Isolated step up/down three-phase AC to DC power supply

A new circuit for providing an isolated DC supply from a three-phase AC source is described. The circuit uses a very simple control scheme to ensure that the current drawn from the AC source is sinusoidal. Unlike previous circuits, the isolation is provided by integration of a second stage converter into the circuit such that pulses of energy are transferred from the input stage to a unique parallel resonant circuit which automatically transfers the energy to the load without any intermediate energy storage. The operation of the circuit is described and some experimental results are given