Research Of Fpga-based Harmonic Detecting In Power System

This paper studies the electric power system harmonic detection problem. Harmonic detection is an important aspect of the problems in power system harmonic, and is a base to solve other problems related to harmonic.The paper describes in detail the damage which the power harmonics bring to the power system and various electrical equipments.The damage shows the necessity and importance of the study of harmonic detection.Based on comparative study of various harmonic detection methods, harmonic detection method based on FFT which was used most widely was selected in this paper,and the Field Programmable Gate Array(FPGA) was used to implement the FFT processors. Harmonic detection for the inevitable phenomenon of spectral leakage, the article by comparing a variety of commonly used window function, decided to use Hanning window to reduce spectral leakage,and experiments show that the use of Hanning window has played a very good effect. In this paper, we carried out an overall hardware design to harmonic detection system, and introduced the function of each module and working principle. In addition, this paper focuses on the FPGA data processing unit, describes how to use FPGA to implement FFT processor.First, from theory and hardware implementation to determine the entire design,through many discussions,such as the FFT algorithm, fixed-point or floating-point data format, sampling points and the hardware realization of the structure,we finally decided to use the frequency extracted by the based-2FFT algorithm, sequential processing structures and VHDL language to achieve the 128-point fixed-point operations,which was at the hardware base of EP2C7OF672C6 FPGA chip of Altera CYCLONEⅡseries and at the software base of QuartusⅡ8.0 software platform. FFT processor for the various functional modules have been designed and described in detail, and finally integrated modules, simulation, get the result. Simulation results show that the results of their calculations has reached a certain precision, the reliability of the system has been verified,and compared with similar FFT processors ,it has reached the purpose of high-speed computing.