Design Of Data Acquisition System For Electronic Transformer Based On FPGA

Electric power which is widely used in all areas of the national economy is the most important energy. The power system plays an important role in the development of the national economy, and its development and changes are highly regarded by all countries in the world,especially developed countries. In the 21st century, the smart grid has become a new direction for the development of the power system. Intelligent digital substation is an important part of smart grid. Electrical equipment for measuring, protecting, controlling and so on starts from analog signal transmission to digital signal transmission. So the electronic transformer came into being.Based on IEC60044-7/8 electronic current and voltage transformer standard, the communication characteristic and function of the electronic transformer acquisition system are analyzed and studied in detail with reference to IEC61850-9-1/2 standard. FPGA + AD7606 as the hardware platform, completed the 8-channel electronic transformer acquisition system design. Firstly, the FPGA peripheral hardware circuit of the acquisition system is designed,including AD7606 peripheral circuit, optical fiber communication circuit and serial communication circuit. And then the system based on FPGA is divided into data acquisition module, data processing module, data transmission module, and designed by Verilog HDL. The data acquisition module includes second pulse validity detection, sampling pulse synchronization signal generation and AD7606 sampling. The data processing module includes FIFO, FIR digital filter, CRC check code generation and FT3 data framing. The data transmission module includes manchester coding and UART serial transmission. And the paper completes the function simulation and verification using Modelsim software.Finally, the design of the FPGA-based electronic transformer acquisition system is downloaded to the development board to experiment, the collecting and processing data is sent to the host computer through the USB interface, the FT3 data frame is analyzed accurately and the accuracy of the data is analyzed. It is proved that the acquisition system is designed correctly.