Research And Manufacture On Metro Auxiliary Inverter System Based On High Frequency DC-DC Link

Subway Auxiliary Inverter System is an indispensable electrical part in subway vehicle. It provides the three-phase 380V power supply for AC load such as air conditioning units, fan, lighting, electric heater etc. As an important part of the subway vehicle, the operational reliability of the Auxiliary Inverter System has a significant influence on the stable and reliable operation of the whole vehicle. Based on the system research and engineering practice, this text puts forward a solution of Auxiliary Inverter System and examines the theory and engineering. Finally simulation experimental results verify the feasibility of the scheme.Firstly, this text expounds the Subway Auxiliary Inverter System. It compares the advantages and advanced technology between high frequency inverter and power frequency inverter. It adopts ISOP circuit structure for high frequency inverter front-end DC link. ISOP circuit structure optimizes reliability and power density of the system. According to the engineering requirement, this text choose the right topology.Secondly, according to the requirements of the technical indexes, this text makes a design to the parameter of Subway Auxiliary Inverter System.Comprehensive consideration of the voltage, current, frequency, temperature, product reliability, efficiency, factors and the price of products, this text choose suitable products. I do an optimization design transformer, absorbing circuit and drive circuit, etc. Finally the rationality of the design parameters is verified by simulation.Then, this text makes a control strategy analysis. DC-DC circuit adopts ISOP topological structure. It caused input uneven voltage-sharing and output uneven current sharing. It makes an influence to the reliability of system. Piezometer ring and closed-loop control strategy has solved the problems. Interlaced control improves the bad effects of current ripple. Interlaced controlreduces parameters of the filter and improves the power density. DC-AC circuit adopts the SVPWM algorithm. It improves waveform quality. It is a kind of advanced algorithm of inverter. In order to alleviate the starting current, adopts load control soft start-up VVVF. According to the control strategy, this text introduces flow chart of digital signal processor (DSP) algorithm.The experimental results and simulation results agree well with the theoretical analysis. The results verify the feasibility of the practical engineering application. this text provides the theoretical basis and the available experimental basis for the practical engineering application.