Sarawak Energy regrets inconvenience caused by power interruption

0

KUCHING: Sarawak Energy Bhd has expressed its regrets for the inconvenience caused to its valued customers over the power interruption on Thursday.

It assured customers that should there be any incident of power interruption, they would do their level best to restore power within the shortest time possible.

“Sarawak Energy regrets the serious incident that occurred on Thursday which resulted in the loss of supply to our customers in the southern part of the state.

“Restoration works commenced immediately after the tripping and supply was restored progressively, with power to most affected areas restored within two hours,” according to a press statement issued by Sarawak Energy chief executive officer (CEO) Datuk Torstein Dale Sjotveit and Syarikat Sesco Bhd CEO Lu Yew Hung yesterday.

They further explained that the incident happened at 1.31pm when the 275kV transmission lines from Kemena to Selangau and Selangau to Oya sub-station tripped, affecting the Sibu-Kuching system.

Initial analysis indicated that a fault on the Kemena-Selangau line caused tripping on one of the two circuits.

The consequent imbalance caused further tripping of the double circuit of the Selangau to Oya transmission line.

The power interruption happened after the Sibu-Kuching system was isolated from the Northern Grid which affected Sibu, Sarikei, Bintangor, Sri Aman, Kota Samarahan and Kuching regions with a total loss of load at approximately 705MW.

Initial analysis showed that there was a fault on the Kemena to Selangau transmission line which tripped one of the two circuits causing an imbalance to the system.

System oscillation and low voltage was then detected on the Oya to Selangau transmission line which triggered the line protection relay, tripping the two circuits of the Selangau to Oya transmission line.

System oscillation is when the system experiences inconsistent voltage.

Sarawak Energy is conducting further investigations on the cause of the system oscillation to avoid recurrence.

The system isolation cut off power supply to the southern Sibu-Kuching System from major gas and hydropower stations in the north.

To arrest system decline and minimise the number of affected locations, the System Protection Scheme kicked in immediately to perform load shedding.

However, the unstable system conditions caused further tripping of generators in the southern region power stations, consequently leading to a total power outage in this part of the grid system.

Restoration works commenced immediately after the tripping. Power supply was restored progressively after it was verified that there was no equipment failure in the substations. Restoration to almost all affected areas was completed within two hours.

They also said Sarawak Energy was committed to delivering reliable and efficient energy through a major enhancement of the transmission system.

“As part of this, since 2011, we have embarked on constructing a completely new transmission system which will protect the southern part of the state against incidents such as what happened yesterday (Thursday).

“The critical part of this new RM2.5 billion 500kV transmission backbone from Bintulu to Kuching is expected to be completed by mid 2016.”