Plug-In Dual-Mode-Structure Repetitive Controller for CVCF PWM Inverters

Repetitive control (RC) is found to be a high-performance control scheme for constant-voltage constant-frequency (CVCF) pulsewidth-modulated (PWM) converters to eliminate output total harmonic distortion. In this paper, a dual-mode-structure RC (DMRC) is proposed to further improve the control performance of RC. The proposed DMRC controller comprises of two paralleled periodic signal generators: an odd-harmonic one and an even-harmonic one. Without additional complexity and loss of tracking accuracy, DMRC can achieve a faster error convergence rate than the conventional RC does. Moreover, the tracking accuracy of DMRC is higher than that of odd-harmonic RC. In the presence of nonlinear load disturbances and parameter uncertainties, an application example of a DMRC-controlled single-phase PWM inverter is provided to evaluate the proposed DMRC scheme. Systematical experimental results show the effectiveness and superior advantages of the DMRC approach.