IMPROVED ADAPTIVE PREDICTIVE FILTER FOR GENERATING REFERENCE SIGNAL AND ACTIVE POWER FILTER USING THE SAME

摘要

An adaptive predictive filter for generating a reference signal and an active power filter using the same are provided to compensate for a drift phenomenon by using a leakage factor and/or a scale coefficient compensation algorithm. An adaptive predictive filter reduces a distortion due to harmonic components. A pre-filter(420) reduces the harmonic component from an input, which is delivered to an adaptive predictive filter(430). A fifth-order butter-worth IIR(Infinite Impulse Response) filter is used for the pre-filter. A leakage factor is introduced to the adaptive predictive filter to alleviate or remove drifting of filter coefficients. When the coefficient of the adaptive predictive filter is updated, an output is determined by using an FIR(Finite Impulse Response) filter. The leakage factor is set, so that a THD(Total Harmonic Distortion) of output data from the adaptive predictive filter is minimized and the filter coefficient is not drifted.