After berthing, the ship is usually powered by the diesel generator on board. The emissions of nitrogen oxides, sulfur oxides, CO2 and particulate matter generated after the combustion of marine fuel will pollute the port and the surrounding environment.

Shore power supply system refers to the power transmission system that seamlessly transfers the power load on board to the shore by connecting the shore power supply of the wharf and turning off the ship side generator when the ship is docked. In order to meet the requirements of 60Hz power supply system for international ships, a special frequency conversion shore power supply system is required to convert the 50Hz power supply of shore power grid to 60Hz.

The application of shore power supply system can greatly reduce the pollution emission when the ship is berthing, reduce the emission ratio of nitrogen oxide, particulate matter and sulfur oxide by about 90%, eliminate the noise and vibration generated by the generator on board, improve the operation and living environment of the crew, and reduce the unit loss and maintenance.