Improved modified active clamp circuit for a current fed DC/DC power converter

In this paper the performance of an improved modified active clamp circuit (MACC) for an isolated full bridge current-fed DC/DC converter (FBCFC) is presented. The new active clamp circuit reduces power losses in the switching devices by shaping the bridge currents, leading to a more efficient converter. The operation of the new circuit is described in detail. For comparison with a conventional active clamp, the modified active clamp circuit has been simulated and implemented in a prototype 1.2 kW FBCFC. The simulations and test results show a marked improvement in the efficiency of the FBCFC converter with the new active clamp circuit.