Types of electromotor coils
Types of electric motor windings are used in different conditions and different types of electric motors have their own windings. The basis of the work of electric motors is based on the magnetic field, and the windings are responsible for producing the magnetic field required for the operation of the motor, so it is very important for people who work in this field to be familiar with the types of windings in electric motors. Since different motors are produced for different purposes and each has its own winding, in this article we will focus more on introducing the types of electric motor windings that are most used. But you don't need to worry about the completeness of the information, because we explain the main winding methods to you, which are the basis of the winding of different types of motors, and in this way, after reading this article, you will have a general and clear view of the types of motor windings. You will have electric. But first of all, let us share with you the terms that you should know to understand this matter better and then go to the types of windings of single-phase and three-phase electric motors.
Essential concepts for understanding the types of electromotor coils
Pole pitch (Y): Pole pitch is the number of slots of a stator covered by one pole.
Number of motor poles (P): The number of poles for the winding in electric motors is already specified on the main winding map, so you can see the number of winding poles on the motor nameplate.
The number of phases (M): The number of phases, as you can guess, is the number of phases of the mains electricity, which is 3 for the winding of three-phase motors and 1 for single-phase motors.
The number of grooves (Z): the number of grooves inside the motor shell that can be counted objectively and the stator windings are placed inside them.
Types of Tomb Phase electromotors
Winding of single-phase motor with two-phase design: These single-phase motors have a permanent starting coil, and the winding coils are placed in such a way that half of the grooves are related to the starting coil and the other half of the grooves are to the main coil. are allocated These two coils have a 90 degree electrical phase difference. The steps to perform this type of winding are: "Making calculations related to winding, preparing winding table, drawing diagram and winding map, performing winding and winding" you should keep in mind that motor winding The single phase of the two-phase design is done in two ways: fractional step and full step, which we will explain to you in the following.
Fractional pitch winding: If in a winding, the phase difference between the beginning and the end of a coil is less than 180 degrees, it is called a fractional pitch winding. In this type of winding, the electric driving force that is inside the arms of the coils are added together, and in this way, you should keep in mind that the result of the addition will be less than the algebraic addition, and that is why we use this method in the motors. Fractional steps are wound, we see that the driving force of the motor is reduced and this will reduce the final power of the motor. To compensate for this issue, it is used to increase the number of revolutions of the motor coils and shorten the steps.
Full pitch winding: If there is a 180 degree electrical phase difference at the end and beginning of a winding coil, and also the forces in the reciprocating arms of each coil add up algebraically and not vectorially, then we have a full pitch winding. . In this type of winding, the number of grooves between the reciprocating arms of each coil is equal to Y, or in simpler words, the pole pitch is equal to the winding pitch.
Winding of single-phase induction motor with permanent capacitor starter: In these motors, electrolytic capacitors are used for starting, which are mostly used at the moment of starting. Usually, the capacity of the capacitors used to start the motor is up to 200 microfarads. The reason that this capacitor remains in the circuit after starting the motor is to help create a phase difference in the winding of the electric motor.
Permanent auxiliary coil in a fractional step circuit: The placement of the coils on the stator surface is such that to determine the position of the coils in the grooves of the motor shell, we must consider whether q is even or odd. Motors wound by the permanent auxiliary winding method in the circuit have the same structure as three-phase motors, with the difference that in these windings, two separate hypothesized phases are considered, the degree difference of which is 90 electrical degrees, this phase difference It will create a rotating magnetic field and cause the motor to move.
Three -phase electromotor coil
In this section, we will review the types of ends used for winding three-phase motors together and provide you with useful information in this regard. In three-phase motors, there is usually a part called the coil board, where you have access to the winding heads of all the coils, in most cases, the heads in the coil board are such that there are two heads for the coils of each phase. One of these heads is the input of the coil and the other is its output. In the following, we will introduce you the different types of three-phase electric motor winding heads.
Triangle connection: This type of connection is shown on the engine nameplate with the shape of a triangle or English D, and the way to connect the ends of the wires is that the end of the first coil is connected to the end of the second coil, the end of the second coil to the head of the third coil, and the end of the third coil. It is connected to the head of the first coil and it can be said that the three groups of coils corresponding to the three phases form the three sides of a triangle.
Star connection: This type of connection is indicated by Y and it is the way that the ends of all three coils are connected and we connect the main phases to the ends of the coils respectively.
