After berthing, vessels typically rely on onboard diesel generators for power. Emissions from marine fuel combustion – including nitrogen oxides (NOx), sulfur oxides (SOx), CO₂, and particulate matter – significantly pollute port environments and surrounding areas.

A shore power system enables seamless transfer of a vessel's electrical load to shore-based infrastructure by connecting to the dock's power supply while shutting down shipboard generators. To meet the 60Hz power standard required by international vessels, specialized frequency-converting shore power equipment must transform the shore grid's 50Hz supply 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.