Exact computation of the transient and steady-state of Cuk converter with the modified nodal method

Simulation of the Cuk converter, operated in a continuous- or discontinuous-conduction mode, is realized by using a complex frequency-domain method. The key is the use of a time-variable circuit element, called an alternator. The alternator contains all switching elements of the power stage; it is defined by a system of modified nodal equations, in which two time-variable parameters are present to make allowance for the cyclical operation of the circuit. The s-domain equations of the converter are obtained by including the alternator constitutive equations. In this way, a global dynamic model was obtained. The equations are solved in the s-domain; the inverse Laplace transforms of the solutions are taken and particularized for each cycle configuration. The response computed in such a way is both analytic and accurate, even for large-signal perturbations