Research On Merge Unit Of The Electronic Transformer

With the development of the smart grid, our country is vigorously promtingit. In the grid, the transformer is very important device. With the grid levelgradually improved, the traditioned electromagnetic transformer insulation ismore and more difficult and it also can’t be open on the secondary side. So theelectromagnetic transformer is gradually repalaced by the electronictransformer. The electronic transformer has the advantage of highaccuracy,light weight,strong anti-interference ability, so it is gradually applied tothe power system.Firstly, this paper compares the characteristics of the electromagnetictransformers with the electronic transformer, and then make a brief introductionof the research status of the electronic transformer. Introduced the standard ofIEC61850. According to GB20840-8, I design a block diagram of the highvoltage modulation circuit and the merging unit.Secondly I design the signal conditioning cricuit, A/D sampling circuit, thelogic control circuit, the electro-optic conversion circuit and a power supplycircuit. The paper programs logic controller, and simulates Manchester encodingbased on Modelsim software, then debug the circuit boardFinally I introduce the photoelectric receiver, FPGA, DSP, Ethernet andenter and exceed circuit. On the software, I decode the Manchester code andverify by simulation. Then preparation of the DSP program, through CCS3.3restore the data waveform that is passed by the high-pressure side. The mergedunit can communicate with the PC via Ethernet. At the last, I also describes a lineprotection algonrithm, which provides the foundation for the future of thecombined unit extensions.