Control of a Three-Phase Grid-Connected Inverter based on Super-Twisting Sliding mode Algorithm

This paper deals with the robust current control for three-phase Grid-Connected Inverters (GCI) of distributed generation (DG) systems based on a Super-Twisting Sliding mode controller (ST-SMC) during injecting active and reactive power into the grid. This approach is capable of decreasing the chattering phenomena and improving the system's accuracy. The proposed controller is realized for the inner current controller to guarantee proper regulation, such as short-time response, small steady-state error, and so on. To achieve the appropriate synchronization desired between current injected and grid voltage, a phase locked loop (PLL) based on a synchronous reference frame (SRF) is applied. Finally, simulation results are examined by Powersim (PSIM) software and are compared with those of a conventional controller to validate the proposed controller's effectiveness.