Officials announced that services would gradually return to normal at 10.30pm after finding a technical solution to problems caused by the fire, which had been put out but had put the transformer out of operation.
The station is an important commuter hub and serves London and Brussels, as well as Germany and the Netherlands.
Electricity to the tracks was cut and train services suspended at 6.30pm after a fire damaged a transformer just north of Paris.
About 15,000 passengers were removed from 15 trains trapped on the tracks, some of them at some distance from the station, according to Transport Minister Alain Vidalies.
Many were forced to queue to find hotel rooms for the night.