Design And Research On EMU Auxiliary Inverter

ABSTRACT:The EMU project is carried out by CNR Changchun Railway Vehicles Co.Ltd and Beijing Jiaotong University. The auxiliary power supply system is the core part of the electrical equipment in the EMU, which supplies power for all the electrical equipment except the traction drive system. In the auxiliary power supply system, the auxiliary inverter is an indispensable key part, which supplies the380V50Hz power for the air conditioning system, ventilator, lighting, the cooling fan and so on in the EMU. The normal operation of all the electrical equipment including the traction drive system depends on the auxiliary power supply system. Based on the research on the theory and engineering, this paper designs an auxiliary inverter system for the EMU including the design for the main circuit and the control system. The simulation and experiment have been carried out to verify the feasibility of the design.At first, in this paper the auxiliary power supply system of the different type of CRH emu has been carried on the comparative analysis. We compare the characteristics of the different auxiliary power supply system and emphatically analyze their auxiliary inverter topology. With the research and the actual project requirement, we choose the suitable plan for the auxiliary power supply system, and preliminarily determine the auxiliary inverter topology.Secondly, according to the chosen topology plan and the actual technical requirement, the final main circuit topology has been decided. After that, we make the selection of all components of the main circuit by making the calculation and simulation verification, and make sure that they can satisfy the voltage, current, temperature, etc.Finishing the design for the main circuit, it is time for the control system. In this paper, the EMU auxiliary converter control strategy is analyzed and the software is implemented. The whole system adopts digital control technology. The key chip is DSP TMS320F28335made by TI. We use the SVPWM modulation strategy and use PI regulation to achieve the double closed-loop control. On the basis of double closed-loop control, we make the feedforward improvement. Besides, the protection strategy is described. The hardware and software methods both are used to make it sure. At last, we make a brief analysis of problems caused by the unbalanced and nonlinear load.The last part of this paper is simulation and experiment. The simulation can prove the previous selection of the whole device and the control strategy effective. Based on the success of the simulation, we set up the experimental platform and carry on the experiment. The results of the experiment are consistent with those of simulation and the theoretical analysis, which verifies the feasibility of the whole design. The auxiliary inverter works well. At the same time, it provides theory basis and preliminary experimental basis for the engineering application and transition.