A Technique for Increasing the Accuracy of Frequency Measurement When Using a Method Based on Phase Increment Analysis

Currently, the method based on signal phase increment is the most accurate for measuring the frequency of signals from real electrical networks with all their existing and taken into account features. The problems solved in the paper are aimed both at simplifying the implementation of this method and at increasing the accuracy of the measurement. The paper provides a comparative analysis of methods for obtaining signal phase samples and evaluates their advantages and disadvantages. To reduce the measurement error, the use of an adaptive moving average filter as a post-filter is considered. It is shown that this approach can significantly improve the accuracy of the measurements performed. By using the Simulink software package, a simulation model of a measuring frequency converter of the operating principle under consideration was performed. Analytical expressions are obtained that allow one to estimate the frequency measurement error when using the proposed modification.