Abstract:
This seminar report entitled ”Interleaved Active Clamped Dc-Dc Converter with
Fuel Cell for High Voltage Applications” presents analysis and design of interleaved
zero voltage switching (ZVS) active-clamped current-fed full-bridge isolated dc/dc
converter for fuel cell applications. The designed converter maintains ZVS of all
switches from full load down to very light load condition over wide input voltage
variation. Detailed operation, analysis, design and simulation results for the pro-
posed design are presented. As the fuel cell output is very low we are in need of a
step up dc-dc converter. Here a current fed dc-dc converter is used. Two current fed
dc-dc converters are interleaved by connecting their inputs in parallel and outputs in
series. With this proposed methodology input current ripples in the fuel cell stacks
can be reduced and a regulated output voltage ripples can be obtained. The addi-
tional auxiliary active clamping circuit absorbs the turn-off voltage spike limiting the
peak voltage across the devices allowing the selection and use of low-voltage devices
with low on-state resistance. In addition, it also assists in achieving ZVS of semicon-
ductor devices. The converter utilizes the energy stored in the transformer leakage
inductance aided by its magnetizing inductance to maintain ZVS. ZVS range depends
upon the design, in particular the ratio of leakage and magnetizing inductances of
the transformer. Voltage doubler circuits will give double the output voltage than
normal with smaller transformer turns ratio and flexibility.
