Research And Design Of Power Quality Detection Device Based On Zynq-7000

Electric as an indispensable energy in modern society,the application level of electric energy can directly reflect the state of development and comprehensive national strength of a country or region.High quality electric energy is a prerequisite for safe and stable operation of power system.When the quality of electric energy is poor,it will bring serious waveform distortion,frequency deviation,voltage deviation and other hazards,thereby endangering the safety of economic operation of the grid and the normal use of electricity.The evaluation index of power quality mainly includes voltage and current effective value,frequency deviation,voltage fluctuation and flicker,three-phase imbalance,power and power factor and harmonics.And because of the development of power electronic technology in power system,the use of a large number of power electronic equipment(harmonic sources),These devices will produce harmonics that cause pollution to the power grid.Eventually lead to a failure of the equipment and the abnormal phenomenon,harmonic is the key problem in power quality detection.Therefore,it is very important to detect the harmonics in the power quality.With the rapid development of the electronics industry,the update of the hardware conditions and the optimization of the software algorithm,people are constantly improving methods of the power quality detection.The requirements for the diversity,precision and real time of the power quality detection devices are also getting higher and higher.This paper analyzes the representative power quality detection methods and key technologies of power quality detection devices so far and the development of FPGA technology and its application in the field of power quality detection.In view of the current domestic and foreign power quality detection devices,there are many technical bottlenecks,such as large amount of operation,long calculation time,and poor real-time performance,The scheme of using Zynq-7000 chip developed by Xilinx for power quality detection device is put forward.The chip adopts the FPGA+ARM architecture,has rich logical resources,makes full use of the advantage of FPGA technology that inherent hardware acceleration,paralleles data processing.And combines ARM’s flexible scalability and strong signal control and management capabilities.This paper analyzed harmonic based on FFT algorithm with window interpolation the windowed interpolation.The algorithm is implemented by MATLAB simulation to the Zynq-7000 chip.the main task of the chip is to AD sampling for signals containing 50 times harmonics,then add a window to the signal after AD conversion to inhibitionspectrum leakage,and then FFT calculation,the non synchronous sampling and non integral period truncation in the harmonic analysis leading to larger calculation errors,it is necessary to correct the error of FFT correction.This topic chooses to use the Zedboard that carries the Zynq-7000 series chip as the development platform.Use Vivado to build the hardware logic system.It mainly includes windowing module,error correction module,customization of IP core,and call the IPs with Vivado,such as AD,FFT,BRAM,Floating,CORDIC and so on,and the simulation of each module and a synthesis and implementation of logic system.After the PL part of the Zynq-7000 chip completes the logic operation,The PS part of the Zynq-7000 chip is responsible for the transmission and storage of data.Software programming in SDK to achieve data transmission,storage,and display.Finally,the results of the harmonic detection system designed in this paper are compared with the Matlab simulation results,and the results show that the device can meet the requirements of the national power quality basic parameter accuracy.