Nationwide power outage on Thursday was caused by human error and the failure of electrical safeguards protecting the Hsinta Power Plant in Kaohsiung, Deputy Economics Minister Tseng Wen-sheng (???) said Friday.
Some 5.49 million households across Taiwan were hit by blackouts triggered by a problem at the Kaohsiung power plant, which the Ministry of Economic Affairs, which oversees state-run utility Taiwan Power Co. (Taipower), initially blamed on human error.
The power outage was the third major power interruption in Taiwan in the past year and fourth since 2017, and came just two days after President Tsai Ing-wen (???) promised the heads of business groups that the government would maintain a stable supply of electricity.
While visiting the troubled coal and natural gas-fired power plant, Tseng said the incident was caused by three factors — human error, a problem with the power plant’s protective safeguards, and a power grid unable to isolate risks.
The most direct problem, Tseng said, was the mishandling of switches at the plant that caused power generators to trip.
On Wednesday, Taipower employees removed insulation gas, sulfur hexafluoride (SF6), from a switch numbered 3540 after discovering moisture in it.
The next day, when conducing tests aimed at confirming if an adjacent switch, numbered 3541, worked properly, power plant workers turned it on without having added insulation gas back into the 3540 switch, leading the latter to trip.
During the process the foreman on duty failed to double check if the problematic device had been fixed before allowing workers to activate the circuit, Tseng said.
Beyond human error, Tseng said, safeguards in place should have detected a problem with the electric current in the system and triggered circuit breakers to shut the system down.
But the signal transmitting the problem was misjudged as a false alarm, leading the current to build up and cause the power generators to trip, Tseng said.
At the heart of the problem, he said, was that the relay — the component responsible for tripping a circuit breaker when it detects a fault — was a digital model and had trouble working with the factory’s older equipment, according to Tseng.
Because of that, it failed to detect the problem with the fault current.
As for the power grid, Tseng said that when the fault signal was transmitted from Hsinta Power Plant to the Longqi Extra High Voltage Substation in Tainan and other four high voltage substations, circuit breakers at the facilities tripped.
That protected the grid but caused blackouts at all power plants located south of the Longqi substation, Tseng said.
When asked how the problems could be corrected, he cited reinforced training, isolating switches so that problems with one of them would not bring down a whole system, and figuring out how to make the grid less vulnerable to a break in a circuit.
President Tsai Ing-wen, who was also at the power plant, reiterated that the problem was not due to a lack of power — a criticism her government has been particularly sensitive to because of past problems — because there were operating reserves of 24.61 percent at the time.
Instead, she said it was a problem with the resilience of power transmission systems and basic power facilities.
She said a review of critical infrastructure would be accelerated after the incident, referring to the review of the existing power grid design.
Meanwhile, lawmakers of the opposition Kuomintang asked Economics Minister Wang Mei-hua (???) to resign to take responsibility for the massive blackout.
Taiwan People’s Party legislative caucus whip Chiu Chen-yuan (???) asked Premier Su Tseng Chang (???) to apologize for the incident and propose a compensation mechanism for losses suffered by industrial power users, particularly in the steel and petrochemical sectors.
Source: Focus Taiwan News Channel