Last Updated On 17 May,2018 11:55 am
Electricity transmission system which split into North and South due to tripping on Wednesday.
LAHORE (Dunya News) – The electricity transmission system which split into North and South due to tripping on Wednesday at 9:28 a.m resulting in electricity supply failure to Punjab and KPK areas was restored at 5:30 pm ( almost 8 hours) with major power generation plants gradually increasing their input in the national grid.
According to the initial report the 500 kV transmission line Guddu 747-Raheem Yar Khan tripped at 09:28:11 Hrs and at the same time 500 kV Guddu-DG Khan transmission line also tripped. As a result, the load increased on 500 kV Guddu-Muzaffargarh transmission line from 733 MW/ 72 MVAR to 1559 MW/ 717 MVAR as recorded at 500 kV Muzaffargarh end. This line also tripped at 09:28:14 Hrs.
This tripping resulted in under frequency on system from 50.18 Hz to 48.755 Hz within 5 seconds. Resultantly under frequency schemes came in action and frequency again improved from 48.755 Hz to 49.43 Hz at 09:28:38 Hrs. Meanwhile some other power stations also tripped perhaps due to frequency fluctuation/ jerk and cascade tripping started in the northern part from Guddu to Peshawar.
The system went under partial failure from Guddu to Peshawar at 09:28:59Hrs when frequency decayed down to 45 Hz. The Southern part of country from Guddu onward however remained normal during the entire day which includes Sindh and Balochistan areas.
As soon as the partial supply failure was reported the NTDC ground teams were immediately mobilized to check the High transmission lines. Power Division also notified an enquiry committee headed by Additional Secretary Mr. Waseem Mukhatar to ascertain the causes of tripping, the process of restoration and suggestions for system to avoid such incident in the future. The Additional Secretary will be assisted by three experts as member of the committee.
It is however important to note that before the tripping the system was having surplus electricity as compared to the demand therefore the temporary load shedding was purely associated with system fault.