NGCP’s initial investigation on the sequence of events that led to the red alert in Luzon grid yesterday, 08 May 2023, shows NGCP’s Bolo-Masinloc 230kV Line 2 tripped. This line is N-1, or operates with a redundancy. The load carried by Line 2 was automatically transferred to Line 1 when the former tripped. Each of Lines 1 or 2 is more than capable to singularly carry the entire loading of the Bolo-Masinloc 230kV facility at any time.
Thereafter, 2 of 3 Masinloc Units (315MW x 2 units = 630MW) tripped. Together with other units already on forced outage, total power lost to the grid was 1,354MW.
Given the N-1 contingency in place at NGCP’s Bolo-Masinloc Line, and the automatic transfer of loads from Line 2 to Line 1, the tripping of two (2) Masinloc units was both unexpected and undesirable.
NGCP’s Bolo-Masinloc Line 2 was immediately restored within 19 minutes. As of writing, Unit 1 of Masinloc was successfully and fully reintegrated to the grid, and Unit 2 was integrated at 3:26AM, 09 May 2023, at a derated capacity of 150 MW.
NGCP emphasizes that protection settings of customers connected to its system must remain consistent with NGCP’s protection settings and other grid parameters.
We are coordinating with Masinloc power plant and other grid-connected generating plants on the way forward and to ensure that protection settings are in sync between generating plants and NGCP.|- BNN
