新能源同步机并网系统的阻尼特性

Damping Characteristics of Synchronous Motor-Generator Pair System for Integration of New Energy

针对高比例新能源电网存在的低惯性和弱阻尼问题,提出新能源通过驱动同步电动机-同步发电机(MGP)后并网的新方式;阐述了MGP系统小干扰稳定的建模方法,通过小干扰模型研究了MGP的阻尼特性,推导了质量块相同的MGP和单个发电机阻尼比的定量关系;在5 kW实验系统中设计了质量块相同的MGP和单个发电机两种工作模式,对比了相同负载扰动下MGP和单个发电机的频率响应曲线,通过拟合小扰动后的频率响应曲线,分别确定了相同质量块的MGP和单个发电机的阻尼比,对比二者的关系验证了理论推导的结果,证明了相同质量块的MGP相比单个发电机能提供更大的阻尼,为提高高比例新能源电网的稳定性提供了新的解决方案。

Aiming at the problem of low inertia and weak damping existing in power grid with high proportion of new energy,the synchronous motor-generator pair(MGP)system is proposed as a new grid connection method.The modeling method of small signal stability for MGP system is described.On the basis,the damping characteristics of MGP are studied,and quantitative relationship between the damping ratio of MGP and single generator with the same mass block is derived.To verify this quantitative relationship,two working modes of MGP and single generator are designed in 5 kW experimental platform.By fitting the frequency response curves of small disturbance,the damping ratios of MGP and single generator are determined respectively.The comparison results of the relationship between two ratios verify the theoretical deduction,and show that MGP can provide greater damping than single generator with the same mass block.MGP provides a new solution to improve the stability of power grid with high proportion new energy.