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Motor velocity constant, back EMF constant. is the motor velocity, or motor speed, [2] constant (not to be confused with kV, the symbol for kilovolt ), measured in revolutions per minute (RPM) per volt or radians per volt second, rad/V·s: [3] The rating of a brushless motor is the ratio of the motor's unloaded rotational speed (measured in RPM ...
Direct torque control ( DTC) is one method used in variable-frequency drives to control the torque (and thus finally the speed) of three-phase AC electric motors. This involves calculating an estimate of the motor's magnetic flux and torque based on the measured voltage and current of the motor.
An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor that produces torque is obtained by electromagnetic induction from the magnetic field of the stator winding. [1] An induction motor therefore needs no electrical connections to the rotor.
t. e. In physics and mechanics, torque is the rotational analogue of linear force. [1] It is also referred to as the moment of force (also abbreviated to moment ). The symbol for torque is typically , the lowercase Greek letter tau. When being referred to as moment of force, it is commonly denoted by M.
Torsion of a square section bar Example of torsion mechanics. In the field of solid mechanics, torsion is the twisting of an object due to an applied torque.Torsion is expressed in either the pascal (Pa), an SI unit for newtons per square metre, or in pounds per square inch (psi) while torque is expressed in newton metres (N·m) or foot-pound force (ft·lbf).
Stall torque. Stall torque is the torque produced by a mechanical device whose output rotational speed is zero. It may also mean the torque load that causes the output rotational speed of a device to become zero, i.e., to cause stalling. Electric motors, steam engines and hydrodynamic transmissions are all capable of developing torque when stalled.
Vector control, also called field-oriented control (FOC), is a variable-frequency drive (VFD) control method in which the stator currents of a three-phase AC or brushless DC electric motor are identified as two orthogonal components that can be visualized with a vector. One component defines the magnetic flux of the motor, the other the torque.
Torque motor. A torque motor is a specialized form of DC electric motor which can operate indefinitely while stalled, without incurring damage. In this mode of operation, the motor will apply a steady torque to the load (hence the name). A torque motor that cannot perform a complete rotation is known as a limited angle torque motor.