Difference between Generator and Alternator

Generator and Alternator both are very important terms in electrical engineering. Most of the Students have confused about the difference between a generator and an alternator. Some of the students think that they are the same and some of the students think that they are different. In this article, I will clear all doubts about the Difference between Generator and Alternator.

The Alternator and Generator both convert mechanical energy into electrical energy. So what is the difference between a generator and an alternator? The main difference between the alternator and generator is in the generator the magnet (either the permanent magnet or electromagnet) or field system is stationary and the armature is rotating but in the case of the alternator the armature is stationary and the field is rotating.

The other important difference between the generator and alternator are given below:

click on the below table to enlarge

Key Difference between Generator and Alternator:

1. The Generator has Armature as a rotating part and has the main field as a stationary part. On the other hand, the Alternator has the main field as a rotating part and has the armature as a stationary part.
2. The generator may be two types AC or DC. There are both types are available. But the alternator only can produce an Alternating current which is why it is called an Alternator.
3. The generator is always used for a small amount of power generation and the RPM of the generator always less than the alternator. Alternators are mainly used for a large amount of power generation and also used for a small amount of power generation. The alternator has a large RPM rating than the generator.
4. We know that in a DC generator the induced emf in the armature winding is alternating in nature and it causes to produce alternating current so to convert alternating into direct current commutator is used in DC Generator. On the other hand, Alternator has not any commutator mechanism.
5. Among the same rating of generator and alternator, the generator always has less efficiency than the alternator for its brush, commutator, and other reasons. But the alternator has more efficiency than the generator.
6. Among the same rating of generator and alternator, the generator is heavier than the alternator for its commutator and other arrangements. On the other hand, as the alternator has no commutator arrangement so lighter than the generator.
7. We know that DC has polarity positive and negative. So polarization must be taken during the installation of A DC generator. For AC generator it does not need. During installation of the alternator also polarization does not need.
8. As I told you previously that generators are used for only low-power generation purposes but alternators are used for low-power generation as well as high-power generation.

So the main difference between generator and alternator is the constructional difference and power generation capacity. You can write the above differences in your exam.

As there are so many differences but they have some similarities also such as,

1. Both generators and alternators are devices that convert mechanical energy into electrical energy.

2. Both generators and alternators operate based on the principle of electromagnetic induction, which states that a changing magnetic field induces an electric current in a conductor.

3. Both generators and alternators consist of similar basic components, including a stator and a rotor. The stator is the stationary part of the device that contains coils or windings through which the magnetic field passes. The rotor, which is the rotating part, carries the conductive elements (coils or magnets).

4. Both generators and alternators can be designed to regulate the output voltage. Voltage regulation ensures that the electrical output remains within a specific range, regardless of variations in the mechanical input or load conditions.

5. Both devices are used to generate electrical power for various applications. Generators are commonly employed in power plants, construction sites, and backup power systems, while alternators are widely used in vehicles as a source of electrical power.