An experimental study of the effects of non-sinusoidal currents onthe registration of induction watthour meters

摘要

It is known that the registration of the induction disk watthournmeter (WHM) is sensitive to the waveform of the metered current. Thenauthors report an experimental study to determine the registrationnerrors of induction disk WHMs for three cases of nonsinusoidal currentnwaveforms. These cases are: (1) full-wave, phase-delayed sine wave; (2)nfull-wave, phase-delayed square wave; and (3) full-wave, battery chargernwave. In all cases the voltage to the WHMs was sinusoidal. Four WHMsnwere tested, two manufactured by Sangamo Electric Company and twonmanufactured by Duncan Electric Company. These instruments werenconnected for 120 V operation with a class current of 10 A. Annelectronic WHM was used as a standard for the tests. Registrations ofnthe test WHMs exceeding the readings of the standard are considered tonbe positive errors. It was found that the nonsinusoidal currentsnresulted in WHM errors that were generally positive and as great as 7%.nThe error characteristics of the four WHMs were consistent