Ad
related to: motor speed vs torque
Search results
Results from the WOW.Com Content Network
is the torque produced divided by armature current. [10] It can be calculated from the motor velocity constant . = = = where is the armature current of the machine (SI unit: ampere).
Torque forms part of the basic specification of an engine: the power output of an engine is expressed as its torque multiplied by the angular speed of the drive shaft. Internal-combustion engines produce useful torque only over a limited range of rotational speeds (typically from around 1,000–6,000 rpm for a small car).
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.
Brushed DC motors can be varied in speed by changing the operating voltage or the strength of the magnetic field. Depending on the connections of the field to the power supply, the speed and torque characteristics of a brushed motor can be altered to provide steady speed or speed inversely proportional to the mechanical load.
Many useful motor relationships between time, current, voltage, speed, power factor, and torque can be obtained from analysis of the Steinmetz equivalent circuit (also termed T-equivalent circuit or IEEE recommended equivalent circuit), a mathematical model used to describe how an induction motor's electrical input is transformed into useful ...
Direct-current motors with series field windings are the oldest type of traction motors. These provide a speed-torque characteristic useful for propulsion, providing high torque at lower speeds for the acceleration of the vehicle, and declining torque as speed increases.
The motor accelerates from slip speed to synchronous speed during an accelerating half cycle of the reluctance torque. [3] Single-phase synchronous motors such as in electric wall clocks can freely rotate in either direction, unlike a shaded-pole type.
As a result, the induction motor cannot produce torque near synchronous speed where induction (or slip) is irrelevant or ceases to exist. In contrast, the synchronous motor does not rely on slip-induction for operation and uses either permanent magnets, salient poles (having projecting magnetic poles), or an independently excited rotor winding ...
Ad
related to: motor speed vs torque