Reactive power measurement using the wavelet transform

This paper provides the theoretical basis for the measurement of reactive a nd distortion powers from the wavelet transforms. The measurement of reacti ve power relies on the use of broad-band phase-shift networks to create con current in-phase currents and quadrature voltages. The wavelet real power c omputation resulting from these 90 degrees phase-shift networks yields the reactive power associated with each wavelet frequency level or subband. The distortion power at each wavelet subband is then derived from the real, re active and apparent powers of the subband, where the apparent power is the product of the v, i element pair's subband rms voltage and current. The adv antage of viewing the real and reactive powers in the wavelet domain is tha t the domain preserves both the frequency and time relationship of these po wers, In addition, the reactive power associated with each wavelet subband is a signed quantity and thus has a direction associated with it. This perm its tracking the reactive power flow in each subband through the power syst em.