Improved Sliding Mode Control Method of Single-Phase LCL Filtered VSI

This paper presents a sliding mode control (SMC) and design method of single-phase LCL filtered VSI with direct current feedback. The proposed SMC is much simpler since it is based on a new sliding surface which only requires one grid current sensor. The multiple resonant strategies are also applied to enhance the ability to track the sinusoidal reference. In addition, a practical math method is proposed to calculate the optimal parameters of the sliding-surface. The theoretical considerations and analytical results are verified through simulations with a 2-kw grid-connected inverter. The results show that the proposed SMC strategy has fast dynamic response, strong robustness to perturbation, smaller tracking-error and total harmonic distortion.