Electric cars

We live in the most real ocean of energy, it surrounds us everywhere. Even a fixed stone lying on the road can potentially do work. Sometimes it's hard to believe, but the energy is one. It only transforms, changes its nature. It is this property that is used by human-made electrical machines.

If electric energy is supplied to the input, and at the output it is transformed into mechanical work in the form of shaft rotation, then we can say with confidence that this is an engine. In turn, the conversion of mechanical work into electricity is entrusted to the generator. An important feature is the fact that the same electrical machines are characterized by the ability to function as a consumer (motors) and a generator (generator) of electricity. This is due to the same device. However, due to the design features, the operation in the "non-native" mode is characterized by a lower efficiency.

Electric DC machines are divided into two classes: inductor and collector. The most common were the second (a sign of the presence of a brush mechanism). The principle of operation is the following: a permanent magnet is placed on the fixed part of the machine (stator) , creating lines of field strength.

The armature winding can be represented as consisting of a plurality of copper wire frames connected in such a way that the beginning and the end are projected onto the opposite lamellae of the manifold. From the outside, DC voltage is applied to these terminals by means of graphite brushes. And if there is a closed circuit, then an electric current will appear. Moving charge carriers generate around themselves a magnetic field that interacts with the stator field. As a result, a force arises that causes the armature to rotate. Only the main points are described, but they are enough to understand how electric DC machines work. Particularly worth mentioning is only a universal collector motor having the design inherent in DC machines, it is capable of operating from a household power network of 220 V. This is possible due to the serial method of connecting the armature and the field windings. In household electric power tools they are used.

Electric AC machines are structurally more simple and reliable, and the cost of their production is lower. They are divided into synchronous ones, in which the mechanical speed with which the rotor is drawn coincides with the frequency of rotation of the stator field, as well as asynchronous varieties in which the rotor lags behind the field (slips). The first is more rational to use at capacities of more than 100 kW.

The simplest AC electric machines are represented by three-phase asynchronous with a squirrel-cage rotor (squirrel cage). Three windings are placed on the stator, which are shifted relative to each other by 120 °. It is to them that an alternating current of the corresponding phases is applied. The rotor has its own winding, short-circuited, thereby forming a circuit for passing the induced current. It is necessary to apply voltage to the pole-coils of the stator, as a magnetic field is generated around them - this is one of the basic properties of the directed movement of electrons. And since the current is variable, the field turns out to be rotating. Its tension lines cross the turns of the rotor winding and create an induced current (we apply the law of electromagnetic induction). And once there were movements of particles with a charge, then around them, in turn, a magnetic field also appears. It also rotates (you can find the direction by using the rule of the borer). As a result, there are two magnetic fields inside the machine body. Further everything is simple: thanks to Ampere's law , a force appears that tends to displace the windings, and since the rotor shaft is fixed to the bearings, the force creates a torque. To do the work, it only remains to connect the actuator to the shaft.