Improved performance using discrete rotating and shifting switching manifolds of single-phase PWM inverters

This paper proposes a discrete rotating and shifting switching manifolds method for single-phase PWM inverters capable of maintaining low total harmonic distortion (THD) as imposed to parameter variation or rectifier load, and fast transient response subject to step change in load. The proposed method will ensure that the sliding mode proceeds from an arbitrary initial state, whereas the conventional fixed switching manifold can not achieve the robustness against system uncertainties before the sliding mode occurs. The proposed method is implemented based on TMS320F2812 DSP in an inverter laboratory prototype, and only the output voltage is required to be sensed as closed-loop feedback. With the proposed method, the low voltage THD under capacitor-resistive rectifier load is obtained. Design procedures and experimental results are presented to demonstrate the performance of the proposed method.