Difference Between an Alternator and a Generator (With Table)

Both alternators and generators can produce energy, but they are produced in different ways, and it may be difficult to identify the difference. Most people consider generators to be used as backup power sources at home or in recreational vehicles, as well as alternators with equipment to charge car batteries. While this distinction is more or less true, there are significant technological differences in the way these devices produce energy for our cars and houses.

 Alternator vs Generator

The difference between an Alternator and a Generator is that In an alternator, the armature is stationary and the field windings move, while in a generator, the field windings are stationary, and the armature moves. The armature windings are wound on the stator, which is the static part of the alternator, and the field winding is wound on the rotor.

A mechanical device that transforms mechanical energy into AC electrical energy is known as an alternator. The magnetic field (rotor) revolves around the armature in this kind of generator (stator). Using a DC source, a permanent magnet or an electromagnet generates a magnetic field. The armature is surrounded by an electromagnet in a housing (conductor windings). However, in the case of a generator, the armature is at the rotor, and the field winding is at the stator.

A generator is a machine that transforms mechanical energy into either AC or DC electrical energy. The stator, the outer casing that surrounds the armature in the generator, is composed of either a permanent magnet or a fixed electromagnet. Inside this fixed magnetic field, the armature is made up of conductor coils that spin around their axis. The magnetic field line crossing the conductors fluctuates due to the spinning armature. As a result, the spinning armature generates a current.

Comparison Table Between an Alternator and a Generator

Parameters of ComparisonAlternatorGenerator
DefinitionAn alternator is a machine that transforms mechanical energy into alternating current (AC) electricity.A generator is a mechanical device that transforms mechanical energy into electrical energy, either AC or DC.
Output CurrentAn alternator produces an alternating current at all times. Alternating or direct current may be generated by a generator.
EfficiencyVery Efficient.Less Efficient.
Magnetic FieldAn alternator’s stator contains a spinning magnetic field. The magnetic field is stationary or fixed where the armature winding rotates in the case of a generator.
OutputHighLow

What is an Alternator?

In the electric power industry, an asynchronous generator (also known as an alternator) is a machine that transforms mechanical energy from a primary mover into alternating current at a certain voltage and frequency. The numerous advantages of three-phase alternators make them a popular choice for use in distribution, generating, and transmission applications.

Large alternators are used to generate large amounts of electricity in thermal, hydroelectric, and nuclear power facilities. The magnetic pole of the rotor is excited by the direct field current flowing through it. As the rotor rotates, the magnetic flux cuts the conductor of the stator, resulting in the generation of EMF.

An EMF and current are produced in the armature conductor as the magnetic poles alternately spin in the N and S directions. The armature conductor rotates first clockwise and then anti-clockwise. This causes the alternating current to be produced as a consequence.

What is a Generator?

The generator is responsible for converting mechanical energy into electrical energy, also known as power. The functioning of the generator is based on the concept of Faraday laws of electromagnetic induction, which states that anytime the conductors cut the magnetic flux EMF induces, the generator stops working. Even though the conductor is closed, this EMF causes the current to flow. Generators are composed of two basic components: the magnetic field and conductors.

An axially rotating rectangular revolving coil is used in the generator, and it rotates in the magnetic field around its axis. Either a permanent magnet or an electromagnet is used to create the magnetic field in the room. Two slip rings are used to connect the coil’s ends together. During the operation of the slip ring, the current generated in the coil is collected and transferred to the external load resistor R.

The rotating coil is called the armature, and it is made of copper. They can even recharge depleted batteries. When the rotor is linked to the commutator, the direct current supplied by the generator is created. The commutator is a key component in a generator’s direct current generation; it is made up of a series of independent rings that connect the generator to an external circuit in such a manner that the current generated is often DC.

Main Differences Between an Alternator and a Generator

  1. An alternator is a device that transforms mechanical energy into alternating current (AC) electricity, whereas a generator is a mechanical device that transforms mechanical energy into electrical energy, either AC or DC
  2. An alternator produces an alternating current at all times, whereas a generator may generate alternating or direct current. 
  3. The alternator is very efficient, whereas the generator is not much efficient
  4. The stator of an alternator includes a rotating magnetic field. In the case of a generator, the magnetic field is stationary or fixed where the armature winding spins.
  5. Alternators produce more energy than generators. When compared to an alternator, generators have a lesser output.

Conclusion

Electricity is generated by an alternator when a magnetic field in the stator rotates, as in a generator (windings of wire). Instead, the armature or wire windings in a generator revolve in a set magnetic field in order to produce electrical current. Alternators save energy by simply using the amount of energy that is required. Generators make use of all of the energy that is generated. In contrast to generators, alternators generate voltage only when it is required, while generators provide voltage at all times.

Alternators provide a greater amount of output than generators. Alternator brushes have a longer lifespan than generator brushes. This is due to the fact that the brushes in an alternator are solely utilized for the purpose of transporting electricity to power the rotor, and the slip rings on which they travel are smooth. An alternator will not charge a dead battery, and if you attempt to charge it, there is a risk that it may overheat and fail to charge at all. A generator, on the other hand, may be used to recharge a discharged battery.

References

  1. https://www.sciencedirect.com/science/article/pii/S0306261912003455
  2. https://iopscience.iop.org/article/10.1088/1742-6596/1469/1/012179/meta

x
2D vs 3D