Influence To Relaying Protection From Electric Locomotive Loads And Study Of Countermeasure

With the development of the nonlinear loads in the power system, the level of harmonic currents injected to the power system increases obviously. This results in the decline in the power quality and the network safety. The harmonic interference should be paid more attention .So the researchers hope to exam the working process of protection devices under harmonic of power system in lab environment in order to research coordinating relation of every link and dynamic property of the whole protection device, In order to propose the countermeasure and improve the performance of relay protection. Fast development and application of the artificial technology of the computer offer the opportunity of developing the corresponding software. The approach presented by this paper is to develop a detailed simulation software package which can simulate all kinds of function elements of any protective relaying device and harmonic source, based on EMTP/ATP artificial tool and VB6.0 programming language. It may be used to verify the correctness of operation during faults of relay protection in service. It may be also used to research the dynamic performance of the performance of the relay protection in period of designing. This method is very flexible, convenient and effective. This paper introduces its structure, main function and characteristic.