THYRISTOR connected in antiparallel for 3 phase induction Motor

[Vimlesh Motawala]

Hey Guys,,Can u Please tell

If i wan to use THYRISTOR connected in antiparallel for 3 phase induction Motor .Will it work? IF proper heat dissipation factor is also considered?

 

[crutschow]

By thyristor I assume you mean an SCR.

If you can generate the proper isolated gate drive signals for each SCR then they should work in antiparallel.

 

[Vimlesh Motawala]

Thanks Carl ,



But if thats the case than why cant we have the SCR in place of Contactor fed motor for switching purpose.?? and also for Air circuit Breaker.

Is there any thing related with Breaking and making current capacity so that temperature at Junction would lead to thermal runaway and damage to thyristor?

 

[Vimlesh Motawala]

Thanks Carl ,



But if thats the case than why cant we have the SCR in place of Contactor fed motor for switching purpose.?? and also for Air circuit Breaker.

Is there any thing related with Breaking and making current capacity so that temperature at Junction would lead to thermal runaway and damage to thyristor?

 

[crutschow]

You can use and SCR in place of a contactor if you desire. You can also use a TRIAC which is basically two SCRs in anti-parallel.

As long as the SCRs has a current rating greater than the motor requires (including starting surge current) and the heat sink is sufficient to dissipate the power, then the junction temperature will stay at a safe level.