Motor Control Acronyms

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PMSM – Permanent Magnet Synchronous Motor
BLDC – Brushless DC motor
EMF – Electro-Magnetic Force
FOC – Field-Oriented Control (motor control algorithm)
PFC – Power Factor Correction
RMS – Root Mean Square
SVPWM – Space Vector Pulse Width Modulation
CR-PWM – Current-Regulated Pulse Width Modulation (PWM)
MTPA – Maximum Torque Per Ampere (control)
Back-EMFS or Back-EMF Back Electro-Motive Force, refers to using the voltage generated by a spinning motor (BEMF) to conclude the speed of the motor’s rotation
Ke – equals the volts generated at some RPM, usually 1000 RPM. Motor manufacturers usually provide the value of this constant.
Te – electromagnetic torque
iqs – quadrature current component
ids – direct axis current
– direct inductance
– quadrature inductance
– stator phase winding resistance
– stator phase winding leakage inductance
– stator phase winding magnetizing inductance
– rotor electrical angle
– flux linkage due to permanent magnets
Φ – Phase
MCP – Motor Circuit Protection
Electric Brakes – Electric brakes are assemblies consisting of electrical elements for the slowing or stopping of shafts in equipment drives. Electrical power is required to activate the brake.
CEMF – Counter Electromotive Force is the he induced voltage in a motor armature, caused by conductors moving through or “cutting” field magnetic flux. This induced voltage opposes the armature currentand tends to reduce it.
Breakdown Torque – The maximum torque a motor will develop at rated voltage without a relatively abrupt drop or loss in speed.

AC Motors or Asynchronous Motor

AC motors are electric motors which are powered by alternating current (AC).
They are used to convert electrical energy into mechanical energy in order to do work in a system. Specifically, rotational energy is produced by utilizing the force of magnetic fields induced by alternating current flowing through electric coils.
AC motors are used to provide power for a wide variety of systems, from small servomechanisms to large industrial machinery.

DC Motors

DC motors are electric motors that are powered by direct current (DC), such as from a battery or DC power supply.
Their commutation can be brushed or brushless.
The speed of a brushed DC motor can be controlled by changing the voltage alone.

Stepper Motors

Stepper motors are DC (direct current) electric motors designed for precise motion control.
They consist of multiple sets of coils and magnets which are designed to allow rotor movement in angular increments called 12 VDC stepper motor from Digi-KeySteps. Stepping can be done in full step, half step or other fractional steps in both forward and reverse. Stepper motors are rugged, reliable, cheap, and easy to control devices that produce high torque at slow speeds.

Brushless Motors

Brushless motors is an electric motor driven by an electrical input, which lacks any form of commutator or slip ring.
The motor requires some form of alternating current to turn, either from an AC supply, or an electronic circuit.
PMSM or “permanent-magnet motor” (PMM) is a synchronous motor that uses permanent magnets rather than windings in the rotor.

(From: Globalspec & WikipediA)


  • For more info on Electrical Motors see here.
  • How to convert RPM to the Frequency of the sinusoidal current that must be generated for each phase, considering the number of pole pairs, see here.