EEL 4242 POWER ELECTRONICS

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EEL 4242 POWER ELECTRONICS

• THYRISTORS

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Thyristor Symbol
Figure 7.1
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Cross Sections of Thyristors
Figure 7.2
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Characteristics of Thyristors
Figure 7.3
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Two Transistor Model of Thyristors
Figure 7.4
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Current Gain with Emitter Current
Figure 7.5
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Two Transistor Model
Figure 7.6
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Gate Turn-On of Thyristors
Figure 7.7
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Gate Turn-On Characteristics
Figure 7.8
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Line Commutated Thyristor Circuit
Figure 7.9
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Line Commutated Thyristor Circuit
Figure 7.9
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GTOs
Figure 7.15
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GTO Turn-on and Turn-off Pulses
Figure 7.16
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di/dt Protection
Figure 7.32
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dv/dt Equivalent
Figure 7.33
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SPICE Model
Figure 7.34
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Summary

• A thyristor is a latching device and it can be
  turned on with a small gate pulse, typically 100
  µs .

• Thyristors are generally off by line commutation
  due to the natural behavior of the input line
  supply.

• During the turn-off process, thyristors must be
  subjected to a reverse voltage for a certain
  minimum time known the turn-off.

• What was the major idea?

• What was the muddiest idea?