City Rail Traction Power Supply System Short-circuit Test And Short Circuit Characteristics

The transport sector is the main artery of the entire national economy, development of transport is related to the national economy and a strategic task。The development of urban transport system has always been restricted urban development one of the most important factors。Large cities, especially in cities of more than a million people, the urban form depends largely on the development of its traffic。Especially as an important component of urban transport, light railway, the development of the future to protect the city's transport system, with the urban rail transport in the capital's transport system and other big cities play an increasingly important role as a light rail safe and stable operation of the weakest link in rail traction power supply system has become the safe operation of attention and research focus。City rail traction power supply system consists of an external power supply, rectifier system and traction power supply lines, three major components, including traction power supply lines for transient performance analysis and condition monitoring and fault identification of the traction power supply system determine the fault signal analysis, protection and automation technology and issues related to the research has important theoretical significance and social value。In the subway and light rail traction power supply system protection mode, the current rate of change and the current increment Protection (di/dt-(?) I protection) is a Metro power supply system to protect the most commonly used method, and its function is to increase the dynamic current process monitoring, that when the short-circuit fault occurs, the short circuit current rate of increase relative to the start of the train when the rate of current rise will be higher, and is in accordance with the exponential change。However I received from the City the actual fault record track fault waveform view, there is generally the first fault current produced a high amplitude oscillation after the impact of current and attenuation characteristics。Description di/dt-(?) I assumed the protection mode fault current exponentially changes in the characteristics and the reality is that there are some discrepancies。This article discusses the key components of rectification system rectifier transformer and rectifier equivalent circuit of the transformer and rectifier on the short circuit current in the transient current to the impact of the impact of the proposed urban rail traction power supply system as a whole model, collected Beijing-Tianjin high-speed railway ring experiments and inter-city railway actual fault waveforms, and waveform characteristics under the proposed order is different from the RL circuit model of a 2-order RLC circuit model, and finally the actual collected short-circuit current waveform and simulated waveforms comparative analysis to verify the model is reasonable。Finally, fault waveform characteristics of the wavelet packet energy spectrum, proposed one kind of new method of detection fault waveform of variation based on current principles of traction power supply system protection and system errors related to movement of troubleshooting has important significance。...