Why is a minimum firing angle (>0, usually 5-15°) defined for three-phase thyristor rectifier?

I would like a technical explanation.



1 Answer 1


The minimum firing angle for a three-phase thyristor is 30 degree. Below thirty degrees the thyristor is already reverse biased by the third thyristor that is already conducting. Let's understand the waveform: Minimum firing angle of three-phase thyristor

If the minimum firing angle is less than 30, the circuit operates in continuous conduction mode instead.

  • 1
    \$\begingroup\$ Hi, To comply with the rule about referencing material from elsewhere, can you please edit the answer & add a link to that image (or reference the book title & author, if it came from a book)? Thanks. (I'll delete this comment after the reference is added, to avoid clutter.) \$\endgroup\$
    – SamGibson
    Commented Jun 8, 2018 at 1:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.