微网中分布式电源锁相环建模及其稳定性分析  

Modeling and Stability Analysis of Distributed Generation Phase Locked Loop in Microgrid

作　　者：王睿[1] 孙秋野[1] 马大中[1] 王冰玉[1] WANG Rui;SUN Qiuye;MA Dazhong;WANG Bingyu(School of Information Science and Engineering,Northeastern University,Shenyang 110819,Liaoning Province,China)

机构地区：[1]东北大学信息科学与工程学院

出　　处：《中国电机工程学报》2018年第24期7338-7348,共11页Proceedings of the CSEE

基　　金：国家自然科学基金项目(61433004,61573094)~~

摘　　要：多分布式电源的同步失稳对微网的稳定性有重要影响,由微网中各分布式电源的控制策略不尽相同而带来的多类型逆变器并联系统建模及其同步稳定性分析已经成为困扰微网广泛应用的重要问题,其中同步锁相环(phase locked loop,PLL)的失稳又是多分布式电源发生同步失稳的主要原因之一。因此,该文提出一种基于PLL的多逆变器并联系统稳定性分析策略。首先建立基于下垂控制器和P&Q控制器的逆变器系统及其PLL小信号分析模型,其次利用信号流图和梅森增益定理得到多逆变器并联系统的PLL小信号分析模型,最后得到其传递函数。提出的小信号模型可以很好地鉴别多逆变器并网及孤岛情况下系统的同步稳定性。最后通过仿真验证所提出的基于PLL的多逆变器并联系统稳定性分析策略的可行性和有效性。Synchronization instability of the multiple distributed generations is very significant for microgrid stability. However, the control strategies of the distributed generations in microgrid are different so that the modeling and synchronization instability analysis of the multi-inverter parallel system have been a main obstacle to hinder the wide application of microgrid. Wherein, phase locked loop(PLL) instability is one of the significant reason for synchronous instability of multi inverter microgrid system. Thus, this paper proposed a multi-inverter parallel system stability analysis method based on PLL. Firstly, this paper established PLL small signal model based on the droop control strategy and the P&Q control strategy. Furthermore, the whole PLL small signal analysis model of multi-inverter parallel system was proposed by signal flow graph and mason’s gain formula. Eventually, the closed-loop transfer function of PLL was obtained. The proposed integrated small signal model can predict the synchronization stability of the multi inverters PLL in grid-connected mode and the island mode. Finally, the simulation can well validate the feasibility and effectiveness of the proposed stability analysis strategy based on PLL in multi-inverter parallel system.

关 键 词：同步失稳 锁相环 分布式电源 微网 信号流图 

分 类 号：TM73[电气工程—电力系统及自动化]