Autonomous microgrid with energy storage system

Abstract

This paper shows the development of a strategy to connect multiple different types of converters in parallel in an isolated single-phase microgrid harmoniously. First, the droop control strategy for microgrids and the particularities of the microgrid operation are explained, such as controlling the voltage and current of the battery to maintain its integrity. Then three different types of converters in a microgrid are described, and different droop equations are proposed for each converter to perform the correct control. These equations also include the priority feature that prioritizes the renewable sources instead of the batteries, when feeding loads in autonomous operation. Simulations of a modeled microgrid with four converters and two loads are performed. The functionality of the equations are verified in terms of priority selection of generation, the correct power balance and the control to avoid damages in microgrid elements, especially to the batteries.