Controlled Rectifiers

Thyristor

Thyristors have three states:• Reverse blocking mode• Forward blocking mode• Forward conducting mode

Characteristics of Thyristors

+v-

i

Analysis of the Rectifier

Valves are numbered in order of firing.

LC=0

Valve Switching Sequence with no Ignition Delay

Analysis of the Rectifier with no Ignition Delay

Average DC Voltage

Analysis of the Rectifier with Ignition Delay

Current and Phase Relations

Variation of phase displacement between voltage and current of phase a with delay angle

Current and Phase Relations

Variation of phase displacement between voltage and current of phase a with delay angle

Average DC Voltage

Current and Phase Relations

Variation of phase displacement between voltage and current of phase a with delay angle