TY - JOUR T1 - Analysis of Methods for Determining Frequency of the Main Harmonic in the Centralized Systems of Relay Protection and Automation AU - Sh. Misbakhov, R. AU - N. Lizunov, I. AU - G. Mustafin, R. AU - V. Fedotov, V. AU - Z. Bagautdinov, I. AU - N. Funt, A. AU - E. Naumov, O. AU - V. Ivanov, V. JO - Journal of Engineering and Applied Sciences VL - 11 IS - 6 SP - 1257 EP - 1262 PY - 2016 DA - 2001/08/19 SN - 1816-949x DO - jeasci.2016.1257.1262 UR - https://makhillpublications.co/view-article.php?doi=jeasci.2016.1257.1262 KW - Frequency measurement KW -frequency measurement techniques KW -microprocessor terminals relay protection KW -systematic error KW -methodological error KW -fast fourier transform KW -frequency spectrum AB - The measuring of the alternating voltage and current frequency into modern microprocessor devices and systems of relay protection and automation is the major problem and reaction rate on preventing system or its part transition in the emergency mode depends on its solution. In this regard the important aspects are the speed and accuracy of the frequency determination depending on the method used as well as the assessment of the noise and harmonics effects on the frequency measurement as a function of the applied algorithm. The data on the accuracy of the frequency measurement by different algorithms were got and estimation of the highest harmonics and noise content in the input signal influence for calculating the signal frequency by different methods was conducted. The research results can be used in the development of new frequency measurement algorithms, including algorithms for multi-channel centralized relay protection and automation system which can affect the approach of modern relay protection and automation systems development as well as increase the functioning efficiency of the existing protection. ER -