INDUCTION MOTOR TORQUE-SPEED CHARACTERISTICS Figure 6.12a illustrates a squirrel-cage rotor of an induction motor that is operating at no load (near synchronous speed). The magnetization current IM flowing in the motor's equivalent circuit (Fig. 6.7) creates the net magnetic field Bnet. Current IM and hence Bnet are propor- tional to E1.

SECTION 7.6 VARIATIONS IN INDUCTION MOTOR TORQUE–SPEED CHARACTERISTICS. 395. FIGURE 7–25. Laminations from typical squirrel-cage induction motor rotors, 

The torque-slip characteristic curve can be divided roughly into three regions: Low slip region Medium slip region High slip region Motoring Mode In this mode of operation, supply is given to the stator sides and the motor always rotates below the synchronous speed. The induction motor torque varies from zero to full load torque as the slip varies.

Initialize a three-phase induction motor as part of a load flow analysis. When initializing an induction machine that is directly connected to an AC network, in steady state there is one degree of freedom which can be set by any one of shaft torque, shaft power, motor speed or electrical power.

This method is not applicable to squirrel cage induction motors. In this method, the speed of slip-ring or wound rotor induction motor is controlled by connecting external resistance in the rotor circuit through slip rings (as shown in the figure). The maximum torque of the induction motor is independent of the rotor resistance.

The torque-speed characteristics of motor (T M) and load (T L) for two cases are shown in the figure (a) and (b). The load torque is equal to motor torque at points P, Q, R and S The speed of a three phase cage­rotor induction motor depends on. Q6. A 3-phase, 440V, 50 Hz supply is applied to a 3-phase, 4-pole, 440V, star-connected

Our article all about induction motors explains the specifications for all types of induction motors and is a good place to see all the different induction motor characteristics. This article will focus on what needs to be specified for squirrel cage induction motors, which involves phase, speed, torque, and current.

The speed of small squirrel cage induction motors for applications such as driving fans may be changed by reducing the line voltage. This reduces the torque available to the load which reduces the speed (see figure below). Figure 5.17 Variable voltage controls induction motor speed Electronic Speed Control in Induction Motors

A squirrel-cage motor with this type of rotor construction is called NEMAdesign class D. Its torque-speed characteristic is also shown in Figure 7-26. Deep-Barand Double-Cage RotorDesigns, Both of the previous rotor designs are essentially similar to a wound-rotor motor with a set rotor resistance.

At starting of the motor, frequency of induced emf is high because of large slip (slip = frequency of rotor emf / supply frequency). Hence the reactance of 

FIGURE 7 Induction motor torque-speed characteristic. The maximum torque that the motor can produce is called the breakdown torque. The motor cannot operate in the steady-state at

19/08/  · Classification of Squirrel Cage Induction Motor. NEMA (National Electrical Manufacturer’s Association) in United States and IEC in Europe has classified the design of the

Squirrel cage induction motors have mostly been used for their small capacity because the starting torque is smaller than the starting current during start-up.

To obtain the torque-speed characteristics (T-N r) of a three phase squirrel cage induction motor using 1. Variable voltage control 2. Variable voltage variable frequency (V/F) control The cut

Typical Torque-Speed Curve of a Cage Induction Motor · The Locked Rotor Torque or Starting Torque is the torque the electrical motor develops when it starts at 

The construction of squirrel cage induction simple and rugged. Construction of slip ring induction motors needs slip rings, brushes, short-circuiting device, etc. This type of motor has less overhang and better space factor in slots. These motors have the highest overhang and poor space factor in slots. Cost and maintenance are less.

One of the important features of an induction motor is its torque speed characteristics for both the squirrel cage and wound rotor type induction motors 

The principal advantages of the squirrel-cage induction motor are its simplicity of design and robust construction. Its torque/speed and current/speed characteristics are such that, on

01/12/  · The analysis results of the transient characteristics were applied to a 3-phase 4-pole 5-hp induction motor to calculate the starting torque, speed, and rotation angle of the rotors.

We can make rotor of induction motor as wound rotor or a squirrel cage rotor. In majority of the cases industrial scale applications involve the use of three-phase squirrel-cage induction motors

T Nakamuraet al rotor bar end ring Figure 1. Schematic diagram of the rotor windings. motors in electric trains have been fabricated by means of the squirrel-cage-type induction motor in Japan.

Induction motors present a lagging (inductive) power factor to the power line. The power factor in large fully loaded high-speed motors can be as favorable as 

Due to these advantages induction machines have become more popular in industrial applications. For any motor load application, it is imperative to know the torque speed

The squirrel cage induction motor uses a magnetic field to drive a rotor. Its induced voltage is one to three percent higher than the synchronous speed of a magnetic field. This difference in speed is called "motor slip." A squirrel cage induction motor is not a loss-free motor, and the current it produces is not loss-free.

05/07/  · The torque-speed characteristics of a three-phase induction motor is a straight line between the no-load and full-load operating points. The slope of the curve line depends upon the resistance of the rotor circuit i.e. the higher the rotor circuit resistance, the sharper the slope of the curve. The small three-phase induction motors (below 10

One big advantage of a squirrel cage motor is how easily you can change its speed-torque characteristics. This can be done by simply adjusting the shape of the bars in the rotor.