基于平均化理论的PWM变流器电磁暂态快速仿真方法(二)适用PWM变流器分段平均模型的改进EMTP算法

摘要

For power systems containing large number of power electronic converters,when the detailed model of switch circuit such as pulse width modulation (PWM) converter is applied,transient simulations using conventional EMTP method are very time-consuming.An improved EMTP algorithm is proposed to perform simulation with the piecewise averaged model of PWM converters.The proposed algorithm is able to avoid the complicated procedure applied to handle the switching events,while two new sub-procedures are included to predict the parameters of the piecewise averaged model and adjust the errors caused by the inaccuracy of parameters are added.From the test results of three-phase PWM AC-DC converters,it can be seen that by applying the proposed algorithm,the efficiency of transient simulations can be enhanced remarkably.%对包含大量电力电子变流器的电力系统进行电磁暂态仿真时,若使用脉宽调制(PWM)变流器等开关电路的详细模型,将导致电磁暂态程序(EMTP)仿真效率低下.在EMTP中应用PWM变流器的平均模型可以有效解决这一问题.文中提出了一种改进的EMTP算法,可灵活地应用PWM变流器的分段平均模型进行仿真.该算法省略了传统EMTP算法中复杂的开关处理子模块,同时增加了2个子模块分别用于预测分段平均模型的参数和校正参数不准确带来的仿真误差.对三相PWM AC-DC变流器的测试结果表明,采用所提出的算法可在采用较大的积分步长仿真的同时确保仿真结果的正确性.