Effect of voltage crest shape on the harmonic amplification and attenuation of diode-bridge converter-based loads

The single-phase diode-bridge converter-based loads have rapidly proliferated in residential areas. In most harmonic studies, the associated harmonic effect usually does not include the harmonic voltage interaction with the harmonic currents of non-linear loads. This interaction can attenuate or amplify the harmonic current injections of such appliances. This study characterises this effect by showing how prevalent harmonic amplification exists under typical voltage conditions experienced in residential areas, and by understanding how the existence of harmonic attenuation or amplification effect is strongly related to the crest shape of the supply voltage. The analytical model of the single-phase diode-bridge converter-based loads is used to explain why and when harmonic attenuation or amplification happens. The implication is that the impacts of the voltage on the currents at each harmonic order are very different. Failing to include this effect can underestimate or overestimate each order of the harmonic currents.