Modeling and Prediction of DC-Bus Harmonic Resonance for AC-to-AC Motor Drive Systems

This paper presents a modeling and analysis methodology to study the harmonic resonance on the dc-bus filter of ac-to-ac motor drives. Specifically, a system comprised of a synchronous generator, a multi-pulse diode rectifier, a dc-bus filter and a PWM motor drive is considered. The proposed method employs Thevenin and Norton equivalent circuits to model the generator-rectifier and motor drive on the dc-bus, thus resulting in a fully linear system when combined with the dc-bus filter components. Transfer functions of interest describing possible resonance conditions are then readily derived and used to assess and predict harmonic resonance on the system. Detailed simulations with Synopsys Saber are used to validate the proposed methodology, showing its effectiveness for the study of harmonic resonance on this type of application.