For more than a century, mankind has been using electricity in all spheres of activity. Without it, it is simply impossible to imagine a normal life. With the help of special machines, mechanical energy is converted into alternating or direct current. To better understand how this happens, you need to understand what the generator consists of and how it works.
Content
- Conversion of mechanical energy into electrical energy
- Alternator design
- Classification and types of units
- Main areas of application
Conversion of mechanical energy into electrical energy
At the heart of any generator lies the principle of magnetic induction. The first electric cars appeared in the second half of the 19th century. Their inventors were Michael Faraday and Hippolyte Pixie. In 1886, there was a public demonstration of an alternator, a device capable of generating current from mechanical motion.
The first three-phase alternator was developed by the Russian Dolivo-Dobrovolsky. In 1903, he also built the very first industrial power plant on Earth, which became a power source for an elevator.
The simplest circuit for an alternator is a wire coil spinning in a magnetic field. An alternative is when the coil remains motionless and is crossed by a magnetic field. In both cases, electrical energy will be generated. While the movement continues, an alternating current is generated in the conductor. Generators are used to generate current all over the world. They are part of the global power supply system of the globe.
Alternator design
How the generator works depends on its purpose, and various modifications are possible. but there are two main components:
- The rotor is a moving element made of solid iron.
- The stator is stationary, it is assembled from insulated iron sheets. Inside, it has grooves in which the wire winding passes.
To obtain the highest magnetic flux density, the distance between these parts of the unit should be as small as possible. The excitation winding on the rotor is fed through the brush system.
There are two types of construction:
- with a rotating armature and a stationary magnetic field;
- the magnetic field rotates, but the armature remains in place.
The most widely used machines are machines with moving magnetic poles. It is much more convenient to draw electricity from the stator than from the rotor. In general, a generator is built in the same way as an electric motor.
Classification and types of units
Units for converting mechanical energy into electrical energy have a similar design. They can differ in the principle of operation of the generator and the field winding:
-
independent excitation comes from a battery; - the source is a direct current generator;
- the excitation source is located on the same shaft as the main one;
- self-excitation by rectified current;
- from permanent magnets.
By design:
- pronounced poles;
- not expressed.
By the method of connecting the windings:
-
Tesla system; - star;
- triangle;
- Slav.
Depending on the number of phases:
- single-phase;
- biphasic;
- three-phase.
DC units are designed in such a way that the mechanism for removing energy consists of two isolated half-rings, each of which receives a charge of a certain potential. At the output, a pulsating current of one direction is obtained.
Synchronous generators have an armature with a winding that is supplied with direct current. By adjusting its value, you can change the strength of the magnetic field and control the output voltage. In asynchronous, there is no winding, instead the effect of magnetization is used.
Main areas of application
It is worth remembering that ordinary electricity in outlets comes from the work of huge alternators in thermal power plants. The scope of these electric machines includes all types of human activities:
- are used as a backup source of energy at facilities where power outages must not be allowed;
- irreplaceable in places where there are no power lines;
- most of the vehicles are equipped with a generator, it generates electricity for the on-board network;
- power supply for hydrolysis units;
- industry;
- at nuclear and hydroelectric power plants.
Recently, household appliances for generating electricity are gaining more and more popularity. They are compact in size and low in fuel consumption. They can run on gasoline and diesel. They are used in field conditions, in the country or as an emergency power supply.
The invention of a method for producing electricity from mechanical motion was of epoch-making significance for the development of modern civilization. The world around us is full of mysteries, the answers to which are unknown, but, perhaps, other important discoveries that can change their lives await people.
