Wavelet Transform
Dong Xingli1,Ge Yaozhong1,Dong Xinzhou2
(1.School of Electrical Engineering,Xi'an Jiaotong Univercity 710049,China;
2.Department of Electrical Engineering, Tsinghua University)
Abstract:Ratio of initial forward and backward travelling waves is proposed to determine refrative and reflective coefficient of travelling wave at discontinuous point of transmission line. Based on this calculation, a new travelling wave directional relay, ratio directional relay, is presented. Its operating criterion, operating characteristics and algorithm based on wavelet transform are studied. Analysis and EMTP simulations show that new relay has many advantages such as being simple and easy to implement, and is not affected by different circuit connection with buses.
Keywords:transmission line;travelling waves;ratio directional relay;refractive and reflective
coefficient;wavelet transform