Contents
What is indirect field oriented control?
Abstract: Indirect Field Oriented Control (IFOC) is known to produce high performance in induction Motor (IM) drives by decoupling rotor flux and torque producing current components of stator current. In order to perform the control strategy, the rotor flux and magnetizing current estimator is proposed.
What is the slip frequency of an induction motor?
It is common to express the slip as the ratio between the shaft rotation speed and the synchronous magnetic field speed. When the rotor is not turning the slip is 100 %….Number of poles, frequencies and synchronous induction motor speed.
| No. of Magnetic Poles | Frequency (Hz) | |
|---|---|---|
| 50 | 60 | |
| 2 | 3000 | 3600 |
| 4 | 1500 | 1800 |
| 6 | 1000 | 1200 |
What is field oriented control of induction motor?
The field oriented control (FOC) of induction motor provide one of the most suitable and popular speed control technique presently used. In the field oriented control, a d-q coordinates reference frame locked to the rotor flux vector is used to achieve decoupling between the motor flux and torque.
What is meant by field oriented control?
Field Oriented Control describes the way in which the control of torque and speed are directly based on the electromagnetic state of the motor, similar to a DC motor. FOC is the first technology to control the “real” motor control variables of torque and flux.
What is the slip frequency?
Slip frequency can be measured by determining the phase angle traversed in a defined period. For example, with a slip setting of 2 seconds (0.055 Hz) and slip frequency of 0.04 Hz, an angle of approx 29° (elec) is traversed before synchronising is permitted, as shown in Fig 12.15.
How do you calculate slip frequency?
The synchronous speed of the rotor in RPM N = 120f/P where f is the frequency of the stator current and P is the number of poles. The operating speed No = N – Ns where Ns is the slip speed. The frequency of the rotor current fr = Ns x P/120, so fr = 0 if the slip is zero.
What is scalar control of induction motor?
Scalar control is the term used to describe a simpler form of motor control, using non-vector controlled drive schemes. An ACI motor can be led to steady state by simple voltage fed, current controlled, or speed controlled schemes.
Why we use field-oriented control?
This allows electric motors to operate smoothly over the full speed range and generate full torque at zero speed. Another benefit of field-oriented control is that it can deliver fast acceleration and deceleration of the motor, giving more accurate control in high performance motors.
What is direct vector control?
The direct vector control is also known as feedback vector control scheme. Similar to Indirect Vector Control, various controllers have been implemented on direct vector controlled induction motor drives also to improve the performance of the drive.
What is the relation between slip and frequency?
5.3.2 Slip frequency measurement The relationship between timer setting (t), phase angle setting (θ) and slip frequency (fs) is t = (θ/180)/fs seconds. For example, with a phase setting of 20° (elec) and a slip frequency limit of 0.028 Hz (10° (elec)/s) this gives a timer setting of 4 s.