Yallourn Power Station has been restored to near full generation capacity by its operators, after fire ravaged the station on Friday amid a lockout of 75 union workers.

EnergyAustralia took control of the power station on Friday after what it said was a threatened industrial ''takeover'' of the power plant by workers in the Construction Forestry Mining and Energy Union.

Victoria Police are investigating how the power station caught fire on Friday, shortly after the lockout was announced, with electricity generation ceasing as a result.

A police spokesman said on Monday no charges had yet been laid.

EnergyAustralia's operations and construction manager, Michael Hutchinson, said non-union workers had brought back online power generation units at Yallourn.

An existing enterprise agreement expired last July, and it is understood the company has offered employees covered by a new deal pay rises of up to 25 per cent over four years.