What are the disadvantages of stator voltage control method?
Disadvantages of this method is that the smooth speed control is not possible . This method is more costly and less efficient as two different stator winding are required. This method of speed control can only be applied for squirrel cage motor.
What is stator voltage control application?
This stator voltage control method is suitable for applications where the load torque decreases with the speed. For example- In the fan load. This method gives a speed control only below the normal rated speed as the operation of the voltages if higher than the rated voltage is not admissible.
What are methods of speed control of induction motor?
Speed Control Methods of Induction Motor:
- Control From Stator Side:
- Control From Rotor Side:
- Speed Control by frequency variation:
- Speed Control By Pole Changing:
- Speed control by varying Supply voltage:
- Speed control by varying Rotor Resistance:
- Speed control by injected EMF:
- Speed control by Cascade Connection:
What is the stator voltage control?
Stator Voltage Control is a method used to control the speed of an Induction Motor. The voltage is varied until the torque required by the load is developed, at the desired speed. The torque developed is proportional to the square of the supply voltage and the current is proportional to the voltage.
What is speed control of induction motor?
By Injecting EMF In Rotor Circuit Speed control of induction motor is done in this method by injecting a particular voltage in the rotor diagram. The injected voltage (emf) needs to have an equal frequency with the slip frequency. However, there is no limitation for the phase of that emf.
How is the speed of an induction motor controlled?
Thus the speed of the induction motor can be controlled by two methods • From stator side • From rotor side Stator side includes the following methods: • Supply frequency control , called V/f control • Supply voltage control • Controlling number of stator poles • Adding rheostats in stator circuit 6.
How are slip rings used in induction motors?
Wound rotor induction motors with slip rings connected to variable external resistance in the rotor circuit were used to bring about a considerable change in the speed of induction motor. They had many disadvantages such as cost ineffective, resistor losses, large slip rings.
What are the applications of three phase induction?
3. Applications: · heating, · ventilation, · air conditioning systems, · waste water treatment plants, · blowers, · fans, · textile mills, · rolling mills, etc 4. The variable frequency and variable voltage can be obtained by, Voltage source inverter (VSI) Cycloconverter control 5. . 9.
What kind of rotor does an induction motor use?
An induction motor therefore does not require mechanical commutation, separate-excitation or self-excitation for all or part of the energy transferred from stator to rotor, as in universal, DC and large synchronous motors. An induction motor’s rotor can be either wound type or squirrel-cage type.
