The Design Of Remote Terminal Unit (RTU)

With the rapid development of microelectronic technique, computer technology, and communication technology, remote terminal technology (RTU) is playing an increasingly important role in the power automation system. As the core device of power automation system, RTU completes the real-time measurement and monitoring for the electronic power parament. And it is widely used in the data acquisition and process control in the bottom of power automation system. RTU has an important significance improvement on power system security of power supply and reliability.Firstly, this paper analyses the function requirement of the power automation system. On this condition, a new RTU system is designed. This new system has solved the problems such as low data transmission speed, simplex function, bad technology opening of the early RTU system.Secondly, in this paper, aimed at the shortcoming of RTU of original power automation system which are a single data acquisition, bad real-time response and low measurement accuracy, an intellect remote data acquisition terminal with a variety data acquisition, high speed and high precision is designed, so that greatly enhances function of the system. The terminal uses a high-performance digital signal processor (DSP) TMS320LF2407A as the main control circuit, CAN bus as the communication carrier; and the power paraments which are AC voltage, current, freqyency, power, power factor and so on are calculated by the algorithm of Fast Fourier Transform (FFT). Compared to the early data acquisition terminals that always used 8-bit and 16-bit MCU, this new terminal has characteristics with better operation capability and faster processing speed. Besides, it makes peripheral circuit simpler and reliability higher.Finally, with the software which programmed with C, the terminal is tested in this paper, and result of the test shows that the terminal meets the system requirements which are speed, precision and reliability of the data acquisition. And the terminal has some characteristics with a low-cost, high speed, high precision, high reliability and so on.