基于暂态阻尼特性的虚拟同步发电机控制策略研究

Research on Control Strategy of Virtual Synchronous Generator Based on Transient Damping Characteristics

针对分布式能源系统的出力变化所引起的系统频率和功率波动甚至越限的问题,在对虚拟同步发电机(VSG)的暂态运行特性进行分析基础之上,结合VSG的虚拟惯量和阻尼系数可控优势,以系统暂态过程的响应时间为优化目标,并建立了以系统频率及其变化率不超过门槛值为约束边界的优化系统模型,并进一步地设计了VSG的虚拟惯量和阻尼系数的协调自适应控制策略。通过仿真算例结果可知,设计的模型和控制策略能有效抑制VSG系统暂态过程中的频率和功率波动的缺陷,极大地改善了系统的暂态响应时间,从而验证了所设计模型和控制策略的合理性和有效性。

Aiming at the problem of system frequency and power fluctuations even exceeding the limit caused by the output change of the distributed energy system,based on the analysis of the transient operating characteristics of the virtual synchronous generator(VSG),the controllable advantages of the virtual inertia and damping coefficient of VSG were combined,and the transient response time of the system was regarded as the optimization goal,an optimized system model was established with the frequency and its rate of change not exceeding the threshold as a constraint boundary,and the coordinated adaptive control strategy of the virtual inertia and damping coefficient of VSG was further designed.It can be seen from the results of simulation example that the model and control strategy designed can effectively suppress the defects of frequency and power fluctuations during the transient process of VSG system,and greatly improve the transient response time of the system,which greatly verify the rationality and effectiveness of model and the control strategy.