Classification of electric motors

Categorization based on drive and technology

This categorization of electric motors, classifies common rotary and linear electromagnetic motors according to type of drive (AC / DC) and other characteristics.

Bold motors are typically used in EVs. Links go to the section for their drivers.

			Drive
			AC (1Φ, 3Φ, polyΦ, line frequency or variable frequency) / Switched DC	DC or AC (1Φ line frequency)	Straight DC
			Internal commutation
			No commutation inside the motor to generate a rotating magnetic field; an external device must generate the time-varying voltages to drive the motor. (Wound rotor induction motors are brushed, but not to generate the rotating magnetic field.)	Inside the motor a commutator (mechanical or electronic) converts the DC voltage (at the 2 motor terminals) to an AC wave that is in synch with the rotation of the rotor, to power specific windings.
Rotary motors	Iron rotor	The rotor is magnetic metal, not permanently magnetized; it has no winding	Brushless Synchronous Hysteresis Reluctance Synchronous reluctance Switched reluctance / variable reluctance / SRM Variable Reluctance Stepper Unipolar Bipolar
	Magnet rotor (+ iron)	The rotor is a permanent magnet; it has no winding. (Hybrid steppers also have iron.)	Brushless Synchronous (PMAC: Permanent magnet AC) PMSM (Permanent Magnet Synchronous Motor) / BLAC (Brush Less Alternating Current) External controller BLDC (Brush-less Direct Current) Permanent Magnet Stepper Unipolar Bipolar Hybrid Stepper		Brushed commutator PM (Permanent Magnet) Brushless (electronic commutator: transitors / ICs) Integral controller BLDC (Brush Less Direct Current)
	Copper rotor   (+iron)	The rotor includes a winding. (Homopolar motors and some low inertia motors have just the winding and no iron)	Brushless Slip quasi-synchronous Induction, squirrel cage Single phase Split phase Capacitor start Capacitor run / PSC (Permanent Split Capacitor) Capacitor start-run (2 capacitor) Shaded pole Polyphase (e.g.: 3 ph.) Brushed slip ring Synchronous Induction, synchronous, wound rotor 1Φ 3Φ Brushed commutator Slip quasi-synchronous Wound rotor Repulsion Repulsion start Repulsion induction	Brushed commutator Asynchronous Universal	Brushed commutator Wound stator Self-excited series wound shunt wound compound wound SEM / Sepex (Separately excited) Homopolar
Linear motors			Brushless Synchronous Coil gun inductive mass driver Brushless Slip quasi-synchronous LIM (Linear Induction Motor)		Brushed Rail gun mass driver