Frequency robust control in stand-alone microgrids with PV sources : design and sensitivity analysis
Résumé
In this paper, a robust H-infinity control strategy for frequency regulation is proposed in isolated microgrids (MGs) composed of diesel engine generators, photovoltaic (PV) sources, and storage units. First, the linear matrix inequalities (LMI) method is adopted to design a multi-variable H-infinity controller which ensures given specifications. In a second step, uncertainties in the storage device state of charge (SoC) are considered and a sensitivity analysis is carried out in order to determine the maximum variation range of SoC for which the dynamic performances are respected. The controller's robustness and performance in the presence of various load disturbances, PV output power variations, and the SoC uncertainty are validated through a series of nonlinear time-domain simulations performed with MATLAB/Simulink.