A zero-voltage-switching bidirectional battery charger/discharger for the NASA EOS satellite

The design of a pulse-width-modulated (PWM) zero-voltage-switching (ZVS) bidirectional converter is presented. The bidirectional converter employs a buck and boost topology using FET devices for both switches. ZVS is obtained by selecting the power stage inductance so that the switches always turn on when the MOSFET body diode is conducting. A four-module, multiphase topology is employed to significantly reduce the input and output ripple current. Besides obtaining high efficiency and light weight, the converter is also shown to possess excellent small-signal characteristics. It is applied to the design of the battery charger/discharger for the NASA EOS (Earth Observing System) satellite. Both theoretical and experimental results are presented.<
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