控制时延对非同步机电源同步稳定性的影响  

Influence of Control Delay on Synchronization Stability of Non-synchronous Generator Sources

作　　者：张艳霞[1] 刘凯祥 成雅超 韩悦 ZHANG Yanxia;LIU Kaixiang;CHENG Yachao;HAN Yue(Key Laboratory of Smart Grid(Tianjin University),Ministry of Education,Nankai District,Tianjin 300072,China)

机构地区：[1]智能电网教育部重点实验室(天津大学),天津市南开区300072

出　　处：《电网技术》2023年第6期2414-2422,共9页Power System Technology

摘　　要：采用并网逆变器与电网相连的新能源发电系统与旋转电源保持同步由控制器实现,这与同步机电源之间的同步机制不同,常被称为非同步机电源。电力系统中非同步机电源比例的增加使得电网同步稳定性呈现出新形态。为探究控制时延对非同步机电源同步稳定性的影响,分析了锁相环数据采集环节时延、脉宽调制环节的滞后一拍控制时延和换流器开关管死区时延的时延机理,建立了考虑时延的各控制环节数学模型及传递函数。以此为基础推导了考虑控制时延情况下非同步机电源电压与电网电压的相角差微分方程,采用相平面法研究了控制时延对系统同步稳定性的影响。理论分析和相平面法分析结果表明,控制时延降低了系统的同步稳定性,需进一步增大系统阻尼以补偿控制时延的影响,实际中可通过适当减小锁相环积分系数来增大系统阻尼。The new energy power generation system connected to the grid with the grid-connected inverters achieves the synchronization with the rotating power source by controllers.This is different from the synchronized mechanism of the synchronous generator sources,usually known as the non-synchronous generator sources.The increasing non-synchronous generator sources in a power system renders the synchronization stability of the power grid a new form.To reveal the influence of the control delay on the synchronization stability of the non-synchronous generator sources,this paper analyzes the mechanisms of the phase locked loop’s sampling delay,the pulse width modulation’s one-step-delay and the insulated-gate bipolar transistor’s dead-time delay.The mathematical models and transfer functions of the control links considering their time delay.Based on this,the voltage angle difference equation between the non-synchronous generator source and the grid is derived,and the phase-plane analysis is used to analyze the synchronization stability of the system.The theoretical analysis and phase-plane analysis’s results indicate that the delay control deteriorates the system synchronization stability.It is of practical significance to increase the system damping to compensate the control delay’s influence.In practical,decreasing the integral coefficient appropriately is a feasible solution to improve the system damping.

关 键 词：控制时延 同步稳定性 相平面法 锁相环 PI参数 

分 类 号：TM721[电气工程—电力系统及自动化]