Fast and accurate measurement of power system frequency

A simple, fast and accurate method is presented for the measurement of the power system frequency. The method is based upon counting the number of strips (or samples) between zero crossings during one complete cycle of the sinusoidal waveform. Since the number of strips is usually not an integer, an estimate is derived that is very close to the actual value. The frequency is directly calculated from the number of strips. The measurement can be performed in at most 25 ms for a 60-Hz frequency, and at most 30 ms for a 50-Hz frequency. if the sinusoidal signal is sampled at 8 kHz for the purpose of measurement, the proposed method achieves accuracy in measuring the frequency of about 0.0001 - 0.0004 Hz.