Disturbance Feedforward Compensation Control Strategy for Parallel Inverters Systems in Microgrid

When the load is suddenly increased or decreased and different DGs are arbitrarily plugged-in or plugged-out from the parallel inverters system, due to the inherent regulation characteristics of PI controller, a large overshoot will be generated, which makes the output voltage of each inverter inevitably increase or drop in a sudden following way, which will have a non-negligible impact on the islanded microgrid. Due to the lack of inertial components, the parallel inverters system is prone to disturbing oscillation, which will lead to the imbalance of circulating current and power distribution between inverters and cause the fluctuation of operating voltage of microgrid. To ensure the microgrid under the topology changes of stable operation, at the same time without having to join the power quality compensation device and communication links among droop controllers to solve the problems, this paper put forward disturbance feedforward dynamic compensation control for parallel inverters based on the robust residual generator.