Non-disruptive MPC-based frequency and voltage control in microgrids

High levels of intermittent renewables bring challenges to the frequency and voltage control scheme design for microgrids (MGs). This paper studies frequency and voltage regulation of MGs using both generation-side control and load-side control. A switched model predictive control (MPC) controller is designed to achieve twofold targets. First, it makes generators work together with loads to regulate MG frequency and bus voltages. Second, when the preset conditions regarding to bus voltages are satisfied, it minimizes disruption to loads by changing the objective function in MPC. A switching algorithm is designed to determine whether the proposed MPC works in frequency and voltage regulation mode or in load restoration mode. Simulation results show that the proposed controller successfully mitigates the frequency and voltage fluctuations caused by renewables and meanwhile minimizes the impact of the load-side control on loads.