Discrete feedforward sliding mode control of a PWM inverter for sinusoidal output waveform synthesis

This paper presents a new discrete feedforward sliding mode control scheme for closed-loop regulation of PWM inverters in applications of high-performance uninterruptible power supply (UPS) systems. Owing to the existence of the feedforward path, discretization of the reference signal with large step size is not required. Moreover, only the output voltage needs to be measured as feedback in the proposed control scheme. A DSP-based digital-controlled PWM inverter has been implemented to examine the actual response of the designed controller. Simulation and experimental results show that the constructed digital PWM inverter control system has fast dynamic response and low total harmonic distortion (THD) under the proposed discrete feedforward sliding mode control scheme