考虑CVT暂态特性的直流系统换相过程分析  

Commutation Process Analysis of DC System Considering Transient Characteristics of CVT

作　　者：曹依烈 顾丹珍 倪伟伦 赵丹丹 刘晨蕾 CAO Yilie;GU Danzhen;NI Weilun;ZHAO Dandan;LIU Chenlei(School of Electrical Engineering,Shanghai University of Electric Power,Shanghai 200090,China;State Grid Shanghai Electric Power Research Institute,Shanghai 200437,China)

机构地区：[1]上海电力大学电气工程学院,上海200090 [2]国网上海市电力公司电力科学研究院,上海200437

出　　处：《电力电容器与无功补偿》2022年第2期49-56,共8页Power Capacitor & Reactive Power Compensation

基　　金：上海绿色能源并网工程技术研究中心项目(13DZ2251900)。

摘　　要：电容式电压互感器(capacitor voltage transformer,CVT)的暂态特性导致其二次侧输出电压在系统故障时不能及时准确地反映一次侧输入电压的变化,从而影响高压直流输电系统的换相过程。本文从直流换相过程控制逆变侧触发角入手,分析了逆变侧交流母线电压暂态幅值偏差对换相失败预测控制环节及定关断角控制的影响;以及CVT暂态过程导致母线电压波形畸变对关断角的影响。通过PSCAD/EMTDC仿真得到,CVT暂态特性对大部分交流侧故障的影响是会延缓换相失败恢复过程,仅在极少故障情况下对换相结果产生影响,主要表现为增加换相失败次数。The transient characteristic of capacitor voltage transformer(CVT)can,in case of system fault,cause the output voltage at its secondary side not inaccurately reflect the output voltage variation of the primary side in time,thus affecting the commutation process of HVDC transmission system.In this paper,the influence of the transient amplitude deviation of AC bus voltage of the inverter side on commutation failure predictive control block and the fixed switching off angle control as well as the influence of bus voltage distortion on the switching off angle due to the transient process of the CVT are analyzed.It is concluded through PSCAD/EMTDC simulation that the impact of transient characteristics of CVT on most of the faults at AC side is to delay the commutation failure recovery process,and commutation result is affected only under rare fault conditions,mainly in the increase of the number of commutation failures.

关 键 词：高压直流输电 CVT暂态特性 换相失败预测控制 换相过程 

分 类 号：TM721.1[电气工程—电力系统及自动化] TM451.2