Discrete-Time Model for PWM Converters in Discontinuous Conduction Mode

A new discrete-time model for pulse-width modulated (PWM) converters operating in the discontinuous conduction mode (DCM) which leads to the exact discrete-time mathematical representation of the averaged values of the output signal is proposed. This model can also provide the averaged values of other internal signals with little increase in simulation time. The use of piecewise linear (PL) iteration method dramatically reduces the simulation time, while introducing a little simulation approximation. It is compared to other existing models with respect to accuracy and simulation speed through a numerical example of boost converter. This method gives the exact one-cycle-average (OCA) values of signals at switching instants if PL iteration is not used and, by far, more accurate than other methods if PL iteration is not used. Numerical simulations demonstrate the superiority of the proposed method in terms of accuracy and speed.