虚拟同步发电机频率稳定性分析

在电力电子逆变器控制领域,通过仿真同步发电机的同步特性来实现的虚拟同步发电机(VSG)技术作为近年来提高电力系统稳定性的主要手段得到了充分的研究,在一定程度上解决了分布式能源(DG)并网系统缺少惯性的问题,提高了系统电网频率的稳定性。然而,当电网强度发生变化时,原有的VSG控制策略并不能维持系统频率稳定性。为了进一步提升VSG对频率稳定性的作用,在传统VSG控制策略的基础上,对电网强度变化时VSG系统的频率稳定性进行了分析,研究了影响电网强度变化的因素,并在此基础上提出,可以通过增大VSG中系统惯量的方法来提高电网强度变化时频率稳定性。最后,通过MATLAB/Simulink仿真工具,验证了所提方法的有效性。

Frequency Stability Analysis of Virtual Synchronous Generator

In the field of power electronic inverter control, the virtual synchronous generator (VSG) technology realized by simulating the synchronous characteristics of synchronous generator had been fully researched as the main means to improve the stability of power system in recent years. And the stability of the system grid frequency was improved by solving the problem of the inertia of the distributed energy (DG) gridconnected system. However, when the power grid strength changes, the original VSG control strategy could not maintain the system frequency stability. In order to further improve the effect of VSG on frequency stability, the frequency stability of VSG system when the strength of grid is changed on the basis of traditional VSG control strategy was analyzed, and studies the factors that affect the change of power intensity. It was suggested that the frequency stability can be improved by increasing the system inertia in VSG. Finally, the effectiveness of the proposed method was verified by MATLAB/Simulink simulation tool.