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Reluctance motor subtypes include synchronous, variable, switched and variable stepping. Reluctance motors can deliver high power density at low cost, making them attractive for many applications. Disadvantages include high torque ripple (the difference between maximum and minimum torque during one revolution) when operated at low speed, and ...
A stepper motor, also known as step motor or stepping motor, [1] is a brushless DC electric motor that rotates in a series of small and discrete angular steps. [2] Stepper motors can be set to any given step position without needing a position sensor for feedback. The step position can be rapidly increased or decreased to create continuous ...
Michael Faraday made a Homopolar motor in 1831. Superconducting DC homopolar machines use superconductors in their stationary field windings and normal conductors in their rotating pickup winding. In 2005 the General Atomics company received a contract for the creation of a large low speed superconducting homopolar motor for ship propulsion. [1]
Synchronous motor and induction motor stators are similar in construction. [27] The construction of synchronous motor is similar to that of a synchronous alternator. [28] The stator frame contains wrapper plate (except for wound-rotor synchronous doubly fed electric machines). Circumferential ribs and keybars are attached to the wrapper plate.
Lavet-type stepping motor of a quartz clock. A black rotor sprocket provides the mechanical output. The Lavet-type stepping motor has widespread use as a drive in electro-mechanical clocks [1] and is a special kind of single-phase stepping motor. Both analog and stepped-movement quartz clocks use the Lavet-type stepping motor (see Quartz clock).
The switched reluctance motor (SRM) is a type of reluctance motor. Unlike brushed DC motors , power is delivered to windings in the stator (case) rather than the rotor . This simplifies mechanical design because power does not have to be delivered to the moving rotor, which eliminates the need for a commutator .
The low-acceleration, high speed and high power motors are usually of the linear synchronous motor (LSM) design, with an active winding on one side of the air-gap and an array of alternate-pole magnets on the other side. These magnets can be permanent magnets or electromagnets. The motor for the Shanghai maglev train, for instance, is an LSM.
In both induction and synchronous motors, the AC power supplied to the motor's stator creates a magnetic field that rotates in synchronism with the AC oscillations. Whereas a synchronous motor's rotor turns at the same rate as the stator field, an induction motor's rotor rotates at a somewhat slower speed than the stator field.