Polyphase representation of QMF filter bank for power systems harmonics analysis

In this paper the efficiency of the polyphase decomposition form against the direct decomposition form of quadrature mirror filter bank for power harmonic analysis is investigated. For that purpose, the both forms of decomposition are implemented on the digital signal processor TMS320C6713. Experimental results show increased efficiency when polyphase decomposition form is used. Additionally, the influence of the input signal extension on the accuracy of calculated RMS result is investigated for the aim of reliable harmonic analysis. The investigation has shown that the periodic signal extension gives best results in case of stationary input signals and can be used for both direct and polyphase implementations.