Characteristics of induction motor

The slip is defined as the ratio of difference of synchronous speed and actual rotor speed to the . This motor always uses both auxiliary winding and condenser not only when starting but also during operation. Generally speaking, its starting torque is not so great, . Two important characteristics of AC motors that need to be considered for any application are running speed and starting torque. An induction motor can therefore be made without electrical connections to the rotor.

Running speed is dependent on the power supply frequency, the number of motor poles and the amount of slip .

The frequency and number of poles define what the synchronous .

Using the induction machine power and torque equations it is possible to produce the torque speed curve shown below. Learn with us- Electrical Engineering concepts 1views. The torque speed curve is approximately symmetric about synchronous speed.

THREE-PHASE INDUCTION MOTORS In the integral horsepower sizes, i. Sketch the above characteristics of torque-slip ( speed), explaining the various features.

Derive the expression of maximum torque and the slip (speed) at which it occurs. Draw the above characteristics with the variation in input (stator) voltage and rotor resistance. NPTEL provides E-learning through online Web and Video courses various streams.

It also calculates the thevenin equivalent circuit parameters, maximum torque induce starting torque and slip for maximum power or torque.

It finally plots torque speed characteristics of induction . I want , determination of running torque of three phase induction motor . When the motor is starte the initial torque is about 2 of the rated torque. Induction motors are widely used in . This is the torque required by the motor to overcome the inertial of the standstill. As the motor picks up speed the torque drops to the pull-up . For the immediate value of the slip, the graph changes from one form to the other.

Thus, it passes through the point of maximum torque when R= sX20.

The maximum torque developed in an induction . Usually, it needs the dependence of efficiency or power factor or power losses from torque or frequency under different control schemes. Different control schemes employ different . For this reason, not only their static characteristics , but also dynamic response characteristics are very . This minimum is equal to the magnetising current. The slip torque characteristic of an induction motor curves for various ranges of slip with different Rare drawn.

What is Load Torque characteristics of Electric Drive? This Application Note explains how to obtain the current density . In this paper the motor efficiency and motor power factor . Squirrel cage motors get their name from the appearance of early rotors.