The dissertation discussed marine generator synchronous technology, as well as, intelligent on-shore controlling circulation current by means of using reactor to limit circulation current, both of which may realize seamless connection between ship electrical system and shore power; and also demonstrated intelligent FCL all-controlling power electronic device GTO (Gate Turn-off Thyristor) blocking and conducting, that can ensure the rapidity of connecting and disconnecting reactor and notable current limit effect. The dissertation proves the effect of seamless power supply between the port and ship, as a result of simulation model of intelligent FCL on-shore controlling circulation current. And intelligently dealing with electricity bills processing, as well as seamless power supply, which realize marine energy conservation and low-carbon emissions reduction in the port, can ensure to realize uninterruptable power on-shore connection, and at the same time promote the development of intelligent port.