Research on the Standing Wave Phase Shifting Based Background Harmonic Voltages Attenuation

For the conventional resistive active power filter based on impedance matching idea in transmission line theory, which aims to damp out background harmonic propagation on the distribution feeders. The so-called damping refers to the suppression of the existing harmonic propagation, but there is no ability to attenuate the source harmonic voltages along the feeder under all cases theoretically. This article focuses on how to attenuate the source harmonic voltages along the feeder to achieve better performance. Not being based on the impedance matching idea, the proposed standing wave phase shifting active power filter moves the phase of the harmonic voltage standing wave so that the antinode of standing wave closes to or exactly located at the beginning of the feeder to achieve harmonic attenuation. According to the relationship between the wavelength of the harmonics and the feeder length, the application range and the control parameters of standing wave shifting to the left and to the right strategy are discussed, respectively. Finally, the correctness of the theoretical analysis and the effectiveness of the proposed scheme is verified by the simulations and experiments.