回馈式级联型变频器PWM整流控制及其谐波分析

摘要

研究了回馈式H桥级联型多电平变换器,利用移相变压器的二次侧漏抗代替PWM整流器的输入电抗器,采用比例积分加谐振（PIR）的调节方法,设计了电网电压定向控制的PWM整流器双闭环控制策略。同时,文中给出了H桥的功率单元拓扑结构、PWM整流器的数学模型及控制策略,对PIR调节器原理、功率单元及网侧电流谐波进行了分析阐述。通过实验,验证了移相变压器消除谐波的作用,以及控制策略对直流母线电压稳定的有效性,实验结果表明PWM整流器及其控制策略在电动机加速、减速过程中,表现出良好的四象限运行性能。%Regenerative H-bridge multi-level cascade converter is studied in this paper.The secondary leakage reactance of phase-shifting transformer have been used to replace the input reactor for rectifier,and the PIR regulator is adopted in the design of grid voltage oriented double-loop control stragety.In this paper,the topology of H-bridge power converter unit,the mathematical model and control strategy of PWM rectifier,the principle of the PIR regulator and the current harmonics of power unit and grid are analyzed and discussed.The experimental results validate the function of phase-shifting transformer in harmonic current suppression and the effectiveness of control stagey for DC-bus voltage stability.The experimental results show good performance of PWM rectifier under the acceleration and deceleration of the motor four-quadrant operation.