Power Electronics Lecture (5)

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Power ElectronicsLecture (5)

• Prof. Mohammed Zeki Khedher
• Department of Electrical Engineering
• University of Jordan

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Diode Circuits or Uncontrolled Rectifier

• Rectification The process of converting the
  alternating voltages and currents to direct
  currents

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Single-phase half-wave diode rectifier with
resistive load.
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the load and diode currents
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Performance Parameters
rectification effeciency
form factor
ripple factor
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Transformer Utilization Factor

• TUF Pdc/VsIs

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Crest Factor

• CF Is-peak/ Is

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Example 1 The rectifier shown in Figure has a
pure resistive load of R Determine (a) The
efficiency, (b) Form factor (c) Ripple factor (d)
Peak inverse voltage (PIV) of diode D1.
.

It is clear from the Figure that the PIV is
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• VA VsIs 0.707 Vm x 0.5 Vm /R
• TUF Pdc/VsIs (0.318)2 / (0.707 x 0.5)
• 0.286
• CF Is-peak/ Is 1/0.5 2
• PF Pac/VA 0.52 / (0.707X0.5) 0.707

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The main disadvantages of half wave rectifier
are

• High ripple factor,
• Low rectification efficiency,
• Low transformer utilization factor, and,
• DC saturation of transformer secondary winding.

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Half wave Rectifier with a Battery
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