The application of DC cooling fans in our lives is very common, so what is a variable frequency motor? Is it closely related to cooling fans?
The variable frequency motor has the characteristics of a DC motor, but adopts an AC motor structure. In other words, although the external access is direct current, the DC AC frequency conversion control technology is purchased, and the motor body works completely in accordance with the principle of AC. Therefore, the variable frequency motor is also called "self-controlled variable frequency synchronous motor". The rotational speed n of the motor depends on the set frequency f of the controller.
The drive circuit of the variable frequency motor consists of two parts: the main circuit and the control circuit. Now these two parts have been integrated into the same chip, so that all the control functions of the variable frequency motor can be realized with only one device, simplifying the circuit structure. As the industry pays more and more attention to energy saving and noise suppression, many industrial products tend to use brushless motors, which puts higher requirements on motor microcontrollers. As a new generation of motor control digital signal processor chip, cost-effective TMS320C240 is very suitable for this task.
The three-phase star of the DC cooling fan is connected with a variable frequency motor control circuit, and the DC power supply supplies power to the three windings of the motor through a three-phase variable frequency circuit composed of metal oxide semiconductor tubes. At each moment, only one of the three pairs of windings has a current passing through it, generating a magnetic field, and then the power supply to the pair of windings is stopped, and the power supply to the adjacent other pair of windings is supplied, so that the magnetic field axis in the stator rotates 120 degrees in space, and the rotor rotates 120 degrees following the stator magnetic field under the action of magnetic force. When voltages are sequentially applied to A, A, C, B, C, B, A, C, A, C, B−, a rotating magnetic field is formed in the stator, and thus the motor is continuously rotated.
Cooling fan experts know that as long as we disassemble the motor of the DC cooling fan, we can see that the DC cooling fan uses a variable frequency motor, which can be identified from the position of the coil. The variable frequency motor control circuit board and the control chip will integrate the digital signal processor function and the drive instrument to simplify the circuit structure. The speed of the motor can be changed by programming the control chip. Shenzhen Jiangshanlai Electronic Technology Co., Ltd. is a professional brushless DC motor, DC cooling fan, DC brushless fan, DC bracket fan, supercharged cooling fan, micro cooling fan, DC cooling fan, DC blower and non-standard customized fan A large-scale enterprise integrating R & D, manufacturing, sales and service, DC fan manufacturer, DC fan supplier wholesale. Products sell well in Guangdong, Shenzhen, Guangzhou, Dongguan, Fujian, Zhejiang, Jiangsu and other places.
