A Cascaded H -Bridge Converter With Staggered Phase-shifting Transformer for Cruise Ship Shore-based Power Supply System

Shore-based frequency power supply system have been widely used to solve the problem of air pollution caused by ships at ports. However, theoretical and engineering research on cruise ship shore-based power system is not yet sufficient.This paper presents a CHB topology for cruise ship shore-based frequency power system. The input transformer adopts two parallel phase-shifting transformers with epoxy casting structure.The Primary and secondary edges of each one are staggered and form 60 pulses rectification. An energy absorption circuit is developed for the power module to absorb the reverse power when the ship is connected to the shore grid. A high-voltage LC filter is also designed on the output side. It solves the problems of high voltage, difficulty in increasing the capacity, low THD and large volume of the converter. The single 16MVA frequency converter has been developed in a cruise ship port in China. Currently, it is the largest shore-based frequency power supply system in Asia. Moreover, the operating principle, mathematical model, and control strategy are presented. Finally,the method proposed in this paper has been tested by industrial site. The test and application results prove the accuracy and effectiveness of the proposed method.