3-Phase Motor Control

Other Hardware Motors, Mechanics, Power and CNC
1

I need to contol the speed of a 3-phase mains induction motor. I intend to use IGBTs, in pairs to drive each of the phases of the motor U,V and W.

The drive signals required are PWM, to simulate a sinusoidal amplitude that are phase related by 120 degrees. Whilst the rate of the PWM signals needs to be variable, in order to adjust the speed of the motor, the phase relationship of the drive signals is fixed. I've determined the coeiffcients necessary to yield a sinusoidal PWM drive, but I'm struggling to code it. Has anyone come across this before...It would be common practice for a Variable Frequency Drive for instance. The HW design is relatively straightforward, but my brain is struggling with reading out an array in the correct sequence....any suggestions welcome.

2

An IPM(*) includes the 3-phase bridge IGBTs and drivers, that's probably the way to go. Then you'll need a set of high-speed logic opto-isolators to drive it as its at mains potential.

Are you wanting simple V/f or more advanced FOC (field-oriented control)? The latter requires current sensing too.

Have you seen this thread?: 3 PWM for 3 phase inventer - Motors, Mechanics, Power and CNC - Arduino Forum

Or this one?: PWM for 3-phase Inverter - Motors, Mechanics, Power and CNC - Arduino Forum

(*) Something like: https://uk.farnell.com/infineon/im393m6e3xkla1/intelligent-pwr-mod-600v-10a-tiny/dp/3051968?st=intellgent%20power%20module