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I am learning various control techniques for 3-Phase ACIMs. So far I have understood about the SPWM implementation.. in which we save Sin values in a LUT and then modulate the duty-cycle of PWM wave using scaled values from the Sin LUT.

But regarding the SVPWM so I could not understand what are its implementation steps? Does it also require a Sin LUT or not?

And if I am implementing a scalar V/F control loop for the 3-Phase ACIM then is it possible to use SVPWM technique to drive the motor?

scico111
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The following article is a good high-level comparison of the two (also, the first google link): https://pdfs.semanticscholar.org/dded/e02312e0a7c2edabfb22c1d4adaf0be6b065.pdf

Here's my two-cents:

Neither really require a sine look-up table. The sine look-up table just speeds up computational time since computational time is key.

Both Sinusoidal Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM) can be used to control the motor in your question. They are two different methods of achieving the same goal: controlling the three phase inverter.

They each have pros and cons:

  • SVPWM gives you a better voltage conversion
  • SVPWM requires more computation power
  • SVPWM is based on a direct-quadrature-zero computation which is confusing!
  • SPWM is easier to implement in software
  • SPWM may have voltage inefficiencies
  • SPWM is based on sine and a triangle wave, easier to understand in your head!

Things to consider:

  • What kind of computational power do you have available?
  • Is this for a real-life test, or a simulation?
  • What kind of inverter topology do you have. Does it merit the advanced algorithm?

For what it is worth, Allen-Bradley's PowerFlex 525 uses SPWM. So, in conclusion, it really depends on your application, just like anything in engineering.