Applying Adaptive Technique In The Distance Protection Setting

Adaptive protection,which concerns improving protection performance and system running conditions,is one significant research task of modern relay protection techniques.This paper discusses and analyses several principal points affecting the performance of regular distance protection,such as the fault resistance,the branch current,the zero sequence mutual coupling and so on.Then some concrete application of adaptive concept to distance protection will be analyzed and studied.In order to meet the actual needs,the compensation method is used to simulate network topology changes resulted by network operations and faults in this paper at first.And a general simple-fault calculation method allowing for network operations is presented.Secondly,a calculation method for any complex faults allowing for network operation is educed based on simple-fault calculation model here.Then,this paper put forword the adaptive setting algorithm of the triad distance protection with adaptive technique based on traditional triad distance protection. Adaptiveâ…¡protection does not need to calculate the resistance in the maximum or the minimum operation mode, does not need to be considered fortuitous events, but under the current operating mode to calculate impedance.Adapativeâ…¢protection gets the setting value real time in accordance with avoiding actual load impedance,rather than the minimum load impedance.This algorithm advances the protective range and sensitivity.Finally,applying the oriented-object technique and the database technique with Delphi7.0 based on fault analysis method and adaptive setting algorithm,the software has friendly interface and powerful function for protection setting.The function of this software include.flexible graph module,generic fault analysis module,setting calculation modula.The research findings in the paper have been proved valid and right by the simulating this software.