National Grid (Malaysia)

A 500 kV transmission line passing the North-South Expressway near Taiping.

National Grid, Malaysia (Malay: Grid Nasional) is the high-voltage electric power transmission network in Peninsular Malaysia. It is operated and owned by Tenaga Nasional Berhad (TNB) by its Transmission Division^[1]. There are two other electrical grids in Sabah and Sarawak operated by Sabah Electricity Sdn Bhd and Sarawak Electricity Supply Corporation respectively.

The system spans the whole of Peninsular Malaysia, connecting electricity generation stations owned by TNB and Independent Power Producers (IPPs) to energy consumers. A small number of consumers, mainly steel mills and shopping malls also take power directly from the National Grid.

History

The beginnings of the National Grid was slowly taking shape in 1964 when the Bangsar Power Station was connected to the Connaught Bridge Power Station, with the line subsequently extended to Malacca^[2].

By 1965, a plan was set to connect the electricity generating plants that were spread out all over the country. Plants identified to be linked were located at Paka in Terengganu, Temengor, Kenering, Bersia and Batang Padang in Perak, Connaught Bridge, Kapar and Serdang in Selangor, Cameron Highlands in Pahang, Perai in Penang, Port Dickson in Negeri Sembilan, Pergau in Kelantan, Pasir Gudang in Johor and in Malacca.

The central area network with Connaught Bridge Power Station in Klang was the precursor of the energy grid; it also tapped into the Cameron Highlands Hydro scheme from the Sultan Yussuf Power Station, and was extended into a western network. Late in the 1980s, the loop was finally complete with the placement of Kota Bahru within the grid^[3].

Grid description

Transmission system

More than 420^[4] transmission substations in the Peninsular are linked together by approximately 11,000 km^[5] of transmission lines operating at 132, 275 and 500 kilovolts (kV). The 500 kV transmission system is the single largest transmission system to be ever developed in Malaysia. Begun in 1995, Phase 1 involved the design and construction of the 500kV overhead transmission lines from Gurun, Kedah in the North along the west coast to Kapar, in the central region and from Pasir Gudang to Yong Peng in the south of Peninsular Malaysia.

The total distance covered for the 500 kV transmission lines is 522 km and the 275 kV portion is 73 km. Of the lines constructed, only the Bukit Tarek to Kapar sections had been energized at 500 kV. The remaining lines are presently energized at 275 kV. Later, in order to cater for the additional power transmission requirements from the 2,100 megawatt (MW) Manjung Power Station, the 500 kV system was extended from Bukit Tarek to Air Tawar and from Air Tawar to Manjung Power Station. In 2006, the 500 kV lines between Bukit Batu and Tanjung Bin were commissioned to carry the power generated by the 2,100 MW Tanjung Bin Power Station.

A project involving laying a 730 km high-voltage direct current transmission line and a 670 km undersea cable for the 2,400-megawatt Bakun hydroelectric dam has been considered^[6]. This may connect all three of Malaysia's electric utility companies with state grids: Tenaga Nasional Berhad (TNB), Sarawak Electricity Supply Corporation (SESCO) and Sabah Electricity Sdn Bhd (SESB). Many of Sabah and Sarawak's generation plants are still not interconnected to a grid.

Connection to Thailand

The original 117 MVA, 132 kV Single Circuit Line HVAC interconnection of 80 MW with Electricity Generating Authority of Thailand (EGAT) was commissioned in 1981^[7], linking Bukit Ketri in the state of Perlis with Sadao in Thailand. A second interconnection was made via the HVDC Thailand-Malaysia rated at 300 kV HVDC and 300 MW transmission capacity.

Connection to Singapore

In the South of Malaysia, the National Grid is connected to the transmission system of Singapore Power Limited (SP) at Senoko via two 230 kV submarine cables with a transmission capacity of 200 MW.

Power Generation

Power generation capacity connected to the Malaysian National Grid is 19,023 megawatt, with a maximum demand of 13,340 megawatt as of July 2007 according to Suruhanjaya Tenaga^[8]. The generation fuel mix is 62.6% gas, 20.9% coal, 9.5% hydro and 7% from other forms of fuel^[9].

Distribution level

Distribution lines of 33 kV, 22 kV, 11 kV, 6.6 kV and 415/240 volt in the Malaysia distribution network connect to the National Grid via transmission substations where voltages are stepped down by transformers.

Major incidents

• Following a major system collapse in 3 August 1996, TNB has undertaken joint studies with Tokyo Electric Power Company (TEPCO) to develop a controlled islanding scheme to prevent the occurrence of a complete system collapse by ensuring continuity of supply to the Kuala Lumpur Metropolitan and Multimedia Super Corridor (MSC). The islanding scheme would basically be a "last line of defense" after all the normal emergency countermeasures such as underfrequency load shedding have operated^[10].
• In 13 January 2005 a power blackout on northern peninsular Malaysia occurred when a transmission line near Serendah, Selangor, had broken down. In response to this, the Central Area Reinforcement (CAR) project was approved to ensure security of power supply to the Klang Valley^[11].
• In 22 April 2008 Sabah had the worst power outage since the commissioning of the east west power grid. Suspected vandals are believed to have removed steel pieces of a 132kV transmission tower that led to its collapse, triggering a major power blackout^[12]. An emergency temporary tower was to be built immediately but it also collapsed during construction killing a TNB personnel^[13]. On 1 May 2008, another tower collapsed due to missing structural members of the tower that were suspected of being stolen^[14].

See also

• Energy policy of Malaysia
• List of power stations in Malaysia
• Sabah Electricity
• Sarawak Electricity Supply Corporation
• Tenaga Nasional Berhad

References

1. ^ "Transmission Division". Tenaga Nasional Berhad. http://www.tnb.com.my/tnb/bus_trans.htm. Retrieved 2009-05-23. ^{[dead link]}
2. ^ "Spirit of Merdeka & Malayanisation". Tenaga Nasional Berhad. http://www.tnb.com.my/tnb/abus_his3.htm. Retrieved 2009-05-23. ^{[dead link]}
3. ^ "The National Electricity Board". Tenaga Nasional Berhad. http://www.tnb.com.my/tnb/abus_his4.htm. Retrieved 2009-05-22. ^{[dead link]}
4. ^ "Malaysia Power Report Q2 2008", London, UK: Business Monitor International Ltd. Feb 2008
5. ^ "Tenaga Nasional Berhad 500kV Transmission System, Phase 1". Ranhill Berhad. http://www.ranhill.com.my/tenaganasional.asp. Retrieved 2009-05-23. ^{[dead link]}
6. ^ "TNB to raise ringgit loans". Reuters. Business Times, Malaysia. 2009-05-01. http://www.btimes.com.my/Current_News/BTIMES/articles/tena30-2/Article/index_html. Retrieved 2009-05-23. ^{[dead link]}
7. ^ "Malaysia, TNB Interconnection". ASEAN Centre for Energy. 2006-05-09. http://www.aseanenergy.org/energy_sector/electricity/malaysia/tnb/interconnection.htm. Retrieved 2009-05-23. 
8. ^ "Statistics of Interim on the Performance of the Electricity Supply in Malaysia for the First Half Year of 2007" (PDF). Suruhanjaya Tenaga. 29 January 2008. http://www.st.gov.my/images/stories/upload/st/st_files/public/statistik_interim_2007-bi.pdf. 
9. ^ Department of Electricity Supply Regulation, Energy Commission (2007). "Electricity Supply Industry in Malaysia - Performance And Statistical Information 2006" (PDF). Suruhanjaya Tenaga. http://www.st.gov.my/images/stories/upload/st/st_files/public/st_esim_bi.pdf. 
10. ^ "Transmission System Development". ASEAN Centre for Energy. 2006-05-09. http://www.aseanenergy.org/energy_sector/electricity/malaysia/tnb/transmission_system_devt.htm. Retrieved 2009-05-23. 
11. ^ "TNB Gets Selangor Govt's Nod To Resume Transmission Line Project". Bernama. 2007-06-19. http://www.bernama.com/selangor_maju/news.php?id=268305&lang=en. Retrieved 2009-05-23. ^{[dead link]}
12. ^ "Vandals blamed for Sabah blackout". Muguntan Vanar. The Star Newspaper. 2008-04-22. http://thestar.com.my/news/story.asp?file=/2008/4/22/nation/20080422153350&sec=nation. Retrieved 2009-05-23. 
13. ^ "One Dead, Four Injured In TNB Tower Collapse". Bername. Bernama.com. 2008-04-29. http://www.bernama.com/bernama/v5/newsindex.php?id=329821. Retrieved 2009-05-23. 
14. ^ "Another Power Transmission Tower Collapses In Sabah". Bernama. Bernama.com. 2008-05-01. http://www.bernama.com/bernama/v5/newsindex.php?id=330154. Retrieved 2009-05-23. 

External links

• Tenaga Nasional Berhad