Novel frequency measurement method with low sampling time

Measurement of time varying frequency is very important in many fields: acoustics, radar signal analysis, seismology, and power quality analysis. In this paper a comparison of several methods for frequency measuring will be performed. The methods were adopted for power quality frequency measuring according to the European standard EN 50160 “Voltage characteristics of electricity supplied by public distribution systems” [1]. The main idea was to measure frequency with as lower as possible sampling time, while trying to observe transients in frequency. The following methods were used for comparison: Interpolated DFT [2], Sine fitting [3], Chirp z-Transform [4] and Hilbert transform [5]. All signals were simulated as thou they are acquired with 16 bit A/D conversion, 50 kS/s, and with range of ± 10 V. The comparison will be in next step repeated on FPGA module with real measurement data.