Voltage reversal protection for capacitor charging power supplies

In most pulsed power applications, the impedance of the load varies with time. Also a fault mode during the discharge is not unusual. Both cases could lead to a mismatch between the discharged capacitor or PFN and the load. A voltage reversal at the discharged capacitor could occur, due to this mismatch. Such a voltage reversal could drive a very high surge current through the charging power supply diodes. This paper compares two different approaches to limit this surge current for two applications: the series resistor; and the freewheeling diode approach