Question

What are the main parts of a DG set?
1. Engine only
2. Alternator only
3. Engine – Alternator
4. Engine – Alternator – Exciter

Answer 1

Correct Answer - Option 4 : Engine – Alternator – Exciter

Diesel generator set or DG set:

• Diesel generators operate as an electrical machine that converts one source of energy into another form of energy.
• In this case, a power generator works by taking mechanical energy and converting it into electrical energy.

 

The Main Parts Of A Diesel Generator:

Every diesel generator is made up of at least nine different - but equally important - parts. These are the:

1. Diesel Engine
2. Alternator
3. Excitor
4. Fuel System
5. Voltage Regulator
6. Cooling System & Exhaust System
7. Lubrication System
8. Battery Charger
9. Control Panel
10. Main Assembly Frame or Skid

 

Diesel Engine:

• This is simply a basic diesel engine, it’s no different to the ones found in cars, vans, lorries, or other large vehicles.
• This is the source of mechanical energy and the size of the engine matters.
• The larger the engine larger will be the generator output. The larger the engine, the more electrical output you are able to produce.

 

Alternator:

• This is essentially the component that’s responsible for generating power output. The concept of electromagnetic induction comes into play.
• An alternator is made up of many complex components, but one of the most crucial aspects is the rotor.
• This is a shaft that rotates - driven by the mechanical energy supplied by the engine - with multiple permanent magnets fixed around it.
• In doing so, this creates a magnetic field.
• This magnetic field created continuously rotates around another critical part of the alternator: the stator.
• Simply put, this is a variation of different electrical conductors that are tightly wound over an iron core.
• According to the principle of electromagnetic induction, if an electrical conductor remains stationary and a magnetic field moves around it, then an electrical current is induced.

In summary, the alternator takes mechanical energy created by the diesel engine, which drives the rotor to create a magnetic field that moves around the stator, which in turn generates an alternating current.

Excitor:

• The main purpose of an exciter in a generator(alternator) is to provide a stationary rotating magnetic field.
• Which is used to induce the e.m.f in the armature coil.
• So, DC power is given to the exciter and the exciter is nothing but a coil, and the exciter creates a magnetic field.