How does an electric generator work?

An electric generator is a device that converts mechanical energy into electrical energy. More specifically, it does this by spinning a coil of wire inside a magnetic field. The mechanical energy comes from the stem shown in the picture above and rotates the coil, which creates an electric current in the wires within.

The way it works is really simple: as long as you keep turning that handle on top, electricity keeps coming out of those wires! It kinda like when you turn your hand mixer for too long – eventually all your batter will mix together.

What is an electrical generator?

What Is An Electrical Generator?

Electrical generators are mechanical devices that convert rotational energy (such as from a crank, wind, flowing water, or moving magnets) into electrical energy.

How do generators work?

One way to think about a generator is to consider the spinning bicycle wheel (see the picture above). As its tire turns over from pedaling, it turns a shaft inside the hub of the wheel. This shaft drives an electric generator via a set of gears.

The generator produces electricity and sends it via wiring mounted on the outside of the hub to another part of your bike.

How Do Generators Work?

A more technical description is that electricity is produced in generators when an alternator’s field coil is rotated within a magnetic field.

This rotation creates a rotating magnetic field. The rotating magnetic field induces an electrical current in a conductor, which is then used to power an electrical load such as an electric motor, light bulb or rechargeable battery.

Main Parts of electrical generator

The three main parts of an electrical generator

  1. Radiator
  2. Engine
  3. Alternator
  4. Skid (Frame)
  5. Oil Filter
  6. Battery
  7. Air Filter
  8. Control Panel



The air flowing through the radiator heats up as it moves past the coils, which causes a temperature rise in the water-cooled core. The steam inside the radiator transforms into water vapor. After that it absorbs its latent heat and becomes a coolant.



Maintenance for this part of an electrical generator is very important. Because this section is relatively small, a mechanical failure can cause many problems on your generator and require repairs.

The easiest way to maintain it is to ensure that you are only using clean oil with detergents that can remove waste oil spills at regular intervals.

Main Rotor (General)

Main Rotor (General)

The main rotor is a “U” shaped shaft with a number of coils wrapped around it. The main rotor sits in the middle of the shaft and this rotates while the generator runs. The Coil consists of multiple turns of wires with magnets attached to each turn.

The magnets are supplied by a magnet rotor or spool, which is attached to the shaft. Electromagnets create a magnetic field around this spool, which then accelerates the magnet rotor/spool as it spins around inside the generator stator winding.

Power is generated when current flows from one wire to another as the magnet rotates between them (electromagnetic induction).


Generator Alternator

This is one of the best known parts of an electrical generator. The alternator is used to generate electrical current by a rotating magnetic field. It is composed of an armature, which is the revolving part and is made up of commutators and conductors.

A commutator reverses the direction of the current inside the conductor, and there are three different types: Delta, Star, and Matrix Commutators. Matrix Commutation allows for 3-phase electricity to be generated by simple 2-phase power sources, which will be discussed later.

Skid (Frame)

Generator Skid (Frame)

A Skid frame protects a generator from damage during transportation and storage by making it stronger. The Skid frame also serves as the foundation for the generator’s support structure.

This is important as the entire generator weighs up to 100 kg (220 lb) when fully loaded with oil and R22 refrigerant, its rotor or stator and its oil pump, oil filter and the refrigerant lines.

Oil Filter

Generator Oil Filter

This is a very important part of an electrical generator. The oil-water mixture that circulates through the inside of the sealed oil tank must be clean because dirt can cause wear on any moving parts, thereby causing damage to the machine such as wear on bearings and seals which are used in all rotating machinery.

On some generators, there can be as many as 30 oil filters installed over the course of the entire unit’s lifespan. For that reason, it is very important to keep your oil clean and free from dirt or moisture.


Generator Battery

A battery is an electrical storage unit that produces direct current (DC) through chemical reactions. There are many types of batteries used in generators such as cars, trucks, buses, or marine and mobile phone batteries.

A generator uses a battery with a large number of individual cells that are connected together in parallel to produce DC. The battery can be rechargeable (recharging it repeatedly) or non-rechargeable.

Lubrication System

Generator Lubrication System

This is where lubricating oil is pumped through the generator via an internal manifold. This oil is then used to lubricate parts such as the main axle, bearings and gears.

The DC electrical system of a portable generator was first introduced in 1937 by D.C. Coleman Power Equipment Company, and for many years was available only in large industrial plants, power stations and substations.

The term “generator” refers to any facility that converts one form of energy into another for use on site: for example, a hydroelectric dam can be considered a large generator that converts the energy in water into electrical or mechanical energy using its turbines and generators.

How does electric generator work – Working principle

The electric generator is made up of two parts; a magnet and a wire. When the wire is moved inside the magnetic field, electric charges are collected on it. These charges are then collected in separate units called “batteries” and are used to power appliances or equipment.

The simplest generators work by passing direct current through a wire that is wrapped around an iron core. In this way, they produce a changing magnetic field which produces more voltage in the wire when it passes through it.

How Does Electric Generator Work - Working Principle

If you continue to wrap one end of the coil with more coils, you would notice that when the number of turns increased, the energy output would become greater than what was required to make it work. In fact, the voltage produced is directly proportional to the number of turns on the wire.

This relationship between voltage and current has been discovered by several physicists and is called Faraday’s law.

Finding The Voltage Across The Coil

Since, the number of turns=n and rate of change in magnetic flux=ΔΦ then Φ= ΔΦ/ n.

Hence, differentiating Faraday’s law gives:

This equation can be rewritten as:

Using this equation we can find the voltage across a coil if we know flux across it. However, this way cannot give you a good estimation since this doesn’t take into account all factors that affect the actual voltage output from a coil.

I hope now you know how electric generator works.

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