Positive sequence variable quantity differential protection method and device

• Main Authors: ZHU RUOSONG, FAN ZHANFENG, DENG MAOJUN, LIU ZHIWEN, XIAO ZHIGANG, MA YONGNIAN, FENG QIUFANG, CHEN HAILONG, CHENG TIANBAO, MA HEKE, XU LIMING, LI WENZHENG, ZHANG HONGYUE, ZHANG YANCHAO
• Format: Patent
• Language: Chinese; English
• Published: 23.02.2021
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

The invention relates to a positive sequence variable quantity differential protection method and device with a braking characteristic, formed by utilizing converter transformer network side current and valve side current. Whether to implement a protection action or not is determined by judging whether positive sequence variable quantity action current and braking current meet a positive sequencevariable quantity differential protection action equation or not, and a frequency tracking function is introduced in the implementation process, so that slight faults in the protection element equipment under normal operation and voltage reduction operation modes can be well reflected. 本发明涉及一种利用换流变压器网侧电流和阀侧电流构成的带制动特性的正序变化量差动保护方法以及装置，通过判断正序变化量动作电流和制动电流是否满足正序变化量差动保护动作方程，来确定是否实施保护动作，并且在实现过程中通过引入频率跟踪功能，可以很好地反映正常运行和降压运行方式下的保护元件设备内部轻微故障。