Contents
What is direct torque control of induction motor?
Direct torque control (DTC) is an emerging technique for controlling PWM inverter-fed induction motor (IM) drives. It allows the precise and quick control of the IM flux and torque without calling for complex control algorithms. In principle, moreover, it requires only the knowledge of the stator resistance.
How do you control speed and torque of an induction motor?
The speed control of three phase induction motor from stator side are further classified as :
- V / f control or frequency control.
- Changing the number of stator poles.
- Controlling supply voltage.
- Adding rheostat in the stator circuit.
What is the difference between DTC and scalar mode?
Scalar control (also referred to as V/Hz or V/f control) varies both the voltage and frequency of power supplied to the motor to maintain a fixed ratio between the two. But DTC controls motor torque directly, without a modulator, so torque response is much faster.
How do you control torque in a VFD?
Torque control mode allows for the VFD to directly control motor torque instead of motor speed. This is necessary for any application where torque takes priority over speed. Winder, rewinders, capping, and web applications are some good examples of when torque control is utilized.
Why is speed control of induction motor necessary?
Induction motors do not run at synchronous speed, they are generally fixed speed motors. In Industries mechanical loads should not only be driven but should also be driven at desired speed. Therefore, the need of speed control methods for induction motor arises.
What is torque mode in VFD?
What is torque boost in VFD?
VFD generally operates in the constant torque mode by supplying constant volt/Hz to stator of the induction motor. The PWM inverter of the VFD increases the voltage and frequency in the same ratio, and thus the torque delivered by the motor remains constant. This feature of VFD is known as Torque Boosting Feature.
How is direct torque control of induction motor simulated?
In this experiment, a sensorless speed control of an induction motor using direct torque control (DTC) will be simulated. The dq motor model developed in the previous experiment will be used for this as well. The estimator model and the switching algorithm will be modified to implement DTC.
What are the drawbacks of direct torque control?
The major drawbacks of conventional direct torque control are high torque, flux ripples and poor dynamic response at low speed. In this paper the CDTC is improved by fuzzy logic switching controller and fuzzy logic duty cycle controller.
When was Direct Torque Control ( DTC ) introduced?
In the middle of 1980s, Direct Torque Control (DTC) was introduced to compete with conventional controls. This technique was introduced by TAKAHASHI [ 24] and DEPENBROCK [ 25 ]. It has remarkable dynamic performance as well as good robustness with respect to the variations of the parameters of the machine.
How is FDCC used to improve torque control?
By using FDTC with FDCC torque and flux ripples under steady state are reduced by 90% which is very high compared to previous works. The dynamic response of the drive is improved and smooth stator flux trajectory path is achieved compared to previous works. The proposed scheme is validated using simulation results using Matlab/Simulink Environment.
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