弱电网下并网逆变器正交功率同步控制策略  

OrthogonalPower Synchronization Control for Gird-connected Inverters UnderWeak Grid

作　　者：王顺亮 孙瑞婷 马俊鹏 杨文莉 刘天琪[1] 吴子豪[2] 王若谷[2] WANG Shunliang;SUN Ruiting;MA Junpeng;YANG Wenli;LIU Tianqi;WU Zihao;WANG Ruogu(College of Electrical Engineering,Sichuan University,Chengdu 610065,Sichuan Province,China;State Grid Shaanxi Electric Power Research Institute,Xi'an 710099,Shaanxi Province,China)

机构地区：[1]四川大学电气工程学院,四川省成都市610065 [2]国网陕西电力科学研究院,陕西省西安市710099

出　　处：《中国电机工程学报》2022年第23期8475-8485,共11页Proceedings of the CSEE

基　　金：国家电网有限公司科技项目(5400-202099283A-0-0-00)。

摘　　要：功率同步控制(power synchronization control,PSC)是电压源型逆变器(voltage source converter,VSC)连接至弱交流电网的有效控制策略。极弱电网的短路比(short circuit ratio,SCR)接近1,系统稳态功角接近90°的稳定运行极限。电网电压暂降极易引起VSC功角越过稳定极限并出现同步失稳。针对这一问题,该文首先通过相图法对PSC的暂态同步稳定性进行深入的分析,给出一阶同步环的暂态功角响应特性。然后,引入虚拟功率的概念,给出具有正/余弦特性的同步环暂态功角特性。进而,提出一种正交功率同步控制策略,该方法能够防止VSC在不同电网电压暂降深度下失去静态稳定工作点,有效的保证并网系统的暂态同步稳定。所提方法无需检测电网故障工况,且无需进行控制模式切换,提高了并网逆变器的控制性能。最后,通过半实物实时仿真验证所提出控制策略的有效性。Power synchronization control(PSC)is an effective control method for voltage source converter(VSC)connected with a weak grid.Since the short-circuit ratio(SCR)is close to 1,the power angle of steady-state point is close to the stability limit of 90°.Grid voltage sag can easily cause the power angle to exceed the stability limit and synchronization instability.To address this issue,the transient synchronization stability of PSC was deeply analyzed by the phase portrait,and the transient power angle response characteristics of the first order synchronization loop were revealed.Then,the concept of virtual power was introduced,and the transient power angle characteristics of synchronous loop with sine or cosine characteristic were analyzed.Finally,orthogonal power synchronization control(OPSC)was proposed,which can suppress the power angle deviation and maintain synchronization under the grid fault condition.The OPSC can improve the performance of the grid-connected inverter without detecting the grid fault condition and switching the control mode.The control method theoretical analysis was verified by hardware-in-the-loop real time simulation.

关 键 词：极弱电网 功率同步控制 暂态同步稳定 相图 正交功率同步控制 

分 类 号：TM46[电气工程—电器]