As the load torque increases beyond breakdown torque the motor stalls. Motor controller There are three basic types of competing small induction motors: A single phase induction motor requires separate starting circuitry to provide a rotating field to the motor. The normal running windings within such a single-phase motor can cause the rotor to turn in either direction, so the starting circuit determines the operating direction.
Schrage Motor Operation Principle and Characteristics of Schrage Motor Irun is the current flowing through the main or running winding, Istart is the current flowing in starting winding, and VT is the supply voltage.
We know that for highly resistive winding the current is almost in phase with the voltage and for highly inductive winding the current lag behind the voltage by large angle. The starting winding is highly resistive so, the current flowing in the starting winding lags behind the applied voltage by very small angle and the running winding is highly inductive in nature so, the current flowing in running winding lags behind applied voltage by large angle.
The resultant of these two current is IT. The resultant of these two current produce rotating magnetic field which rotates in one direction. In split phase induction motor the starting and main current get splitted from each other by some angle so this motor got its name as split phase induction motor.
Applications of Split Phase Induction Motor Split phase induction motors have low starting current and moderate starting torque. So these motors are used in fans, blowers, centrifugal pumps, washing machine, grinder, lathes, air conditioning fans, etc.
Capacitor Start IM and Capacitor Start Capacitor Run IM The working principle and construction of Capacitor start inductor motors and capacitor start capacitor run induction motors are almost the same. We already know that single phase induction motor is not self starting because the magnetic field produced is not rotating type.
In order to produce rotating magnetic field there must be some phase difference. In case of split phase induction motor we use resistance for creating phase difference but here we use capacitor for this purpose.
We are familiar with this fact that the current flowing through the capacitor leads the voltage. So, in capacitor start inductor motor and capacitor start capacitor run induction motor we are using two winding, the main winding and the starting winding.
With starting winding we connect a capacitor so the current flowing in the capacitor i. Now there occur large phase angle differences between these two currents which produce an resultant current, I and this will produce a rotating magnetic field. Since the torque produced by these motors depends upon the phase angle difference, which is almost 90o.
So, these motors produce very high starting torque. They are available up to 6 KW. Stator has two windings — main and auxiliary winding. It has only one capacitor in series with starting winding.
It has no starting switch. Advantages and Applications No centrifugal switch is needed. It has higher efficiency and pull out torque.
It finds applications in fans and blowers in heaters and air conditioners. It is also used to drive office machinery. Shaded Pole Single Phase Induction Motors The stator of the shaded pole single phase induction motor has salient or projected poles.
These poles are shaded by copper band or ring which is inductive in nature. The poles are divided into two unequal halves. The smaller portion carries the copper band and is called as shaded portion of the pole. When a single phase supply is given to the stator of shaded pole induction motor an alternating flux is produced.Single phase or 3 phase shaded pole motors The range of AC motors uses synchronous permanent magnet technologies and asynchronous single- or three-phase technologies.
Synchronous motors allow rotating at a constant speed regardless of variations in load and voltage. The number of magnetic poles (or simply poles) is the principal design factor affecting speed in AC motors.
a. 3-Phase Induction Motors. The rotor of an induction motor does not rotate at synchronous speed or the speed of the magnetic field of the stator, but lags slightly.
A shaded-pole motor is an electric motor classified as an asynchronous motor.
Like these, it also has an induction (squirrel-cage) motor, in which through a rotating field produced by the stator a torque is created.. However, unlike the asynchronous motors fed with three-phase current, the shaded-pole motor runs on single-phase alternating current.
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.
The stator of the shaded pole single phase induction motor has salient or projected poles. These poles are shaded by copper band or ring which is inductive in nature.
These poles are shaded by copper band or ring which is inductive in nature/5(15). Shaded pole motor is one of the types of single phase induction motors, which are used for producing a rotating stator flux in order to make the single phase induction motor a self starting one.
Let us discuss the constructional details, diagrams and working of shaded pole motors in detail.