Home » Blog » Wiki » 3 phase induction motor designs

3 phase induction motor designs

For 3 phase motor designs, there is hardly any slot combination that will yield a perfectly smooth torque-speed curve. Keeping the following rules in mind will (mostly) avoid the combinations that tend to amplify magnetic noise, harmonics, and parasitic torques.

Let the number of stator slots be S, and the number of rotor slots be R, and the number of poles be P. Undesirable combinations occur when any of the following are true:

1. S - R = 0
2. S - R = +1 OR -1
3. S - R = +2 OR -2
4. S - R = +P or -P
5. S - R = +(P + 1) or -(P +1)
6. S - R = +(P + 2) or -(P + 2)
7. S - R = -(P * 2)
8. S - R = -(P * 5)
9. S - R = +(P * 3) or -(P * 3) .. or multiples of +/-(3 * P).

We know the stator should have an even number of slots to make winding easier - although for certain pole counts, it too can be an odd integer value. And except for a few cases, the number of rotor slots can be either even OR odd.

Then it comes down to the accuracy of the compound die or indexing die for the slot stamping.

Post a Comment:

Calculate (6 - 1) =

You may also like:

In any electrical system, we limit the neutral grounding to 1 or 2 locations at the power source, eg, the star-points of generators or transformers. By keeping the grounded neutrals at the power source, earth ...
There are many factors that govern the performance of rotary tube furnaces. A direct fired rotary unit has a potential for much higher thermal efficiency due to the direct contact of the hot gases with the ...
Our one frequency inverter which drives 0.37 KW 400 V dosing pump motor intermittently (once in a month or once in two months) shows DC link fault and the speed is reduced to zero. Is it because of rewinding ...
Hazardous area classification has three basic components: Class (1,2) : Type of combustible material (Gas or Dust) Div (I, II) : Probability of combustible material being present Gas Group (A,B,C,D): most ...
PWM is shorted for Pulse Width Modulation, it's a variable frequency drive (VFD) regulate way to change the pulse width according to certain rules to adjust the output volume and waveform. PAM is shorted for ...
Gozuk Service Gozuk Blog: all about electric motor control & drives industries development in energy saving applications.


Like pumps, fans consume significant electrical energy while serving several applications. In many plants, the VFDs (variable ... energy consumedA frequency inverter controls AC motor speed. The frequency inverter converts the fixed supply frequency (60 Hz) to a ... Motor starter (also known as soft starter, motor soft starter) is a electronic device integrates soft start, soft stop, ... Soft starter allows the output voltage decreases gradually to achieve soft stop, in order to protect the equipment. Such as the ... Soft Starter reduces electric motor starting current to 2-4 times during motor start up, reduces the impact to power grid during ...

In Discussion