We cannot imagine modern life without electricity, forcing us to find several ways to generate it. Using generators is one way of producing electricity and AC (alternating current) generators are a crucial part of the power source. They transmit electrical energy over a long distance and are used for powering electrical devices for facilities and cities. An AC generator is an electric generator that converts mechanical energy into electrical energy in the form of alternating current.
The mechanical energy is supplied through combustion engines, steam turbines, and gas turbines. Unsurprisingly, an AC generator has advantages and disadvantages.
What is an AC Generator?
An AC Generator is an alternator that is used for converting mechanical energy into electrical energy in alternating current form. It follows the principle of electromagnetic induction to carry out its work. Electromagnetic induction was discovered by Michael Faraday, who found out that the above change in magnetic field within a closed loop of wire induces an electromotive force (EMF) in the wire.
In the AC Generator, there is a coil that rotates in the magnetic field. It causes a change in the magnetic flux and induces an AC voltage across the coil’s ends.
AC and DC both get compared with each other often, but one cannot deny AC has one advantage over DC. That is its voltage level can be changed easily with the help of transformers, which makes it more suitable for long-distance transmission.
You will find AC generators being used more frequently as compared to DC ones. They are the primary source of electrical power in the world and are also used in power plants to generate electricity. That electricity in power plants is further distributed for residential, commercial, and industrial use.
How AC Generator Work?
AC generator works on the principle of electromagnetic induction. Here, the relative motion between the coil and the magnetic field induces the electric current in the coil. The AC generators are further classified into various types.
A few of them are three-phase generators, single-phase generators, induction generators, and synchronous generators. Typically, an AC generator includes a coil, strong magnetic field, slip rings, and brushes.
Fleming’s right-hand rule determines the direction of the induced emf (electromotive force) in these generators. The magnetic field moves from left to right, so when the coil moves in the clockwise direction one side moves down while the other moves up. This induces emf in one direction.
As the rotation continues, one side moves up and the other side moves down, therefore inducing emf in the reverse direction. In a nutshell, this is how AC generators operate. Now that you have a brief overview of the functionality, let’s delve straight into the pros and cons of its use.
Advantages of an AC generator
These generators allow the use of transformers to step up and step down, which further reduces transmission losses. Some other upsides of an AC generator are:
1. It is easy to use and maintain
The working of the AC generator that we showed above might give you an idea of its simple design. The only moving part of this generator is the rotor. Its straightforward design makes it simpler to understand its working principle.
Unlike other generators, it does not include complicated parts that tend to wear out. Additionally, AC generators are easier to maintain and are highly reliable.
2. AC generator is cost-effective
The cost of ownership with AC generators is low. It does not require an additional system for power generation. Therefore, in the long run, using AC generators becomes cost-effective. Furthermore, it is more efficient in transmitting power over long distances. Plus, they require low maintenance, which further lowers the operating cost.
3. It does not require matching voltages
With a DC generator, the voltage needs to be produced at a certain level for optimal use. However, there are no such requirements when it comes to AC generators. This is because you can use a transformer to convert the current into the other voltage.
The additional benefit of using a transformer is that it makes the distribution of the output from an AC generator easier. Whereas in a DC generator, you cannot use a transformer as it is incompatible.
4. AC generators promote the consumption of power
In the 19th century, Nikola Tesla created a system for turning current into motion efficiently. This system was an AC motor that used electromagnetic induction to convert electrical energy into mechanical energy. He patented the first AC motor used with the alternating current power.
Due to increased efficiency and cost-effectiveness, these generators became popular in the factories and industries in the United States. Earlier, direct current motors existed that were not only complex in design but also costly. The invention of AC generators additionally promoted power consumption.
5. It operates silently
The other advantage of AC generators is that it operates silently. This is because it has fewer rotating parts that do not make noise. It is unlike a DC generator, where several moving parts in its design produce noise during the operation. Additionally, AC generators don’t have a smell. Whereas in a DC generator, a typical smell and noise are produced due to the friction between its components.
Disadvantages of an AC generator
When working with an AC generator, you need to take extra caution as it includes high voltages, bringing us to a handful more downsides of its use:
1. It requires greater insulation
Compared with DC generators, the AC generator is difficult to work with. The reason is the AC motor requires massive voltage to supply a fixed amount of power. Plus, there are risks associated with the handling of this type of generator. This system requires higher insulation as a result of greater voltage requirements.
2. AC generators are not durable
The AC generator produces massive currents, which can result in hazards, thereby affecting its durability. This shows AC generators aren’t long-lasting compared to DC generators. Additionally, AC generators are not suitable for the production of alternating current on a large scale.
3. It is susceptible to overheating
AC generator produces high currents which make it sensitive to sparks and overheating. This happens as the resistive heat is produced in the AC generator when the electricity flows through the generator and transformer coils. The resistive heat results in hazards. It damages the insulation, therefore causing the fire. Unquestionably, electric shocks and fire are detrimental to the employees and the properties.
4. AC generators require a transformer
While it’s an advantage to use a transformer to convert the current into another voltage, on the flip side, using a transformer becomes a limitation. This is because, without transformers, long-distance transmission can be a problem in AC generators. Additionally, utilizing a transformer is the only efficient way of generating high voltage in AC generators.
AC generators come with their sets of advantages and disadvantages. However, there’s no denying that the benefits it offers outweigh the associated drawbacks. AC generators are highly efficient and reliable and are mostly used for powering smaller motors and electrical appliances at home.
Plus, the energy losses are reduced in AC generators, hence making them more efficient. But when using this generator, you should put extra safety measures in place to avoid dangers.
Applications of AC Generator
AC Generator is used for many causes, let us have a look at some of them:
- Electricity Generation: When we talk about the cornerstone of modern electric power generation, AC Generators are the first thing that comes to our mind. They are everywhere. We see them being used in power plants that use coal, natural gas, and whatnot.
- Automobiles: You will be surprised to learn that AC Generators are the heart of many automobiles. They are known as alternators in cars. They charge the battery and power the electrical system when you run the engine. Without them, the vehicle may not operate.
- Portable Power and Emergency Backup: In places where electricity cannot be provided, portable AC Generators are used. They provide electricity there. Those places can be construction sites, camping sites, etc. They are also used as power backup sources during emergencies.
AC Generator vs DC Generator
Difference between AC (Alternating Current) and DC (Direct Current) generators:
| Aspect | AC Generators | DC Generators |
|---|---|---|
| Current Type | Produces an alternating current, which changes direction periodically | Produces a direct current, that flows only in one direction |
| Complexity | Generally more complex due to the need for a secondary device (rectifier) if DC power is needed | Simpler as they directly produce DC power |
| Efficiency | Higher efficiency at high voltages and long distances | Lower efficiency at high voltages and long distances |
| Use Cases | Power grids, high-power electrical devices | Battery charging, automobiles, electronic devices |