Design Of 0.2S Class Three Phase Harmonic Energy Meter

With the fast development of electric and electronic, Nonlinear loads,especially electric and electronic equipments, are widely applied in power system , power harmonic pollution is becoming increasingly serious, Serious deterioration in the quality of power is affecting the safe and economical work of power-system. The precise analysis and accurate measurement of the harmonic power can provide a reliable scientific basis for the power management.At present,There are already exist power meter ICs with harmonic analyze function. Such as ATT7022B, which can be used to accurate calculate power and energy of fundamental, or can provide total harmonic power and energy. But it can not provide separate harmonic power and energy.To meet the urgent demand of electric power industry on harmonic energy measurement, one kind of three-phase multi-functional harmonic energy meter structure composed by AD73360L+ TMS320VC5502+ M30624FGPFP was presented. The operating principle of electric energy meter was described. The data acquisition circuit of six-channel synchronous-sampling A/D converter and the data processing circuit with the DSP core of TMS320VC5502 were introduced in detail. the harmonic power measurement method based on the Nuttall window double-spectrum-line interpolation FFT was used . Correction method of ratio error and phase error of harmonic energy measurement was discussed.Experiment detect show that, the kind of three-phase harmonic energy meter with the Nuttall window double-spectrum-line interpolation FFT can achieve the demand of precise harmonic analysis Harmonic Energy and accurate measurement.The error of fundamental active power measurement lower than 0.2%, error of fundamental reactive power measurement lower than 1%, amplitude error of harmonic electric voltage lower than 2%, phase error of harmonic electric current lower than 5%, and phase angle error between harmonic voltage and electric current lower than 5°. Above data results meet the accuracy requirement of the A class harmonic measurement instruments according to GB/T-14549-93.