Average Model-Based Sliding Mode Control for Quality Improvement of a Grid-Connected PUC Inverter

This article presents a new sliding mode phase shift PWM (SM-PSPWM)-based control strategy for a grid-connected Packed U-Cell (PUC) inverter. The proposed control strategy is based on the average model of the PUC inverter while using a multicarriers phase shift pulsewidth modulation (PS-PWM) technique. The use of the pulsewidth modulation (PWM) strategy, based on the inverter average model, ensures high steady-state performance, low harmonic current, and enhanced thermal properties. In addition, the sliding mode control (SMC) is applied to generate the input signals to achieve a fast dynamical response and high robustness against disturbances. To further improve the robustness under parameter mismatch and distorted grid voltage conditions, an integral term is added to the surface function for better accuracy and stability. To validate the performance of the proposed controller (fast dynamics, global stability, low current total harmonic distortion (THD), etc.) shown by the simulation results, a laboratory setup is used to validate the theoretical analysis.