sliding mode controller design for stabilization of the three-phase grid-connected inverters in the presence of unbalanced local loads

Considering the presence of different model parameters and controlling variables, as well as the nonlinear nature of dc to ac inverters; stabilizing the closed-loop system for grid current balancing is a challenging task. to cope with these issues, a novel sliding mode controller is proposed for the current balancing of local loads using grid-connected inverters in this paper. the closed-loop system includes two different controlling loops: a current controller which regulates the output current of grid-connected inverter and a voltage controller which is responsible for dc link voltage regulation. the main features of the proposed nonlinear controller are reactive power compensation, harmonic filtering and three-phase balancing of local nonlinear loads.  the developed controller is designed based on the state-space averaged modelling its stability and robustness are proved analytically using the lyapunov stability theorem. the accuracy and effectiveness of proposed controlled approach are investigated through the pc-based simulations in matlab/simulink.