
Written by SOLO Team
15/10/2020
1. The Stator, which is the stationary part of the motor, and is in charge of generation of the magnetic field
2. The rotor, which is the rotating part without any physical contact to the stator


So despite other types of 3-phase motors with magnets like Brushless DC or Permanent magnet synchronous motors, there is no physical magnet used in the stator of ACIMs, and therefore the stator field intensity is adjustable by controlling the amount of current we inject into the stator (known as magnetizing current), and this phenomenon, gives an extra degree of freedom in control of AC induction motors with respect to permanent magnet counter parts in which the field intensity (flux) is constant and depends on the strength of the magnets used.
There are two main types of AC induction motors based on the formation of their rotor :
1. Squirrel cage type rotor
2. AC induction motors with wound type rotor
The first category of the AC motors however, are more popular among the industry as they are more cost effective and reliable.

AC induction motors are normally controlled with devices called “Variable Frequency Drives” known as VFDs, in which they apply the rotating field on the stator in a controlled manner so the rotor can follow and reach the desired mechanical speed.
There are lots of ways that an AC induction motor controllers can fix the speed of the rotor on desired speed, but the most advanced and reliable ones are normally coming from the Field Oriented Control or Vector Control enabled models. In Field Oriented Control (FOC) enabled versions, the Torque and the stator field ( flux ) are controlled separately, and this gives a huge advantage over normal VFDs as they offer much more reliable and robust control, specially in applications that the mechanical load on the shaft of the motor can vary time to time.
SOLO is using FOC for controlling AC induction motors with a methodology that can be seen below in the diagram. In simple words, SOLO tries to control the speed of ACIM motor using two different control parameters:
1. Controlling speed with regulation of Torque using quadrature current (Iq)
2. Regulation of magnetizing current to control the intensity of stator’s field (flux) using direct current (Id)

SOLO UNO wiring
SOLO MINI wiring
SOLO BETA wiring

To learn more, you can watch the following video which demonstrates the speed control of an AC induction motor both in fully analog mode using a pair of potentio-meters and later in digital mode, using SOLO Motion Terminal and a single USB cable!
Hey,
I ordered a Solo controller today. And would like to ask you kindly if it is possible to get the configuration software from this site “https://solomotorcontrollers.com/SOLO-motion-terminal/#” to it. I would need it for my project at uni.
Kind regards
Osman Kaya
Hi Osman,
sure, that software is called SOLO Motion Terminal which naturally works with SOLO without any specific installation on your local PC, you just need to connect the USB of SOLO to your PC and having a browser like chrome and you need to activate the Serial API in your browser too, to learn about that you can read it below:
https://www.solomotorcontrollers.com/forum/solo-motion-terminal/serial-api-not-supported/#post-290
You can also learn more about Motion Terminal by reading the following article:
https://www.solomotorcontrollers.com/setup-tune-motors-using-solo-motion-terminal/
We have also a video in which you can see how to use Motion Terminal in action:
https://youtu.be/LeQuX0OEh9w
for your technical questions, you are welcome to use our Forum.
Thanks
Milad