Virtual Resistor/Capacitor Droop Control based Power Allocation Strategy for Virtual Synchronous Generator

Abstract

Virtual synchronous generator can effectively alleviate the inertia drop of the power system caused by the grid-connection of renewable energy. This paper applies the virtual synchronous machine control strategy to the hybrid energy storage system of battery/ultracapacitor, and then extends the traditional DC microgrid virtual resistance droop control to a generalized virtual resistor/capacitor droop control to achieve decentralized power allocation of the hybrid energy storage system. Furthermore, the connection between the hybrid energy storage side and the virtual synchronous machine side is established, so that the ultracapacitor simulates the inertia of the virtual synchronous machine, and the battery simulates the prime mover of the virtual synchronous generator. Each energy storage unit has a clearer physical meaning. Simulation results verify the effectiveness of the proposed power allocation strategy.