多电压等级直流配电系统小信号稳定性评估方法  

Small-signal Stability Assessment Method for DC Distribution System with Multiple Voltage Levels

作　　者：陈庆 袁栋 袁宇波 刘瑞煌 陈武[3] 何棒棒 CHEN Qing;YUAN Dong;YUAN Yubo;LIU Ruihuang;CHEN Wu;HE Bangbang(State Grid Jiangsu Electric Power Co.,Ltd.,Nanjing 210000,China;State Grid Jiangsu Electric Power Co.,Ltd.Research Institute,Nanjing 211103,China;Center for Advanced Power Conversion Technology and Equipment,Southeast University,Nanjing 210096,China)

机构地区：[1]国网江苏省电力有限公司,江苏省南京市210000 [2]国网江苏省电力有限公司电力科学研究院,江苏省南京市211103 [3]东南大学先进电能变换技术与装备研究所,江苏省南京市210096

出　　处：《电力系统自动化》2022年第21期80-88,共9页Automation of Electric Power Systems

基　　金：国家重点研发计划资助项目(2018YFB0904700)。

摘　　要：随着直流配电技术的快速发展,直流配电系统已逐渐呈现多电压等级、多直流母线、多电力电子变换器接入等显著特点。这导致变换器间的阻抗耦合关系更加复杂,系统稳定性问题突出。为评估多电压等级直流配电系统的小信号稳定性,首先建立了系统小信号等效模型。然后,根据相邻母线间直流变压器的不同控制模式,推导了母线电压与系统所有输入扰动间的统一传递函数表达式。在此基础上,提出了系统稳定性评估方法,并以含两个电压等级直流母线的配电系统为例,进一步分析了影响系统稳定性的阻抗因素,同时提出了基于系统等效环路增益的稳定判据。最后,设计了两种系统案例,并基于MATLAB/Simulink仿真平台验证了所提多电压等级直流配电系统稳定性评估方法的正确性。With the rapid development of DC distribution technology,the DC distribution systems have gradually shown the remarkable characteristics of multiple voltage levels,multiple DC buses and multiple power electronic converter access,which leads to more complex impedance coupling relationship among converters and the increasingly prominent problem of system stability.In order to evaluate the small-signal stability of the DC distribution systems with multiple voltage levels,the small-signal equivalent model of the system is established,and then the unified transfer function from all system input disturbances to any bus voltage is derived according to the different control modes of the DC transformers between adjacent buses.On this basis,the system stability assessment method is proposed.Furthermore,a distribution system with two-voltage level DC buses is taken as an example to analyze the impedance factors affecting the system stability.At the same time,the stability criterion based on the system equivalent loop gain is proposed.Finally,two system cases are designed,and the correctness of the proposed stability assessment method of the DC distribution system with multiple voltage levels is verified based on MATLAB/Simulink simulation.

关 键 词：直流配电网 小信号稳定性 阻抗建模 等效环路增益 Nyquist稳定判据 

分 类 号：TM721.1[电气工程—电力系统及自动化]