Modelling and calculating the harmonic penetration of the high power traction using the double domain simulation method

The paper presents the results of a long term research work. The authors are modelling the penetration and elimination of harmonic disturbance originating from the high power railways. This kind of problem is usually handled using time domain or frequency domain simulation. As it is well known, the modelling of harmonic sources is more accurate in time domain simulation, while the frequency dependence of the passive network is more accurate in frequency domain. That is why a novel method was developed named double domain simulation method, which is a combination of frequency and time dependent models. To calculate the sophisticated model of the electric locomotive as a non-linear load a time dependent model must be used. The traction supply system together with the equivalent supply network impedance could be calculated accurately in frequency domain. An iteration algorithm is developed converting the variables in every iteration step between the time and frequency domain. The application of the double domain simulation method to solve the harmonic filtering of high power railway system is introduced. The results prove that the method is suitable for studying the effect of different filtering methods, like the passive, active and hybrid filtering