In the study of electrical controls within electrical engineering, all content will be concentrated on electrical machines and their starters and at this point the need arises to understand what electrical machines are. Under the concept of electric machines, motors, generators, and transformers are combined. It is common in electric machines that they all work with the transformation of one type of energy into another and magnetic energy is present in all of them, this is the common denominator of electric machines.
Among the types of electrical machines, we can separate them into two types to understand, rotating electrical machines and stationary or resting electrical machines.
- The rotating electric machines are the motors and the generators, they are called rotary because they have a rotating part in relation to a part at rest (rotor and stator respectively).
- Stationary or resting electrical machines are transformers as they have no moving parts.
The three electrical machines above have in common to transform energy into another type but what mainly differ are what types of energy and the transformations they promote:
- The electric motor, widely used both in industries and in household appliances, is powered by electrical energy and releases mechanical energy, which enables the activation of numerous other devices.
- The electric generator basically does the opposite of an engine, powered by mechanical energy releases electrical energy, this mechanical energy can be from a turbine for example and is the basis for the generation of electrical energy that arrives in our homes.
- The transformer is powered by electrical energy and releases electrical energy, but electrical energy from other parameters, with an increase or decrease in electrical voltage.
Each of the aforementioned electric machines has its complexity and is composed of a mechanical structure that transforms the study of electric machines into a multidisciplinary subject comprising, in addition to electrical, mechanics, physics, thermodynamics, lubrication, refrigeration and many others.