Machanism Analysis On The Overvoltage Of Articulated Phase Insulator

In the AC traction system, the locomotive is single-phase load. The phase and section power mode is adopted in the system. Articulated phase is widely used in the electric railway. Nevertheless, with the speed-up of electrified railway, the problems of over-voltage during the electric locomotive passing articulated phase equipments are found many times. The over-voltage becomes a key issue which holds back the development of our electric railway. Study of the over-voltage and its suppression measures has a high theoretical and practical value.This paper calculates the interrelated parameters to the structure of Overhead Contact Line System after the simple expatiation of it. In succession, the electrical course of locomotive passing through the articulated phase insulator is described with the analysis of over-voltage. The cause of over-voltage and several factors which affect the level of it are discussed.Based on the analysis and calculating of the electrical structure, this paper studies the passing course over-voltage with two methods. One is a method which adopts the power system simulation tool Pspice, builds a model simulating the course of electric locomotive passing through articulated phase, and uses the model simulates course in the situations of different voltage transformer saturation levels. The other way is a method of physical experiment to simulate the passing course. According to the electrical structure and dynamic course of passing the articulated insulator, the author and his assistants design and install the physical experimental platform along with the experimental data acquisition system and data-change system. Then this paper simulates the dynamic passing course when some waveform data are acquired. Through the analysis of data, the paper verified the effectiveness of those two simulate methods. After that, a technical measure of inhibiting the over-voltage level with RC damping circuit is presented and discussed.