Brushless Alternator Working principle| Advantages, Disadvantages | Applications

This Article is all about What is Brushless Alternator ? Its Working Principle, Parts , Operations , Applications, Advantages and Disadvantages.

A brushless alternator mainly consists of two parts :-

1. Main alternator and
2. Excitor alternator

A Brushless alternator is made up of two alternators that are built end-to-end on a single shaft. Smaller brushless alternators may appear to be a single unit, but the two parts are easily distinguishable on larger models. The main alternator is the larger of the two sections, and the exciter is the smaller. The exciter contains stationary field coils as well as a rotating armature (power coils). The primary alternator employs the inverse configuration, with a rotating field and a stationary armature.

1.Main alternator

The main alternator which has a rotating field and a stationary armature (power generation windings). This is the part that can be confusing, so keep in mind that in this case, the armature is the stator, not the rotor.
The high current output does not have to pass through brushes and slip rings because the armature is in the stationary portion of the alternator. Although the electrical design is more complicated, it results in a very reliable alternator because the only parts subject to wear are the bearings.

2.Excitor alternator

The exciter field coils are located on the stator, while the armature is located on the rotor. The exciter armature’s alternating current output is fed through a series of diodes mounted on the rotor to produce a direct current voltage. This is fed directly to the main alternator’s field coils, which are also located on the rotor. Brushes and slip rings are not required to supply current to the rotating field coils in this configuration. In contrast, a simple automotive alternator uses brushes and slip rings to supply current to the rotating field.

Basic terminology of Alternator

stator – The stator is the stationary component of a motor or alternator, and

rotor :-the rotor is the rotating component.

Magnetic field :- The coils of wire used to generate a magnetic field are referred to as the field, and

Armature :- the coils that generate power are referred to as the armature.
This can be perplexing because most people associate the armature with the rotor. Traditionally, the armature was located on the rotor, but this is not always the case. The two terms are not interchangeable. In a typical automotive alternator, for example, the field is on the rotor and the armature is on the stator. The mechanical configuration consists of a rotor and a stator.

This is very confusing because most people associate the armature with the rotor. Traditionally, the armature was located on the rotor, but this is not always the case. The two terms are not interchangeable. In a typical automotive alternator, for example, the field is on the rotor and the armature is on the stator. The mechanical configuration consists of a rotor and a stator.

Basic working theory of alternator

A magnetic field is created when an electric current is passed through a wire coil (an electromagnet).
When a magnetic field is moved through a wire coil, a voltage is induced in the wire. When the electrons have somewhere to go, such as a battery or other load, the induced voltage becomes a current. Both of these processes occur in alternators, motors, generators, or dynamos.

When a wire coil is moved through a magnetic field, voltage or emf is produced. It makes no difference whether the coil or the magnetic field is moving. Depending on mechanical, electrical, and other objectives, either configuration works equally well and can be used separately or in combination. The old direct current (DC) generators (dynamos) had a stationary field and a rotating armature.
Alternators in automobiles use the opposite configuration, with a rotating field and a stationary armature. Both configurations are used in a brushless alternator in the same machine.

Working principle of Brushless alternator

Alternator works on the principle of faraday’s law of electromagnetic induction.

Brushless alternator Working

We understand the construction of working now let us know about working. There is a residual magnetism attach to the exciter stator. Now when main rotor starts rotating, excitor stator also rotates. Due to faradays law of electromagnetic induction ac current is produced in coils of rotor excitor ( excitor coil ).

Now this ac current is used for exciting. This AC current is passed through bridge rectifier converted into DC. This Dc supply is given to the main rotor. This Dc current produced magnetic field.

Due to rotation of main rotor, Flux of magnetic field cut and AC Current generated in the Coil of\ Stationary main stator. This DC output is used for different applications. Thus, we understand here that how brushless alternator work.

AVR

The another main components of brushless alternator is AVR, It is called automatic voltage regulator. It is used for maintaining constant voltage. In Many diagrams in parts and components and explanations will use the term “AVR” without explaining what it is. Automatic Voltage Regulator (AVR) is an abbreviation for Automatic Voltage Regulator. An AVR performs the same function as a car’s “voltage regulator” or a home power system’s “regulator” or “controller.”

Advantages of Brushless alternator

1. Not use of Brushes and Slip rings
2. less maintenance.
3. The output power of this alternator is more than brushed alternator.

Disadvantages

1. Initial cost is higher than brushed alternator.
2. Required expert person to do maintenance.

Application Of brushless alternator

1. It is used in the wind turbine.
2. In the train
3. It is used only in the Case of Alternating current.

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