The National Grid Corp. of the Philippines (NGCP) has traced the cause of Saturday’s massive power outage to the “underbuilt” lines owned by the Peninsula Electric Cooperative, Inc. (PENELCO).
The NGCP said these underbuilt distribution lines were constructed underneath its transmission lines and were within the grid operator’s right-of-way.
The underbuilt lines breached the safety clearance along NGCP’s Hermosa-BCCPP 230kV line, causing the transmission outage. NGCP already wrote to distribution utilities requesting the removal of underbuilt lines.
“We are also doing the necessary coordination with PENELCO to remove the underbuilt lines within the transmission corridor. We appeal to other electric cooperatives to check their facilities and take the
needed action to prevent similar incidents,” the NGCP said.
The firm said its protection system was automatically activated to isolate the affected Hermosa-BCCPP 230kV lines 1 and 2 when the system recorded the grid disturbance at 1:53 PM on June 1.
These lines were restored on Saturday at 2:35 PM and 2:44 PM.
The NGCP placed the Luzon grid on yellow and red alert during the incident, as it caused multiple plant outages.
The red alert status was lifted at 5:30 PM, while the yellow alert status lasted until 10:19 PM, allowing affected generating plants to ramp back up.
However, NGCP said 596MW from the 1,997MW actual loading of plants that tripped remains unavailable, but the company expects 316MW to return to the grid on Monday, depending on the status of the generating plant.