Analysis of frequency measurement of power signals with varied amplitudes

Frequency is one of the most important operating parameters of a power system. Thus accurate frequency measurement plays a key role in understanding the system performance and developing effective control strategies. So far various approaches have been proposed. However, one important area, which has been neglected, is what is the effect of varied signal amplitudes on these approaches. Starting with the traditional definition of frequency, this paper analyses the basic requirements for frequency measurement, and presents new concepts for various frequency definitions. The difference between actual frequency and measured frequency by various approaches is discussed in detail. Postprocessing approach is proposed to improve the accuracy of the measurement.