Research Of Urban Rail Vehicle Auxiliary Power Simulation System

Railway vehicle auxiliary power is a very important part of the normal operation of the subway, in addition to vehicle traction power supply, mainly used for passenger vehicles of auxiliary power supply facilities, including vehicle air conditioning units, ventilation, air compressor, electric heater, ac lighting ac power supply and dc lighting, vehicle signals, communications equipment, such as control circuit of dc power supply.Urban rail auxiliary power system is mainly composed of the auxiliary inverter(sivs) and charging unit.With the rapid development of subway construction, around the track teaching is becoming more and more broad market.In view of the existing in higher vocational colleges in the subway train equipment is expensive, the high voltage, large volume, complex issues, aims to develop a low cost, good effect, high safety, to compare the real simulation of the auxiliary power supply system for urban rail vehicles, the simulation system.Based on the simulation of the system as the background, the course of the development of the auxiliary power simulation system design methods are studied and described.Through real subway principles and functions of the auxiliary power supply system, on the basis of retain the actual functional voltage levels, the reduction of power processing, general design scheme of simulation system is put forward.Using DC150 V analog voltage, third rail sivs DC110 V simulation output voltage, DC48 V DC24V and simulate the charger output voltage.By analyzing the advantages and disadvantages of many kinds of topological structure, the use of electrical isolation, auxiliary inverter simulation device with two level processing frequency transformer isolation scheme as reference model, in front of the isolation transformer step-down chopper circuit is designed for the prototype battery charger.Simulation system hardware parts, respectively, set up the third rail simulator module, SIV simulation system module, battery charging device module, ac/dc load simulator, etc.The detailed design of battery charger unit.The main circuit uses IGBT as the switch tube, driven by TLP250 switch tube, main circuit using hall sensor detection circuit voltage current.Control chip uses PIC18F2331, sensor feedback value through sampling circuit sampling, through the digital PID algorithm, automatically adjust the output PWM duty ratio, make the output stability in DC48 V.Communication device and the upper machine adopt RS485 serial interface communication mode, use MAX485 chip, the communication protocol, realize communication between the parties.Finally, made a physical prototype, the output voltage, communication, through the simulation, experiment and verification in accordance with the design requirements.