The Study Of Transformer Terminal Unit(TTU) Based On DSP

Distribution Automation is a new technology developing rapidly in recent years, and it is the necessary trend of modernization of power system. Terminal Transformer Unit (TTU) is an important portion of Distribution Automation. But most TTU products have some disadvantages like costly price, few functions, lack of compatibility, and so on. This paper aims at the request of Distribution Automation and the disadvantages of existent TTU products and puts forward a scheme of TTU design: DSP IC TMS320LF2407A of TI Ltd. is chosen as a controller because of its high performance; a three-phase power/energy IC developed by SAMES Ltd. is used as a measure module to simplify the hardware circuit and software program; the embedded modem and RS485/RS232 mode communication interfaces are designed to make the data transfer more flexible and effective; the 101 communication protocols of international electric power standard are adopted to improve its compatibility. In addition, there are another functions, such as analyzing harmonics, to boost up the functionality of TTU because of the strong data processing ability of DSP.This paper summarizes distribution automation system and expatiates TTU's important situation in it; introduces the DSP IC, emphasizes on the performances and characteristics of TMS320LF2407A as well; studies the calculation methods of harmonics analysis, mainly the principle and arithmetic of Fast Fourier Transform (FFT); researches the hardware and software design of TTU like measure module, display module, communication module, and so on. Lastly, this paper compares the common communication protocols used in TTU and introduces the101 communication protocols used in this paper.