Which control is mostly used for speed variation?
This method is called PWM control. The speed control method of our inverter units is divided into the two types: open-loop control that simply changes the speed and closed-loop control that reduces the speed variation with load changes of the motor.
How can varying supply frequency in control speed?
(1) and (2), it can be seen that the synchronous speed and hence the speed of the motor can be controlled by changing the supply frequency. Eqn. (3) shows that, if the supply frequency is changed, the stator EMF Es will also change to maintain the same flux in the air gap of the motor.
What are the converter used in the speed control of induction motor below the rated frequency?
Cyclo converter converts a fixed voltage and fixed frequency AC to a variable voltage and variable AC frequency. The variable frequency control allows good running and transient performance to be obtained from a cage induction motor.
Which of the method can be used for speed control of induction motor Mcq?
Cascade method of speed control involves the use of two coupled induction motors. The necessary condition for speed control is that. (a) both the motors are of the wound rotor type having the same number of poles.
Which of the following methods of speed control of induction motor is done from rotor side?
Following methods are employed from rotor circuit side for speed control: Cascade Operation of Induction Motor. emf Injection in Rotor Circuit. Rotor Circuit Resistance Control Method.
Which of the given speed control methods can be employed for controlling the speed of an induction motor drive fed from AC voltage controller?
Constant V/F control of induction motor This is the most popular method for controlling the speed of an induction motor. As in above method, if the supply frequency is reduced keeping the rated supply voltage, the air gap flux will tend to saturate.
How do you control the frequency of a motor?
Variable frequency drive is a technique used to control the speed and frequency of AC induction motors thus it is also known as adjustable speed drive or variable speed drive.in this phenomenon voltage and frequency of the motor is controlled using a technique named as PWM (Pulse Width Modulation).
On what factors does the speed of an induction motor depends?
From the above expression, the speed of an induction motor is depends upon the the supply frequency and the number of poles.
Which method is used for high speed control in induction motor Mcq?
Which methods are used for speed control of three-phase induction motor Mcq?
The speed controls of three-phase induction motor from rotor side are classified as: Adding external resistance on the rotor side. Cascade control method. Injecting slip frequency emf into rotor side.