An improved power diode model for PSPICE, applied to converter simulation

The authors present an improved and simplified model to simulate the soft recovery of the power diode in simulations using PSPICE. The new model is demonstrated by a two-MOSFET forward DC-DC converter. The soft recovery of the power diode is simulated by means of an external circuit injecting an exponential current with a time constant L/R, to palliate the missing soft recovery current of the PSPICE diode model. This circuit has been substantially improved, compared with previously published works, by replacing the controlling elements (ideal diodes and FETS) by a single controlled resistor, also used in the L/R operation. Computing times are significantly reduced, and the convergence problems occurring with the growing complexity of the topologies are brought down to a further limit. The authors confront simulations and measurements on a basic chopper with an inductive load, and on the aforementioned forward converter