Harmonic Resonance Analysis Of Train-network Coupling System With Multi-harmonic Sources

Now the rapid development of high-speed railways brings the convenience for people’s lives. However, the resonance problems caused by the trains may threat the safe operation of high-speed railways. There are different reasons for the vibration phenomenon in train-network coupling system with different research methods. For low-frequency resonance phenomenon which is usually considered without the distribution parameters of power supply system, the emphasis of research will always be put on the stability analysis of four-quadrant converter and its control system. For high-frequency resonance phenomenon, it is always focused on the harmonics near the integral multiple of switching frequency of converter with the distribution parameters of power supply system. With the multiple-trains running model, this paper builds the mathematical model, involves the interactions between different harmonic sources of multi-trains and further studies train-network coupling phenomenon and its influencing factors.First, the train model and traction power supply system are introduced in this paper. Unlike traditional simplified model of harmonic sources, in order to considering the interactions between harmonic sources, this paper adopts the harmonic admittance matrix model of train. Because the transmission of harmonics relies on the gird and the harmonics will act on other trains in the shape of background harmonics, considering relevant control theory of four-quadrants and on the basis of harmonic admittance matrix model, the influences of the background harmonics are summarized by researching the effects of background harmonics on four-quadrants in this paper and the harmonic admittance matrix model has been modified. In addition, this paper uses the experimental platform of four-quadrant converter and the programmable AC source to obtain the theoretical and experimental validation of these disciplines.Then, this paper designs the fundamental and harmonic power flow calculation diagram of train-network coupling system, and writes the programs with the language of m based on MATLAB. According to the actual system parameters, this paper simulates the distribution conditions of harmonic voltages when there are two trains running at the same power range.At last, this paper also discusses the influencing factors of high-frequency resonance of train-network coupling systems, applies the orthogonal testing method to conduct multi-group experiments and analyzes the important order of the influencing factors.