Control of Uninterrupted Switching Using a Virtual Synchronous Generator Between Stand‐Alone and Grid‐Connected Operation of a Distributed Generation System for Houses

Abstract

SUMMARYThe home applications of distributed generations facilities such as photovoltaic and gas engine cogeneration systems are growing and many distributed generations are connected to a grid by a DC/AC inverter. The DC/AC inverter is controlled by a phase-locked loop (PLL) in order to be synchronized with the power system frequency. However, the control scheme of stand-alone operation uses voltage control, and the PLL is unnecessary. Therefore, it is hard to realize uninterrupted change between stand-alone and grid-connected operation. In this paper, we propose a virtual synchronous generator control scheme in order to use the same control scheme in stand-alone and gridconnected operation. We carried out experiments to demonstrate the control characteristics. C⃝