Comparison of high voltage dc power supply topologies for pulsed load applications

High voltage power supplies for radar applications are investigated, which are subjected to pulsed load (125 kHz and 10% duty cycle) with stringent specifications (<0.01% regulation, efficiency>85%, droop<0.5 V/micro-sec.). As the converter needs to be switched at much higher frequency than the pulse load frequency, transformer poses serious problems of insulation failure and higher losses. Two power converter topologies are presented, one with input voltage modulation (IVM) and the other with output voltage modulation (OVM). In each of the topologies, power conversion is done in two stages to take care of the critical aspects of the HV transformer and to satisfy all the performance specifications. Both the topologies are critically evaluated for their performance and their relative merits and demerits are discussed.