NEWS & UPDATES

Introduction

Sarawak Energy regrets the serious incident that occurred yesterday 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.

The Incident

The incident happened at 1.31pm when the 275kV transmission lines from Kemena to Selangau and Selangau to Oya Substation tripped, affecting the Sibu-Kuching system.  

Initial analysis indicates 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 Region with a total loss of load at approximately 705MW.

Technical Details

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.

System Restoration

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.

Our Commitment

Sarawak Energy is committed to delivering reliable and efficient energy through a major enhancement of our 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.  The critical part of this new RM2.5 billion 500kV Transmission Backbone from Bintulu to Kuching is expected to be completed by mid 2016.

Conclusion

Sarawak Energy regrets the inconvenience caused to our valued customers.

We assure our customers that should there be any incidents of power interruption, we will try our level best to restore power within the shortest time possible.

Please be assured that our Sarawak Energy team is doing all we possibly can to ensure reliability of power supply across the state.  

We thank the people of Sarawak for your kind understanding and patience.  

Datuk Torstein Dale Sjotveit
Group Chief Executive Officer
Sarawak Energy Berhad

Lu Yew Hung
Chief Executive Officer
Syarikat SESCO Berhad