A new signal processing technique for evaluation of the reactive power in the power transmission and distribution systems

Abstract

This paper presents a new modified Walsh function (WF) based method for the measurement of reactive power (RP) in sinusoidal as well as in noise conditions. Proposed method simplifies the multiplication procedure to evaluate the reactive components from instantaneous power signal using peculiar properties of the WF. One of the advantages of proposed measurement approach is that in contrast to the known existing methods which involve phase shift operation of the input signal, the proposed technique does not require the time delay of the current signal to the pi/2 with respect to the voltage signal. Another advantage is related to the computational saving properties of the proposed approach coming from use of the Walsh Transform (WT) based signal processing method. Proposed method eliminates an influence of the prevalent third order current harmonic to and reduces the effect of the highest order current harmonics on the RP measurement results. Validity and effectiveness of the suggested method for evaluation of the RP components of the electrical power have been tested by use of a simulation tools developed on the base of "Matlab".