FPGA based power quality monitoring using FFT method for single phase power metering

摘要

Power Quality monitoring is very important especially for high frequency nonlinear loads, high speed adjustable drivers. Accurate measurement of electric parameters is required to determine the quality of power which involves collecting, analyzing and processing of voltage and current samples over a period of time. So addressing to this a power meter is required that measures electric parameters with high accuracy and computation speed for different loads. Existing Electromechanical power meters are of low cost but still are being replaced by electronic power meters because of their better accuracy and dynamic range. This paper presents power meter to measure electric parameters like real power, reactive power, and power factor of different loads where data processing is FPGA based. FPGA based processing has been implemented as it provides more flexibility, speed, and ability to update system functionality. The meter includes ADS1220 which is 24 bit ADC interfacing with FPGA (Artix 7) which provides voltage and current digital samples. The analytical calculation and output developed in Xilinx 14.7 version and implemented on Artix 7 AC701 evalution board. For 50 Hz power system with sampling frequency 12.8 KHz 256 point FFT is implemented for power calculations. The meter is tested on different loads like resistive load 40 watt bulb and industrial drill(inductive load). Micro controller interfaced with FPGA is used to control circuits of analogue part, monitoring the results obtained from FPGA, communication with components via RS 422 interface.