3 Phase inverter

[sp_vibes]

Hi,

I am looking to build a 3 phase inverter to control an induction motor. What would be the best way to go about this? I am looking to control the inverter bridge through a microcontroller with a DC source variac to feed the inverter. I know there are a few ways of doing it, but which is the best route to go down?

 

[Diver300]

If you get something like:-
EUROTHERM DRIVES|650-011-230|INVERTER, 1 PHASE, 1.1KW | Farnell UK

That does the whole lot for you.

If you want to control the motor differently, buy one and just use the power electronics from it.

They have a bridge rectifier, and 6 transistors to make the variable 3 phase. Some have a regulator to change the DC voltage.

 

[sp_vibes]

If you get something like:-
EUROTHERM DRIVES|650-011-230|INVERTER, 1 PHASE, 1.1KW | Farnell UK

That does the whole lot for you.

If you want to control the motor differently, buy one and just use the power electronics from it.

They have a bridge rectifier, and 6 transistors to make the variable 3 phase. Some have a regulator to change the DC voltage.

This is a project and I must build at much as the drive as I can without buying things that do things for me. I am looking to either use PWM techniques or a six step voltage source to run the motor effectively. Any ideas?

 

[sp_vibes]

Any advice guys?

 

[jrz126]

How big is the motor you need to drive?

If it is small, you might be able to use one of these: https://www.electro-tech-online.com/custompdfs/2008/10/FS2FFSBB20CH60C.pdf I think this module is capable of 2kw at 220VAC
You may even be able to get some free samples. Fairchild Semiconductor - Site Search - Motion - SPM(TM)

 

[sp_vibes]

Very small motor, about 50watt at about 40VAC. This may work then, thanks.

 

[fsmyth]

3-Phase Stepper Motor Drivers

 

[sp_vibes]

Ok guys, I have a DC source variac to supply the inverter circuitry. However, this DC souce must be altered in accordance with the frequency to maintain the air flux gap, therefore I am going to build a DC-DC buck boost converter to control the DC voltage into the inverter. The inverter will then switch this DC voltage to generate a six step square wave across the 3 phase induction motor. Can anyone see any problems with doing this?