The Energy Market Authority (EMA) is moving closer to finding the cause of Tuesday's massive blackout, said Minister for Trade and Industry Chan Chun Sing.
Speaking at the launch of the nationwide open electricity market yesterday, Mr Chan said: "The good news is that EMA, together with the generation companies and the original equipment manufacturer, has been able to quickly zoom in on the source of the problem.
"But we are conducting further tests because some of these components are also used by plants in Singapore and in other parts of the world.
"So, we are working closely with the original equipment manufacturer to make sure that such things don't get repeated."
On Tuesday at 1.18am, 146,797 residential and commercial customers in 19 areas of the country were plunged into darkness for 38 minutes in Singapore's worst blackout in 14 years.
Mr Chan said the episode showed Singapore's back-up procedures worked well, because even though both the original and the back-up power-generating units failed, fresh capacity was started 15 minutes afterwards with power gradually restored to the rest of the island.
Asked if the responsible power suppliers would face penalties, he said that it was too early to say.
"I would like to assure Singaporeans that we have sufficient capacity in our system, and this is what we demonstrated that night - that when the first system failed, the back-up system kicked in immediately.
"And even when the second system failed, we had sufficient capacity to start up the power from 15 minutes onwards."