NGCP calls for proper system planning after Luzon grid, Panay island brownouts

The National Grid Corporation of the Philippines (NGCP) on Friday called for better and proper system planning following the recent incidents of power outages which hit the Luzon grid and Panay island.

“The system disturbance and the widespread outages in Panay Island between 27 and 29 April, and the red alert raised in the Luzon grid resulted from a confluence of events that support its call for better and proper power system planning across all three members of the energy supply chain: generation, transmission and distribution,” the NGCP said in a statement.

On May 8, the grid operator place the Luzon grid under red alert which prompted Meralco to implement rotational brownouts after five power plants were on a forced outage amid the summer heat. 

A red alert status indicates that there is zero ancillary service or that a generation deficiency exists.

Late April, Panay island was hit by a series of power outages which affected the provinces within the island. 

The NGCP, the country’s sole power transmission operator, said the trippings on utility lines which caused grid disturbances in Panay island could have been avoided.

The grid operator said that only the consumers connected to the line that tripped should have been disengaged from the grid.

However, it said that “it was unfortunate that a power plant disengaged from the transmission system unexpectedly.”

“The resulting undervoltage and underfrequency was severe and unrecoverable, and was the direct cause of the tripping of other power plants connected to the system, and ultimately, the Panay sub-grid collapse,” the NGCP said. 

In the case of the Luzon red alert, the company said initial investigation on the sequence of events on May 8, shows the tripping of Bolo-Masinloc 230 kilovolt (kV) Line 2.

The NGCP said the line operates with a redundancy and load carried by the Line 2, when it tripped, was automatically transferred to Line 1.

“It should have ended there. Similarly, there was an unexpected and undesired response from a generating plant which tipped the balance of supply and demand, and a red alert was raised,” the NGCP said.

The grid operator added that prior to the occurrence of the faults, unplanned outages of plants and the deration of other plants contributed to the situation.

“These unplanned outages are outside of the Grid Operating and Maintenance Program planned well ahead and coordinated by NGCP with the power plants and approved by the Department of Energy,” it said.

As a long-term solution, the NGCP said it commits to complete several large transmission projects within the next few months to help strengthen the transmission system and better support the power system.

“We continue to advocate for a holistic approach to power planning. Development in all sectors involved in the power industry must be coordinated, with due attention given to each. We support the Department of Energy in all its efforts, and we are confident of its continued support to all sectors,” the company said. — RSJ, GMA Integrated News