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A transformer transfers electrical power from one circuit to another without changing the supply frequency, i.e. it only step-up or step-down the level of voltage and current, whereas induction motor converts electrical power into mechanical power.
Why an induction motor is considered similar to a transformer?
The Induction motor is similar as a Transformer with a rotating short-circuited secondary. The stator winding in induction motor corresponds to the primary winding in the transformer and the rotor winding in induction motor corresponds to the secondary winding in the transformer.
Can we use induction motor as a transformer?
An induction motor is a well-known device which works on the principle of transformer. That is, when an EMF is supplied to its stator, then as a result of electromagnetic induction, a voltage is induced in its rotor. So an induction motor is said to be a transformer with rotating secondary.
What are the types of motors?
Types of Electric Motors
- AC Brushless Motors. AC brushless motors are some of the most popular in motion control.
- DC Brushed Motors. In a DC brushed motor, brush orientation on the stator determines current flow.
- DC Brushless Motors.
- Direct Drive.
- Linear Motors.
- Servo Motors.
- Stepper Motors.
Why the synchronous motor is not self-starting?
Above a certain size, synchronous motors are not self-starting motors. This property is due to the inertia of the rotor; it cannot instantly follow the rotation of the magnetic field of the stator. Once the rotor nears the synchronous speed, the field winding is excited, and the motor pulls into synchronization.
Why is it called induction motor?
The asynchronous motor is based on the currents induced in the rotor from the rotating magnetic field of the stator. That’s why it’s called an induction machine. For this reason the motor rotates at a different speed than the stator field and therefore rotates asynchronously.
What is the fundamental motor equation?
In the case of a generator, the emf of rotation is called the Generated emf or Armature emf and is denoted as Er = Eg. In the case of a motor, the emf of rotation is known as Back emf or Counter emf and represented as Er = Eb.
Why is DC motor current so high?
Answer: The starting current is high as there is no back EMF or counter EMF present in the armature circuit because atstarting counter EMF is zero. It’s armature has very less resistance due to this it need more current at starting time. Hence DC starters are used to limit the starting current ofmotor.
Is a transformer a motor?
A motor is an extended version of a transformer. Here we can introduce the analogy between a transformer and a motor that is a motor is like a transformer with a moving secondary. The primary that is not moving is called stator and the secondary that is moving is called rotor.
What is the function of induction motor?
An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor can therefore be made without electrical connections to the rotor.
Why motor takes more current?
Electrical overload or over-current is caused by an excessive current flow within the motor windings, exceeding the design current which the motor is able to carry efficiently and safely. This can be caused by a low supply voltage, resulting in the motor drawing in more current in an attempt to maintain its torque.
What is no load test of induction motor?
The no-load test of an induction motor is similar to the open-circuit test of a transformer. The motor is not connected from its load, and the rated voltage at the rated frequency is applied to the stator to run the motor without a load. The 2-wattmeter method measures the input power of the system.
What are step up and step down transformers?
A transformer designed to increase the voltage from primary to secondary is called a step-up transformer. A transformer designed to reduce the voltage from primary to secondary is called a step-down transformer.
How does a transformer motor work?
The core of the transformer works to direct the path of the magnetic field between the primary and secondary coils to prevent wasted energy. Once the magnetic field reaches the secondary coil, it forces the electrons within it to move, creating an electric current via electromotive force (EMF).
What happens when induction motor is loaded?
If the load on the induction motor is increased the current will increase to deliver the demanded power. The slip of the motor will increase with an increase of loading on the motor, and the speed of the motor will decrease accordingly.
What are the types of induction motor?
Types of Induction Motors
- Split Phase Induction Motor.
- Capacitor Start Induction Motor.
- Capacitor Start and Capacitor Run Induction Motor.
- Shaded Pole Induction Motor.
How does an induction motor start?
A three-phase Induction Motor is Self Starting. When the supply is connected to the stator of a three-phase induction motor, a rotating magnetic field is produced, and the rotor begins rotating and the induction motor starts.
Why the exciting current of induction motor is so high as compared to the power transformer?
(i) The induction motor has an air gap, but the transformer has a core. Therefore, the magnetizing current in an induction motor is much larger than that of the transformer. Therefore, the leakage reactances of stator and rotor windings quite large compared to that of a transformer.
What is induction motor principle?
The motor which works on the principle of electromagnetic induction is known as the induction motor. Electromagnetic induction is the phenomenon in which the electromotive force induces across the electrical conductor when it is placed in a rotating magnetic field.
Why starting current is high in motor?
Why High Starting Currents: Resistance and leakage reactance circuit consist of resistance and leakage reactance of stator and rotor of induction motor connected in series. A load resistance (variable) is connected in series to the fixed rotor and stator impedance. During starting of the motor, slip will be one.
