直流配电系统阻抗判据与导纳判据的比较分析  

Comparison Between Impedance-based Criterion and Admittance-based Criterion for the DC Distribution Power System

作　　者：张辉 朱刘柱 潘鹏鹏 陈武[3] ZHANG Hui;ZHU Liuzhu;PAN Pengpeng;CHEN Wu(Economic and Technology Research Institute of State Grid Anhui Provincial Electric Power Co.,Ltd.,Hefei 230022,Anhui Province,China;Zhenjiang Power Supply Company of State Grid Jiangsu Provincial Electric Power Co.,Ltd.,Zhenjiang 212001,Jiangsu Province,China;School of Electrical Engineering,Southeast University,Nanjing 210096,Jiangsu Province,China)

机构地区：[1]国网安徽省电力有限公司经济技术研究院,安徽省合肥市230022 [2]国网江苏省电力有限公司镇江供电分公司,江苏省镇江市212001 [3]东南大学电气工程学院,江苏省南京市210096

出　　处：《电网技术》2021年第3期1167-1174,共8页Power System Technology

基　　金：安徽省电力公司科技项目:楼宇群低压柔性直流配电系统规划与运行控制研究(521209190004)。

摘　　要：阻抗法是解决级联变换器系统稳定性分析问题的有效方法,随着直流配电技术的快速发展,直流配电系统的拓扑结构与控制策略更加复杂,由变换器间阻抗不匹配导致的直流母线电压不稳定问题日益突出。总结了目前直流配电系统的主要阻抗判据,可分为阻抗比判据与并联阻抗判据两类。在分析多并联并网逆变器系统的谐波稳定性问题时,基于全局导纳的稳定判据被提出,即通过系统的全局导纳是否满足广义奈奎斯特判据,判断系统的稳定性。由于导纳是阻抗的倒数,且在电路上可以相互转化,所以也可以从导纳的角度分析直流配电系统的稳定性。因此,提出了一种基于导纳的直流配电系统稳定判据,并与现有的阻抗判据进行对比分析,表明了各判据的主要特征。最后,通过仿真验证了所提导纳判据的正确性,并通过案例对比得出了阻抗判据和导纳判据的优缺点。Impedance-based method is an effective one for stability assessment of cascaded converter systems.With the rapid development of DC distribution technology,the topology and control strategy of DC distribution power system(DPS)are becoming increasingly complicated.Consequently,the instability issue of DC bus voltage caused by the impedance mismatch of the converter is significantly prominent.This paper summarizes the current major impedance-based criteria for DC DPS,which can be divided into two types:the impedance ratio criteria and the parallel impedance criteria.Recently,a stability criterion based on global admittance(GM)is proposed to analyze the harmonic stability problem of the multi-paralleled grid-connected inverters system,i.e.a criterion to judge the system stability by whether GM satisfies the modified Nyquist criterion.As is well known,admittance is the reciprocal of impedance and they can be mutually transformed,so that the stability of DC DPS can also be analyzed from the perspective of admittance.Therefore,an admittance-based criterion is proposed to assess the stability of DC DPS.Besides,comparison analysis is executed to illustrate their main characteristics.Finally,the effectiveness of the proposed admittance-based criterion is verified by simulation results and the advantages and disadvantages of each criterion are obtained through case comparisons.

关 键 词：直流配电系统 阻抗判据 导纳判据 全局导纳 

分 类 号：TM721[电气工程—电力系统及自动化]