A DSP-based electric power meter

The authors describe a novel approach to the design of digital algorithms for electric power measurements under nonsinusoidal conditions. Using the discrete Fourier transform (DFT) of two sets of real data in one pass, the voltage and current spectra are obtained simultaneously. Real and imaginary parts of both spectra are then processed to obtain the terms of the electric power components according to various definitions in both sinusoidal and nonsinusoidal conditions. Some results of simulated measurements using an assembler program for the TMS32010 microcomputer are given