Manufacture Of Wide Area Synchronous Monitoring Device For Low Voltage Side Of Power System

Because of the serious imbalance in energy and load distribution, determined that the only way to change China power grid is interconnection grid development. China UHV grid construction and smart grid are also being implemented, which makes the major regional power grid closer together, but also the control operation of power grid become more complex, so the higher demand of WAMS of power grid is also being proposed. This paper analyzes the present situation of the WAMS development, and then, the monitoring device of low voltage side of power system based on single phase220V voltage waveform on the user side of the grid is researched and developed. The wide area synchronous measurement system of low voltage side of power system is formed by many devices and the server terminal to implement wide area measurement. The main of this paper’s research contents are as follows:(1) This paper firstly introduces the research background and status of WAMS, and then describes the significance of wide area synchronized measurements technology at the low voltage side of power system. Finally, the structures of synchronous wide area monitoring system for the low voltage side of power system are presented.(2) Signal conditioning module, data acquisition module, data processing module, synchronous clock module and communication module are included in the hardware structure of the monitoring device. This paper describes the function of each module in detail, and the specific procedures and methods of the module design are introduced to make the device to meet the functions of data synchronization acquisition, real time processing, and fast communication.(3) The software design of device mainly use FFT Library functions provided by TI FFT transform to get the fundamental component of220V voltage waveform, and then the data of frequency, RMS and phase angle is obtained. The C programming language is used in program to complete the compiling of main and sub-module program. The watchdog technology is used to improve the stability and reliability of the device.(4) The sampling impulse of monitoring device are provided by the FPGA to use the standard of1PPS rising edge, and the3200Hz synchronous sampling pulses are generated by the internal oscillator count of FPGA. In this pepper the ALTERA’s Cyclone II generations EP2C8Q208C8is chose to use, and Verilog HDL language is used to descrip hardware circuit.1PPS discriminating unit,1PPS generator unit and synchronous sampling pulse generator unit are included in this part.(5) In order to verify the accuracy and reliability of the device the standard source is used as input signal by setting different frequencys. These devices connect with the server terminal to form into the wide area measurement system for the low voltage side of power system, and the frequency information of power system to be got through this wide area measurement system. Experimental results shown that the device have high accuracy of frequency of power system and running stable, and can meet the requirements of WAMS.