can traic replace igbt

hi friends
me want to design a ac motor drive.inwhich i want to use traics instead of igbt cause of project cost limitations. will the traic be able to drive the motor with following specifications:

* 3 phase ac induction motor
* 440volts -50 hz
* 960 rpm
*10A

and if yes which traic to use and how?
thank you.

Theoretically I would think you can run with the triac's but there will be disadvantages as far as torque and control at low speed.

To run with IGBT's you first need to rectify the AC and run from a DC bus with 6 devices.

I you replace the TRIAC's with Thyristors, REmove the DC-link capacitor and replace with a DC-Link choke of suitable inductance (w.r.t. torque ripple) and replace the 3ph rectifier with a tyristor-controooled bridge (to controlled the DC-Link voltage and thus the DC-Link current) you can create a current-source drive

A current source drive has alot of advantages over a voltage-source drive

Many years ago when I was still very involved with research/design of drives for mining applications and traction control, we found it not to be cost effective to design current source drives under 37kW. Up to 37kW all our designs were voltage fed. The bulk (banks of huge commutating caps - to turn off the thyristors), and size of the drive as well as the size and weight of the choke (we had a small crane to lift the 100kW's choke into position) made it unacceptable in some applications. Over 37 - 100kW (this was the biggest drive we produced running on 575V, 3-phase) it was all current source because of the controlled rectifier's ability to pump energy back into the mains under regen conditions. We even managed to apply vector control on these big thyristor drives to deal with high inertia loads. Back then IGBT's just became available and were low power and very slow. That were the good old days...with puck's, LOCMOS chips, no or very few uP controlled drives. The industry standard for PWM control was the Philips HEF4752V chip https://www.alldatasheet.com/datasheet-pdf/view/PHILIPS/HEF4752V.html. Our first current source control card was designed entirely out of discrete logic chips, opamps, pots (oh yes lots, there were a lot of things to tweak then) The control card size was about 2' x 1' packed solid with components up to the pulse transformers for the thyristors. Looked very impressive. The whole pcb was laid out with "bishop graphics" tape, on a plastic sheet using a light box. No instant undo function!
Today IGBT based drives can handle a lot more power.

EDIT: found a picture of the control card out of an old brochure. The 12 pairs of leads can be seen at the top (6 per side coming from the orange pulse transformers). One side for the controlled rectifier and the other side for the motor stack.
I believe the company produce up to 500kW current source drives these days. Scary stuff :shock:
EDIT2: After speaking to the owner, they are up to 800kW now :shock: :shock:

TheOne, you reminded me of the early 80's when I worked for a consulting Engineer that specialized in inverters and industrial controls using very similar set-ups. We built or maintained several power supplies for galvanizing plants using IR's puk SCRs in massive copper clamping frames. Everything was basic logic gates, comparators and op-amps, no special IC's at all. We used to cringe when a new or repaired unit was put into service. When things went wrong is was generally a spectacular ( expensive ) display. I remember one unit, made by some other company, that had a potted timing module that would randomly lock-up, resulting in cross firing, or shoot through, and the inevitable destruction of several hundreds of dollars of SCR's.

Sorry about the off-topic...

Man that was power electronics! I can remember how shocked-impressed I was seeing for the first time how cable as thick as my thumb rise into the air of the floor like a snake, during short circuit tests on massive soft-starters with a few thousand amp rating!