Based On The Embedded System Substation Rtu Research Design

With the power network becoming increasingly large and complex, the stable and reliable operation of the distribution automation request higher and higher level on real-time and accuracy. This paper introduces the at home and abroad development of RTU running for power system, in light of the current development and applications in control area of embedded microprocessors and embedded operating system, a new RTU based on ARM9 and embedded Linux operating systems is design for the 110kV substation of distribution automation. And this paper has designs the RTU modularly combining the related tagging functions standards and technical norms of power system.In this paper, ARM9 chip S3C2410A is designed as the CPU of the RTU. From the functional point of view, the RTU system is devided to four modules: power measurement and voltage detection module, harmonic current detection module, testing switches' state and controling switches module, and communication module. A high-precision energy measurement chip SA9904A is designed as the core of power measurement and voltage detection module, which measure the three-phas active power, reactive power , voltage and frequency of the generatrix; With high-speed, low-power consumption, four-channel AD sampling chip- AD7864 sampling of the bus current , by using Fast Fourier algorithm, harmonic current detection module gets the harmonic analysis result; hrough optocouplers, testing switches' state and controling switches module gets the state of the switches and export the control commands from control center to the switches; By using CAN controller MCP2515, optocoupler and CAN bus access transceiver, Communication module reports the field data to and ges the commands from the control center through CAN bus. Based on embedded Linux operating system, the software of the RTU system is designed modularly with C programming language and compiled by gcc cross-compiler.Experiment about the design was debugged successfully in the laboratory finally. the result shows that both the function and the performance indicators of the power RTU designed in this paper meet the design standards of power industry. If the RTU was applied in distribution automatic system, active effect wil be brought to several aspects such as ensuring power quality, improving the DA's real-time feature and reliability, and reducing loss caused by power accidents.