with relevant PPL operations and maintenance professionals at head office and at PPL generation and sub-station sites. The main outputs of this Report as provided for in the MOA include the following aspects:
Examination of the: o
Operational scheme of the generation stations, the transmission grid and the 11/22/33/66 kV sub-stations (see diagram Dwg. No. SOD-284/1 as of 24/08/2011).
o
Operating regimes of the generation, transmission and transformation sub-station systems (bus ties, zero-point regime, short-circuit currents, automation, SCADA).
o
Condition of the main equipment and its adaptation to the conditions of the system (switching gear, circuit breakers, disconnects, main transformers and measurement equipment and safety)
Review and assessment of maintenance regime.
Review and assessment of the transmission lines system and sub-station equipment o
Protection systems.
o
Utilization of capacitor banks for improving power factor.
o
Automation system for improving response to power supply interruptions and disturbances.
4
Identifying critical locations at which priority should be given for equipment enhancement and maintenance.
Recommendations
In network control and power system operations to bring about change in “culture” towards efficiency and industry's best practices in power system operations.
Propose short and long term development strategies including: o
An IPP proposal for Port Moresby
Assessment of energy consumption and demand levels and projected growth for Port Moresby.
Miscellaneous
The report does not include a survey as to the condition of the distribution and low voltage grids. Separate attention should be given to these issues. Site visits in PNG were held by the experts s during the second and the third weeks of November 2011. LR Group wishes to thank PNG Power management and staff for the hospitality and assistance rendered. 1.2 Geographical Location Papua New Guinea (" PNG") is located in the western part of the South Pacific Ocean and occupies the eastern half of the island of New Guinea and has numerous offshore islands. The capital is Port Moresby which is located on the shores of the Gulf of Papua, on the southeastern coast of the island. Port Moresby is located in the National Capital District. Port Moresby population is 804,000 and is estimated to grow to 3.5 Million by the year 2030.
5
1.3 PNG Economy PNG is richly endowed with natural resources, but access is hampered by rugged terrain, and this is the one of the contributing factors to high cost of developing the infrastructure. The economy has a small formal sector, focused mainly on the export of natural resources from its mining and hydrocarbon industries , while the informal sector employs the majority of the population. Agriculture provides a livelihood for 85% of the population. The Country has a notable coffee industry and other crops include Coco a, Palm Oil and Tea .
Mineral deposits, including oil , copper and gold , account for 72% of export earnings and Natural gas reserves amount to an estimated 227 billion cubic meters. A consortium led by EXXON-MOBIL- is constructing a liquefied natural gas (LNG) production facility 25 KM south of Port Moresby and first shipment of LNG is expected in 2014. The Project is the largest investment in the Country's history, it has the potential to double GDP in the short-term and triple Papua New Guinea's export revenue. Table 1.3 – Economic Data 2010 Population
2009
2008
6.187
Unit Million
Port Moresby Population
314,000
Population growth rate
1.985
GDP
14.95
13.97
13.24
Billion USA $
7
5.5
6.6
%
2500
2400
2300
USA $
2.757
Billion kWh
GDP Growth Rate GDP per Capita
%
Electricity Consumption Oil production
30,570
bbl/day
Oil consumption
33,000
bbl/day
Natural Gas Production
130
6
Million cu m
1.4 Land The PNG legislature has enacted various laws in which a tenure termed "customary land title" is recognized, meaning that the traditional lands of the indigenous people have some legal basis to inalienable tenure. This customary land covers most of the usable land in the country (some 97% of total land area); alienated land is either held privately under State Lease or is government land. Freehold Title (also known as fee simple) can only be held by citizens of Papua New Guinea. Only some 3% of the land of Papua New Guinea is in private hands; it is privately held under 99 year state lease, or it is held by the state. There is virtually no freehold title; the few existing freeholds are automatically converted to state lease when they are transferred between vendor and purchaser. Un-alienated land is owned under customary title by traditional landowners. 1.5 Climate Conditions The Port Moresby weather is tropical with average temperature around 27 C◦ with slight seasonal temperature variations. The average rainfall is around 1000mm per year.
28°
28°
27° 196
27°
27°
26°
26°
26°
28°
27°
26°
28°
190
179
121
120
65
55 39 26
_ Jan
_ Feb
_ Mar
_ Apr
_ May
_ Jun
_ Jul
_ Aug
35
33
25
_ Sep
Temperatures °C (degrees Celsius) in Port Moresby Rainfall (mm) in Port Moresby (Average values for each month)
7
_ Oct
_ Nov
_ Dec
1.6 Seismic Hazard PNG is located on the Pacific Ring of Fire, at the point of collision of several tectonic plates. There are a number of active volcanoes, and eruptions are frequent. Earthquakes are relatively common, sometimes accompanied by tsunamis.
2. Electricity Industry 2.1
National Energy Policy
PMG’s Energy Sector policy formulation is managed by the Ministry of Petroleum and Energy and, specifically, by the Energy Division of the Department of Petroleum and Energy (DPE). Technical regulation of the electricity industry is currently performed by PNG Power Ltd. under a contractual agreement with Independent Consumer and Competition Commission (ICCC), which is responsible for the regulation of the electricity industry. However, it is intended to eventually transfer this function to the Energy Division of (DPE).
The Electricity Industry Act, 2002 currently governs activities of the power sector in PNG.
The PNG Government has recognized the range of issues facing the power sector and has prepared the electricity industry policy (EIP) including: facilitating competition and contestability in the electricity industry and bringing certainty to investors in the sector by developing a clearly defined access regime, and encouraging private participation in the sector. National Executive Cabinet (NEC) approval of the EIP is pending.
The Energy Division of the Department of Petroleum and Energy with support from the Asian Development Bank (ADB) completed the national power sector development plan in 2009 under a technical assistance (TA) project. The long term objective of the TA is to increase the availability of reliable and sustainable power supply in PNG at reasonable cost.
Electrification is important for economic growth and an expanded and more efficient electricity system will be an integral element of successful economic development in PNG. The Government’s Medium Term Development Strategy 2005-2010 (MTDS) does not prioritize government spending on electrification, which
was predicated on the expectation that the
private sector would finance necessary power investments, and that national budget resources
8
could focus on nonrevenue-generating economic and social infrastructure, education, health, law and order and physical infrastructure (roads, airports, wharfs and others). The Government, IPBC and PPL recognize that the private sector will play an important role in providing investment and management capacity for power sector expansion. The government has prepared the Public Private Partnership (PPP) Policy, which will support development of private sector participation in the power sector, along with the EIP. To date the market has not responded as expected, investments in power generation, transmission, and distribution capital assets, especially in smaller urban centers (towns), villages, and rural areas, appears to be less attractive. However the PNG Sustainable Development Ltd (PNGSDP) has made some intervention in the power sector.
2.2
PNG Power Limited
PNG Power Limited (PPL) is the national state-owned corporatized power utility company, established in 2002 following the commercialization of the former PNG Electricity Commission. The government's ownership in PPL is maintained through the Independent Public Business Corporation (IPBC). PNG Power operates 19 independent grids and transmission systems. These grids supply power to the national capital, Port Moresby, and to 26 other urban centers. Total installed capacity of the state-owned utility is around 300 MW. There is an additional 280MW generated by other entities that consume power mainly for their own use.
These
include power supply from the Hides Gas Field in the Southern Highlands Province to the Porgera gold mine, the OK Menga hydro and diesel generation of 56MW by the OK Tedi mine and 54MW of geothermal capacity utilized by Lihir Gold. The other main area of generation is the Ramu hydro system, which has 87MW of installed capacity. Said capacities are supplemented by standby diesel generators in Lae, Madang, Mendi and Wabag in the Momase and Highlands regions. There is an additional 12MW of hydro capacity in the Islands Region, also supplemented by diesel generation. PPL’s generation capacity is summarized in Table 2.2.1.
9
Table 2.2.1 – PNG Power Generating Capacity System
Site Capacity Hydro MW
Site Capacity MW Thermal
Total
Port Moresby
62
65
127
Ramu
82
21
103
Gazelle
9
6
15
Minor Centers
2
26
28
155
118
273
Total
PPL’s main transmission systems are located in the Port Moresby, Ramu and Gazelle power systems. While the distribution network covers some 3,300km of which 2800km are in the Port Moresby, Ramu and Gazelle areas and 500km in other locations.
Table 2.2.2 – PNG Power Transmission Systems System
Line length km 132kV
Line length km 66kV
33kV
Total
Port Moresby
-
151
17
168
Ramu
155
558
-
713
Gazelle
-
75
-
75
Total
155
850
17
956
Energy sales are expected to be in line with the level of economic activity and are forecast by PNG Power to grow at 1-2 % per annum over the next five years.
11
Table 2.2.3 PNG Power - Energy Sales Energy Sales MWh System
Demand
General
Household
Total
Supply Port Moresby
17,306
258,384
53,336
329,026
Ramu
40,070
139,805
41,020
220.895
Gazelle
-
24,336
5,922
30,258
Minor Centers
-
42,889
17,222
60.111
57,376
465,414
117,500
640,290
Total
2.3
Private Sector Participation
There are a number of private sector power generators currently operating in PNG: (i) Hanjung Power Ltd, a private company that operates a power station (26.4 MW) supplying the Port Moresby grid; (ii) A PNG Sustainable Energy Ltd subsidiary company which operates a number of rural grids in Western Province and is expanding operations to other parts of the country; (iii) Mining operations that maintain significant levels of self-generation capacity. (iv) Provincial Governments have responsibility for maintaining a number of stand-alone rural generation facilities (C-centers). (v) Churches provide electricity to some off-grid rural areas. (vi) The larger mining sites sometimes provide power to adjacent communities.
From 1999 the Korean-owned Hanjung Power Ltd; under a 15-year build-operate-transfer agreement, provides power from its 24MW Kanudi diesel power station to the Port Moresby
11
electricity grid. Hanjung Power Ltd has operated and maintained the Kanudi IPP plant underan O&M agreement by DECCO PNG LTD. 2.4 The Independent Consumer and Competition Commission (ICCC ) The ICCC is the Consumer Watchdog and Economic Regulator in Papua New Guinea. It was established by an Act of Parliament namely, the Independent Consumer and Competition Act, 2002 (ICCC Act) and came into operation on 16 May 2002. The primary function of the ICCC is to promote competition and fair trading, protection of the rights and interests of consumers in the market place, and to regulate the prices and standards of certain goods and services that are stipulated by Government The ICCC Act introduces a regime for the regulation of a number of government-owned utilities, including the electricity industry.
The framework was introduced in conjunction with the
corporatization and possible privatization of a number of those utilities. The corporatized utility business will be subject to a 'regulatory contract', which sets out, among others , a future ten-year price path for the monopoly services provided by the utility, together with requirements covering about the quality of service. The utilities' obligations under the regulatory contract are supervised by the ICCC, which is a party to the contract..
2.5 The Independent Public Business Corporation – (IPBC) The Independent Public Business Corporation of Papua New Guinea (IPBC) was established in 2002 as an Independent Entity under its own Act to hold the majority of state-owned commercial assets in trust and to manage those assets prudently to improve commercial performance and underpin economic development IPBC's mission is to institute stronger governance, best practice and commercial accountabilities structures in IPBC to maximize the value of its assets and investments for the benefit of the State and the people of Papua New Guinea. 3
PNG Electricity Market
In all Papua New Guinea (PNG), less than 10% of the population has access to electricity. Where power is available the supply is often unreliable. The unreliability of power in urban areas discourages economic development.
12
Due to the unreliability of the power supply all of the important consumers have considerable self-generation and back-up generation capacity, which is expensive and inefficient. It is estimated that there is around 80 MW of self-generation in the Port Moresby area. PNG has about 580 megawatts (MW) of installed generation capacity, including hydropower (230 MW, or 39.7%), diesel (217 MW, or 37.4%), gas-fired (82 MW or 14.1%), and geothermal (53 MW or 9.1%). PNG has significantly underutilized indigenous energy resources such as hydropower, natural gas, geothermal, and solar. 3.1 Electricity Tariffs Power tariffs are independently regulated by the ICCC and allow full cost-recovery for PPL. Power tariffs are set on a national basis, resulting in uniform tariffs irrespective of local generation costs. The uniform tariff structure cross-subsidizes tariffs for consumers in high-cost centers (provincial centers) through the lower generation costs from the main grids (the Port Moresby and Ramu grids, which are predominantly hydropower-based, and therefore relatively low cost). However, the uniform tariff provides a disincentive for PNG Power to invest in high costgenerating areas, including provincial centers where high reliance on diesel generation and high diesel transport costs have resulted in high generation costs. The current average single national tariff structure which came to effect on 1 January 2011 is 0.77 Kina/kWh (0.41 $ /KWh)
3.2 Consumers The consumers are divided into 3 categories: Industrial Customers (above 200 kVA) General Supply Customers Domestic Customers Billing is based on both credit and prepaid metering. Small electricity consumers are obliged to buy electricity from PNG Power, consumers over 10MW can buy the electricity they need from alternative suppliers if they exist in their specific region. Large industrial users operate off-grid with self-generated power. 3.3 Load Demand As shown in the diagram below, the maximum demand retains the same level throughout the year with a minor fluctuation during summer and winter variation.
13
The demand reached peaks of 91.5 MW in 2009, 94 MW in 2010 and 96 MW in 2011 (0/11/11 13:00). The overnight load drops to approximately 40–50 MW. The weekend maximum load drops to 75-65 MW.
In order to evaluate the daily load demands profile, we chose the 10/11/11 as a Test case day. It turned out to be the day of maximum demand ever in POM. As should be expected, the Rouna hydro scheme runs base load, providing 58% of the energy required. Kanudi IPP is the second contributor using HFO supplying 26% of the demand (24 MW during the day time and 12 MW during the night). The balance of load is supplied Moitaka Diesel (9.6%), Moitaka GT 4.7%), and Kanudi GT (1.4%).
14
Taking into consideration the available generation units, this is the appropriate operating method to minimize fuel cost and to keep enough spinning reserve to be able to pick up the load quickly in the event of a default in one of working units.
15
Port Moresby -Energy Contribution
Gas Turbine 6%
Engine 36% Hydro 58%
3.4 Load Forecast PPL electricity forecast are updated each year on a center by center basis and then aggregated on a system-wide basis for PPL's total. Several sources of data are considered in developing the forecast, including economic indicators such as the non-mining GDP, government budgets and policies, the population and known load developments. Taking into account the impact of the PNG LNG project, PPL has derived the forecast peak demand growth rate. With a loss factor of 25% (losses) the required generation in the following years will reach 113 MW in 2012, 121.6 MW in 2013 and 127.3 MW in 2014, as provided in the diagram below:
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
160.9
155.3
149.7
144.1
138.5
132.9
127.3
121.6
113
98.9
90.11
16
Year Peak Load
The impact of the expected LNG boom in the coming years has a major impact on the forecast demand and it could reach up to 14% in 2012 and 8% in 2013 as reflected in the generation growth graph adopted by PPL, the long term growth rate is 3-4%
The forecast should be reviewed in the context that historically PNG Power’s previous forecasts tend to be higher than the actual demand. PPL will be required to review its generation forecasts as soon as the full impact of the new LNG plant and other resource boom becomes clearer
17
2020 826 657 25.7%
2019 797 634 25.7%
4.
2018 769 611 25.9%
2017 740 588 25.9%
2016 711 565 25.8%
2015 682 542 25.8%
2014 653 519 25.8%
2013 624 496 25.8%
2012 580 461 25.8%
2011 508 403 26.1%
2010 482 401 20.2%
Year Generation Sales Loss
Port Moresby Power Generation The Port Moresby system consists of three generation sources: The Laloki Hydroelectric scheme, the Moitaka thermal station and the Kanudi thermal stations.
The system is compact and the distance from Rouna 2 to Kanudi is less than 30 KM.
The PPL total installed capacity in Port Moresby is 171.5 MW but the actual capacity is 128.6 MW (including 15 MW which are now out of service due to long-term maintenance).
Except for the Kanudi IPP units no PPL thermal generation unit achieved its nameplate rating. The thermal total name plate capacity is 102 MW, the actual capacity is only 78 MW,
18
there is a 23% loss of output without a formal reason for the de-rating of the units. It seems that the operators tend to de-rate the units in order to ensure the sustained work of the production units and improve their reliability. Another aspect of working with de-rated thermal generation units is that fuel consumption is unnecessarily increased by as much as 30% more per MWh when working at 50% output and furthermore this mode of operation impairs long term development planning.
4.1 Laloki hydroelectric scheme (for equipment details see appendix 3) The Laloki hydroelectric scheme is located on the Laloki River, 35 KM out of Port Moresby, utilizing a total head of some 300 meters. There are two catchments. The uncontrolled catchment flow is measured in the Eworogo River and is utilized first by the four (4) Rouna cascade stations. The controlled catchment discharge is regulated from the 345 million cu m storage reservoir at Sirinumu dam. The Rouna power stations were constructed between 1955 and 1986 in stages and today include four power stations in a cascade design scheme: 4.1.1
Rouna 1 - Constructed between 1955 and 1961 with original capacity of 5.5 MW,
from 4 horizontal Francis turbines. Today the penstock for units 1 and 2 has been dismantled and unit 4 with 2.5 MW capacity is out of service due to main valve sealing problems. We understand that currently there is a bidding process taking place for rehabilitation of this unit and that PPL has already received proposals for the works and a decision for their award is pending. 4.1.2
Rouna 2 - The station was excavated out of solid rock, 150 meters beneath the
bed of the river with a total capacity of 30MW from 5 vertical Francis turbines each of 6 MW capacity. The design output capacity of Rouna 2 is 24 MW. Following a recent refurbishment and upgrade project, the station now has 3 units each of 8 MW capacity and 2 units each of 6 MW capacity. The refurbishment and upgrade work was carried out in 2008 by VA Tech an Austrian company and who installed four new “Andritz” turbines and three “Elin” generators. 4.1.3
Rouna 3 - This station is adjacent to the Rouna 1 station and has a capacity of
12 MW (two Bell Engineer 6 MW horizontal Francis turbines) and was completed in 1974. 4.1.4
Rouna 4 - This 13.5 MW power station is located last in the chain of stations and
picks up water downstream from Rouna 1 and Rouna 3 stations. It has an installed capacity of 13.5 MW (two Ebara 6.9 MW horizontal Francis turbines). 4.1.5
Sirinumu – a toe-of-the-dam generating set with a 1.6 MW (Andritz vertical
Francis turbine) original capacity, installed in 1971.
19
In summary, the Rouna 1 plants are old and should be replaced during 2012-2013 with a new plant. Rouna 2 station is in good condition due to the 2008 refurbishment and upgrade project. Rouna 3 plant, unit 1 is out of service due to shaft problems that should be repaired by early next year. The Rouna 4 station is in good condition.
The Laloki hydroelectric scheme also supplies the raw water supply for the Port Moresby municipal water treatment plant at Mt Eriama at the combined rate of 2.8 cumecs from the Rouna 1/3 and Rouna 4 head ponds. The Laloki hydroelectric scheme can be considered as fully developed for the high head station as well as reaching the water flow maximum capacity.
4.2 Moitaka Power Station (for equipment details see appendix 4) 4.2.1
Moitaka Engines
The four engines were installed between 1985 and 1989. The Moitaka unit 1 is out of service due to head service (by "Wartsila"), all other engines (unit 2, 3 and 4) were working at time of visit with de-rated capacity of around 4000 hours per year. The units are half way through their nominal designated design life.
4.2.2
Moitaka Gas Turbine: LM 2500 GE gas turbine, installed in 1982 and works at around 3000 hours per year. The GT name plate capacity is 20 MW, the calculated capacity (due to air temperature and turbine age) should be around 17-18 MW, however the actual capacity is 10 MW. In 2008 the GT was overhauled by “Air New Zealand”.
4.3 Kanudi Power stations (for equipment details see appendix 4) 4.3.1
Independent power producer (IPP) with two HFO 12 MW Hanjung engines operating at industry standard availabilities with the original output.
4.3.2
PNG Power installed two new (2010) Solar turbines T-130 –Titan 13.5 MW gas turbines which were installed with only 10 MVA transformers (The transformers are scheduled to be replaced).
4.4 Generation long term development program PNG has not utilized yet indigenous energy sources such as hydropower and the country is going to produce natural gas by 2014 from the PNG LNG project.. The development of hydrobased power remains a high priority wherever economically and financially justified.
21
Additional generation capacity identified in PPL’s Power Development Plan for 2009-2018 to meet the growth in the Port Moresby system demand include: Rouna 1 upgrade to 6–8 MW, schedules to be installed by January 2013 Naoro Brown hydro power will proceed with the installation of 2X20 MW units by 2016 - 2017 Kanudi IPP units should remain in service after the end of the Power Purchase Agreement in 2014.
Comparing the forecast peak demand and the forecast generation capacity for the years 2011 to 2020, it is considered that there is sufficient name plate capacity (the existing capacity is a lot less) and the system will have between 21% to 50% reserve plant margin, a reserve plant margin of 25% for power systems such as Port Moresby are considered sufficient to avoid unserved energy due to generation shortfalls. However, if existing site ratings are used, then the reserve plant margin falls to 16.5% in 2014 and 11.6% in 2015.
Under the existing rating the reserve plant margin falls to 16.5% in 2014 and 11.6% in 2015.
21
We conducted a simulation to find out what units can be taken off the grid to avoid shedding and found that in 2011 up to 3 units (N-3), 2012-2013 up to 2 units (N-2 ), 2014 up to 1 unit (N-1) and from 2015 to 2019 up to 2 units (N-2).
4.5 Generation Reliability and Availability In 2001 the ICCC and PPL entered into an "Electricity Regulatory Contract". Under this contract (Clause 6.3) PPL must supply electricity with Un-served Energy Ratio (UER) below a target
22
that was set in the Port Moresby zone at 0.22% (1156 minutes per annum) for 2009, 2010 and 2011 . UER during the last few years has improved significantly compared to the years before but it is clear that the stipulated and agreed target has not yet been met. The 2009's UER of 0.8% and 2010's with UER of 1.37 % mean that the Port Moresby consumers suffered between 4200 to 7200 unsupplied minutes per annum . This situation is unacceptable for modern electric generation systems and is well below industry standards.
The typical industry standards for stand-alone systems such as that of Israeli
Electric Corp. is around 130 minutes.
An analysis of the Un-served Energy (UE) results down into sub categories of generation, transmission and distribution showed that the main UE cause is due to generation and the distribution sectors.
Port Moresby System - Unserved Energy Ratio Distribution Transmission 8.00%
Generation
7.00% 6.00% 5.00% 4.00%
Unserved Energy as a % of total Generation
3.00% 2.00% 1.00% 0.00% 2005
2006
2007
2008
2009
2010
Year
The generation URE for 2008 was 0.38%, for 2009 – 0.25% and for 2010 – 0.73%. An analysis of the UE causes into sub categories of planned and unplanned, it is clear that the main UE accrues from unplanned causes. The absence of a planned maintenance program for the system with an acceptable redundancy level that can permit plants to be taken out of service, causes high UE in the generation and transmission systems.
23
Port Moresby -2005-2010 - Unserved Energy - Planned and Unplanned causes
8.00% 7.00% 6.00% 5.00% 4.00%
UER as % of the Total Generation
3.00% 2.00%
Planned
1.00%
Unplanned
0.00% 2005
2006
2007
2008
2009
2010
Year
Below are the available statistics of the plants in the Port Moresby system, the data was provided by PPL for the period between 14/2/11 to 29/4/11:
These figures are well below industry standards and the poor availability is the root cause for the un-served energy.. The north American Electric Reliability Corp. (NERC) provided for the following industry performance standards in the years 2006-2010: : Hydro Units
84.07%
Diesel Units
93.55%
Gas Turbine
87.33%
4.6 Power System Losses Generation losses can be caused by technical deficiency (low power factor, over loading and design adequacy) or by commercial causes (administration errors, meter bypass and illegal connections).
24
Based on information provided by PPL for the period from 1993 to 2010 the total losses of the system increased and in 2010 were over 30%!! The preliminary estimate of the technical losses on the POM system provide a total loss of approximately 13 MW which represents a loss factor of around 11%. The conclusion is that more than 19% of system losses each year are due to non- technical causes either from metering or billing errors or theft. Non-technical losses seem to be a serious problem at PPL. The high loss factor impacts and impairs the long term development plans by requiring more generation than is actually required or paid for.
The Port Moresby Power system appears to operate at a power factor of approximately 0.8 and it is recommended that PPL should aim to improve power factor to 0.9 – 0.95 by a combination of repairing and/or adding capacitor banks. Nontechnical losses are particularly not fair to paying customers as it they who carry the cost at the end of the day.
25
5.
Conclusions and Recommendations – Generation Short-term (by January 2012) PPL should take immediate remedial actions to return out of service generating units. . This action will restore over 15 MW of generation as follows: Rouna 3 unit 1 (6 MW) Out of service for more than a year due to shaft alignment problem, to be repaired ASAP with top priority. Rouna 1 unit 4 (2.5 MW) to be repaired ASAP with top priority. Rouna 2 unit 3 – Turbine Governor Problems limits the unit capacity to 4 MW – to be repaired immediately. Moitaka unit 1 – (6MW) Out of service for more than 24 months, overhaul to be completed ASAP. Sirinumu – (1.6 MW) require overhaul of the Turbine rotor.
It seems that the Port Moresby system works without a planned maintenance program. PNG Power needs to consult the equipment manufacturers and develop and implement an integrated maintenance schedule for the electric power system assets. Power Plants should be taken out of service for maintenance activities at weekends when peak demand is about 20 MW lower then on weekdays. Use of O&M subcontracting should be considered.
A detailed survey of the technical and non technical losses in the Port Moresby system is recommended with a target to reduce technical and no-technical losses to around 10% Medium-term (by December 2012) Rouna 1 upgrade to 6 – 8 MW achievable by Jan 2013 The thermal units de-rating as well as units availability needs attention for improvement. This improvement could provide the system with up to 24MW and it is recommended that the following actions are taken for each de-rated unit: (see annexure 5 ) Repair out-of-service units and return them to their name plate output and pursue practical efficiency and industry standards availability. The work done by the manufacturers shall be backed with guarantees and warranties. Plan multi-year maintenance and operating schedules and carry them out Develop O&M agreements. Immediately implement training and capacity building program for key staff in the power system O&M areas.
26
Maintenance and operating crews require training to implement ongoing maintenance and inspection programs. PPL should change the work culture such that key personal take responsibility for ensuring that necessary activities for on- going maintenance are completed on time. Long-term (from December 2012) Naoro Brown hydro power shall be added in line with the PNG Power Development plan to meet growth in system demand. Installation of 2X20 MW units by Jan 2016.
ICCC and PNG Power should agree that the
subsequent Electric Regulatory Contract
provides for realistic reliability targets. The Un-served Energy Ratio (UER) together with other performance criteria (SAIDI, SAIFI and CAIDI) are built into the ERC and provide balanced approach with regard to incentives and penalties.
We found that the generation unit remote operation infrastructure is out of service. We recommend that all power stations shall be repaired /converted to allow remote operation from a central control room supervised by professional and trained operators.
Kanudi IPP units should remain in service after the end of the PPA contract in 2014.
Natural gas should be introduced into the Port Moresby power system generation fuel mix. Conclusions and Recommendations – Transmission
6.
General o
During the visit there were several long power outages (blackouts) in the city, in addition to equipment malfunctions, such as an explosion in a transformer at the 66 kV site at the KANUDI power station, blackout events as we witnessed, and from discussions with the operating personnel and a witnessed by the
reports in the duty logs at the power
stations, are unacceptable. To improve the system
investments must be made in
infrastructure, maintenance and in supporting systems. o
We have also found that there is no organized learning and debriefing process following failure events due to a lack of on-line equipment that can monitor and control the system and record past events.
o
In the list of recommendations we shall try to focus on the main reasons that may cause these singular events, but we must state from the outset that there is no single cause,
27
there are many such causes along the segments of the electric chain that may result in local and extensive blackouts in the Capital. o
However, we should note that there is a trend of improvement in the field of replacement of the protections of the transmission and distribution grid, switchgear and control and protection systems for 66 kV and 11 kV switchgear. There is also the beginning of a process of shifting the operational communication infrastructure to a fiberoptic system.
A simplified diagram of the 66 kV system in Port Moresby
28
Equipment maintenance and spare parts The maintenance of equipment both at the power stations (especially the hydroelectric ones) and at the substations and the grid is far from satisfactory when compared to the instructions of the equipment manufacturers and the experience accumulated in various electric companies. We found oil leaks from transformers, broken insulators, exposed water-drenched cable ducts and lack of awareness regarding the protection of cables against fire. Following are some recommendations on which to focus in order to improve the current conditions: Recommendations
Establish an organized work plan for the frequency of maintenance treatments and what they entail for each type of equipment, based on the equipment manufacturers' instructions.
Step up transformers of the generation units – provide a better maintenance response, especially at units ROUNA 1, 3, 4.
Specifically for old equipment – examine the spare parts stock required for short and intermediate-term response to equipment maintenance until replacement.
Preference should be given to the maintenance of transmission lines (of which preference should be given to generation lines) as crucial starting points that trigger blackout events. Additional technological solutions should be examined to address the harsh weather conditions that characterize this tropical region. We recommend the use of SYLGARD insulator coating material which the IEC uses and has good experience with. The material is suitable for high-pollution areas, with decreased need for washing the insulators of the grid and of the power station and substation facilities (preliminary information was given to the staff at PPL).
Several transformers were found to have oil leaks and untreated rust in radiators.
Note: The allocation of authority for the maintenance of power stations/switchgears/substations is not suitably defined..
29
Safety and station environment
The considerable precipitation in the area, combined with failure to close the ducts of control cables results in permeation of water into control cable ducts. Some of them are immersed in water, which is an immediate risk.
Coating of the power cables with a fire retardant and sealing of the cable ducts with a sealant are not implemented at the stations and these deficiencies should be addressed to ASAP.
Transformers with corroded bodies, some with oil leaks which were not properly repaired, or which were not addressed at all.
Lightning protection for 22, 33, 66 kV transmission lines using surge arresters
The large number of lighting storms which is typical of the area requires the completion of deployment of ZiOx surge arresters at the exits from the circuits.
Preference should be given to the installation of surge arresters at the exits of the line bays from the power stations:
Station
Circuit #
Notes
ROUNA 2
111,115,111,111
Total 12 units
MOITAKA
111,111,115,111,115,115
Total 18 units
KANUDI
548,544,545,549
Total 12 units
BOROKO)*(
542,539,541,538,537
Total 15 units
BOMANA
547
Total 3 units
WAIGANI
539,543
Total 6 units
(*) Large switching station
Operation of the 66kV transmission system from Transmission Control and testing the system stability
From discussions with the operation personnel we got the impression that the operation of the transmission system from the transmission control is not conservative in the context of disconnecting transmission circuits for maintenance without taking into account accumulated events that may cause N-2 malfunctions and higher.
There is no central remote control over the power stations with a systems approach, so that the process of restoration from blackout is not organized and even dangerous to the employees in the field and to the equipment.
31
Recommendations
In view of the condition of the system, the capabilities of the 66 kV grid should also be designed for N-2 malfunctions. To this end an extensive check of the system should be made using power flow simulation software, as well as a dynamic simulation test that includes the generation units to test the stability of the system and provide suitable coverage by means of protection systems and main equipment (see surge arrester section), in order to prevent blackouts.
The short-circuit power (triple phase) should be checked in the 66 kV system in the present state and at the state of addition of production units in order to check the suitability of the equipment (bus bars, circuit breakers) for the required short-circuit power. Today the existing equipment is ordered for a short-circuit current of 25 kA for 3 sec.
The SCADA system should include the data from the generation units and control data in cases of emergency from the central control.
The process should be improved by means of software that is integrated with the SCADA system in order to test the condition of the system in steady state, and which can also access N-1 and N-2 risk situations that may degrade the system down to blackout.
Circuit breakers at the generation units, 3.3kV, 11 kV
The circuit breakers of the hydroelectric generation units which are of the OCB (oil circuit breaker) type are old, but at this stage there is no recommendation for their replacement.
The circuit breakers at the ROUNA1 site for a voltage of 3.3 kV are old, and priority should be given to their maintenance at least once every 6 months in view of the switching end and their synchronization with the system. Special attention should be given to oil replacement and to checking the level of water in the oil (ppm) and the breakdown voltage (Vp)
The circuit breakers of the units at the ROUNA 3, 4 sites for a voltage of 11 kV are in good condition, and can be used until a decision is made as to the future of the units and/or up-rating.
From the spare parts aspect there does not seem to be a problem and, for example, equipment from the decommissioning of units 1, 2 at ROUNA1 site can be utilized.
31
66 kV circuit breakers
The circuit breakers in the line bays in the 66 kV grid are critical elements in the transmission system, and priority should be given to the maintenance of this equipment, which may cause blackouts in the area.
Check the suitability of the circuit breakers to the existing and expected short-circuit power (triple-phase short-circuit current) in accordance with the equipment unit addition plan. Also, the capability of the bus bars and their suitability to the short-circuit power are to be checked (with a view to at least the next 5 years).
Concerning the circuit breakers in the 66 kV segments, it should be noted that these have a triple-phase connection and disconnection mechanism. In addition the starting voltage for the mechanical drive mechanism is AC voltage from the station's home consumption. The clear disadvantage of this arrangement is that during blackout situations the circuit breakers can’t be operated until the start of the system restoration process, at least to a stage where the station has voltage. This puts the operating personnel in the field and the equipment itself at risk. Discussions made with the field personnel revealed that malfunctions in the starting mechanism do occur, and especially so after blackouts, which causes a condition where the system does not return to its regular operating state (usually without one or more line bays).
In view of the large number of outages (blackouts) and obstacles from the route along which the lines/circuits pass, the following activities in the field of equipment and automation should be considered:
Recommendations
A process of integration of circuit breakers at the exits from the circuits with a singlephase activation mechanism and integration of a reclosing automation system to reduce the number of long interruptions of the transmission lines.
Check the possibility to supply the circuit breaker motors from a DC source, rather than from an AC source as used today. From experience with suppliers of circuit breakers and dis-connectors for the circuit breakers are of universal motor type, which allows this supply. In this respect, it is recommended to also check the power of the batteries installed at the stations (AH).
32
Capacitor Banks
Capacitor banks at the substations at the 11 kV distribution voltages have a major role in maintaining the power factors. They influence the maintenance of voltage levels in the transmission and distribution grids, the reduction of losses the transmission and distribution grids.
During a tour of the substations, we found capacitor banks installed at the stations: Station
Nominal
Operating
CAPACITY
voltage
BOROKO
2X5MVAR
KONEDOBU
1X5MVAR
Actual power 11KV
WAIGANI
1X2.5MVAR
BOMANA
1X2.5MVAR
Notes
2.8MVAR
The power rating of the capacitor bank at the KONEDUBO substation was calculated and matched to the actual readings of the capacitance current. The power was found to be 2.8 MVAR, which is about 50% of the nominal power. The reason for this is removal of malfunctioning capacitors and not replacing new capacitors in the capacitor bank.
Recommendations
Priority should be given to replacement of faulty capacitors with operational ones, and returning the bank to its nominal power.
In order to maintain accepted power factors (between 0.9 to 0.95), a project for adding capacitor banks with a power of 5 MVAR should be initiated for the following stations:
Station BOROKO
Complete capacitor Operating bank voltage -
KONEDOBU
1×5 MVAR at busbar 2
WAIGANI
1×5 MVAR at busbar 1. Complete bank 1 to 5 MVAR 1×5 MVAR at busbar 2. Complete bank 1 to 5 MVAR
BOMANA
11KV
33
Notes 2 capacitor banks exist at busbar 1,2 A capacitor bank exists at busbar 1. There is capacitor bank in connect to busbar 1 A capacitor bank exists at busbar 2. There is capacitor bank in connect to busbar 2 A capacitor bank exists at busbar 1. There is capacitor bank in connect to busbar 1
Add surge arresters at the capacitor bank entries as a means for protecting against switches (especially after transition to 11 kV switchgear with vacuum switches).
There is no remote control on the capacitor bank and no operation in day/night mode. This has to be completed at the stage of medium voltage switchgear upgrade and connection to the regional SCADA system (line control).
Add INTERLOCK control in back to back connection of capacitors, and a delay time of 15 minutes between the connection of a battery and its disconnection for reconnection.
Add line capacitors in 11 kV distribution grids where the lines are longer than average (1.5 MVAR capacitors).
Operating regime of the substation transformers and 11 kV switchgear (transformers in parallel)
Existing state
Substation transformers operate in parallel by closing bus ties in 11 kV switchgear and 66 kV switchgear. Currently there are 2 transformers that operate in parallel at the substations, aside from the BOROKO substation, where 3 transformers operate in parallel.
As surveyed in the section on substation loading, an additional transformer is required, so that the substations operate with 3 transformers (currently, the T2 transformer at the BOROKO substation is scheduled to be moved to the WAIGANI substation). The 11 kV distribution voltage switchgear is being upgraded (see changes and improvements) and its transformation capabilities are being enhanced. Attention should be given to the operating regime of the transformers to be integrated in the expansion of the substations, and to addition of transformation.
34
Shortcomings of the current method for operating transformers in parallel
At present the short-circuit currents on the distribution voltage side are large, which puts the switchgear in danger, and in particular endangers the distribution grid gear that leaves the switchgear. (Short-circuit currents exceeding 10 kA on the 11 kV and distribution grid side). At the BOROKO switching station there are 3 transformers in parallel, and this puts the equipment and the switchgear in danger. The operation of the voltage regulator of the transformers which requires that one regulator be operated as master and the other as follower, results in suboptimal regulation of voltages for different end users.
Recommendation
With the current stage of upgrading the high-voltage switchgear and adding required transformation at the substations, the following recommendations should be considered: •
Opening of the 11 kV high-voltage bus ties.
•
Implement balanced and/or equal distribution of loads between main transformers must
be balanced between load transformer in each bus bar.
To design the operation of the transformers' voltage regulators from each basbar to which the transformer voltage are connected, to avoid voltage problem control to customers near and far from sub- station. Monitoring disturbances
Disturbance monitoring (and installation of event recorders) is currently not carried out in the Port Moresby power system particularly for transmission grid faults. Detection of the fault distance, will assist in locating the fault and minimize power outage duration. There appears to be no awareness concerning the requirement of debriefing and deriving to conclusions to prevent repetition of power outages thereby improving system performance.
Recommendation
Install event recorders at the stations to provide full coverage of the distribution lines in the regional 66 kV grid.
35
Station
# of bays to connect to event
Notes
recorder
ROUNA 2 MOITAKA
6 6
BOROKO KANUDI
5 4
Digital protection Electromechanical protection Digital protection Digital protection
Connecting current and voltage channels and digital data from the circuit protection
Add an operational logger to record events at the power stations and at substations.
Additional issues
Updating the one-line diagram – there are discrepancies between the actual state in the field and the diagram as presented to us: Station MOITAKA
BOROKO WAIGANI
KANUDI
Finding in the field There is a full tie between the fields of circuits 543 and 538 in the 66 kV switchgear Current transformer in the bay of the 66 kV busbar tie Disconnector in the bay of the tie (towards circuit 543) There are four 13 MVA transformers for the generation units of PPL and 19 MVA transformers. The separation boundary and the private generation switchgear are not marked
BOMANA
Status in liner diagram No tie
No current transformer Without side disconnector in the tie bay SLD not up-to-date with respect to transformers, including the transformers of the Kanudi IPP
Transformer T1 transforms 66/11 kV when the supply from bay 402 is at 33 kV from ROUNA1 The scheme shows 33 kv line connection (402) to transformer BM4T1 in Boana with ratio of 66/11kv/ Wrong scheme!
36
Changes and improvements
It should be noted that there is a trend of improvement with respect to the replacement of protections for the transmission and distribution grid, and the control systems for the 66 kV and 33 kV switchgear.
Replacement of the 11 kV switchgear that feeds the regional distribution grid. Replacement of low oil circuit breakers with new circuit breakers with vacuum extinguishing chambers.
Installation of optical fibers in 66 kV grids at the points of energy transfer from the power stations to the substations.
Replacement of old power transformers (from the 1950's and 1960's) with new transformers, though not to the extent required based on the age of the equipment. The age component of the outdated equipment in the tested system is large when compared to all the main equipment (provided for in detail in the appendix to the report). The 66 kV generation and transmission system in Port Moresby as pictured from the SCADA system
37
Increase of demand and transformer loading at the substations: The capital Port Moresby is supplied from 4 substations: Station
Transformer
Installed power of the
Notes
transformers under ONAF operating conditions T2
19MVA
BOROKO
Planned to be moved to WAIGANI
WAIGANI
BOMANA
T3
30MVA
T4
30MVA
T1
20MVA
T2
20MVA
T1
15MVA
T2
15MVA
T2 transformer with an output of 15 MVA for a voltage of 33/11 kV maintained for operability of the ROUNA1 power station
KONEDOBU
T1
20MVA
T3
20MVA
In the current status there is great difficulty in removing a transformer for maintenance (N-1) based on the extent and data of transformer loading at the substations, particularly when one transformer malfunctions. Therefore the addition of a third transformer in each substation is strongly recommended.
From the numerical peak demand data obtained from PPL the following is to be observed for the next 5 years:
It can be assumed that the forecast annual rate of growth in the medium and long term is about 4% and the Port Moresby power system should be developed on this basis.
Based on this forecast, a simulation of power flow should be carried out.
During the Survey the loading values of the circuits and transformers were sampled at the BOROKO substation which is the central and largest substation in
38
Port Moresby. The loading on the transformers at BOROKO reached 70% of their nominal loading capacity. It should be noted that transformer T2 is a very old and any malfunction of T2 would increase the loading on the remaining transformers to more than 90% of their nominal capacity.
From the peak demand data in the table in section 3.4 " load forecast",
and the
requirements for transformation the following additions are recommended:
Site
Addition of
Required
Notes
30MVA
Third transformer
transformation planned by PNG BOROKO
19MVA
KONEDOBU
30MVA
WAIGANI
19MVA
BOMANA
Third transformer
-
30MVA
Third transformer
30MVA
second transformer required 4T1 transformer connection to 66kv bus bar see dwg. SOD298
39
Diagram for development of a future transformation system (*)
41
Appendixes
41
Appendix 1 - Port Moresby- Generation transmission and water flow system
Appendix 2 Survey of the status of equipment in outgoing bays of power stations and sub-stations (66, 33, 22, 11 kV switchgear).
The following table reviews the problematic equipment which needs to be overhauled or replaced at the respective power stations and substations switchgear. It was not possible to enter all sub-station sites, and the inspection was only visual. The latest inspection results are to be reviewed to test the status of the electric equipment.
42
43
Site
Facility/ equipment
ROUNA1 3.3 kV switchgear Oil. Circuit.Breaker
Status
Obsolete equipment, old protection and electromechanical control
Recommendation/ upgrade
Qty
Required Cost
Continued operation. Requires maintenance twice a year
15
-
Notes
Maintenance intensive OCBs $30,000 for alternative SF6 or vacuum chamber
If it is decided to upgrade the units to new ones, the switchgear is to be upgraded to bring the energy to the grid at 66 kV as standard. The connection transformer 66/33 kV switchgear in ROUNA shall be used to supply the 22 kV grid from existing transformers Step-up One of the three transformers Carry out 1 3.3/33 kV 3.3/33KV winding transformers can Auto In order insulation, be stopped transformers transformer oil 1 - Cost $50,000 per ROUNA1 33/22KV tests 3.3/33 kV transformer Cost $80,000 per 33/22 kV transformer Surge old model Replace by 24 $700 per Obtain arrester age arresters newer model units unit data from the 22,33KV designer 33 kV In order Complete 2 $25,000 Impact on unit switchgear 33 kV side units per unit critical times During transformer fault condition CBs there is no tripping time may C.B connected affect the stability of to 33 kv the generators transformer sides 22 kV In order Replace load 1 $25,000 Impact on unit switchgear disconnector unit per unit critical times During RA3F1 by CB fault condition tripping time may affect the stability of the generators
44
Site
ROUNA2
Facility/ equipment
Status
11 kV switchgear
New equipment of units 1,2,4,5 In order
Step-up transformers 11/66 kV
66 kV surge arresters
66 kV CB switchgear
Old model
In order
Equipment 11 kV switchgear includes old metal clad switchgear and OCBs
Recomendation/ upgrade Switchgear of unit 3 requires upgrade Carry out winding insulation, transformer oil tests Replace surge arresters by newer ZiOx model Complete 12 arresters at line exits Complete 3 sets of surge arrester in line bay Replace CB in bay 534, 535 Continued operation, maintenance twice a year
Qty
Require d cost
Generator switch
$50,0 00 per unit
1
$1555 per unit 12 units $1555 per unit
2 CBs
ROUNA3 Step-up transformers 11/66 kV
In order
66 kV Old model surge arresters Without CBs in 66 kV switchgear the transformer bays
Broken 66 kV insulators equipment
2 Carry out winding transformer s insulation, transformer oil tests Replace by 6 units newer ZiOx model Addition of 2 units circuit breakers
Replacement of 6 insulators
45
6
CB unit 3
Test winding and insulation resistance including oil
24 units
6 units
Notes
Obtain arrester age data from the designer Complete surge arresters at line exits
15,55 New CB with per $5 single phase unit activation Highmaintenance $30,000 OCBs for alternative SF6 or vacuum chamber $100,000 per transformer
$1555 per unit $100, 000 per unit
$10,0 00 per insula tor
Obtain arrester age data from the designer Required in order to maintain unit stability against external malfunctions Immediate risk of breakdown
Site
Facility/ equipment
Status
11 kV switchgear
ROUNA4
ROUNA AUTO
Equipment includes old metal clad switchgear and oil CB 11/66 kV T2 step-up transformer transformers in order, leaks oil
66 kV surge arresters
Old model
66 kV switchgear
In order
66 kV switchgear 33 kV switchgear Autotransformers 33/66KV Surge arresters 66,33KV
SIRINUMU
In order
Repair T2 transformer, test insulation, windings and transformer oil Replace by newer ZiOx model Replace CB in field 536
Add 66 kV exit CB Add 33 kV exit CB
In order In order
Recomendation/ upgrade Continued operation, maintenance twice a year
Perform winding insulation, transformer oil tests
Old model
Replace by newer ZiOx model
Qty
2 CBs
Notes
Maintenanceintensive
Repair transformer T2
12 units
$1000 per unit
3 units
$15,555 per unit
1 CB 1 CB
Obtain arrester data from the designer New SF6 CB with singlephase activation
$100,000 Per CB $50,000 Per CB
1
Replace oil if required
6 units
33 kV switchgear
Old OCB, insulators with bad insulation
Requires 1 replacement
Step-up transformer 22/6.6KV
Bad, rust marks on transformer
Repair transformer, replace oil, check insulation
1
Grounding transformer
Old rusty
Replace
1
46
Required cost
555$ Obtain arrester per unit data from the designer $24,000 Per CB
$50,000 Based on results make decision on continued operation or replacement $5000 Replace grounding transformer
Site
BOROKO
Facility/ equipment
Status
Recomendation/ upgrade
11/66KV switchgear
New equipment including control and protection
Replacement of SF6 CBs at the 66 kV switchgear bays 535, 536 by a singlephase device vacuum CBs at the 11 kV switchgear
T2 transformer requires repair and testing
Perform winding insulation, transformer on oil tests transformer T2
Step-up transformers 11/66KV
T3, T4 units
Qty Required cost
6
$20,000 per unit
Notes
New switchgear
T2 transformer requires overhaul, oil leak repair before its transfer to WAIGANI
1
are in order
Surge arresters 66KV
11KV
Developme nt- added transformation
Loads balancing between 11 kV bus bars
Check model and type of surge arresters in the transformer bays
Old models in transformer bays to be replaced by newer ZiOx model. Complete arresters in line bays, add arresters at entries to capacitor banks
6 units
$1000 per unit
18 units
$1000 per unit
6 units
Add third transformer
30 MVA transformer 1 66/11KV
Medium voltage switchgear 11KV Capacitor bank 5MVAR Transfer distribution outlets between busbars to Balance load
Section 3 1
Number 3 5MVAR
1
$700 per unit
Receive data from the designer concerning surge arresters Complete missing surge arresters
In view of the use of vacuum CBs
$300,00 0 Per transformer $100,00 0 per section $30,000 per bank To work with open ties between busbars
47
Site
Facility/ equipment
Status
11 kV switchgear
In order. Equipment includes metal clad switchgear with low-oil CBs
WAIGANI Main transformer s11/66KV 20MVA
66 kV surge arresters
Complete arresters at outlet bays 539, 543
Medium
Complete additional capacitor bank #1 Repair faulty capacitors
Development voltage - added capacitor transformatio bank n
Medium voltage capacitor bank #2 Add third transformer
Add section 3
Add capacitor bank
Load balancing between 11 kV busbars
In order
Reccomen- Qty Required dation/ cost upgrade Continued 2 operation busba with rs maintenanc e once a year
Notes
Perform winding resistance, winding insulation and transformer oil tests ZiOx Surge arresters
Paint transformer tank, replace oil if required
Power rating of 5MVAR
1
6 units
$1000 per unit
$30,000 for capacitor bank
Complete to power rating of 5MVAR
From operational reserve stock
Transformer 66/11KV 30MVA
$300,000
11 kV medium voltage switchgear 11 kV capacitor bank
Section 3
$100,000
Number 3 5MVAR
$30,000 for Capacitor bank
Transferring distribution outlets between busbars
Load balancing
48
Obtain data from designer concerning surge arresters at transformer bays. If they are of spark gap type – replace them
Underground grid work
New transformer
For work with open ties between busbars
Site
Facility/ equipment
Status
11 kV switchgear
In order. New switchgear with vacuum CBs, control & digital protections In order. External switchgear with SF6 CBs, digital line protections
66 kV switchgear
KONEDOBU Step-up transformers 11/66KV 20MVA
Developmen t - added transformation
Load balancing between 11 kV busbars
Recomendation/ upgrade
Requi red cost
Notes
New switchgear
T1 new In order
Surge arresters 66KV
Complete ZiOx surge Surge arresters at arresters the exit bays 541,548,549 ,542
MV capacitor bank
Complete additional capacitor bank #1
Rated at 5MVAR
Existing MV capacitor bank #2
Repair of faulty capacitors (power rating 2.8 MVAR)
Complete to rating of 5MVAR
Add third transformer
Qty
66/11KV 30MVA Transformer
11 kV MV switchgear
Section 3
11 kv MV capacitor bank Transfer distribution exits between busbars
Number 3 5MVAR Load balancing
49
12 units
$10 00 per unit
transformer T4 - ABB transformer from 99 Obtain data from the designer concerning arresters at transformer bays and ones of spark gap type require replacement
$30, 000
Complete to maximal bank power rating. Add arrester at entry $30 0,00 0 $10 0,00 0 $30, 000 For work with open ties between busbars
Site
Facility/ equipment
Status
Recomendation/ upgrade
1
11 kV switchgear
BOMANA )*( Station was not reviewed during tour
Development - added transformation
Load balancing between 11 kV busbars
Step-up transformer s 11/66KV 15MVA Surge arresters 66KV
MV capacitor bank Add second transformer
11 kV switchgear 11 kV capacitor bank Transfer distribution exits between busbars
Qty
Required cost $30,000 per cell
Notes
Expansion by 2 additional exit cells
1
Complete ZiOx surge Surge arresters arresters at exit bays 547
Number 1
Power rating of 5MVAR 66/11KV 30MVA Transforme r Section 2 Number 2 5MVAR Load balancing
51
3 units
1
1
$1000 per unit
Obtain data from the designer concerning arresters at transformer bays and ones of spark gap type require replacement Add surge arrester at entry to the bank Design $300,000 standard for at least 2 transformers $30,000 Expansion by 3 additional cells $30,000
For work with open ties between busbars
Site
Facility/ equipment
Status
11 kV switchgear
In order. Equipment includes metal-clad switchgear with low-oil CBs
MOITAKA
Step-up transformers Old T4 11/66KV transformer 20MVA with oil leaks
Surge arresters 66KV
Complete surge arresters at the outgoing bays ,111,111,115 111,115,115
Recomendation/ upgrade Continued operation, maintenance once a year
Repair oil leaks and perform extensive test including winding resistance, winding insulation and transformer oil tests to check its condition ZiOx Surge arresters
Future Add 2 bays development for connecting to the NarroBrown generation site
51
Qty Required cost
Notes
Give priority to the maintenance of generator CBs
1
$1555 )*(
18 $1000 units per unit
(*) Overhaul the generator and/or replace, according to test results
Obtain data from the designer concerning arresters at transformer bays and ones of spark gap type require replacement Requires 2 $100,000 balanced bays per bay diagram between busbars (the company has presented a possibility of connection through a 132/66 kV transformer)
Site
Facility/ equipment
Status
11 kV generation switchgear
In order
11/66KV 13MVA Step-up transformers
KANUDI
66KV Surge arresters
66 kV switchgear
Transformer in order, power rating is low for the sizes of gasturbine units and their nominal power (15 MW) Complete surge arresters at the bays of T1, T2 transformers of the generation units and the switchgear for a 66 kV voltage: 548, 544, 545, 549 In order
Recomendation/ upgrade
Update transformers by adding vent units and controller or replacement with 2 existing 19 MVA transformers ZiOx surge arresters
Qty
1
Required cost
$2500
Notes
Design error in the purchase of the transformers for units 1, 2 Cost taken for up rating
15 Units
$1000 per unit
Current transformer breakdown event in the 66 kV side transformers
52
AUTOMATION
In order to reduce the number of 66 KV network interruptions which could cause blackouts in POM, it is recommended to replace the line circuit breaker in the critical line field in power stations and substations with one phase reclosing.
We recommended that the Circuit breakers which are dismantled be used as Operational reserve or be used for future development (as transformer breakers or couplers).
Following is a table
Between stations
Importance
Note
536
Rouna4-boroko
long line
111
Rouna2-boroko
Long line
Replace both ends
111
Rouna2-bomana
Generation line
Replace both ends
which outlines our recommendations for replacement of circuit breakers In 66kv switchgear:Line no. Replace both ends
66KV LINE INSULATOR MAINTENANCE
Sylgard consists of silicon rubber as the main component of the coating and is a very good solution for a polluted environment and for porcelain insulators, with a good reputation around the world. Israel Electric Corp.has good experience with sylgard in a substation in the Dead Sea Region of Israel.
We recommend to start coating insulators in the main circuit from Boroko to Rouna 4 and Rouna 2. Material costs: 23$/KG
53
EVENT RECORDER FOR 66KV LINES
For detection and monitoring of transmission and network interference, event recorders must be installed in the following locations:
Station
Field no. connecting
General information. costs
Rouna2
6
Connecting c.t
Muitaka
6
protective core and
6000$
Boroko
5
v.t with digital
Including p.c
Kanudi
1
protection output
Scada system
The Supervisory Control And Data Acquisition (SCADA) system is outdated and does not support the current activities. The Software and Hardware connecting to the power stations and Telemetering equipment in substation with remote operation needs to be upgraded.. A group of specialist operators must also be trained. The cost for SCADA equipment is estimated at US$2 million .
54
Appendix 3 – Hydro Generation Equipment – Summary
55
Appendix 4 – Thermal Generation Equipment – Summary
56
Appendix 5 Generation unit inspection report – Summary Site Surinumu
Equipment Governor operate on manual mode only
Recommendation Repair
Main valve vibrates (probably sealing
Repair
problem) 6" by-pass valve leaks
Repair
Mud & dirt cover generator filters
Clean
Due to the rotor condition, capacity de-
Overhaul needed
rates to 1.1 MW Rouna 1
Unit 1 & 2 – Penstock pipe is missing
To be replaced by a new turbine
Unit 4 – Main valve actuator is not working Rouna 2
River vegetation blocking the trash rack
Automatic trash rack should be considered
Unit 1 – water leak from turbine shaft
Generally in good condition
Unit 2 – water leak from turbine shaft Unit 3 - Governor problem limits the capacity to 4 MW Unit 5 – water leak from turbine shaft Rouna 3
Unit 2 – shaft and bearing problem
Must be put immediately back in operation
Rouna 4
Vegetation blocking the penstock inlet
Remove vegetation and bring
screening system
the screening system back to work.
Unit 1 & 2 – Operate at less than full
Check and repair
output due to governor problem Moitaka
Unit 1 – Overhaul - Out of service
Engine Unit 2 – Manifold expansion limits
Replace manifold
exhaust temperature and de rates engine to 6 MW. Moitaka GT
Capacity de-rated to 10 MW
Kanudi Engine Kanudi GT
Generally in good condition Transformers limits capacity to 10 MW
57
New and in good condition
Appendix 6 - a survey of the generation sites and substations in the Port Moresby supply area Day 1: 12/11/2011 – Tour of the areas of the power stations ROUNA and SIRINUMU. SIRINUMU generation site
Electric description: The site includes a 1.5 MW hydroelectric unit for a voltage of 6.6 kV. The energy output is to the 22 kV system at the ROUNA 1 site (see *).
Specifications of the main switchgear: Step up transformer: 22/6.6 kV 2 MVA YnD11 ONAN The 22 kV entry bay includes: Medium voltage capacitor 22 kV side at 0.5 MVAR Surge arrester Incoming dis connector for auxiliary transformer Dis connector and circuit breaker in step up transformer bay
* Connection of 22 kV line after ROUNA1 generation, exit RA3 (see scheme SOD-284/1).
58
Circuit breaker - oil type circuit breaker
Induction motor Nominal voltage: 6.6 kV Power factor: 0.83 Nominal power: 1940 kVA Star connection Turbine Rotation speed: 432 rPOM Power: 1600 kW Condition of the equipment in the 6.6/22 kV switchgear:
The transformer switchgear includes an obsolete transformer, transformer rusty at the radiators. The insulators of the circuit breaker have bad insulation (it is recommended to replace the switch by a new one) The grounding generator of the 6.6 kV side is in bad condition.
ROUNA2 generation side – switchgear
59
Description of the switching site Operational scheme: Single busbar at a voltage of 66 kV 5 transformer bays 6 line bays: (531) to ROUNA 66/33 kV connection transformers switchgear (532) – ROUNA3 (533) – ROUNA3 (534) – BOMANA (535) – BOROKO (540) – ROUNA4 2 busbar ties Bypass bay 5 transformers Transfer - 11/66 kV Power (MVA): for unit G1 – 10 MVA for unit G2 – 7.5 MVA for unit G3 – 7.5 MVA for unit G4 – 10 MVA for unit G5 – 10 MVA Condition of the equipment: Transformers: Fair Busbars: Check suitability to nominal and short-circuit current
Completions: Add surge arresters in the line bays: 533 to ROUNA3 531 to ROUNA AUTO 540 to ROUNA4
61
Control: units 1, 2, 4 – new with digital control and protection unit 3 not utilized – not upgraded
Control - generation units 1,2,4
Outgoing line protections side 66 kV
ROUNA 1,3 Switchgear ROUNA1
Operating scheme Connection of the units by 11 kV cables 3×2.5 MVA transformers 3.3/33 kV 2×2 MVA transformers 33/22 kV 1 auxiliary transformer for 50 kVA ROUNA3
61
Shortcomings of operating scheme: Circuit breakers missing at the transformer bays (RA4T1, RA4T2, RA4T3) 33 kV side. At critical times (the generator can get out of synchronization) units G3 and G4 are affected. Completion of circuit breakers in the bays of transformers RA4T3 and RA4T4 side 22 kV.
ROUNA3 – Switchgear (1975) Old switchgear, that includes: 2 transformers at a power of 7.5 MVA for a voltage of 11/66 kV; 2 old unit switches type low oil circuit breakers in closed cabinets; 2 auxiliary transformers 200 kVA 11/0.4 kV
Shortcomings of operating scheme No transformer switch on 66 kV side. This affects critical time when tripping short circuits in transformer bay 532, 532 at the generation units at the sites ROUNA2 and ROUNA3. Condition of the equipment Broken insulators
62
ROUNA autotransformer 5 MVA, 66/33KV
ROUNA4 – Switchgear (1986) The site includes: 2 generation units with an output of 6.625 MW each 2 transformers rated at 9 MVA each 66 kV busbar (without tie) 2 line bays issuing from the 66 kV switchgear: (540) to ROUNA2 (536) to BOROKO Low-oil type circuit breakers. Protection systems for 66 kV switchgear - electromechanical
ROUNA4 66 kV switchgear protection
Findings in the field: 63
T5 transformer in Rouna 4 has been leaking oil for quite a while – request for servicing was transferred from the substation personnel to the maintenance personnel of the power station (within the scope of their responsibility)
MOITAKA - Switchgear of generation site Diesel Generator 2×7.5 MW, 2×8 MW and private generation IPP 16 MW The site includes: Generation switchgear for 11 kV voltage (4 low-oil circuit breakers including ties) 2 transformer bays Transition from 11 kV cable connections from the generation units to an overhead connection to the transformer bay.
Two 11/66 kV ONAF 25 MVA transformers. 66 kV switchgear that includes: 6 line bays: 2 lines to KUNUDI 1 line to WAIGANI 1 line to BOMANA 2 lines to BOROKO
Reserve low-oil circuit breaker generation unit Future expansion 64
Expansion of the 66 kV switchgear in MOITAKA with 2 bays of additional generation units from the Naoro Brown site. A solution has been presented, which requires balancing between the busbars and this future addition in a 66 kV switchgear diagram.
Upgrades and retrofits at the station Circuit breaker in the bay of unit GT2 replaced by SF6. New digital protections in lines 544 and 545 to KANUDI.
Fiber optic communications on line to KANUDI
Required improvements
Surge arresters are to be added at the line bays! Preventive maintenance treatment has to be given to the insulators of the 66 kV busbars against dirt and contamination. T4 25 MVA transformer is old, replacement should be considered (based on test of insulation and winding resistance, oil replacement according to breakdown voltage and ppm level tests)
65
WAIGANI – 2×20 MVA, 66/11 kV substation The station includes:
Two 66 kV line bays (to MOITAKA and BOROKO) Single 66 kV busbar including tie Two 20 MVA 66/11 kV transformer bays 11 kV busbar, busbar tie Capacitor bank – designed for 5 MVR (in practice 2.8 MVAR)
Findings
T2 transformer is old, slight oil leaks Add surge arresters in the line bays New MV protections (digital) Add 5MVAR #2 capacitor bank
66
BOROKO 2×30 MVA and 1×19 MVA switching and transformation station for a voltage of 66/11 kV The 66 kV switchgear includes: 7 line bays: 2 to MOIKATA (537, 538) 2 to KONEDUBU (541, 542) 1 to WAIGANI (539) malfunctioning! 1 to ROUNA2 (535) 1 to ROUNA4 (536) 3 transformer bays: T2,3,4 11 kV switchgear including 2 busbars Two 2×5MVAR capacitor banks
* 19 MVA transformer T1 moved to the KANUDI site 19 MVA transformer T2 shall be transferred to the WAIDANI site
67
KONEDOBU – 2×20 MVA substation Station includes 66 kV switchgear with 4 line bays: 541, and 548, 549 to BOROKO and KANUDI respectively. Transformers: (New, manufactured by TBEA China – 2006) (ABB transformer from 1999) (out of utilization)
542
T1 T3 T2
Fiber-optic line protection communication 66 kV switchgear includes SF6 circuit breakers. Line protections include double protections: distance and differential (aside for 542 line which includes only a differential protection and line 548 which includes only distance protection)
68
11 kV Medium Voltage switchgear – Includes new vacuum circuit breakers
– Equipped with digital protections and control (in final testing phase)
Medium voltage capacitor banks The planned power of the bank is 5 MVAR. In practice the measured power was 2.8 MVAR. Some capacitors were disassembled due to malfunctions, and were not replaced with new ones.
Capacitor and capacitor bank in the KONEDUBU substation
Cleaning of the bank insulators is required. It is recommended to add a surge arrester at the entrance to the capacitor bank
69
KANUDI – generation site Includes a connection of two 2×12 MW Diesel Generator generation units. Connection of private producer, IPP, at an output of 2×12.8 MW. The 11 kV switchgear of units 1 and 2 (2×12 MW) includes: generator switch (for each unit), 11/66 kV step-up transformer with a power of 13 MVA with ONAF cooling. The 66 kV switchgear is shared by the private producer and PPL . The connection to the transmission system is through 4 lines: 2 lines to MOIKATA (544, 545) 2 lines to KONEDOBU (548, 549) Units G1, G2 of the PNG-POWER company
Unit transformer with limited power! (13 MVA) Proposal: Consider replacing the unit transformers with the 19 MVA transformers from the BOROKO substation (after overhaul and extensive testing) and those from inside the station.
13 MVA step-up transformer
19 MVA transformer
During the visit at the site a breakdown of a current transformer occurred with damage to unit G2. As a result a local tour of the circuit breakers at the switchgear site was not possible.
71
Meeting with the manager of system operations in PPL, and visit to transmission control in the Port Moresby area
The meeting took place in the offices of PNG POWER on 16/11/2011 A table of system development up to 2025 was presented at the meeting. A discussion was held with the transmission system operation manager, Mr. Joseph S. Basse on matters presented in the report concerning improvement of the transmission system in terms of equipment, protections and operation of the system, in order to reduce the non-supply time of the transmission system. The SCADA system of the transmission control was presented. The system is based on the Cytec software of the Schneider Company. It is planned to upgrade it to an Alsthom system.
71
The Neutral point mode of the system At the 3.3, 6.6, 11 kV generation facilities, the 66 kV transmission grid, the 22/33 kV grid and the 11 kV distribution grid 1. The Neutral-point mode 1.1 Generation units: 11 kV, 3.3 kV, 6.6 kV: insulated grounding regime through grounding transformer. 1.1 22 kV transmission system – directly to the ground solidly earthed. 1.1 Secondary 33 kV transmission system – solidly earthed directly to the ground 1.1 Primary 66 kV transmission system – solidly earthed
2. Operational mode switching- and sub-stations 2.1 Closed 66 kV busbar ties 2.2 Closed MV busbar ties (transformers operating in parallel) 2.3 11 kV and 3.3 kV switchgear in power stations with closed ties Short-circuit power and suitability of original equipment Characteristics of 66 kV circuit breaker switchgear: Triple phase mechanism - no return connection to the transmission grid Meeting a short-circuit current of 25 kA during 3 sec. 11 kV distribution switchgear: 31 kA for 3 sec
72
