• CHERYL G. CRUZ
The Department of Energy (DOE) Jan. 3 reminded the National Grid Corporation of the Philippines (NGCP) to adhere to its responsibilities as system operator (SO) in ensuring supply security and reliability of the grid.
The power disturbance in the Panay grid and part of Negros that started Jan. 2 “could have could have been resolved differently” by the NGCP, the DOE said in a statement, adding that with its monitoring of the grid 24/7, “NGCP is in a position to immediately coordinate with the power plants to ensure that their respective unit protection and control settings will not cause grid instability that could lead to black outs”.
Energy Undersecretary Rowena Cristina Guevara said the system disturbance that happened April 27-29 last year in the Panay and Negros sub-grids “was already a lesson for all stakeholders involved…what happened yesterday could have been resolved differently.”
The DOE said the power disturbance cascaded into the entire Western Visayas beginning at past noon of Jan. 2, with the tripping of Unit 1 of the Panay Energy Development Corporation (PEDC) coal-fired power plant in Iloilo due to a boiler feed pump issue.
Subsequently, Unit 1 of Palm Concepcion Power Corporation (PCPC) and Unit 2 of PEDC simultaneously tripped due to grid voltage imbalance, and other power plants within the Visayas grid were also affected by the Panay grid disturbances.
Guevarra said that while the NGCP is still analyzing the data to determine the cause and order of tripping of the six power plants, the DOE is continuously coordinating with the SO and affected power plants and distribution utilities on the status of the power plants, including the estimated timeline for the restoration of power supply.
She noted that, as per the NGCP, the grid needs about 300 megawatts (MW) to stabilize and that it is awaiting the remaining PCPC plant, with a 135MW capacity, to synchronize back to the grid. Target synchronization is between 10 p.m. to midnight of Jan. 4, with full power restoration in Western Visayas expected on Friday, Jan. 5.
As of 8 p.m. Jan. 3, the NGCP said 202.9MW is being served by Panay power plants, augmented by 49.8MW from sources elsewhere in the Visayas, for a total of 245.6MW served loads.
“NGCP implemented emergency load dropping and manual load dropping in Negros and Panay at 5:49 p.m. and 6:28 p.m., respectively, to protect the integrity of the grid due to undervoltage brought about by the generation deficiency in the grid,” its latest advisory said, adding that restoration of the affected loads is ongoing.
Load restoration will be done conservatively, by matching loads to restored generation, to prevent repeated voltage failure. NGCP is ready to transmit power once it is available, it added. | CGC
