ISLAMABAD: The Power Division has constituted a two-member committee to probe reasons for recent power breakdowns across the country including explosion at Guddu 500 kV switchyard, well-informed sources told Business Recorder.
On January 1, 2024, the Power Division, in an official statement said due to dense fog, the NTDC faced tripping of 500 kV and 220 kV Transmission Lines in the vicinity of Guddu.
During the said period one of the poles of 500kV circuit breaker was damaged; the faulty part was isolated from the healthy system immediately and switch yard was energized.
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On January 2, 2024, NTDC said that the technical teams at National Transmission and Despatch Company Limited (NTDC) have accomplished the replacement of a damaged circuit breaker at the 500 kV Guddu Switchyard.
On the direction of NTDC management, additional staff was deployed to ensure the swift completion of replacement works. Moreover, NTDC also successfully energized the 500kV Guddu-Muzaffargarh transmission line.
According to the notification, Minister for Energy took cognizance of transmission network failures that occurred on December 26, 31 and January 3, 2024, as well as the fire incident at Guddu 500 kV switchyard.
In the notification issued by the Power Division to probe the matter, the Minister for Power and Petroleum desired to constitute an Inquiry Committed, comprising Ali Zain Banatwala, DMD (SO)(NPCC) – Convener and Dr. Fiaz Chaudhry, LUMS Energy Institute- Member with the following Terms of Reference: (i) establish the cause of the circuit breaker explosion at Guddu 500kV switchyard on December 31, 2023; (ii) What was the contribution of inadequate asset management, planning/design failures, change in short-circuit power over time, ageing infrastructure, etc. in the failure? (iii) What infrastructure upgrades were undertaken in this grid station keeping in mind the importance of this node in the AC corridor and the central role of this grid station in prior blackouts? (iii) Is NPCC forced to disconnect transmission lines for voltage control due to lack of voltage control devices such as shunt reactors? Disconnecting transmission lines for voltage control weakens the network. What is the operational status of shunt reactors for voltage control on 500kV transmission lines and switchyards? Verify shunt reactors installed and in operation in accordance with approved designs stipulated in vendor contracts; (iv) identify the headcount of technical and maintenance staff at Guddu 500kV grid station in accordance with the Board approved yard-stick. Establish the impact on asset management due to the shortage of adequately trained staff at Guddu 500kV grid station that may have contributed to the blast on the circuit breaker; (v) transmission lines are designed to be fog resistant. Yet all transmission lines on the 500kV AC corridor tripped on December 26, 2023 from 05:11 to 08:45 and on 31 December 2023 from 00:26 to 1:48, leaving the system islanded with HVDC in asynchronous mode of operation. Establish the causes of repeated cascading failures with respect to inadequate asset management (maintenance/washing), design failures (insulator creepage, RTV coating, etc), ageing infrastructure or any other contributing reason; (vi) identify whether system protections operated as designed during the transmission line tripping and circuit breaker failure; and (vii) fix responsibility on those responsible for system failure.
The sources said the NTDC has not yet shared required information with the committee to go through it to reach the conclusion. The committee, sources said, has sent a questionnaire to NTDC/NPCC for specific technical information for the probe.
