特高压直流输电系统异常换相失败的机理研究  

Abnormal Commutation Failure Mechanism in UHVDC Transmission System

作　　者：金祖洋 杨洪耕[1] 赵海杉 

机构地区：[1]四川大学电气信息学院,成都市610065

出　　处：《电力建设》2016年第7期126-132,共7页Electric Power Construction

摘　　要：针对特高压直流输电系统故障恢复过程中出现的换相失败,无法利用换相电压降低或直流电流上升进行解释的异常现象,考虑换相电压波形畸变的影响,提出了一种基于谐波分解与换相电压时间面积的换相失败分析方法。该方法通过畸变换相电压的各次谐波最大可能换相面积的正负和大小,定性和定量分析其对换相失败的影响。考虑到谐波相位的不确定性,提出谐波风险系数作为评价谐波促进换相失败的最大风险指标。应用所提方法分析了某特高压直流输电系统故障恢复过程中出现的异常换相失败现象,结果说明了引起换相电压波形畸变的原因,揭示了主要谐波对换相失败促进或抑制的影响程度及其风险性,验证了方法的有效性。In allusion to the abnormal phenomenon that commutation failure occurred in the fault recovery process of UHVDC transmission system cannot be explained by commutation voltage reduction or DC current rising,this paper proposes a method for commutation failure analysis based on harmonic decomposition and commutation voltage-time area,w ith considering the influence of commutation voltage w aveform distortion. The method can qualitatively and quantitatively analyze the influence of harmonic voltage on commutation failure through the nature and size of every maximum possible harmonic commutation voltage-time area of distorted commutation voltage. Noting the uncertainty of harmonic phase,w e use the harmonic risk coefficientas the maximum risk index to evaluate harmonic to promote commutation failure. Then w e adopt the proposed methodto analyze the abnormal commutation failure occurred in the fault recovery process of a UHVDC system. The results show the cause of commutation voltage w aveform distortion,reveal the stimulative or inhibited influence degree and risk of the main harmonic on commutation failure,and confirm the effectiveness of the method.

关 键 词：特高压直流输电系统 异常换相失败 直流偏磁 谐波分解 换相电压时间面积 谐波风险系数 

分 类 号：TM721.1[电气工程—电力系统及自动化]