# how does a three- phase squirrel cage induction motor work

How Does a Three-Phase Squirrel Cage Induction Motor Work?

Induction motors work by transforming electrical energy into mechanical energy. Generally, three-phase motors work with three-phase AC supply. However, they have some common differences: single-phase and poly-phase motors require an initial “shove” to start and two-phase motors use a three-phase AC supply. Single-phase motors cannot simulate the rotating field, which is what separates them from squirrel cage motors.

## Electromagnetism

Squirrel cage induction motors use the principle of electromagnetism to produce rotation. The rotor of these motors is made from highly conductive metal, usually aluminum or copper. The alternating current that passes through the rotor produces a rotating magnetic field. This magnetic field is in close relationship with the current that flows through the stator. The resulting torque is the result of the interaction of the magnetic field between the rotor and stator windings.

The rotor of a squirrel cage induction motor is cylindrical in shape. This shape helps induce currents in the rotor bars. This current causes a pulling torque toward the direction of the rotating field. This pulling action allows the rotor to accelerate to match the speed of the rotating field, but the rotor never reaches synchronous speed. If the two components rotate at equal speeds, there would be no loss in the magnetic field or induced currents.

## Electromagnetic induction

An Electromagnetic induction motor for squirrel-cage induction systems combines a rotating magnetic field with an inductive component to produce a current. The resulting current depends on the temperature of the materials and the rotor’s position in the squirrel cage. The corresponding parameters are listed in Table 10.1. The inputs are the instantaneous voltages at the three terminals and the unknown currents in the windings. The rotor is free to rotate, and the rotor bars are each represented by independent circuits. They are connected to an end ring with a constant resistance and inductance. Depending on the amount of distortion, the rotor bars may re-mesh at each time step.

The squirrel cage induction motors have the advantage of having a high peak torque at zero speed and low speed. Because of the low starting torque, they are good for self-starting and constant speed applications. Besides, they require very little maintenance. The squirrel cage induction motor is an excellent option for many applications, and is also very cost-effective. In addition to these advantages, it is suitable for industrial settings, including packaging, weighing less than 20 kg, and requiring no electrical wiring.

## Self-starting

A squirrel cage induction motor is a great choice for a number of applications. They are relatively inexpensive, have good heat regulation, and are safe. They lack speed control, but have many benefits. They can be easily maintained and come in different voltages, depending on their application. This article will focus on one type of self-starting squirrel cage induction motor – the wound rotor. A self-starting squirrel cage motor can save a business a lot of money on repairs and replacement parts.

The basic mechanism of a squirrel cage induction motor is similar to other types of induction motors. The key difference between them is in the specific interaction between the rotor and stator. For example, a power hammer requires high starting torque, while an HVAC fan can benefit from a class A or B motor. There are several sizes of self-starting squirrel cage induction motors available.

## Rotor resistance

A squirrel-cage induction motor has a rotor resistance of 0.14 ohm per phase and a reactance of 0.8 ohm per phase. A squirrel cage induction motor has a transformer ratio of unity and a speed range of 50% to 100%. Its primary windings are wound, which decreases the overall starting resistance. The rotor secondary has a slip to achieve maximum torque.

A squirrel cage induction motor is the most common type. These motors are low in starting torque because of their low rotor resistance. Rotor resistance is directly proportional to starting torque, and increasing the rotor resistance will reduce the starting torque of the motor. Moreover, external resistance will not work on a squirrel cage motor rotor, because the bars are permanently short-circuited. A double-squirrel cage induction motor, on the other hand, has high starting torque and higher efficiency.

## Applications

Squirrel cage induction motors are one of the most common types of induction motors available. They operate at a constant speed and low starting torque, but can reverse direction when needed. A squirrel cage motor’s power factor is defined as the ratio of its actual power to its apparent power, and is expressed as a percentage. This ratio is low when the motor is running at no load and high when it is operating with a load.

The squirrel cage induction motor is composed of three-phase windings that are positioned 120 degrees apart in space. The windings of the stator are delta or star-connected, creating a low-reluctance path for the flux generated by the squirrel cage. The windings of the squirrel cage induction motor are usually varnish or oxide-coated. Their shorting causes an emf on the rotor’s conductor bars.