Design of robust digitally controlled DC–DC converters in the presence of strong interference. (28th April 2017)

• Record Type: Journal Article
• Authors: Hayes, Brendan; Condon, Marissa; Giaouris, Damian
• Is Part Of: International journal of circuit theory and applications. Volume 45:Number 11(2017:Nov.)
• Page Start: 1742
• Page End: 1759
• Publication Date: 2017-04-28
• Subjects: bifurcation -- chaos -- intermittent operation -- dc–dc converters -- controller design -- noise; Electric circuit analysis -- Periodicals; 621.319205
• DOI: 10.1002/cta.2351
• Languages: English
• ISSNs: 0098-9886

Abstract

Abstract: One of the main advantages of digital control is the ability to design more sophisticated control strategies to enable high‐performance dc–dc converters. One such example is a buck converter operating with a digital state‐feedback controller. Previous works characterise the nonlinear dynamics of such systems under ideal operating conditions. However, in practical applications, these conditions cannot be guaranteed. The focus of this work is on the behaviour of such systems when they operate in the presence of strong interference signals. Previous works on the effect of noise have shown that intermittent operation is possible when the frequency of the noise signal is close to the switching frequency. Intermittent operation can be characterised by long periods of stable operation interspersed with periods of unstable or chaotic operation, which greatly downgrade the efficiency and performance of the converter and reduce its lifetime as for example increase the current ripple or add extra AC components at its output. Typically, such behaviour is avoided by modifying the circuit parameters. However, little or no work exists on developing design guidelines in order to effect its elimination. This is the focus of this research, that is, by utilising Filippov's theory on discontinuous differential equations, to set out a design procedure that can be applied to any dc–dc converter, to tune its controller in order to eliminate intermittent operation. As a case study, the digitally controlled buck converter with a state‐feedback control law is selected. Copyright © 2017 John Wiley & Sons, Ltd. Abstract : Intermittent operation can greatly downgrade the efficiency and performance of a dc–dc converter and reduce its lifetime. This work aims to develop a design procedure that can be applied to any controller to eliminate intermittent operation. The procedure utilises Filippo's method.