Optimization Design Of Power Supply Control System For Locomotive Air-conditioner Based On DSP

With development of railway transportationthe towards high speed and high density orientation,it is very important to optimize the working environment of locomotive cab,which can insure the driving safty.However,locomotive power is not suitable to link to air-conditioning directly because of the complex environment in locomotive,such as big vibration amplitude,high temperature,strong electromagnetic interference,opening and closing doors repeatedly and so on,and the poor locomotive power.So,the air-conditioning should be installed special power supply system which can ensure the normal running of air-conditioning,improve the environment of locomotive cab and insure the driving safty.Digital technology,especially the use of DSP in power control,make the power control more precise and agile which overturn the impasse that complex control can not be achieved by analog circuit and MCUbefore.This paper designed a kind of locomotive air-conditioning power supply system based on a chip of TMS320F2812 type,which can achieve digital control of locomotive air-conditioning power supply,provide more stable voltage,power and current correspond to the power demand and ensure the stable work of air-conditioning.The main circuit of control system of locomotive air-conditioning power supply include chopper circuit and inverter circuit.The former uses step-up chopper circuit to boost the DC voltage,which can increase locomotive 110V DC voltage to 540V.The latter uses a three-phase AC inverter,which can inverted the DC obtained by the former to a three-phase 380V AC for the use of air conditioning units.The core of control circuit of control system of locomotive air-conditioning power supply is DSP chip of TMS320F2812 type.The corresponding external auxiliary circuits and control module are designed,which can achieve the system collection,control and output of air-conditioning power and stable work of power system.The main research work are as follows:(1)Main circuit design of the locomotive air-conditioning power supply.Compare study on the two design plan of main circuit based on environment factors of locomotive air-conditioning power supply.Using a "chopper-Inverter" program after selection of the circuit used in the device.(2)Hardware design of the control system of the locomotive air-conditioning power supply.The whole circuit design based on the F2812 model DSP chip,including display,capture,simulation interface,signal reset,clock,power supply circuit protection and so on.At last,detailed research on the relevant requirements of IGBT drive signal and design of the power driver circuit isolation.(3)The software design of the system.The whole design of modular control software by combination of main drive and the subroutine based on F2812 DSP chip.Drawing flow chart of program modules to design the corresponding modules.Among these,the digital PID control,analog-digital conversion for generating signal acquisition and generation of control signals of two circuit switches are core functions.(4)Experiment confirmation of the locomotive air-conditioning power.Hardware circuit building based on schematic diagram of control system.Debugging modules online.Recording output oscillogrm of chopper-Inverter switch signal.Data analysis of experiment results.The resuts showed that the running state meet the performance index of control system.