Research Of Modeling And Test On Impedance Bond In The High Speed Railway

ABSTRACT:With rapid development of rail transportation in China recently, greater traction current and stronger electrical interference are brought by high-speed and heavy haul railways. Under this background, station track circuit is in the severe environment with complexity line networks, so it is very important to ensure its normal work. BES (K) impedance bond, combining track circuit system and power supply system, play a crucial role in the electrified railway. It is a traction return path between the track circuit sections in traction power supply system. And it is also the important impedance matching device in the track circuit equipment. If interferences change the signal impedance of impedance bond or distort the signal waveform, which may lead malfunction of track circuit or cab signaling, then may cause casualties and property losses. Thus, the modeling and simulation of BES (K) is of great significance and value for the reliable working of power supply system and track circuit system and the safety of the railway system.Considering this background, this thesis make a detailed research about key parameters and working characteristics of BES (K) which consists of transformer and adapter (QSP) under the interference by building the BES (K) model. Main works include the following four aspects:1. Working characteristics and key parameters of transformer and QSP are studied based on the experiments and simulations. BES (K) transformer circuit model is built on MATLAB platform, and impedance simulation curves are made.2. According to the validation experiment data and the research of the BES (K) transformer operating characteristics the established model parameters are optimized to make the simulation result closer to the real value. At last final mode is simulated on MULTISIM.3. Operating characteristics of BES (K) transformer that under the disturbance of100A unbalance current and harmonic interference and DC interference are studied based on the tests. Working characteristics of BES (K) transformer is deeply analyzed combined with the final circuit model.4. Application of the BES (K) model in the four-port network of ZPW-2000track circuit is analyzed. Based on the established model the semi-coil model of BES (K) transformer is built, and application of the Semi-coil model in circuitous track circuit is introduced.The model proposed in this thesis is in accordance with the actual characteristics of BES (K) transformer. The full and semi-coil two-port circuit model of BES (K) transformer can be applied in four-port network model of ZPW-2000station track circuit and circuitous track circuit directly to simulate and analyze. Model has a certain value in the comprehensive analysis of traction power supply system and signal system.