电流互感器暂态饱和特性分析与参数校核

Analysis on Transient Saturation Characteristics and Parameter Verification of Current Transformers

中文关键词:电流互感器  暂态饱和  特性分析  参数校核

keywords:current transformers  transient saturation  characteristic analysis  parameter verification

中文摘要:针对电流互感器 （current transformer，CT） 在连续故障过程中易发生暂态饱和的问题，阐明了CT的暂态饱和特性，并提出了一种通用的CT参数校核方法。通过理论推导与仿真分析，系统研究了故障初相角、故障开断时间、一次侧时间常数以及二次侧负载对CT暂态饱和特性的影响，揭示了“故障-跳闸-重合-再跳闸”全过程中的磁通变化规律，得出了以二次侧极限电势为判据的通用CT参数校核方法。该方法适用于稳态保护级（P级）、暂态保护级（TPY级）等不同类型的CT，可用于工程设计阶段的CT容量校核以及投运后的CT性能周期性校验。

Abstract:To address the transient saturation of current transformers（CTs） during continuous faults，this study clarifies the transient saturation characteristics of CTs，and thereby proposes a general parameter verification method for CTs. Based on theoretical derivation and simulation analysis，the influences of fault inception angle，fault clearing time，primary time constant and secondary burden on CT transient saturation characteristics are systematically studied. The flux variation law in the whole process of “fault-tripping-reclosing-tripping” is revealed，and a general CT parameter verification method is proposed with the secondary limiting electromotive force as the criterion. The proposed method is applicable to different types of CTs such as protection（P-class） and transient protection（TPY-class），and can be used for CT capacity checking in engineering design stage and periodic performance verification after operation.