Nonlinear modelling of switching DC-DC converters with independent inputs

Abstract

Analytical modelling of switching DC-DC converters to account for their nonlinear responses due to both control signal and supply voltage inputs is presented. These independent inputs can be composed of perturbations with large amplitudes and phase shifts. The key is to extend the Volterra functional analysis to nonlinear systems with two independent inputs. By applying the extended Volterra functional series, the converter output response is expressed as a summation of nth-order nonlinear transfer functions, which can then be determined by explicit and recursive formulae. The modelling approach not only predicts various higher harmonic frequency components, but also provides information about the intermodulation frequency components.