LC串联式脉宽调制整流器及其电流迭代控制方法

针对非线性负载引起的无功功率和谐波电流问题,研究了一种电感—电容(LC)串联式脉宽调制(PWM)整流器及其电流迭代学习控制方法,使三相PWM整流系统不仅能够整流输出能量供给负载,而且能补偿非线性负载产生的无功功率和谐波电流,实现PWM整流功能和功率补偿功能的有效集成。该整流器采用一种LC串联滤波,使电容承担大部分电网基波电压,整流器可直接连接电网,降低装置成本。为克服LC串联式滤波器的电容惯性阻尼作用,采用一种迭代学习算法的电流无差拍控制,并结合输出电流前馈控制和反馈控制的特性,有效提高控制系统的响应速度和控制精度,并推导了算法收敛的条件。仿真和实验结果证明了所提结构和控制方法的正确性和有效性。

Pulse-width Modulation Rectifier with LC-series Filter and Its Current Iterative Control Method

For the reactive power and harmonic current caused by nonlinear loads closed to pulse-width modulation(PWM)rectifiers, a PWM rectifier with LC-series filter and its current iterative learning control method are proposed. Here, PWM rectifier can not only provide loads with energy, but also compensate for reactive and harmonic current caused by the nonlinear loads. It can achieve effective integration of the rectification function and power compensation. The LC-series filter is adopted to make the capacitor bear the fundamental voltage, so that it can be directly connected to the power grid. In order to overcome inertia damping of the LC-series filter, a deadbeat control method based on the iterative learning algorithm is proposed for integration with the performance of feed-forward and feedback control to effectively improve the response speed and control accuracy of the system. The convergence condition of the algorithm is also derived. Simulation and experimental results have verified the correctness and validity of the proposed structure and method. This work is supported by National Natural Science Foundation of China(No. 51607062).