What is an electric motor and detailed discussion?
The electric motor is a technique by which electrical energy is converted into mechanical energy. In other words, with the help of the motor we are giving electrical energy as input and we are getting mechanical energy as output. The structure of the electric motor and generator is almost the same but opposite to each other in terms of function.
Types of motors
The motor is mainly divided into two parts.
- AC motor.
- DC motor.
AC motor.
AC motors run water pumps, fans, etc. An AC motor is an electric motor driven by an alternating current.
DC motor.
There are many types of DC motors. There are many types of DC motors available in the market. Some of them have more or less torque and some have more or less RPM.
The most available DC motors in the market
- Gearless motor
- Geared motor
- Stepper motor
- Servo motor
Motor structure
There is no difference in the structural aspects of DC Motor and DC Generator. But they are different in terms of work.
The main parts of a DC motor are basically two parts
- Stator
- Rotor
Stator
It is usually stationary in the motor and receives a power supply.
Rotor
It is a rotating part that produces mechanical rotation. Besides, the motor consists of many more parts
- Yoke or frame
- DC motor pole
- Field winding
- Armature winding
- Commutator
- Brush
All the parts come together to form a DC motor.
Motor torque
Many of us know more or less about motor torque. Torque is the value obtained by multiplying the amount of energy produced in the opposite direction by their internal angles. That is energy × conic distance
This frictional tendency is called torque when the current flowing through the conductor generates a force and the conductor tries to rotate clockwise. The value of torque is equal to the product of the perpendicular distance from the center of force and rotation.
T = F × r
T = Torque,
F = Force
r = Perpendicular distance from the center of rotation.
Torque causes a reverse voltage. A motor reverse voltage or Back EMF
The voltage at which the reverse energy of the current produced is predominant and consumes energy is called reverse voltage.
It is not possible to eliminate EMF from the back of the motor, but it is possible to reduce it as much as possible. The following circuit is used to reduce the back emf.
The inductive load is used here so that the back emf generated from the reel coil cannot enter the transistor. The diode is used to protect the circuit. The reverse voltage can be much higher due to field-specific reasons which protect the diode. The diode is in reverse bias with inductive load.
The voltage at which the inverse energy of the current produced is predominant and consumes energy is called reverse voltage / Backemf.
To produce a magnetic field in any place means to create back emf. There is no such thing as a motor. It is in a simple inductor. The motor has mainly two parts Starter & the rotor. This produces back emf in the magnetic interaction of the stator & rotor.
Now the question is it beneficial or harmful?
It actually works. What’s the use?
It basically minimizes the surge / rushes current of the motor.
How?
The inverse voltage of the input. So the reverse orientation of the input voltage suppresses the excess current.
For example, a speeding car slows down when it sees a car in front of it by pressing the brakes. Now the question is why the current take more at the beginning?
Because, in the beginning, the winding/turns are in a relaxed condition. Then the back EMF is 0. So he pulls a lot of currents.
Moreover, this back emf is also useful to reduce copper loss.
Motor winding
A Motor winding refers to the wire patch or coil. Motor winding must be in every motor and generator.
Motor shunt and series winding
The coils whose wires are thin are called shunt-winding. This type of coil has many punches and its resistance is very high. The series winding is the exact opposite. There are fewer punches and the current can flow much easier.
RPM of the motor
RPM is the revolution per minute, that is, the number of times a motor can rotate in one minute is called RPM. These are mentioned in motor and vehicle specifications. So the higher the RPM, the higher the rotational capacity.
Motor Efficiency and Losses
How much efficiency does it have to say motor efficiency? The ratio of the output power of the motor to the input power is called the efficiency of the motor. It is never possible to get 100 percent efficiency of the motor. Some of the reasons for this loss are copper loss of motor, loss of iron of motor, mechanical damage of motor, the strength of friction, back EMF, etc.
0 মন্তব্যসমূহ