National Grid Corp. of the Philippines on Friday called for a holistic solution and better coordination within the energy supply chain to address the country’s power supply situation.
NGCP spokesperson lawyer Cynthia Perez-Alabanza said while the power grid had some “inadequacies”, planning should be well coordinated across all sectors—distribution, generation and transmission.
Alabanza said there should be cooperation among generational companies and distribution utilities to avoid a repeat of the yellow and red alerts recently.
“All protection settings of gencos should be checked, together with grid settings,” she said.
Alabanza said NGCP is open to calls for audits from various sectors. “We also opened ourselves to inspections and audits by different government agencies. For so long as covered by regulatory framework, we are open to it,” Alabanza said.
“As long as it is under the regulatory framework we function in, including our concession agreement, our franchise and all applicable rules and regulations, we are open,” she said.
Meanwhile, NGCP committed to completing several large transmission projects within the next few months to help strengthen the transmission system and better support the power system.
Alabanza said there were many factors that resulted in the delays such as right-of-way, permitting and COVID-19.
“We need to make up for the years of difficulties that we encountered. Even during COVID, we did as much as we could. But we are committed to finishing within the next few months, so we can help strengthen the power system. But again, we can only commit to developing our part, but the whole energy supply chain needs to be resilient,” she said.
NGCP said many factors came into play concerning the grid alerts and incidents in recent days.
It said the system disturbance and the widespread outages in Panay Island between April 27 and 29 and the red alert status raised in the Luzon grid resulted from a confluence of events that support its call for better and proper power system planning across the entire energy supply chain.
NGCP said that while there were grid incidents monitored in both the Luzon red alert on May 8 as well as the Panay Island outages, these incidents by themselves, ought not to have caused the effects seen.
The company said that in the case of Panay Island, NGCP’s protection systems, which were communicated and coordinated with its grid-connected customers from both the generation and distribution sides, functioned as intended.
NGCP said only consumers connected to the line that tripped should have been disengaged from the grid. and it was unfortunate that a power plant disengaged from the transmission system unexpectedly.
“This response from the generating unit is both unexpected and undesirable. 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,” NGCP said.
It said the subsequent trippings that occurred on April 28 and 29 were a direct result of the avoidable events of April 27.
NGCP’s initial investigation on the sequence of events on May 8 showed the tripping of Bolo-Masinloc 230kV Line 2.
This line is N-1, or operates with a redundancy. The load carried by Line 2 when it tripped was automatically transferred to Line 1. 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, NGCP said.
“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,” NGCP said.
NGCP said that prior to the occurrence of the faults, unplanned outages of plants and the deration of other plants contributed to the situation.
It said the unplanned outages are outside of the Grid Operating and Maintenance Program planned and coordinated by NGCP with the power plants and approved by the Department of Energy.
