Research And Development Of Auxiliary Power And Its Monitoring System On Subway Vehicle

In a subway vehicle, there is a traction converter system which supplies power for traction motors, but also an auxiliary power system (APS) which provides power for various loads of the vehicle. Auxiliary power system is an important part of the whole subway vehicle system, it can be divided into AC power systems (SIV) and DC power systems (BCU). AC power system (SIV) provides three-phase AC and single-phase AC power for AC loads such as air conditioning units of vehicle passenger compartment, air compressors, AC lighting, ventilation, electric heater, etc. DC power system (BCU) provides DC power for DC loads such as DC lighting, control circuits of each system, vehicle-mounted equipment of communication signal, electric doors, batteries, etc. As a part of the train control and management system (TCMS), auxiliary power monitoring module aims at monitoring the working status of APS in real-time, detecting and diagnosing faults, and making it convenient to mainten and manage auxiliary power equipments. The safety and reliability of auxiliary power and its monitoring module have an important influence on the normal operation of the vehicle.Firstly, the paper compared several circuit topologies of inverter and rectifier of subway auxiliary power. Based on the supply features of the auxiliary power, the paper selected the programs of transformer-isolated12-pulse inverter and full-controlled three-phase rectifier, and determined the overall structure of the auxiliary power in this article. Then, the paper made a simulation study of that program, the results show that the program has many advantages such as more simple control and good output characteristics with little harmonic content.The paper has also studied the closed-loop control strategy for SIV. Because traditional voltage-rms PI loop control exist problems that the voltage of output has big fluctuations and high harmonic content when the loads switch and the bus voltage fluctuates, we add an inner ring of instantaneous voltage and feedforward control link based on traditional PI. The result of simulation shows that, with the double-loop feedforward compensation PI control, the fluctuation of SIV’s output voltage is significantly smaller than that with conventional PI; For better output characteristics, we add fuzzy inference engine to self-adaptively adjust PI controller parameters based on double-loop PI control strategie with feedforward compensation, the simulation results show that the control strategy greatly improves the stability and adaptability of the system. Second, refering to APS systems of Korea Hyundai Corporation, we designed a hardware architecture of auxiliary power monitoring system consisting of7circuit boards based on VME bus. With the goal of furthest reducing the amount of hardware and improving the independence of each control module and the error-tolerant rate of communication among modules, the design realizes the optimization and integration of the circuit structure.Furthermore, we designed auxiliary power monitoring software based on the modular thinking. The monitoring software is divided into three modules:communication layer, data layer and interface layer. The communication layer uses the MVB protocol to realize the data transmission between upper and lower computers. The data layer uses the mechanism of two caches to achieve the caching of real-time data such as operation data and fault recording data and the management of disk data files. The interface layer obtains the required data from the data layer, realizes the real-time display and playback of the operation and fault recording data and the upload and download of parameter, and could display the various types of data in the form of states and curves.Finally, the paper verified the subway auxiliary power control scheme with its monitoring system based on the experimental platform of subway auxiliary power manufactured by Xiangtan Electrical Machine Ltd. Co. The joint debugging and tests of the system show that the experimental prototype and the monitoring software worked stably, the quality of auxiliary power’s output waveform was good, the monitoring software meets the requirements of real-time and effectiveness.