Research And Implementation Of Calibration And Parameter Calculation For High Precision Power Analyzer

Presently,with the development of the power industry,all kinds of power equipments have been deeped into life.The electronic signal generated by these equipments reveals its features of diversity and complexity,particularly the emergence of more broadband and non-stationary signals.Traditional measuring instruments have been getting more hard to meet the requirements of broadband,unbalanced and transient signal testing.With the appearance of high precision power analyzer,the measurement requirements of such signals have been satisfied.The high precision power analyzer has the function of measuring voltage,current,frequency,power,harmonic and other parameters in a broadband,and provides multiple measurement channels for synchronous measurement of input and output.Then the difficult points of this project are analysed in this paper: the nonlinear system's calibration algorithm and the high precision power parameter measurement.Aimed at these difficult points,reasonable algorithms are designed in this paper,and have been verified on the simulation platform and the actual platform.First of all,a new calibration algorithm is proposed for the problems of nonlinear systems.The core idea of the algorithm is to reasonably establish the mapping relationship between the sampled values and the theoretical sampling values.Secondly,the calculation method of the three parameters include frequency,harmonic and power is introduced in this paper.A new method of frequency measurement is put forward,the frequency spectrum obtained by Fourier transform is refined in a section,and the accurate frequency is calculated by using one dimensional search algorithm in the refine section.Then aimed at the limit of the integer power of 2 of the number of sampling points,this paper propose Cooley-Tukey algorithm for harmonic analysis.This method is not limited by the number of sampling points,with the low calculation and high precision.At last,the principle of power parameter measurement for non sinusoidal and unbalanced systems is analyzed and a suitable calculation method is given.Thirdly,the software implementation plan of the three core platform based on FPGA+DSP+ARM selected in the actual project is described in detail.Finally,this paper introduce the design and realization of software framework,then build a practical platform for the measurement.The required parameters measured in high precision power analyzer are compared with other high precision devices,and the test results show that the precision of the volatage measurement precision reaches 0.2% of range,the current precision is 0.1% range plus current sensor precision,and the frequency and power parameters also meet the precision requirements of the 0.001Hz+0.01% range and the 0.4% range.