Abstract:

There is a serious harmonic interference problem in the power system, and in order to enhance secure and effective operations, removing the harmonic interference and improving system stability becomes a hot research topic. As for the challenges of strong fluctuations in the grid frequency or frequent intense white noise interference, although the FFT algorithm for triplespectrum line interpolation (based on Kaiser window) has strong antiinterference ability, and the harmonic parameter estimation may also have  a higher accuracy, the combination of the modal harmonic detection algorithm (EEMD) and the straightness error analysis has better effect. Online monitoring of the overall harmonic components can improve not only the detection precision of the steadystate signals, but also the dynamic performance of the system. The proposed analysis strategy can improve calculation accuracy and system stability. Simulation analysis proves its strong capability in preventing spectrum leakage and reducing the probability of fence effect significantly. The amplitude error of power harmonic signals, initial phase and frequency are less than 0.004 1%, 0.002 4% and 0.003 9%, respectively.

Key words: EEMD;straightness error;triplespectrum line interpolation;accuracy improvement