Design Of Power Quality Analysis System Based On FPGA And ARM

With the large-scale grid connection of new energy such as wind and solar power,the complexity of the power system is getting higher and higher,and the number of non-linear and impact interference loads connected to the power line is increasing,and power quality issues are increasingly prominent,including voltage fluctuations,three-phase imbalances,harmonics,etc.Poor power quality will not only reduce the performance of high-precision equipment and industrial production efficiency,cause power loss and waste of resources,or even threaten the reliability of power supply to the grid.Therefore,in order to ensure the reliability of power supply and improve the quality of power supply,real-time monitoring and analysis of the power quality of the power grid must be achieved.This article first outlines the causes and harms of power quality problems,compares the current status of domestic and foreign research on power quality standards and analysis devices,and discusses future development trends.Then it introduces the definition of power quality evaluation index and its measurement method,compares the advantages and disadvantages of various measurement methods and chooses the method suitable for this design.Finally,a power quality analysis system based on FPGA and ARM is designed according to the national standards for power quality.The system in this paper is mainly composed of three parts: data acquisition,FPGA + ARM control,and host computer software.The data acquisition part includes a voltage and current signal conditioning circuit and an AD7606 analog-to-digital conversion circuit.The data processing module is based on the ARM + FPGA dual-core architecture.Through FPGA control,the three-phase voltage and current signals of the power grid are synchronized to be sampled.The three-phase phase-locked loop algorithm is used to track the frequency synchronously.Fast Fourier transform with depth of 256 for harmonic analysis of current signals.FPGA and ARM utilize FSMC for communication.Transplant the embedded real-time operating system FreeRTOS on STM32 to perform task scheduling,manage various peripherals and perform data calculation and processing,and transmit various power quality parameters to data analysis software through serial communication.The upper computer software is completed on Microsoft Visual Studio 2013 with C # language,which realizes the display of power quality indicators and waveforms.Finally,a signal generator is used for system testing,and a representative input signal is used to test the measurement accuracy of the system.The test results show that the system meets the basic requirements of power quality analysis and has application value.