Analysis of the working principle of variable frequency motor

Variable frequency motor is a widely used motor, which can be seen in our daily life. In the construction site, whether it is a low mixer or a tall crane, they all use variable frequency motor as an electric engine to work. In agricultural production activities, variable frequency motor also plays a very important role. Harvesters, seeders, and large combine harvesters all use variable frequency motors to a certain extent. So why can variable frequency motor play such an important role? This has to start with its working principle.

The variable frequency motor is mainly composed of two parts: the motor and the inverter. The inverter here plays the role of adjusting the frequency of the machine. When the machine is powered on, the inverter works normally and controls the frequency within a certain range, so that the motor always remains in a stable state. The working (rotation) frequency of the motor will not change due to long-term work. In this way, the machine can always be in an efficient and stable working state, which is conducive to improving the working efficiency of semi-automatic machinery. We can see that when mixers and cranes are working, they can always work at a stable rate after setting the speed or lifting speed, and rarely fail. This is thanks to the inverter device.

In addition, some high-quality variable frequency motors are equipped with variable frequency power sensors, which can make timely adjustments by sensing the frequency changes of the inverter, so that the motor can make corresponding changes. This can adjust the speed of the motor more quickly and achieve the effect of stabilizing the mechanical operation.

The working principle of the variable frequency motor is to control the power frequency and speed of the motor through the inverter, so as to achieve precise control and energy matching of the motor. Its basic working principle is as follows:

The inverter converts the AC power of the power grid into DC power, and adjusts the output DC voltage and current through the controller to achieve the conversion of power frequency and voltage.

The inverter outputs the converted power frequency and voltage to the motor, and controls the motor speed and load by adjusting the power frequency and motor speed.

Under the control of the inverter, the motor can achieve precise control of the power frequency and motor speed, so that the power frequency and motor speed can be automatically adjusted according to different load and speed conditions to adapt to different working occasions.

Variable frequency motors can run at different speeds and can be used in variable speed transmission systems to meet different process requirements.

In short, the variable frequency motor controls the power frequency and motor speed through the frequency converter to achieve precise control and energy matching of the motor, so that it can adapt to different load and speed conditions and improve the operating efficiency and performance of the equipment.

In addition to the above basic working principles, variable frequency motors also have the following important working principles:

Motor control principle: The control principle of variable frequency motor is to control the output frequency and voltage of the inverter through the controller, so as to achieve precise control of motor speed and load. The controller can set different control modes as needed, such as speed closed-loop control, torque control, position control, etc.

Vector control principle: Vector control means to achieve precise control of motor speed and load by precisely controlling the motor current and magnetic field. This control method can greatly improve the motor's response speed and control accuracy, and is suitable for high-precision and high-requirement industrial control fields.

Working principle of induction motor: Variable frequency induction motor is the most common type of variable frequency motor. Its working principle is based on the principle of induction motor. The speed and load of the motor are controlled by the inverter to achieve precise control of the motor. Variable frequency induction motor has the advantages of simple structure, low cost and high reliability, and is widely used in industrial production.

In short, the variable frequency motor is a motor that can achieve precise control and energy matching. Its working principle is based on the principle that the frequency converter controls the power frequency and motor speed. It can be applied to various industrial control fields to improve the efficiency and performance of equipment.