Research On Integrated Main And Backup Protections For Traction Transformer

With the rapid development of China’s national strength, the total mileage of electrified railway emerged as the world first. This shows that rail transport is the backbone of transport. Among the electrified railway, Traction transformer is not only the most important one in the power supply system of electric traction which plays a very important role, but also affects the security of the whole railway transport. Currently, traction transformer protection devices used on the electrified railway is still the traditional one which separates main and backup protection. This configuration still has some problems in reliability and cost-effectiveness. Thus, it’s necessary to study on integrated main and backup protection and double configuration for traction transformer.The development of the current status of microcomputer protection for traction transformers, as well as identification method of inrush current are introduced in this paper. Then, the reliability of integrated main and backup protection with traditional configured protection are compared by using Markov process. MATLAB software is used to build a traction transformer model for simulation of several ways to distinguish inrush current. Two kinds of those are elected for theory of double configured protection.The functions of integrated main and backup protection are briefly analyzed in this paper. Based on this data, the design of protection hardware part has been completed. Protel electronic design automation software is used as a way to design schematic of CPU board, AC board, I/O board, power board, backplane and LCD display panel.Finally, protection criteria and principles of setting are simply explained. And the difference-Fourier method is selected as a basis for the protection algorithm. CCES programming software is also used to design supporting software for the hardware and detailed flow chart of the programs.