Dynamic Single-Phase Synchronized Phase and Frequency Estimation at the Distribution Level

This paper proposes a method for estimating synchronized phase and frequency at the distribution level under both steady-state and dynamic conditions. The discrete Fourier transform-based method is widely used for phasor and frequency estimation, thanks to its low computational burden. However, errors arise when the power system is operating at off-nominal frequency, especially under dynamic conditions such as phase modulation. Additionally, the power grid signal at the distribution level contains more noise and harmonics, which cause phase and frequency estimation errors. In this paper, a synchronized phase and frequency estimation algorithm suitable for measurement at the distribution level is proposed and tested under noise and harmonic conditions, as well as various conditions in the phasor measurement unit Standard (C37.118.1-2011 and C37.118.1a-2014), to verify its measurement accuracy at the distribution level.