ISLAMABAD: The Inquiry Committee on power breakdown of October 13, 2022 has recommended the government to take disciplinary action against the technical teams from Project Delivery South, involved in execution of interim arrangement Asset Management South for lack of O&M activities, sources close to Minister for Power told Business Recorder.
Sharing details, sources said, HVDC Converter Station Lahore was importing 1800-MW from Matiari-end prior to the incident. Unlike HVAC system, HVDC system is incapable of changing the direction of power flow during continuous operation. Thus, it did not support the system during this disturbance.
The four-member Inquiry Committee observed that response of Lucky and Thar Energy Limited against the disturbance was not supportive. Tripping of such huge quantum of generation affected system frequency adversely. The operation of existing system protection schemes, i.e., under-frequency load shedding, cross trips, rate of change of frequency & out of step played a major role in saving the system from total collapse.
Based on the forgoing discussion, documentary evidence and available record, the Enquiry Committee maintains that partial blackout/ collapse initiated due to mechanical failure of line hardware of 500kV NKI-K2/K3 and 500 kV Jamshoro-K2/K3 circuit-1 could have been contained, if PSS at Lucky and Thar Energy Limited had been commissioned to sustain the system disturbance like Port Qasim and Engro Thar Power Limited and 500-kV link between Gatti and Barotha could have withstood the tripping which aggravated the already compromised system.
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The implementation status of the recommendations of previous inquiry reports were collected from concerned stakeholders and reviewed by the Enquiry Committee. It was revealed that majority of those were found either implemented or under implementation stage.
The Inquiry Committee has submitted following recommendations: (i) during planning and design phases, condition of aged transmission lines shall be assessed while interconnecting with new power plants;(ii) during execution stage, quality of the material/ workmanship shall be ensured as per international standards;(iii) O&M activities of transmission lines including thermography needs to be carried out as per SOP with available resources;(iv) ongoing projects of permanent network for evacuation of power in general and in particular from K2/ K3 shall be completed instead of relying on interim arrangements;(v) implementation of SCADA-III shall be ensured as per timelines to enhance the live visibility of system parameters to System Operator;(vi) measurement units are required to be installed to timely indicate the oscillations in system;(vii) stability control system shall be activated at the earliest to enhance the system stability;(viii) for more effective maintenance of transmission lines, a yardstick for creation of new Transmission Line Divisions/ Subdivisions be developed so that with the addition of new Transmission Lines, the requisite posts can be sanctioned accordingly;(ix) transmission Line maintenance staff shall be equipped with proper PPEs, T&P, spare material/ hardware and vehicles to ensure healthiness of NTDC’s Transmission Lines as per NTDC maintenance SOPs;(x) condition assessment of the section of old 500-kV Transmission Lines near coastal/ polluted areas should be carried out on war footing basis and remedial measures may be taken accordingly; (xi) based on the visual inspection and documentary evidence, the Enquiry Committee is of the opinion that if deemed necessary, disciplinary action under the relevant Rules may be initiated against the technical teams from Project Delivery South, involved in execution of interim arrangement and Asset Management South for lack of O&M activities as per SOP keeping in view the criticality of said arrangement.
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Both the breakdowns occurred at Tower No. 26A which was installed around 3 years ago for the interim arrangement of power evacuation from K2/K3 power plants. The Inquiry Committee argued that failure of the Transmission Line hardware/ accessories within three years of commissioning is a question mark on the quality of the material/ workmanship. The connectors used at these locations were not standard transmission line hardware items rather they were an improvised arrangement, meant for interim interconnection arrangement.
It further observed that 25 years old deteriorated conductor was used for interim arrangement between location No. 26, 26A & 27 by Project Delivery Formation, adding that despite the criticality of the interim arrangement, O&M has not been carried out as per SOP by the concerned Asset Management Formation.
Copyright Business Recorder, 2022