Modeling the frequency-domain behavior of magnetic-amplifiercontrolled high-frequency switched-mode power supplies

A small-signal equivalent circuit which models the frequency-domain behavior of magneticamplifier- controlled switched-mode converters operating in the continuous-mmf mode is presented. The equivalent circuit, which is based upon stateaveraging techniques, can be used with a circuitanalysis program such as SPICE to evaluate the frequency-domain behavior of a magneticamplifier- controlled converter prior to circuit implementation. Two high-frequency switched-mode converters which employ magnetic amplifiers as output-voltage regulators are discussed. To show the validity of the derived equivalent circuit, measurement results of the small-signal frequencydomain behavior of the two switched-mode converters are compared with results produced by simulations employing the equivalent circuit.