Induction motor - calculating rotor flux angle

In summary, the conversation discusses the implementation of a Field Oriented Control algorithm for an induction motor. The hardware for the project is already completed, and now the focus is on implementing the FOC algorithm. To do this, the Clark&Park transformation is needed, which requires knowledge of the rotor angle flux position. The conversation includes links to resources that discuss how to calculate the Park transformation and suggests using speed integration to determine the rotor field angle. The final part of the conversation suggests empirically determining the function for the rotor field angle.
  • #1
fasset
Hello.
I'm trying to write my own soft for Field Oriented Control of induction motor. I have finished hardware - 3ph 3kW inverter, controlled by STM32F4, and V/F open loop algorithm to control ACIM - it works. Now I'm trying to implement FOC algorithm.
As we know we need to do Clark&Park transformation.
To calculate Park transformation it's necessary to know rotor angle flux position. Here some details:
ftp://ftp.ti.com/pub/dml/DMLrequest/Christy_FTP-10-30-12/controlSUITE/development_kits/HVMotorCtrl+PfcKit_v2.0/HVACI_Sensored/~Docs/Sensored%20FOC%20of%20ACI.pdf
http://ww1.microchip.com/downloads/en/AppNotes/ACIM Vector Control 00908a.pdf
Another note propose to use speed integration to do this:
http://tinyurl.com/y9lrb4cr
Could anyone expalin how to do this exactly?
I'm measuring currents (5kHz sampling), calculate Clark and also measure speed, slip.
Thanks for any response.
 
Engineering news on Phys.org
  • #2
Hi @fasset, my BSc degree project was a sensorless IM-DTC. Had you asked this question 15 years ago I could have given you a precise answer, but that was the last time I did anything like that and now my answer is pretty much just a guess.

I would start with a simple assumption that the rotor field angle is some function ##F(I_s, s)## taking values from 0 to 90deg, ##I_s## being the stator current and ##s## the slip. You may need an additional parameter for ##F## which is the frequency of the stator current. At slip 0 the angle must also be 0, and the motor should stall when the angle tries to go over 90 (max torque). So starting there you can try to empirically work out what ##F## is. Run the motor with a few fixed stator current values applying load to the shaft until it stalls. Make some plots of torque vs slip (do you have a torque transducer?). The torque is the cross product of the stator and rotor field vectors.

Of course you can just find the answer in the literature but the above is more fun :)
 

1. What is an induction motor?

An induction motor is a type of AC motor that works on the principle of electromagnetic induction. It is commonly used in industrial and commercial applications for its simplicity, reliability, and low maintenance.

2. How does an induction motor work?

An induction motor has a stator and a rotor. The stator is the stationary part and the rotor is the rotating part. When an AC current is passed through the stator windings, it creates a rotating magnetic field. This magnetic field induces currents in the rotor, which in turn creates a torque that makes the rotor rotate.

3. What is the significance of calculating the rotor flux angle in an induction motor?

The rotor flux angle is the angle between the stator and rotor magnetic fields. It is an important parameter in determining the performance of an induction motor, as it affects the torque, power, and efficiency of the motor.

4. How is the rotor flux angle calculated in an induction motor?

The rotor flux angle can be calculated using the slip equation, which relates the rotor speed to the stator frequency and number of poles. It can also be calculated using mathematical models and simulation software.

5. What factors affect the rotor flux angle in an induction motor?

The main factors that affect the rotor flux angle in an induction motor are the stator frequency, number of poles, and load conditions. Other factors such as temperature, rotor resistance, and stator voltage also play a role in determining the rotor flux angle.

Similar threads

Rotor and stator flux in 3 phase Induction motor
    • Electrical Engineering
Replies
14
Views
6K
Engineering How to calculate rotor flux of the three phase squirrel cage induction motor?
    • Engineering and Comp Sci Homework Help
Replies
4
Views
2K
Induction motor rotor and stator fluxes
    • Electrical Engineering
Replies
1
Views
3K
Clarke-Park transform for an induction motor current
    • Electrical Engineering
Replies
9
Views
3K
Induction motor flux variations
    • Electrical Engineering
2
Replies
43
Views
15K

Hot Threads

Recent Insights

Back
Top