Modelling of voltage-commutated dc-to-dc converters in discontinuous operation mode

In discontinuous operation mode, voltage-commutated dc-converters show at least two additional subintervals during the repetition period, commutation-time and current-flow-duration. These pulse-widths depend on the momentary state of the circuit. In the effective system, the appertaining storages disappear, considered by a corresponding reduction of the state vector. Based on piecewise linear differential equations the sample- and mean-value behavior is exactly modelled. Sufficient smoothing provided, a continuous equivalent differential equation can be set up. Approximated by the first terms of its series expansion is leading to state space approximation models. Interpreted as continuous equivalent circuit, these models allow a simple approximated analysis.