Synchronization of Three-Phase Grid-Connected Inverter Using Second-Order Sliding Mode Controller

This article presents Second-Order Sliding Mode Control (SOSMC) to synchronize the three-phase grid-tied inverter and discuss the existing problem in the synchronization process through conventional PLL schemes and so to eliminate the problems related to the PLL the proposed PLL-less strategy employ the Second-Order Sliding Mode Controller, the suggested controller is implemented in stationary reference frame (alpha-beta reference frame) to eliminate the need for PLL and since Park's transformation is also not required the computational burden is also reduced in this approach, further the proposed model is compared with the existing PLL-less strategy and the results shows the effectiveness of the proposed method in reducing the power ripples and keeping the system stable even in unbalanced conditions.