What is torque speed characteristic of induction motor?
The induction motor torque-speed characteristic gives information on the dependence of induced mechanical torque on mechanical speed. Sometimes this characteristic is called torque-slip characteristic, where slip is defined as speed relative to synchronous speed expressed as a fraction of synchronous speed.
What are the characteristics of a three phase induction motor?
Three-Phase Induction Motor Torque-Speed Characteristics
- If the rotor speed is less than the synchronous speed (NS), the machine acts as a motor; it delivers torque to a load. …
- The only part of the curve, which is almost linear, is good for operation. …
- As a motor, the machine has a starting torque (at zero speed); thus, the machine is a self-starter.
What is Torque slip characteristics of induction motor?
The Torque Slip Characteristic is represented by a rectangular hyperbola. 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 R2 = sX20.
Which motor has the speed torque characteristics?
Figure 1 showed a plot of induction motor torque vs speed from zero to synchronous speed. This curve is called the torque-speed characteristic curve.
What is the relationship between torque and speed?
Torque is inversely proportional to speed. Thus, when speed increases, torque will decrease.
What are the types of induction motor?
Types of Induction Motor: A Concise and Useful Guild
- Types of Induction Motors. Types of Single-Phase Induction Motors. Split Phase Induction Motors. 2&3. Capacitor Start and Capacitor Start Capacitor Run Induction Motors. Shaded Pole Induction Motors. Types of Three-Phase Induction Motors. Squirrel Cage Induction Motor. Slip-ring or Wound Rotor Induction Motor.
What are the applications of 3 phase induction motor?
The squirrel cage induction motors are used in residential as well as industrial applications especially where the speed control of motors is not needed such as:
- Pumps and submersible.
- Pressing machine.
- Lathe machine.
- Grinding machine.
- Flour mills.
- And other low mechanical power applications.
Is torque proportional to slip?
Thus, the torque is inversely proportional to slip towards standstill conditions. We can represent the torque-slip characteristic by a rectangular hyperbola. … The maximum torque developed in an induction motor is called the pull-out torque or breakdown torque.
What is synchronous speed?
: a definite speed for an alternating-current machine that is dependent on the frequency of the supply circuit because the rotating member passes one pair of poles for each alternation of the alternating current.
What is Torque slip?
The torque slip curve for an induction motor gives us the information about the variation of torque with the slip. The slip is defined as the ratio of difference of synchronous speed and actual rotor speed to the synchronous speed of the machine.
What is torque and speed?
Torque is the rotational equivalence of linear force. Speed measures the distance covered in unit time. … The torque of a rotating object can be mathematically written as the ratio of power and angular velocity.
What is induction motor efficiency?
Efficiency of three-phase induction motors can vary from 85% to 96%. See the chart below for torque vs. slip. Induction motors of 50-100 HP for industrial applications vary in weight from 700 to almost 1,000 lbs.
What is the speed torque characteristics?
Torque Speed Characteristic of an Induction Motor
The greater, the value of the R2, the greater is the value of the slip at which maximum torque occurs. As the rotor resistance increases, the pullout speed of the motor decreases. In this condition, the maximum torque remains constant.
What is torque in AC motor?
Torque is the turning force through a radius – with the units Nm in the SI-system and the units lb ft in the imperial system. The torque developed by an asynchronous induction motor varies when the motor accelerates from zero to maximum operating speed.
Which motor is used for elevators?
Conventionally, there are, in general, three types of motors used in elevator systems: AC, DC and a hybrid between the two. The AC-2 motor is a primitive motor drive popular at least half a century ago for low-speed elevators. It is usually coupled with a worm gear to reduce speed and increase driving torque.