基于控制绕组电流基频分量的磁控式并联电抗器匝间保护新原理  

New Principle of Protection Scheme Based on Fundamental Component of Control Winding Currents Against Turn-to-turn Fault of MCSR

作　　者：郑涛[1] 刘校销 ZHENG Tao;LIU Xiaoxiao(State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources (North China Electric Power University), Changping District, Beijing 102206, China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学)

出　　处：《电网技术》2019年第8期3016-3024,共9页Power System Technology

基　　金：国家自然科学基金资助项目(51677069);中央高校基本业务费资助项目(2018ZD01)~~

摘　　要：基于实际工程介绍了一种超/特高压磁控式并联电抗器的本体结构及其工作原理,分析了预励磁合闸时控制绕组三相电流之和(简称总控电流)的基频分量产生机理,结合MATLAB/Simulink仿真结果以及动模实验结果,说明预励磁合闸可能会导致基于总控电流基频分量的控制绕组保护方案误动。深入分析发现,总控电流基频分量的产生并不是控制绕组发生匝间故障时的特有现象,内部故障时总控电流基频分量主要来源于相应的故障相控制绕组;预励磁合闸时,总控电流基频分量来源于三相控制绕组电流分相电流基频分量之和,且各相占比与合闸角有关。基于此,提出以分相控制绕组电流基频分量与总控电流基频分量比值为判据的MCSR保护改进方案,该方案不受预励磁合闸影响,在控制绕组轻微匝间故障时仍具有很高的灵敏度,仿真结果验证了新原理的有效性。Based on an actual project, the main structure and working principle of EHV magnetically controlled shunt reactor (MCSR) is presented. The generation mechanism of fundamental component in total control current during pre-excitation closing is analyzed. It is illustrated that maloperation may happen due to applying the protection scheme based on fundamental component in total control current in pre-excitation closing situation. Further analysis find out that generation of the fundamental component is not a unique phenomenon when fault occurs on control winding and it is derived from the fault phase control winding during internal fault. Under pre-excitation closing condition, the fundamental component is derived from three-phase control winding currents and its proportion is related to closing angle. An improved MCSR protection scheme is proposed, applying the ratio between the fundamental component of the winding current and total control current. This scheme is not affected by pre-excitation closing, and highly sensitive in the case of light turn-to-turn faults. Simulation results demonstrate effectiveness of the improved scheme.

关 键 词：磁控式并联电抗器 总控电流 谐波分析 匝间故障 基频分量 

分 类 号：TM721[电气工程—电力系统及自动化]