A Faster μ -PMU Algorithm Using Arctangent Framework With Parameter Step Change

Phasor Measurement Units (PMUs) play a vital role in modern power systems by enabling real-time monitoring, control, and protection under dynamic conditions. However, their performance exhibits inaccuracy and longer response time when encountered with abrupt transients. To address these limitations, the paper introduces a highly responsive and precise algorithm for estimating synchrophasor, frequency and rate of change of frequency (ROCOF) that effectively cope with sudden amplitude or phase changes. The approach integrates the initial frequency estimation with a Logarithmic Entropy Ratio strategy for effective transient detection. A step modeling is used based on the Arctangent Laplacian Continuous Mixed p-Norm (ALCMpN) algorithm on asymmetric windows. Subsequently, a compensation technique enables blend between pre and post estimates which eliminates the influence of phase step and reduces the ROCOF error. IEC/IEEE 60255-118-1a compliance tests show that the proposed algorithm achieves TVE < 0.001%, FE < 0.05 mHz, and RFE < 0.005 Hz/s which are within the P-class constraint. Field validation using Grid Event Signature Library (GESL) test data further verifies robust performance under real fault conditions. Real-time validation using RTDS–DSP hardware demonstrates reliable operation confirming its suitability for real-time PMU and protection applications in active distribution networks.