Benefits and limitations of ac generator motors

AC generator motors have advantages such as simple design and not requiring matching voltages, but they do have some drawbacks such as higher levels of insulation.
By David Manney, L&S Electric May 24, 2017

Image courtesy: Bob Vavra, CFE MediaMost commercial areas rely on ac to power a wide range of electrical appliances and pieces of equipment. AC results from the movement of the electrical charge through a medium. The direction of movement varies over time. This variation is not the case with DC since it only involves a single direction for its movement.

AC generator basics

An ac generator is a type of electromagnetic device, responsible for converting mechanical energy into electrical power, essential in electromagnetic induction applications. This device comes with a rectangular coil of wire, and this component rotates on an axis. Moreover, this coil lays between the poles of the two permanent magnets. With the rotation of the coil, this leads to the changes in the magnetic field. Thus, the process generates an electromotive force between the coil’s ends.

Benefits of ac generators

AC generators provide several benefits to a user’s facility including:

Simple design

For the most part, an ac motor comes with a simple design since it only contains a single moving part, the rotor. AC motors are easier to maintain as a result. They are also cheaper to own and have quieter operation. They also have a longer life compared to dc motors. In fact, dc motors have carbon brushes and a commutator that tend to wear out over time. These have to be replaced throughout the life of the motor. There is also a loud noise and a distinct smell typical with a dc motor due to the friction produced by its components.

Matching voltage not necessary

For optimal use, it is important for a dc generator to produce a voltage at a certain level. The ac generator allows the user to convert the current to another voltage using a transformer. In fact, transformers are compatible with ac, but not with dc.


While ac generators have benefits, there are also some limitations to consider including: 

Greater insulation required

There is a higher level of insulation due to the massive voltages required to supply a fixed amount of power from an ac motor. As a result, there is the challenge in the safe handling of ac generators. Working with ac may pose some difficulties and risks, as compared to what you can expect from dc motors.

Transformer use

While it may also be an advantage, the need for a transformer can also be a limitation for ac generators. For instance, the motors need a special design that prevents the discharge of the higher voltage generated on one side. Since it is not possible for an efficient way to generate high voltages, it is necessary to use a transformer to ease long distance transmission. This transmission occurs once the low voltage converts to a much greater level necessary.

Issues involved

AC power may be susceptible to sparks and overheating due to its production of high currents. Such phenomenon results in electric shock and fires. These fires are detrimental to properties and lives of your employees. Besides these safety risks, ac generators appear to be less durable considering its need to produce massive currents resulting in such hazards.

Bottom line

Just as with dc, there are benefits and drawbacks involved in the use of an ac generator. Overall, though, the advantages of ac appear to outweigh the limitations involved.

David Manney is a marketing administrator at L&S Electric. This article originally appeared on L&S Electric Watts New Blog. L&S Electric is a CFE Media content partner.

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