Title: High-voltage ac. controllable parallel-connection reactor high-differential protection method
Application Number: 200610145567 Application Date: 2006.11.22
Publication Number: 1979991 Publication Date: 2007.06.13
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H02H3/26;H02H7/00
Applicant(s) Name: Sifang-Jibao Automation Co., Ltd., Beijing Address:
Inventor(s) Name: Su Yi;Tu Liming;Zou Dongxia;Liu Jianfei;Huang Shao
Attorney & Agent: wuhong wei
Abstract:
    The method includes steps: sampling waveforms of current transformer (TA) at primary and secondary sides of high voltage, AC controllable type shunt reactor, protector of reactor obtains instantaneous values of current; using Fourier algorithm determines complex form of each electric quantity; based on TA transformation ratio input from user to calculate balance coefficient automatically, and to output the coefficient for users to check it out; using the balance coefficient to calculate secondary current at secondary side of reactor after compensation of balance; calculating differential current and braking current; based on differential quick break and ratio brake characteristic to determine protection logic of large differential in order to carry out protection action. The method also includes tests of vacancy throw, TA DC saturation, and TA abnormity. The invention protects fault inside the said reactor, especially winding and grounding faults of coil at secondary side.
Time: 8