Theoretical Analysis Of The Transient Process While Locomotive/Emus Passing Eiectric Phase Break

Single-phase AC power system, 25 kV, is applied in china electrified railway. In order to solve the problem, single-phase loads' negative sequence current effects on the stability of the power system, home and abroad set electric phase break. With the help of this equipment, method of phase by phase cycle can be used to reduce the negative sequence current content.Identified in the operation, while the electric locomotive/Electric Multiple Units is passing the electric phase break, contact lines are burned out by arc, and locomotives' discharge gap is broke down by over-voltage. Substation tripping accident caused by the gap's breakdown which leads metal grounding short fault, takes serious impact on the electric rail way system safety.Therefore, carrying out the research on transient process and manifesting the failure mechanism is very important for high-speed passenger dedicated railway construction and operation.First of all, this paper narrates the two phase break structures and modes of passing the electric phase break in detail, and compares them according the technical and economy.Then, the model of electric locomotive/EMUS and electric phase break were established. On the principle of circuit, the transient change process of the line was analyzed, the formula for the complete response of neutral line's voltage was deduced, and the conclusion that property of the over-voltage is the switching over-voltage was determined.On the basic of simulation analysis and combining with the test data, the correctness of the theory was verified.Finally, in support of the analysis of the theory, this paper gives some effective measures to resolve and reasonable suggestions.