Harmonics estimation in stressed electric power networks

The paper presents an integrated approach for the estimation of harmonic components of a power network in the presence of frequency changes 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 Fourier coefficients of the signal data corrupted with noise very accurately. Once the 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. Also the approach is tested with data obtained from a power network in the laboratory environment.