虚拟同步机多机并联稳定控制及其惯量匹配方法

虚拟同步发电机(VSG)技术作为一种分布式电源主动参与电网频率电压调整的新型控制方式,得到了越来越多的关注。通过对同步发电机外特性的模拟,使得微电源逆变器具有同步发电机相同的转动惯量、一次调频、无功调压等特性。提出简化的VSG虚拟惯量控制器,避免了锁相环(PLL)误差引起的频率指令波动对系统稳定性的影响,建立包含中间控制环节状态变量的VSG并联系统小信号模型,并针对主要控制参数对系统稳定性及动态响应的影响进行了分析,最后利用等效同步发电机原理,提出了虚拟同步发电机多机并联运行的虚拟惯量匹配方法,仿真和实验结果验证了所提方法的正确性和有效性。

Stability Control and Inertia Matching Method of Multi-Parallel Virtual Synchronous Generators

Virtual synchronous generator technology has attracted more and more attention. As a new control method, it can allow the distributed generation actively taking part in the frequency and voltage regulation of the grid. By mimicking the characteristics of the synchronous generator, the micro power source inverters have the same characteristics of the synchronous generator, such as the inertia, primary frequency modulation, reactive power and voltage modulation etc. Simple VSG virtual inertia controller is proposed to avoid the impacts of frequency command fluctuation on the stability of the system caused by the phase-locked loop (PLL) error. The small signal model of parallel VSGs including the state variables of intermediate control link is established. And then the influences of the main control parameters on system stability and dynamic response are analyzed. At last, based on the principle of equivalent synchronous generator, virtual inertia matching method of the parallel virtual synchronous generators is proposed. Simulation and experimental results verify the proposed method.