Design And Implementation Of Hardware Circuit Of High Precision Power Analyzer

With the continuous development of power electronics technology,the requirements for various power measurement equipment are becoming more and more stringent.The performance indicators of domestic power analyzers have become more and more difficult to meet the testing requirements of high-bandwidth,high-precision,and transient complex signals,so it is necessary to design a high-precision power analyzer.The instrument provides multiple measurement channels and is capable of high-accuracy measurement of electrical energy parameters such as current,voltage,frequency,harmonics,and power over a wide frequency range.This paper introduces the hardware design of the high-precision power analyzer in detail,and analyzes the details of the analog acquisition channel board and digital processing board in detail.A complete high-precision power analyzer is realized by combining with software.The main research contents of this paper are as follows:1.System hardware overall design: The project is modularized.The signal is processed by the acquisition circuit,signal conditioning circuit and ADC in the analog acquisition board,and then transmitted to the FPGA in the digital processing board to complete the data acquisition.Finally,the data collected will be transmitted to the industrial computer for calculation and display of various parameters.2.Analog acquisition board: The two distributed capacitances in the voltage acquisition that affect the frequency response of the resistor-capacitor voltage divider are analyzed and optimized.The equivalent inductance effect of the resistor in current acquisition is optimized.According to the overall scheme for the requirements of the signal conditioning circuit,the differential amplifier circuit,the gain amplifier circuit,the ADC driver circuit and the protection circuit are designed.The feasibility of the design is verified by the noise theory.3.Digital processing board: The FPGA chip selection and its peripheral circuits are introduced in detail;The FPGA power supply and power-on sequence are designed in detail;And the key signals of DDR3 are analyzed and the method of power integrity with DDR3 is introduced as an example.At the end of this paper,the debugging method of the the resistor-capacitor voltage divider is introduced and the modules are tested.Finally,the range,acquisition accuracy,frequency acquisition accuracy of the voltage and current are tested in detail.According to the test data analysis,the design achieves the highest accuracy of 0.05% of the design requirements.