Research on the Control Strategy of Unbalanced Three-phase Three-wire Micro-grid

The three-phase unbalanced conditions of microgrid will affect the control performance, so it is required to study the control of asymmetric systems. In this paper, based on three-phase unbalanced micro-grid system, connected with three-phase three-wire voltage source converter (VSC), the effect of asymmetric conditions on the VSC current control was studied. With the application of adaptive discrete variable structure sliding mode control (SMC) method, the micro-source VSC model of the alpha-beta domain was established, and a new strategy of micro-source VSC inner current decoupling control was put forward to. This method can eliminate the micro-power three-phase current conditions of asymmetric coupling effect on the output current control, and it helps to improve the micro-power VSC current tracking performance. Simulation results verified the validity of this method.