The Research And Implementation On Traction Substation Relay Protection

The sustainable and stable development of China's economy requires the electrified railway system with stronger transport capacity and better safe reliability. The traction feeder and traction transformer occupies a decisive position In the electric railway power supplying systems. Their safe and stable work is a prerequisite for the electrified railways's normal and stability. But the traction substation secondary system is relatively backward, so it is important to develop the electric railways protection equipments of home-made. The main task is to develop the electric railways feeder protection and traction transformer protection devices and to achieve communication function with IEC60870-5-103 communication standard.First of all, the paper summarizes the structure of traction power supply system and power supply type, compares the traction power supply system and the electric system. This paper studies the feeder protection theories and transformer differential protection theories, proposes the relay system configuration and the implement discriminants of the feeder protection and transformer protection.Then the paper discusses the design and implementation of the traction substation monitoring and Microcomputer Protection devices based on the 32-bit ARM microprocessor——STM32 and embedded real-time operation system RL-RTX in the hardware and software. The paper introduces the hardware structure of the microprocessor and communications module, directs the important tasks and interrupt service routine in this real-time multi-tasking system, draws the flow diagrams of the feeder protection and transformer protection. The paper verifies the correctness of the feeder protection and transformer protection.Finally, the paper reseaches the serial communication theory and Ethernet communication theory, studies the MODBUS protocol and IEC60870-5-103 protocol. The communication function with the MODBUS protocol and IEC60870-5-103 protocol has been realized through the serial port and Ethernet. The reliability of the communication function has been verified by the experiments.