An Improved Harmonic Energy Measurement Algorithm Based on Instantaneous Reactive Power Theory

Aiming at the unreasonable phenomenon that the different harmonic power will be cancelled out in the current harmonic background, a harmonic energy measurement algorithm is proposed to improve the instantaneous reactive power. First, the three-phase voltage and current signals are constructed by the delay of single-phase voltage and current signals. Then by changing the rotational speed of the p-q coordinate system in the instantaneous reactive power theory, the signals of different frequency harmonics in the voltage and current are obtained after filtering. Finally, the active power and reactive power of the system are obtained by the power conversion. This method can not only measure the power in positive and backward separately, but also avoid the unreasonable phenomenon of the positive and reverse power offset when the electric energy is measured, and can be used in the single phase system and the three-phase system. Finally, the simulation results of Matlab verify the effectiveness and accuracy of the proposed method.