Research On Control Strategy Of Auxiliary Converter For Tram

The auxiliary converter of rubber wheel tram provides powers supply for control power,traction battery,air compressor and other auxiliary equipment.As one of the core technologies of the tram,it directly affects the safe and reliable operation of the tram.Based on the "Tram auxiliary converter control system",the control strategy of the tram auxiliary converter which consists of the control power,traction charger and auxiliary inverter,is studied in this paper.The control power part is the DC-DC converter,which main function is providing 24V DC power for the auxiliary equipment such as the control chassis and the battery.Considering the output requirements and battery charging characteristics,a double loop control strategy with constant current charging and constant voltage charging is adopted.The traction charger part is the DC-DC converter.The main function is to recharge the battery which uses constant current charge control strategy according to the charging instruction provided by the battery management system.The auxiliary inverter part is a cascade connection of a DC-DC converter and a DC-AC converter.The DC-DC converter adopts constant voltage control to provide stable DC voltage for the DC-AC converter.The DC-AC converter establishes a dual loop control strategy in the synchronous rotating coordinate system,which is responsible for providing three phase sinusoidal alternating current for the AC load such as air compressor.In addition,the hardware and software are designed respectively.The hardware control chassis includes DSP+FPGA,AD,PWM,and so on.The software control includes the system logic,control algorithms,fault protection,fault storage and other functions.Field power experiments are carried out on the actual operating auxiliary converter.The experimental results show that the auxiliary converter has an excellent output performance,and it can operate reliably under complex conditions.