A Linear Quadratic Regulator With Optimal Reference Tracking for Three-Phase Inverter-Based Islanded Microgrids

This article proposes a power sharing control method based on the linear quadratic regulator with optimal reference tracking (LQR-ORT) for three-phase inverter-based generators using inductor-capacitor-inductor (LCL) filters islanded mode. Compared to single-input single-output (SISO)-based controllers, LQR-ORT controller increases robustness margins and reduces value of error inputs during transient response. Supplementary loops are used reduce frequency voltage deviations in ac bus without communications. The supplementary loop regulation is droop by reducing direct quadrature output voltages according active reactive demand. A model synchronous frame that integrates voltage-current dynamics also proposed. In addition, methodology develop an microgrid Robustness analysis demonstrates stability under variations LCL filter components. Experimental results demonstrate accuracy proposed effectiveness improving response