Hi,

I am trying to simulate a single phase semi converter in multisim.
I can't work out what to use as the trigger for the thyristors.

What do i use as the trigger and also how do you set the firing angle for a thyristor to eg 30° 60°?
If it is simpler to do it in Pspice i could use that.

Thanks,
Nick

 

Hi!

U have to send a pulse signal with a certain pulse width duration in order to activate the thyristor. U can set ur firing angle by delaying the pulse signal so as to match the required angle corresponding to ur source voltage. I guess ur using an ac source n i suppose u know its frequency, u can find its time period, T.

2pi = T , in case α = 30° = pi/6

Delay time of pulse signal, DT = T/12

There you go firing angle set!

Actually im doing the same simulations right now, but im just getting started with pspice n its driving me crazy. Lazy me waited for the end of the semester to complete my simulations and the dead line expired 1 minute ago! I should figure out my way thru pspice during the weekend and discretely slide my report into the lab 1st hour Monday before the professor comes to collect them

For the pulse signal use "VPULSE".