On-line tracking of time varying harmonics using an integrated extended complex Kalman filter and Fourier linear combiner

The paper presents an integral approach for the estimation of harmonic components of a power system based on the use of Fourier linear combiner (FLC) and extended complex Kalman filter (ECKF). The ECKF estimates the accurate frequency of the signal to update the nominal frequency of the input vector to the FLC. The FLC tracks the the Fourier coefficients of the signal data corrupted with noise very accurately. Once signal is modeled properly, the time varying harmonics of a power system can be estimated accurately using this new approach. Several numerical tests have been conducted to highlight the effectiveness of the technique even in the presence of frequency jump, amplitude variations, noise etc