基于暂态虚拟电阻VSG同步频率谐振抑制策略

Synchronous Frequency Resonance Suppression Strategy for Virtual Synchronous Generators Based on Transient Virtual Resistance

虚拟同步发电机(VSG)技术通过模拟同步发电机运行外特性,提高了系统的惯性,成为解决分布式电源高渗透率问题的有效方案之一。然而考虑线路电感磁链的动态过程后,发现功率传输小信号模型存在频率为50 Hz的谐振峰,在线路电阻较小的情况下可能引发VSG的同步频率谐振现象,导致功率暂态过程中的振荡。基于同步频率谐振现象的产生原理,提出基于暂态虚拟电阻的阻尼控制策略来解决该谐振问题。最后通过搭建实验平台,验证了VSG的同步频率谐振现象及暂态虚拟电阻阻尼策略的有效性。

Virtual synchronous generators (VSG) technology improves the inertia of the system by simulating the external characteristics of the synchronous generators, and becomes one of the effective solutions to solve the high permeability problem of the distributed power supply. However, considering the dynamic process of the line inductance magnetic chain , there will be a resonant peak of 50 Hz in the power transmission small signal model, which may cause the synchronous frequency resonance of the VSG in the case of small line resistance, which leads to the oscillation in the power transient process.Based on the generation principle of synchronous frequency resonance, a damping control strategy based on transient virtual resistance is proposed to solve the resonance problem.Finally, an experimental platform is built to verify the synchronous frequency resonance of the VSG and the effectiveness of the transient virtual resistance damping strategy.