SoftSwitching DCDC Converter

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Soft-Switching DC-DC Converter
Is to shape the voltage or the current waveform
by creating a resonant condition to Force the
voltage across the switching device to drop to
zero before turning it ON ? Zero-Voltage
Switching (ZVS) Force the current through the
switching device to drop to zero before turning
it OFF ? Zero-Current Switching (ZCS)
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Overview

• Many soft-switching dc-dc converter families were
  introduced in the open literature
• The objectives of these topologies are to develop
  high switching frequency converters with high
  power density and high efficiency
• This was accomplished by adding additional
  components to the power stage.
• Steady-state analysis tend to be time consuming.
• Provided little insight into the converter
  switching-cell operation.

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Hard-Switching and Soft-Switching
Hard-Switching
Zero-Voltage Switching
Zero-Current Switching
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Why Soft-Switching?

• Reduce switching losses especially at high
  switching frequencies
• Increase the power density, since the size and
  weight of the magnetic components is decreased by
  increasing the operating frequency
• Reduce the Electromagnetic Interference (EMI)

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Conventional DC-DC Converters(Hard-Switching)
Boost
Buck
Buck-Boost
Cuk
Zeta
Sepic
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Switching-Cell Sharing

• All the Conventional DC-DC Converters shares the
  same switching-cell
• With different orientation of the cell in a
  specific converter

The Conventional DC-DC Switching-Cell
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Analyzed Soft-Switching Cells
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Zero-Voltage-Switching Quasi-Resonant
ZVS-QRC Switching-Cell
ZVS-QRC Cell Basic Switching-Waveforms
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ZVS-QRC Family
ZVS-QRC Boost
ZVS-QRC Buck
ZVS-QRC Buck-Boost
ZVS-QRC Cuk
ZVS-QRC Zeta
ZVS-QRC Sepic
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Zero-Current-Switching Quasi-Resonant
ZCS-QRC Switching-Cell
ZCS-QRC Cell Basic Switching-Waveforms
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ZCS-QRC Family
ZCS-QRC Buck
ZCS-QRC Boost
ZCS-QRC Buck-Boost
ZCS-QRC Cuk
ZCS-QRC Zeta
ZCS-QRC Sepic
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ero-Current-Transition PWM Cell
ZCT-PWM Switching-Cell
ZCT-PWM Cell Basic Switching-Waveforms