Design And Research On The Auxiliary Inverter Of Diesel Locomotive

The auxiliary inverter plays an important role in railway rolling stocks, it provides auxiliary equipments on the locomotive with AC frequency power, and provides important security for locomotive’s normal running. However, locomotives usually run in such surroundings as a wide range of temperature, forceful shock vibration and bad sand environment, they all require a high level of reliability to the auxiliary inverter. The property of auxiliary inverter impacts locomotive’s normal working directly, so it is that significant to design a high-performance auxiliary inverter for railway rolling stocks.This paper mainly studies on the auxiliary inverter of diesel locomotive, completes the hardware structure design of auxiliary inverter, and introduces the design thought of the system control software. Firstly, this paper confirms the overall design to the system of auxiliary inverter, employing the three-phase full-bridge inverter circuit as main circuit topology of aided inverter, choosing vector control strategy based on SVPWM modulation as inverter control system and TMS320F2812DSP as main control chip. Secondly, the hardware circuit design of auxiliary inverter is done, it includes type selection of main circuit switching device, designs of in-out filter circuit, of switching device’s driving and protecting circuit and of signal detection circuit. Thirdly, based on the above hardware circuits, the paper analyses the basic principle and implement method of SVPWM modulation technique and vector control strategy in detail. The paper also puts forward the digital design thoughts of auxiliary inverter system control software in combination with Digital Signal Processor (DSP). In which, it emphatically introduces space vector SVPWM control algorithm’s DSP implement method.Last of the paper, it sets up a simulation model of auxiliary inverter vector control system based on MATLAB/Simulink simulation platform, by means of the waveform of the simulation results, proving the feasibility and availability of vector control strategy based on SVPWM modulation. At the same time, through different circumstance waveforms between unload and load in simulation system, it is observed that the design of auxiliary inverter of diesel locomotive in this article has a good stability and practicability.