渝鄂直流背靠背联网工程交直流系统谐振分析与抑制  

Analysis and Suppression of Resonance Between AC and DC Systems in Chongqing-Hubei Back-to-Back HVDC Project of China

作　　者：郭贤珊 刘斌[2] 梅红明[2] 刘杰 于华龙 操丰梅[2] GUO Xianshan;LIU Bin;MEI Hongming;LIU Jie;YU Hualong;CAO Fengmei(State Grid Corporation of China,Beijing 100031,China;Beijing Sifang Automation Co.,Ltd.,Beijing 100085,China)

机构地区：[1]国家电网有限公司,北京市100031 [2]北京四方继保自动化股份有限公司,北京市100085

出　　处：《电力系统自动化》2020年第20期157-164,共8页Automation of Electric Power Systems

基　　金：国家重点研发计划资助项目(2016YFB0900905);国家电网公司科技项目(5100-202014009A-0-0-00)。

摘　　要：2018年12月中国渝鄂直流背靠背联网工程(以下简称"渝鄂工程")鄂侧空载加压试验中交流电压出现1810 Hz谐振,使用典型高频谐振抑制措施后,渝侧空载加压试验中交流电压出现700 Hz谐振。根据奈奎斯特稳定性判据,文中使用基于阻抗理论的波特图对交直流系统整体进行谐振机理研究,分别对柔性直流系统和交流系统的阻抗特性进行分析,结果证实柔性直流系统与鄂、渝两侧交流系统在1780 Hz和750 Hz附近存在谐振风险,与现场试验基本吻合。提出了一种基于电压前馈环节非线性滤波的控制策略,通过改造柔性直流系统在中高频段的阻抗特性,达到规避与交流系统谐振的效果。利用电磁仿真模型对渝鄂工程柔性直流系统和两侧交流系统进行仿真,复现了现场谐振现象,仿真结果验证了所提策略对谐振抑制的有效性。最后,将所提策略应用于渝鄂工程现场,典型运行方式下未再出现谐振现象。In December 2018,a 1810 Hz resonance of AC voltage occurred during the open line test(OLT)of Hubei-side AC system in Chongqing-Hubei back-to-back HVDC project of China(referred to as"Chongqing-Hubei project").After adopting the typical suppression measures for high-frequency resonance,a 700 Hz resonance of AC voltage occurred during OLT of Chongqingside AC system.According to the Nyquist stability criterion,this paper adopts the Bode diagram based on impedance theory to study the resonance mechanism of the whole AC/DC system.The impedance characteristics of the flexible DC system and AC systems are analyzed.And the results show that there are risks of resonance near 1780 Hz and 750 Hz in the flexible DC system and Hubei-side and Chongqing-side AC systems,which basically coincides with the field test.This paper proposes a control strategy based on the voltage feedforward link with the nonlinear filter,which changes impedance characteristics of flexible DC system in middle and high frequency bands to avoid its resonance with the AC system.An electromagnetic simulation model is established to simulate the flexible DC system and AC systems on both sides of Chongqing-Hubei project,and the resonance is reproduced.The simulation results verify the effectiveness of the proposed strategy for resonance suppression.Finally,the proposed strategy has been applied in Chongqing-Hubei project,and no resonance has been observed in typical operation modes.

关 键 词：柔性直流输电 谐振抑制 稳定性分析 阻抗分析 电压前馈控制 非线性滤波器 

分 类 号：TM721.1[电气工程—电力系统及自动化]