Modeling Of Switching DC-DC Converters Research Articles

Nonlinear modelling of switching DC-DC converters operating in discontinuous conduction mode

Analytical large-signal frequency-domain modelling of switching DC–DC converters, operating in the discontinuous conduction mode, is presented. The modelling approach is to derive analytical expressions of the converter output response using the extended Volterra functional series. Nonlinear frequency responses, including additional DC offset as well as significant subharmonic and higher harmonic components, due to large-signal perturbations of both the duty ratio and source voltage, are investigated. Their vulnerability to switching frequencies are also described. This modelling approach has been applied to various PWM DC–DC converters, including boost, buck and buck-boost types, operating in the discontinuous conduction mode, and the results are verified. Since the approach is so general, it can readily be extended to other switching power converters.

Nonlinear modelling of switching DC-DC converters with independent inputs

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 inter-modulation frequency components..

Modelling of switching DC-DC converters by time-averaging equivalent circuit approach Part 2. Discontinuous conduction mode

The sophisticated PWM switching DC-DC converters operating in discontinuous conduction mode (DCM) are investigated by use of a new time-averaging equivalent circuit (TAEC) approach (Xu 1993). The parameters of the TAEC model can easily be determined by the new approach without a priori knowledge of the DC solution for the converter. The DC steady-state and AC small-signal analysis can then be performed based upon its TAEC model with inductor current state included, while according to the state space averaging approach, the inductor current state has been lost in AC small-signal analysis.

Modelling of switching DC-DC converters by time-averaging equivalent circuit approach Part 1. Continuous conduction mode

Modelling of switching DC-DC converters by time-averaging equivalent circuit approach Part 1. Continuous conduction mode