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.
What is torque speed characteristic of induction motor?
Torque Speed Characteristic is the curve plotted between the torque and the speed of the induction motor. As we have already discussed the torque of the induction motor in the topic Torque Equation of an Induction motor. The equation of the torque is given as shown below.
What is rated torque of motor?
Rated torque is the maximum continuous torque available at the design speed that allows the motor to do the work without overheating. Starting torque is the torque the motor delivers at zero speed. i.e. startup. It is also called the stall torque.
How is rated torque calculated in an induction motor?
So, when slip s = R2 / X2, the torque will be maximum and this slip is called maximum slip Sm and it is defined as the ratio of rotor resistance to that of rotor reactance. NOTE: At starting S = 1, so the maximum starting torque occur when rotor resistance is equal to rotor reactance.
What is Torque 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. …
How does an induction motor start?
When the supply is connected to the stator of a three-phase induction motor, a rotating magnetic field is produced, and the rotor starts rotating and the induction motor starts. … At the time of starting, the motor slip is unity, and the starting current is very large.
How do I calculate torque?
A practical way to calculate the magnitude of the torque is to first determine the lever arm and then multiply it times the applied force. The lever arm is the perpendicular distance from the axis of rotation to the line of action of the force. and the magnitude of the torque is τ = N m.
How is rated torque calculated?
- Torque (lb.in) = 63,025 x Power (HP) / Speed (RPM)
- Power (HP) = Torque (lb.in) x Speed (RPM) / 63,025.
- Torque (N.m) = 9.5488 x Power (kW) / Speed (RPM)
- Power (kW) = Torque (N.m) x Speed (RPM) / 9.5488.
What is pull out torque?
The maximum torque that can be applied to a motor operating at a given speed without losing synchronism.
Why electric motors have more torque?
The benefit of using an electric motor to power a car is that it can help drivers reach maximum torque from 0 RPM. This is because electric motors use an electric current, which moves through a magnetic field and creates the force necessary to rotate the armature and get the car moving.
What is 120 in motor speed formula?
The equation for calculating synchronous speed is: S = 120 f/P speed = constant (120) times frequency of power source (60 Hz) divided by number of poles used in the motor (P). Where does the 120 come from and what units does it have? There is RPM on one side and Cycles/second divided by #of poles on the other.
What is maximum torque in induction motor?
The developed torque is maximum when the rotor resistance per phase is equal to the rotor reactance per phase under running conditions. By putting the value of sX20 = R2 in the equation (1) we get the equation for maximum torque.
What is Torque vs power?
What’s the Difference Between Horsepower and Torque? The two are very much two sides of the same coin as one goes with the other—torque being the force and horsepower being the rate at which that force is done. The difference is torque is doing the work, while horsepower is how fast that work is being done.
Is it better to have more torque or less torque?
Of course, horsepower is tied to torque mathematically. … Because there is generally a limit on how fast you can spin an engine, having higher torque allows for greater horsepower at lower rpms. This is also why people talk about “low-end torque” being important for better power at slower speeds.
What is torque equal to?
The torque, specified with regard to the axis of rotation, is equal to the magnitude of the component of the force vector lying in the plane perpendicular to the axis, multiplied by the shortest distance between the axis and the direction of the force component. …