Research Progress of Urban Rail Transit Traction Power Supply System with Bidirectional Converters

Objective Most of the traditional traction power supply systems of urban rail transit lines in China use diode rectifier units, which have the deficiencies that electric energy can only flow in one direction and the regenerative braking energy can not be fed back to the power supply system. The bidirectional converter based on IGBT (insulated gate bipolar transistor) is successfully developed and applied in actual cases. In order to promote the further development of bidirectional converter technology, the relevant research progress needs to be studied. Method The characteristics of bidirectional converters, rectifier/inverter bidirectional conversion technology, and the integrated management system architecture of bidirectional conversion power are described. The status quo of bidirectional converter application in China and abroad is analyzed, and the DC voltage and current output characteristics under two voltage control strategies i.e. constant voltage control strategy and droop control strategy, are expounded. The existing current calculation algorithms are introduced, and the algorithm requirement of the urban rail traction power supply system with bidirectional converters is discussed. Result & Conclusion The successful application of bidirectional converters in urban rail transit power supply system realizes the train regenerative braking energy feedback, improving the operation efficiency of the whole power supply system.