Research Of Effects On Generator Protection By Harmonics And Negative Sequence Of Electric Railway

The electric locomotives are special load in the Traction Power Supply System.Caused by the electric railway,the negative current and harmonic current affect the operating characteristics of the relay protection.Firstly,the paper introduces the major protection of the generator,summarizes the past research achievement.Through analyzing action principal of the generator protection and binding the characteristics of the electric railway load,this paper makes a detailed analysis on the relay protection.Secondly,Based on the regional power supply network of railway loading,the simulation model of the load is conducted using PSCAD/EMTDC.The paper describes in detail the over-load of rotor negative current that is affected obviously by the electric railway load.For the traction transformer connect is different,the negative current is different to flow in the power system.The paper analyzes the negative current that occurs in the generator stator by simulating the electric railway load model,and studies further that negative current of electric railway impacts on the operating characteristics of generator negative current protection to the different capacity generator.It gives some advices about regulating the setting value of the over-load of rotor negative current and loading the series reactor to meet the requirement.