PWM变流器分段平均模型中的纹波估计方法  

A Ripple Estimation Method for Piecewise Averaged Model of PWM Converters

作　　者：许寅[1] 陈颖[1] 陈来军[1] 杨阳[2] 

机构地区：[1]电力系统及发电设备控制和仿真国家重点实验室(清华大学电机系),北京市海淀区100084 [2]西北工业大学电气工程学院,陕西省西安市710072

出　　处：《电网技术》2013年第8期2143-2150,共8页Power System Technology

基　　金：国家863高技术基金项目(2012AA050217)~~

摘　　要：在电力系统稳定性分析和控制策略研究中,PWM变流器的平均模型被广泛采用。然而,仅考虑状态变量的平均分量而忽略其纹波,可能导致系统暂态仿真及分析结果的不正确。为此,提出了PWM变流器状态变量纹波估计的一般方法,并得到了纹波的近似表达式。三相PWM AC-DC变流器和升压斩波器的仿真结果表明,所提出的纹波估计方法能够给出实际纹波的精确近似表达式,从而显著提高PWM变流器平均模型的准确性。Averaged models of PWM converters are widely used in the research on system stability and control strategy of power grids.However,it may lead to incorrect results of power system transient simulation and analysis while only the average components of state variables are considered and their ripples are neglected.A general method to estimate the ripples in state variables of the piecewise averaged model of PWM converters is proposed and approximate expression for ripples is attained.The influence of ripples on the accuracy of simulations using the piecewise averaged model is analyzed.Simulation results of three-phase PWM AC-DC converter and boost copper show that the proposed ripple estimation method can give accurate approximate expression of actual ripples,thus the accuracy of the piecewise averaged models of PWM converter can be improved remarkably.

关 键 词：PWM变流器 平均模型 电磁暂态 纹波估计 

分 类 号：TM721[电气工程—电力系统及自动化]