Publish Time: 2022-10-06 Origin: Site
In real life, the selection of DC motors and AC motors should be considered from many aspects, not only the production and maintenance costs, but also the actual working conditions for comprehensive consideration and selection. Today, Xiaobian will take you to briefly understand the working principle of these two motors, so as to help you choose the equipment motor correctly and reasonably.
Here is the list
How DC motors Work
Principle of AC Motor
Comparison of DC motors and AC Motors
1. DC power supply, the current flows along the positive pole of the power supply to the left brush, the brush and the commutator rub against each other, the current flows into the coil through the left commutator, flows out of the coil from the right, and passes through the commutator on the right and the brush on the right flows back to the negative terminal of the power supply, forming a closed loop.
2. Since the coil is in the magnetic field of the main magnetic pole, the coil will be affected by electromagnetic force. Since the current directions on both sides of the coil are different, the two sides of the coil are subjected to electromagnetic forces of the same magnitude and opposite directions. As soon as the electromagnetic torque is formed, the coil starts to rotate under the pull of the electromagnetic torque. In a DC motor, the coils are embedded in the rotor and the motor starts to spin.
3. The left and right commutator segments rotate with the shaft, and the brushes are fixed. After one turn, the coil on the right turns left and the coil on the left turns right. However, due to the existence of the commutator, the current direction in the left coil is now the same as the current direction changed by the left coil, so the direction of the electromagnetic force remains unchanged, and the same is true for the right side. From the perspective of space, the direction of the electromagnetic force on the coil side at the same position is always unchanged, which ensures the cyclic rotation of the motor.
4. But for a coil, because the magnetic field is different when the coil rotates to different positions, the electromagnetic force on the coil is also changing all the time, so the coil rotation is unstable, sometimes fast and sometimes slow. Therefore, multiple coils can be installed to ensure uniform and stable coil force.
AC motors are divided into synchronous motors and asynchronous motors. Synchronous motors are mainly used as generators, and asynchronous motors are mainly used as electric motors. Here we mainly introduce the motor. Asynchronous motors have been widely used due to their simple structure, low price, convenient maintenance, and reliable operation. Although the structure of the AC motor is simple, its working principle is actually more complicated than that of the DC motor.
The three-phase symmetrical alternating current is connected to the stator of the alternating current motor, and the stator does not move, and a rotating synthetic magnetic field can be generated only by the change of the current. This magnetic field is like a magnet that revolves around the stator. Using this rotating magnet, a closed coil is randomly placed inside the stator, electromotive force and current are induced in this closed coil, electromagnetic force is generated, and the closed coil rotates. It can also be understood that there is a selected magnet on the stator, while the closed coil of the rotor is actually an electromagnet due to inductive charging. The rotor turns. The rotational speed of the stator magnetic field is also called the synchronous rotational speed. The rotor actually rotates by the stator magnetic field, so its speed will be slower than that of the stator magnetic field, so it is called asynchronous speed.
Advantages of DC motors
1. It can realize stable and economical speed regulation.
2. It does not need the cooperation of other equipment, just change the input or excitation voltage and current to achieve speed regulation.
3. The torque of the DC motor is relatively large.
AC motor advantages:
1. Simple structure.
2. Low manufacturing cost.
3. Maintenance is simple and economical.
Hangzhou New Hengli Electric Machine MFG. Co., Ltd. (Originally Hangzhou Hengli Electric Machine MFG. Co., Ltd.) was founded in 1954. Over 68 years of manufacturing experience in kinds of DC & AC Motors built up the customer-centered product development methodology and do under the special requirements of customers.