ONLINE TRACKING OF CHANGING HARMONICS IN STRESSED POWER-SYSTEMS - APPLICATION TO HYDRO-QUEBEC NETWORK

This paper applies to a practical test case two schemes for determinin g harmonics in power systems that are not limited to stationary wavefo rms, but can equally estimate harmonic phasors in waveform with time-v arying amplitudes and changing fundamental frequency, The first scheme relies on the short-time Fourier analysis performed using the Fast Fo urier Transform (FET) with time-domain windowing and frequency-domain interpolation, Another scheme combines fundamental-frequency tracking with a Kalman filter based harmonic analyzer, yielding a uniformly sam pled, self synchronizing harmonics tracker, The performance of these a dvanced measurement schemes for changing harmonics is illustrated conv incingly on nonstationary waveforms generated in the EMTP using a real istic series-compensated transmission network.