A Control Method for Virtual Synchronous Generators in Microgrids under Voltage Unbalance

Microgrid generation can lead to significant stochastic energy fluctuations, which can subsequently impact the reliable and stable operation of the entire power network. Virtual Synchronous Generator (VSG) technology offers an effective way to emulate the characteristics of synchronous generators. To address voltage imbalance in microgrids, a dual-closed loop reactive power voltage control method is proposed based on the mathematical model of synchronous generators. The complete control system for the Virtual Synchronous Generator is designed, incorporating a full-state observer to monitor the droop control coefficient of active power and the changing status of reactive power. Additionally, a reactive power voltage controller is designed to accommodate varying voltage amplitude states of the Virtual Synchronous Generator during different time periods. The proposed control method is verified through a simulation model constructed using the MATLAB/Simulink platform. The results indicate that the control method, which utilizes self-tuning and self-setting power coefficients, enables the Virtual Synchronous Generator to effectively manifest its characteristics.