Research On Resonance Overvoltage Of Traction Power Supply System Caused By Electric Locomotive

After the sixth railway speed-up, and with the use of AC-DC-AC electric locomotive, there are many accidents happened in traction substation, such as the breaker’s tripping, the capacitor’s fuse burn out, the arrester exploding. The main reason of these accidents due to internal overvoltage, and the fluctuations of traction load can easily cause electromagnetic transient oscillation, resonance overvoltage is one of typical examples. This paper gives related researches about resonance overvoltage in traction power supply system, throughing theoretical analysis and model simulation.Based on the theoretical analysis of traction power supply system and AC-DC-AC electric locomotive, the overhead line model of simulation software PSCAD/EMTDC was used to build a mew model, it’s parameters can reflect the change of frequency; the motor model is used to build the control circuit of traction drive system as the load of pulse rectifier, the rotor field oriented control technology is used to control motor. After preliminary simulation, the simulation results are consistent with theoretical analysis, and the measured data also indicate the correctness of the model.Based on the building model, the linear resonance overvoltage is studied through researching the impedance frequency characteristics of traction network system and the harmonic characteristics of AC-DC-AC electrical locomotive. Find that, the harmonic overvoltage is determined by the resonant frequency of traction network system and the harmonic current of harmonic source. The resonance overvoltage was generally between40kV-50kV, all of the voltage distortion are more than3%, and lasted for a long time. Using the process of electrical locomotive passing neutral section as an excitation condition, researched the ferromagnetic resonance of the process, and find sub-harmonic resonance was happened. The resonance overvoltage was up to108.9kV, more than the withstand voltage of400mm insulator-100kV.Finally, according to the characteristics of harmonic source, the minimum installed capacity method was used to design the parameters of high pass filter to change the resonant frequency of the traction network and absorb harmonic. Through the simulate calculation of different install position of different sets of high pass filter, find one was installed on the locomotive, one was installed at the partition have the best result, when there are some difficulties to install filter on the locomotive, high pass filter was installed at the traction substation and the partition also can make voltage less than40kV, the voltage distortion less than3%; An integrated restrain scheme based on the voltage phase of contact line to control locomotive passing the neutral section was proposed to achieve the dual purpose of suppressing the operation overvoltage and the ferromagnetic resonance over voltage. It can control the overvoltage of the process lower than50kV. The achievement of this paper can provide reference on the theoretical analysis or Overvoltage suppression of resonance overvoltage in the traction power supply system.