Research On Key Technology Of Wideband Power Measurement Based On Digital Sampling

With the development of economy and national defense and an increase in measurement requirements,more and more power traceability have put forward a wide range of requirements for frequency range and the upper limit even reached 100 kHz,far more than the 15 kHz of original standard.Traceability requirements of wideband power value involving military,aviation,power,energy,magnetic materials and other fields,it is necessary to establish power national standard for 400Hz?100 kHz.Digital sampling measurement technology plays an increasingly important role in the field of electrical parametric measurement,not only widely used in the fields of AC voltage and current measurement,but also used in power measurement.This paper first introduces several common methods of AC power measurement and the research status of sampling measurement technology,and an overview of the development of virtual instrument technology.Then introduce DFT sampling principle and study the phase traceability problems in digital sampling.And analyzing the applicable situation of integer-periodic sampling algorithm and non-integer-periodic sampling algorithm,obtain the conclusion by the experimental comparative analysis.Secondly,this paper using the high-speed digitizer NI PXI-5922 as the digitizer,it is obvious that the phase angle differences between the two-channel and amplitude measurement errors of digitizer are important factors for measuring power.Evaluating the characteristic of high-speed digitizer based on digital sampling technology,including linearity errors,load errors,amplitude errors and phase angle errors.The experimental results show that the digitizer can need requirements of wideband power measurement.Finally,designing and developing the wideband power measurement system based on Lab VIEW,and write automated measurement software with a friendly interaction of interface,to achieve accurate measurement of power automatically.This paper builds a device of power value for transfer that using the developed system of power measurement and completes the measurement experiments of the power meter Yokogawa WT3000.The test results are given and measurement results are analyzed briefly.