Extended C37.118.1 PMU Algorithms for Joint Tracking of Fundamental and Harmonic Phasors in Stressed Power Systems and Microgrids

This paper extends synchrophasor algorithms approximating C37.118.1 filtering requirements to provide phasor measurement units (PMUs) with the capability of accurately tracking single-phase harmonic phasors subject to varying nominal frequency and out-of band interharmonic interference. The fastest solution is built on a Kalman filter (KF) bank responding with notches at harmonic frequencies, while the most accurate solution relies on a five-cycle finite-impulse-response filter with more than 80-dB harmonic rejection. Highly distorted standardized test signals following WECC and Hydro-Québec experiences for stressed transmission systems and IEC recommendations for medium- and low-voltage system distortions are used to demonstrate the good performance of the two algorithms in tracking nonstationary fundamental and harmonics quantities. The two schemes are compared advantageously in terms of computation speed and performance with a four-cycle short-time fast Fourier transform algorithm. Finally, the effectiveness of harmonic phasors-enabled PMUs is demonstrated on a generation-rich microgrid subjected to a severe fault, followed by an offnominal frequency operation in islanded mode and subsequent grid re synchronization.