Requirements for motor speed regulation under different working conditions

Motor speed regulation can be divided into two categories based on output characteristics: stepless speed regulation and stepped speed regulation. When it comes to specific speed control methods, there are many types. List some common and representative speed regulating motors, analyze the speed regulating mechanism and application characteristics, roughly outline the spectrum of speed regulating motors, and share with everyone.

Variable frequency speed regulating motor

Variable frequency speed regulating motor is a general term for electric motors driven by frequency converters. Variable frequency speed regulating motor, abbreviated as variable frequency motor, is a general term for electric motors driven by frequency converters. In fact, the motor designed for the frequency converter is a dedicated motor for frequency conversion. The motor can achieve different speeds and torques under the drive of the frequency converter to adapt to changes in load requirements. Variable frequency motors have evolved from traditional squirrel cage motors, replacing traditional motor fans with independent fans and improving the insulation performance of motor windings. In situations with low requirements such as operating at rated frequency with low power and frequency, ordinary squirrel cage motors can be used instead.

Variable frequency speed regulation is a method of changing the synchronous speed of an asynchronous motor by continuously adjusting the frequency of the input power to the stator end of the motor. Ms., the old customer of the senior salesperson who participated in the company wants to get involved in environmental protection projects. Variable frequency motors should be the best option, with mature technology and high comprehensive economic indicators.

Advantages: No additional slip loss, high efficiency, wide speed range; For situations where the low load operation time is longer or the start stop operation is more frequent, the purpose of energy saving and motor protection can be achieved.

Disadvantages: The technology is complex and the price is high.

Variable pole multi speed motor

In some special drag circuits, dual speed motors are required; Sometimes it is even necessary to use a three speed or four speed electric motor. The principles and control methods of these multi speed motors are basically the same. Mainly used for various transmission machinery such as machine tools, mining, metallurgy, textiles, printing and dyeing, chemical industry, etc. that require step-by-step speed regulation according to the nature of the load. The requirement of achieving multiple speeds on the same motor is solved by different connections of the same winding and multiple sets of windings on the same motor.

Variable pole speed regulation is a method of changing the number of magnetic poles of an electric motor by altering the wiring of its stator winding, which allows for a step-by-step adjustment of the synchronous speed and achieves speed regulation of the motor. This type of speed regulating motor currently has a standardized series of products available for selection, such as single winding multi speed motors

Advantages: No additional slip loss, high efficiency; The control circuit is simple, easy to maintain, and has a low price; Cooperating with the electromagnetic differential clutch can achieve smooth speed regulation with high efficiency.

Disadvantage: It has a step speed regulation and cannot achieve stepless smooth speed regulation. And due to the limitations of motor structure and manufacturing process, only 2-3 pole pairs of graded speed regulation can usually be achieved, and the speed regulation range is quite limited.

There are many occasions in industry that require speed regulation, such as driving, fans, conveyor belts, machine tools, etc. Adopting pole changing speed regulation has the characteristics of low implementation cost, low power consumption, and good output torque rigidity. With the popularization of frequency converters, dual speed motors still have certain application space.