annual report - Tenaga Nasional Berhad

Operations Review – Sabah Electricity Sdn Bhd[ Tenaga Nasional Berhad ] [ Annual Report 2008 ]106Transmission DivisionThe key mandate for theTransmission Division is toensure supply reliability andquality. In its endeavour to fulfilthis responsibility, the Divisionhas formulated the followingobjectives:• To carry out planning,operation, maintenance andsystem improvement worksof the transmission systemt h ro u g h o u t S a b a h a n dFederal Territory of Labuan.• To operate the Sabah Grid inthe most efficient manner.• To t r a n s m i t a d e q u a t epower supply efficiently andeconomically with minimuminterruptions.T h e s u p p l y re l i a b i l i t y o ftransmission lines contributes tothe overall image of SESB astransmission lines and substationsare the linkages between supplysource and distribution system.SESB Transmission Divisionunderwent restructuring duringt h e p e r i o d u n d e r re v i e wresulting in the creation oftwo new departments - theEnergy Procurement Unit (EPU)and Operation Planning (OP).The EPU is responsible formonitoring the IndependentPower Producers (IPP), while OPwould dedicate itself to shortterm planning and forecastingfor operational purposes.Table 1Targets and Objectives1 Delivery Point Unreliability Index(DPUI)2 System Average InterruptionFrequency Index (SAIFI)Table 1 below showed the DeliveryPoint Unreliability Index (DPUI)and System Average InterruptionFrequency Index (SAIFI) achievedby the Transmission Divisionduring FY2007/2008.As indicated in Table 1, there wasa mark difference between “TotalAchievement” and “Achievementwithout Major Incident”. A majorincident is defined as a loadloss of 50 MW and above. Thesegregation between the twoscenarios is necessary for thepurpose of continuous monitoringon the effectiveness of the routineand preventive maintenanceperformances.Three major incidents thatled to the large disparity inachievement during the periodunder review were:• Total blackout on the EastCoast due to tripping of both275 kV Kolopis – Segaliudlines with a total load loss of124 MW on 30 September2007.• VT faulted at KaramunsingSub-Station with total load lossof 308 MW on 6 November2007.• Tower collapsed of 132 kValong Kayu Madang – UMSlines due to theft on towermembers with a total loadloss 459.3 MW on 21 April2008.KeyPerformanceIndicators/MeasuresTargetTotalAchievementW/O MajorIncidentSystem Minutes 42 154.38 11.89Interruption/Delivery PointThe Division had implementeda total of 21 projects form a i n t e n a n c e a n d s y s t e mimprovement. The followingseven projects were completedwhile 14 more are in variousstages of implementation.• Replacement of neutralearthing resistor (NER) atKaramunsing Sub-Stationand UMS 66 kV Sub-Stationcompleted on 1 December2007.• Installation of three-pole132 kV & 66 kV SF6 gascircuit breaker at the 66 kVSub-Stations in Tenom Town,Penampang, Kota Kinabalu,and Inanam completed on4 April 2008.• 132 kV transmission linerentice clearing for year 2008from Sandakan to SegaliudSub-Station 13 May 2008.• 132 kV transmission linerentice clearing for year2008 from Semporna toKalumpang Sub-Stationcompleted on 13 May 2008.• 132 kV transmission linerentice clearing for year 2008from Tawau to KalumpangSub-Station on 13 May 2008.• Procurement and trainingof 132/275 kV EmergencyRestoration System (ERS)Tower completed 13 June2008.0.29 1.125 0.108