Electricity is an indispensable part of our lives. The domain is as big as going into space, and as small as static electricity when undressing. We use electricity in all aspects of our lives, and we cannot do without electricity. For example, household electricity, factory electricity, and driving vehicles. For such an important electricity, it is very important to learn some necessary knowledge about electricity usage. Here I will introduce all the knowledge and common sense about electric motor boundaries encountered in an empirical way for your reference, I hope it will be helpful to you.
This passage is going to talk about the followings of electric motor:
(1)Introduction of electric motors
(2)Steps to wire an electric motor
(3)Working principles of electric motor
The single-phase electric motor uses a power supply consisting of a live wire and a neutral wire to work. So, connect the power cord first. Although there is a red line and a blue line, there is no difference in position, that is, the two lines in the picture can be interchanged. There is no distinction between zero line and hot line. A single-phase motor also relies on the coil to generate a magnetic field to make the motor rotate. Since single-phase electricity has no phase difference, it must have a phase difference like three-phase electricity to rotate. So, a single-phase motor also has at least two sets of coils. It can be rotated by generating a phase of 90 degrees.
Before wiring any AC motor, be absolutely sure to remove all electricity from the motor circuit. Turn on the circuit breaker that will provide power. Mark the circuit breaker to ensure that power is not accidentally restored to the circuit.
Check the motor manufacturer's manual for advice on proper wiring for your application. If the motor does not have a manual, please look for the connection diagram somewhere on the motor. The schematic can be on the outside of the motor, or under the inspection board or cover of the motor.
For connection diagrams of most modern motors, see the following link in the references section. Find the correct wiring for your specific motor. For example, if the motor is single-phase, single-voltage, and you want it to rotate counterclockwise, the graph will show that the input power is connected to L1 and L2. For CCW rotation, wires 1 and 8 are connected together, and wires 4 and 5 are connected together.
Open the motor cover to access the motor terminals. Strip the end of the power cord and crimp the terminal. Connect the wires to the motor terminals. Use a wire cap to connect the wires together for proper rotation.
After the wiring is complete, replace the cover and energize the motor circuit. Make sure the motor is running in the correct direction.
The basic idea of an electric motor is very simple: you plug in electricity at one end and rotate the shaft (metal rod) at the other end to provide you with the power to drive a certain machine. How does this work in practice? How exactly do you convert electricity into exercise? In order to find the answer, we must go back nearly 200 years.
Suppose you take a piece of ordinary wire, make it into a large loop, and place it between the poles of a powerful permanent horseshoe magnet. Now, if you connect both ends of the wire to the battery, the wire will jump up briefly. When you saw this for the first time, it was amazing. It's like magic! However, this is a completely scientific explanation. When the current starts to creep along the wire, it generates a magnetic field around the wire. If the wire is placed near a permanent magnet, this temporary magnetic field will interact with the magnetic field of the permanent magnet. You will know that two magnets placed close to each other will attract or repel each other. Similarly, the temporary magnetism around the wire attracts or repels the permanent magnetism in the magnet, which is the cause of the wire jumping.
After the motor coil is energized, it is rotated by the force of the magnetic field, and its coil cuts the magnetic line of induction. According to the phenomenon of electromagnetic induction, it does not produce an induced current. This current, together with the current passing through it, does not increase the current passing through the coil. The coil is rotated by the force of the magnetic field again. Why is the direction of the induced current generated by the coil being rotated by the current and cutting the magnetic induction line in the opposite direction? Can electric motors generate electricity?
This passage is going to talk about the followings of ac motor:
(1) Principle of Ac motor
(2) Generator is not motor
(3) How do electric motors generate electricity?
According to the left-hand rule and the right-hand rule, the current directions of the coils are indeed opposite.
However, the motor will not stop rotating because of this, it will keep rotating and output power to the outside. The reason is that the current that causes the coil of the motor to be subjected to ampere force is generated by the applied electromotive force. When the applied electromotive force forces the coil current to flow in one direction, the electromotive force generated by electromagnetic induction at this time has a tendency to weaken the coil current. But it is never possible to overcome the additional electromotive force, otherwise an ideal state without any energy loss will appear. The final effect is that the current in the coil always flows continuously in the direction of the applied electromotive force.
Electric motors equipped with permanent magnets can generate electricity, the principle is electromagnetic induction. However, the alternator made by using the "squirrel cage principle" generally cannot be directly used as a generator because it lacks the necessary circuitry to make the coil a controllable electromagnet.
An electric motor is a device that converts electrical energy into mechanical energy. It uses energized coils (that is, stator windings) to generate a rotating magnetic field and act on the rotor squirrel-cage closed aluminum frame to form magneto-electric power rotating torque. Motors are divided into DC motors and Ac motors according to different power sources. Most of the motors in the power system are Ac motors, which can be synchronous motors or asynchronous motors (motor stator magnetic field speed and rotor rotation speed do not maintain synchronous speed). The motor is mainly composed of a stator and a rotor. The direction of the force movement of the energized wire in the magnetic field is related to the direction of the current and the direction of the magnetic line of induction (magnetic field direction). The working principle of the motor is the action of the magnetic field on the force of the current to make the motor rotate.
Ac motors rely on electricity to provide a magnetic field for work, but they must first have a magnetic field to generate electricity.
Specific to different motor power generation methods have their own characteristics. For permanent magnet motors, because they have a native magnetic field (permanent magnets have a magnetic field), rotating the motor in any direction without energization can generate electromotive force in the windings to generate electricity. Similarly, AC synchronous motors are exciting When the winding is energized, it is basically the same when the working winding is not energized. When the AC asynchronous motor is not energized, because there is no magnetic field, the rotating motor will not generate electricity. When it is energized, in the four quadrants of the motor operation, the two external mechanical energy can generate electricity when the output power of the motor is greater than the output power of the motor. The same applies when the magneto is energized. The situation of DC motor is more complicated, so I won't describe it. Therefore, it is not that the motor can generate electricity by reversing.
Brushless DC motors are common in industrial applications worldwide. At the most basic level, there are brush and brushless motors, as well as DC and AC motors. You might think that a brushless DC motor does not contain brushes, but uses DC current. Compared with other types of motors, these motors have many specific advantages, but fundamentally speaking, what exactly is a brushless DC motor? How does it work and what is its purpose?
This passage is going to talk about the followings of brushless DC motor:
(1) The working principle of brushless DC motor
(2) What are the uses of brushless DC motor?
(3) Select the best motor
It usually helps to explain the working principle of a brushed DC motor because it has been used for a while before the brushless DC motor is available. The brushed DC motor has permanent magnets on the outside of its structure and a rotating armature on the inside. The permanent magnets fixed on the outside are called stators. The armature that rotates and contains electromagnets is called a rotor.
In a brushed DC motor, when current flows to the armature, the rotor rotates 180 degrees. To advance further, the magnetic poles of the electromagnet must be reversed. When the rotor rotates, the brushes come into contact with the stator, which reverses the magnetic field and makes the rotor rotate a full 360 degrees.
Brushless DC motors actually flip from the inside out, so there is no need to use brushes to flip the electromagnetic field. In a brushless DC motor, the permanent magnet is located on the rotor and the electromagnet is located on the stator. The computer then charges the electromagnet in the stator to rotate the rotor 360 degrees.
The efficiency of brushless DC motors is usually 85-90%, while the efficiency of brushed motors is usually only 75-80%. The brushes will eventually wear out, sometimes causing dangerous sparks, thus limiting the service life of the brushed motor. Brushless DC motors are quiet, light, and have a longer service life. Because the computer controls the current, the brushless DC motor can achieve more precise motion control.
Because of all these advantages, brushless DC motors are usually used in modern equipment that requires low noise and low heat, especially in equipment that runs continuously. This may include washing machines, air conditioners and other consumer electronics products. They may even be the main power of service robots, which will require very careful control of force for safety reasons.
Compared with other types of motors, brushless DC motors have several obvious advantages, which is why they have entered many household products, and may be the main factor in the development of service robots inside and outside the industrial field.
If you think your application can benefit from this technology, please browse the list of brushless DC motor suppliers and integrators.
Finally, let's talk about what to look for when choosing a motor. The most important characteristic is the electric motor Kv. The motor with a voltage of 2000Kv per volt delivered to the motor will rotate at a speed of 2000 revolutions per minute. The size is closely related to Kv. Large motors usually have higher torque, but lower Kv, and use larger propellers, while slender but longer motors will have higher Kv, low torque, and are most suitable for small propellers. The maximum power of the motor is also a factor to be considered. Exceeding the power limit of the motor will cause the motor to heat up, thereby greatly reducing its efficiency or even damaging it. For the same Kv value, the performance of one brand of motor may be better than other brands. This is why you should test the electric motor before building a drone or other equipment around it.
