Research on Frequency Control of Virtual Synchronous Generator without Frequency Deviation in Microgrid

The Virtual Synchronous Generator (VSG) is viewed as an efficient approach to simulate traditional mechanical inertia of micro-sources inverters in microgrid. But the traditional frequency control of VSG cannot rectify the frequency deviation. This paper aims to reveal the reason of VSG frequency deviation by comparing different power-frequency control methods. Then the paper proposes a novel strategy directly inputting frequency deviation into the equation of rotor motion to get better performance of frequency control. Finally, a VSG grid-connected model with loads changing is used to test the characteristics of frequency response. The discussion and analysis of the results show the proposed frequency control strategy has good performance on secondary frequency regulation and system stability of microgrid.