A decentralized control strategy for multiple distributed generation in islanded mode

A technical challenge is designing a controller to control multiple distributed generation (DG) and its local loads by voltage-sourced converter (VSC) to operate in an islanded mode under the load parameters uncertainty, and unbalanced and transient conditions. Model predictive control (MPC) for the autonomous operation of multiple DG is proposed. The MPC is designed for multiple inputs and multiple outputs (MIMO) systems, and takes into consideration constraints, and nonlinearities. In this paper, the MPC-based voltage controller is combined with a fast current controller using a discrete time sliding mode controller (DSMC) for limiting the inverter currents under overload condition. The proposed control strategy provides fast tracking, robustness, fast transient recovery, less distortion, and minimal overshoots in voltage and current under 1) the short circuit conditions, 2) load transients and 3) unbalanced loads. Various scenarios including the reference signal tracking and robustness against the load perturbations are considered.