Single-Phase Energy Management System Operating in Islanding Mode With Repetitive Control and Active Damping

This paper presents a novel digital control strategy for the islanding mode operation of a power electronics-based energy management system (EMS). Thanks to the use of a high-performance repetitive controller combined with active damping, the EMS is capable of supplying a high-quality sinusoidal voltage to critical loads when the ac grid is not available. The proposed control scheme is analyzed and implemented in a field-programmable gate array-based control platform; it achieves a very low output voltage total harmonic distortion and holds a large stability margin for a wide range of load conditions. Analysis and simulations demonstrate the superiority of the proposed controller versus open-loop control. Laboratory experiments with linear and nonlinear loads validate the model used for the simulations that demonstrate the excellent performance of the new control strategy.