三相电压PWM整流器闭环系统控制策略研究

摘要

由于三相电压脉宽调制(PWM)整流器具有网侧电流正弦化、电能双向流动以及单位功率因数控制等优点,可广泛应用于各类电力电子领域.为了提高PWM整流器闭环系统的控制性能,针对传统控制算法所带来的直流母线电压不稳定、动态响应速度慢以及电流谐波较大等问题,在PWM整流器数学原理的基础上,对其闭环系统提出了一种改进型的控制策略.上述算法中的电流内环采用欧拉-拉格朗日模型的无源控制,实现网侧单位功率因数、电流低谐波;电压外环采用电压平方作为控制量,实现线性化的间接电压控制.仿真结果表明,采用改进型的控制策略能够有效地提高系统的直流母线电压精度,保证更小的电流波形畸变.%In order to improve the control performance of PWM rectifier closed loop system,aiming at the problems caused by traditional control algorithms,such as unstable DC bus voltage,slow dynamic response and large current harmonics,based on the mathematical principle of PWM rectifier,this paper proposes an improved control strategy for the closed-loop system.Passive control of current inner loop in the algorithm by using the Euler Lagrange model,realize the network side unit power factor and low harmonic current;and the voltage outer loop uses the voltage square as the control quantity,realizes the linearization indirect voltage control.Simulation experiment results show that the improved control strategy can effectively improve the DC bus voltage accuracy and ensure smaller current waveform distortion.