A fixed-frequency quasi sliding-mode repetitive control (QSMRC) for voltage source inverters

In this paper, a hybrid quasi sliding-mode repetitive control (QSMRC) method with fixed-frequency modulation is proposed. By employing the equivalent control approach, the quasi sliding-mode control (QSMC) is first derived and implemented. The repetitive control strategy is embedded in the derived QSMC to reduce the steady-state tracking error and the total harmonic distortion (THD). The proposed QSMRC successfully combine the inherent robustness of sliding-mode control (SMC) and the harmonic suppression capability of RC. Further improved THD performance is realized compared with RC. Moreover, the proposed QSMRC provides similarly excellent transient response as SMC. It significantly improves the system robustness and dynamic performance. The theoretical analysis and the promising features are verified by simulation comparisons based on PSIM models. The proposed QSMRC method performs high steady-state precision, fast dynamic response and low THD for voltage source inverters.