What are the speed torque characteristics of induction motor?
What are the speed torque characteristics of induction motor?
Torque Speed Characteristic of an Induction Motor
- Torque Speed Characteristic is the curve plotted between the torque and the speed of the induction motor.
- At the maximum torque, the speed of the rotor is expressed by the equation shown below:
What are the characteristics of a three phase induction motor?
Three-phase currents flowing within the stator create a rotating magnetic field which induces a current and consequent magnetic field in the rotor. Rotor torque is developed as the rotor slips a little behind the rotating stator field. Unlike single-phase motors, polyphase induction motors are self-starting.
What are the three regions in speed torque characteristics of induction motor?
The torque-slip characteristic curve can be divided roughly into three regions:
- Low slip region.
- Medium slip region.
- High slip region.
What is the name of torque speed characteristics curve of the motor?
The Torque-slip curve of an induction motor shows the variation of torque with the slip. If R2 and X20 are kept constant, then the torque τ will depend upon the slip s. The torque-slip characteristic curve is divided into three regions: Low-slip region.
What are the types of load torque?
3 Types of Loads (Constant Torque/Constant Power/Variable Torque)
- Type 1 – CONSTANT TORQUE LOADS.
- Type 2 – CONSTANT POWER LOADS.
- Type 3 – VARIABLE TORQUE LOADS.
What is torque and speed?
Speed: The speed of a motor is defined as the rate at which the motor rotates. The speed of an electric motor is measured in revolutions per minute, or RPM. Torque: The torque output of a motor is the amount of rotational force that the motor develops.
What are the operating modes of 3 φ induction motor?
The induction machine can be operated in three modes: motoring, generating, and plugging. If the stator terminals are connected to a three-phase supply, the rotor will rotate in the direction of the stator rotating magnetic field.
What is standstill rotor EMF?
When rotor is stationary i.e. s = 1, the frequency of rotor e.m.f. is the same as that of the stator supply frequency. The value of e.m.f. induced in the rotor at standstill is maximum because the relative speed between the rotor and the revolving stator flux is maximum.
What is relation between torque and speed?
Torque is inversely proportional to speed. Thus, when speed increases, torque will decrease.
What are the three components of load torque?
Components of load torques:
- Friction Torque (TF) The friction torque (TF) is the equivalent value of various friction torques referred to the motor shaft.
- Windage Torque (Tw) When a motor runs, the wind generates a torque opposing the motion .
- Torque required to do useful mechanical work ( Tm)
What type of force is torque?
Torque is a measure of the force that can cause an object to rotate about an axis. Just as force is what causes an object to accelerate in linear kinematics, torque is what causes an object to acquire angular acceleration. Torque is a vector quantity. Torque can be either static or dynamic.
What is the torque speed of an induction motor?
FIGURE 6 Induction motor torque-speed characteristic. The slip is negative in the region to the right of the motor region, which implies the rotor is rotating faster than the stator field.
What is the slip of an induction motor?
The slip is defined as the ratio of difference of synchronous speed and actual rotor speed to the synchronous speed of the machine. The variation of slip can be obtained with the variation of speed that is when speed varies the slip will also vary and the torque corresponding to that speed will also vary.
Is the voltage of a three phase induction motor always constant?
The supply voltage to the three phase induction motor is usually rated and remains constant, so the stator emf also remains the constant. We define the transformation ratio as the ratio of rotor emf to that of stator emf. So if stator emf remains constant, then rotor emf also remains constant.
Can a three phase induction machine work as a generator?
Similar to other types of electric machines, a three-phase induction machine can work as a generator and as a motor. For this machine, however, because the stator must be connected to the three-phase circuit, the difference between being a motor or functioning as a generator lies in the speed of the rotor.