基于动态时间弯曲的差动保护算法  

A Differential Protection Algorithm Based on Dynamic Time Warping

作　　者：王业[1] 陆于平[1] 徐以超[1] 蔡超[1] 

机构地区：[1]东南大学电气工程学院,江苏省南京市210096

出　　处：《中国电机工程学报》2012年第28期133-141,8,共9页Proceedings of the CSEE

基　　金：国家自然科学基金项目(50977012)~~

摘　　要：多数字源环境下,保护从通信接口中接收不同采样率的数字量,导致差动保护误差较大。针对此问题,提出一种基于动态时间弯曲的发变组差动保护算法,利用该算法可比较差动保护两侧不同采样率数据序列的相似度,从而解决多数字源信号采样频率不一致问题,并且提高了保护的耐同步误差特性及速动性;同时,该算法通过设置浮动门槛,可在兼顾区外故障保护抗互感器(current transformer,CT)饱和性能的同时,进一步增强区内故障时保护的灵敏性。仿真结果表明,该保护在两侧不同采样率环境下可正确动作,且能够在轻微匝间故障时快速动作,动作时间约为15ms。该算法为多数字源混和输入环境下保护算法的研究提供了新思路。For multi-rate source, protection receives the digital signals with different sampling rates from communication interface, which would result to differential protection errors. In order to solve this problem, a differential protection algorithm based on dynamic time warping （DTW） theory for large generator-transformer unit was proposed. The similarity between the data sequences at both sides with different sampling rates was calculated in the algorithm and thus the problem caused by different data sampling rates at two sides was solved. Moreover, the performance of the protection in synchronous error tolerance and quick operation is improved. Simultaneously, by setting a floating threshold, the protection has good performances when current transformer （CT） saturation happens during an external fault or when a slight internal fault occurs. Simulation results show that the proposed protection can operate correctly in the case of both sides with different sampling rates, even the fault is slight, and the operation time is 15 ms. The new algorithm provides a new method for the study on the protection with mixed input from multi-rate source.

关 键 词：发电机 差动保护 变压器 动态时间弯曲 多采样率 同步误差 匝间短路 抗电流互感器饱和 

分 类 号：TM77[电气工程—电力系统及自动化]