To institutionalize N-1 contingency in a major transmission backbone in the Luzon grid, transmission firm National Grid Corporation of the Philippines (NGCP) has completed a project that will improve reliability of electricity wheeling in the country’s main power grid.
The recently energized Santo Domingo (in Albay) load-end substation as well as the 230-kilovolt San Manuel-Nagsaag transmission line, according to NGCP, had been intended for redundancy in the system, so service interruptions could be prevented even if there are technical glitches in the transmission network.
The company had spent P382 million for the completed facilities, which is a critical component of the 69-kV Eastern Albay Line Project-Stage 2.
Having N-1 contingency in a power system entails that if one equipment would fail, there is still a spare that can prevent interruption or blackout in the network, hence, ensuring more reliable services to load customers.
The N-1 contingency is a requirement under the Philippine Grid Code, which sets the ability of the power grid to withstand a major system disturbance through redundancies or having back-up contingency in the system.
As noted by NGCP, “the project involves the installation of two additional power circuit breakers and other associated equipment to cater to the entry of new transmission lines and improve system reliability in the southeastern and eastern parts of Albay.
It noted that a day after the commercial operation of the substation in Santo Domingo, Albay; the company subsequently energized the San Manuel-Nagsaag line “to improve transmission services by providing an additional power highway to the region.”
The transmission firm emphasized that the facility is a priority project with several components, including the San Roque-Nagsaag lines 1 and 2; followed by the Binga-Nagsaag lines; and the San Manuel-Nagsaag tie lines; and these were energized from November to December last year.
The final component of the project was the Nagsaag 3x 200-megavolt ampere 500kV transformer that was energized on December 22 last year.
NGCP expounded that “the San Manuel-Nagsaag 230kV line prevents the congestion of the transmission highway in North and Central Luzon and provides N-1 contingency. It stressed the completed project will likewise “improve voltage and power quality in the area,” which in essence will guarantee reliability of transmission services to customers.