一种改进的逆变器并联列车辅助供电系统

Research on an Improved Inverter Parallel Train Auxiliary Power System

针对基于下垂控制逆变器并联技术的DC600V列车辅助供电系统,改进了其下垂控制策略,将并联逆变器输出有功功率的积分项引入系统下垂控制策略中。采用小信号分析法构建了并联逆变器功率控制环的小信号模型,应用根轨迹法分析了下垂控制器参数对系统稳定性及动态性能的影响,并确定了逆变器并联列车辅助供电系统下垂控制器参数。构建了由两台辅助逆变器并联的列车辅助供电系统仿真模型及实验系统,进行了负载突变仿真及实验。仿真及实验结果表明所设计的下垂控制器参数及改进的下垂控制策略能够使得逆变器并联系统快速、稳定地响应负载突变过程,并始终保持对负载电流的均分及对并联系统输出电压给定值的跟踪,且进一步减少了并联逆变器之间的环流,改善了系统均流性能。

In this paper,the control strategy of the DC600V train auxiliary power system based on droop control inverter parallel technology is improved,and the integral of the inverter output active power is introduced into the system’s droop control strategy.The small-signal model of parallel inverter power control loop is built by the method of small-signal analysis,and then the impact of each parameter in droop controller on system stability and dynamic performance are studied using the root locus method.The parameters with excellent system performance are selected for the droop controller of the inverter parallel train auxiliary power system.The simulation model and experiment system with two auxiliary inverters paralleled are built,and the mutation load simulation and experiment are done.Simulation and experiment results verify that the parameters and the droop control strategy designed in this paper enable inverter parallel system to response to the load changing process fast and stably,in the whole process of which the system load is averagely distributed,and the given output voltage of inverter parallel system is tightly tracked.The loop current between inverters is decreased and the sharing current performance of the inverter parallel train auxiliary power system is improved.