三相PWM变换器分式延迟重复控制策略

Fractional Delay Repetitive Control Strategy for Three-phase PWM Inverter

在固定采样频率下,当延迟环节的指数为整数时,重复控制器(RC)能对电力电子变流器实现高精度波形控制。然而,当延迟环节出现分式指数时,重复控制系统的性能受限。针对三相脉宽调制(PWM)逆变器输出波形控制,提出了分式延迟重复控制(FDRC)方案。对常规重复控制和FDRC进行了系统性的分析与讨论;在固定采样频率下,采用一种非递归型(FIR)滤波器逼近分式延迟环节,并给出FDRC系统的稳定条件。最后开展了基于dSPACE1104平台的三相PWM逆变器实验研究。实验结果验证了所提控制方案的有效性。

In case of a fixed sampling frequency,when the exponent of delay link is an integer,repetitive controller（RC） can achieve high-precision output waveform control of power electronic converters.While the exponent is fractional in delay link, the system performance of repetitive control is limited.A fractional delay repetitive control（FDRC） scheme is proposed for output waveforms control of a three-phase pulse width modulation （PWM） inverter.The conventional repetitive control and FDRC are systematically analyzed and discussed.A finite impulse response（FIR） filter is employed at a fixed sampling frequency to approximate fractional delay link, and the stability conditions of FDRC system also are presented.Finally,experimental study of three-phase PWM inverter based on dSPACE1104 platform is carried out.Experimental results demonstrate the effectiveness of the proposed control scheme.