Measurement of Voltage, Current and Power at Distorted Waveforms

Electric power systems have been designed to operate under sinusoidal voltage and current conditions at power frequencies, mainly 50 Hz and 60 Hz, and by far most electrical energy transmission occurs at 50 Hz and 60 Hz. Electric utilities are responsible for providing a sinusoidal voltage to their residential, commercial and industrial customers. The customers are, on their side, responsible for not causing excessive distortion of the voltage and current in the system. Since voltage and current, in practice, are periodical but not exactly sinusoidal, they contain higher frequency components—harmonies—in addition to the fundamental frequency component (50 Hz or 60 Hz).