Alternator: Design and Purpose
Alternator - what is it? This is an electric machine that converts the energy of mechanical interaction into electricity. How does she work? The law is fundamental to the principles of operation of such a device as an alternator. As is known from the laws of electromagnetism, an electromotive force (EMF) can be induced (generated) only in a few cases: when the magnetic flux parameters change around the conductor itself or when the conductor moves in magnetic fields. The magnetic field is a material medium that can be found exclusively empirically (empirically). That is, to identify the presence or absence of such a force field in the area of its possible action, it is necessary to introduce a conductor with a current or a magnetized body.
Characteristics of the generator
In a device such as an alternator, the main part is occupied by an electromagnet.It consists of a ferrimagnetic core and a coil and is designed to form a magnetic flux. There are a set of basic requirements that apply to such machines: rotation range from 50 to 12000 revolutions per minute, the widest range of possible capacities (from a few watts to hundreds of megawatts), minimum weight and dimensions, high reliability and performance.
Three Phase Alternator
Usually such a machine is synchronous. Its main task is the conversion of any type of energy into electricity. Traditionally, this is mechanical energy. Why is an alternator called synchronous? This is such a brushless machine, whose rotation speed is constant and at a given frequency is determined by the number of poles. The alternator received a huge spread in production and in rail transport. It is precisely due to the synchronism of rotation that it is used in refrigerator sections and diesel locomotives.
Alternator: device and basic principles of operation
If the rotor and the inductor are rotated, then an emf will be induced in the stator windings.This phenomenon is the basis for the operation of both three-phase and single-phase machines. Due to the widest application in diesel locomotives, the primary engine in such traction synchronous generators can even be diesel (internal combustion engine). The fixed part of the alternator is the stator, which consists of a core and a housing.A winding is inserted into the grooves of the stator, due to which EMF is induced. The core is assembled from pressed sheets of special electrical steel. The rotor is a shaft on which the cores of the generator poles are fixed. There are poles bright and weakly expressed. The winding is made of copper wires, usually round or rectangular section. The ends of the winding lead to slip rings. With the help of brushes installed in the brush holders, which are pressed to the contact surfaces by springs, current collection is performed. Given the simple design, it is quite possible to make an alternator with your own hands. The principle of its operation is extremely simple. The rotor rotates with the engine. The magnetic field of the rotor rotates with it.It is on this principle that the alternator works.