峨眉山Speed regulation method of three-phase asynchronous motor

The speed regulation characteristics of three-phase asynchronous motors are used in fan type applications or mechanical applications with high slip, while ensuring a control system with feedback effect on the gearbox.

There are various speed regulation methods for three-phase asynchronous motors, mainly including variable pole speed regulation, variable slip speed regulation, and variable frequency speed regulation.

Pole changing speed regulation refers to changing the winding resistance wiring method to change the number of poles of the motor, in order to ensure that the speed of the three-phase asynchronous motor can change.

Pole changing speed regulation is a type of stepwise speed regulation, which can be adjusted in three different ways: Y-YY, D-YY, and Y in series and Y in reverse.

The speed regulation method of Y-YY is constant torque, while the other two methods are constant power for speed regulation.

When adjusting the pole changing speed, the two-phase wiring should be adjusted to ensure that there is no deviation in the direction of the motor's rotation after speed adjustment.

The variable slip speed regulation method also includes cascade speed regulation, step-down speed regulation, and asynchronous motor series resistance speed regulation with wound rotor.

Variable frequency speed regulation is currently the main adjustment technology vigorously advocated in China, which can achieve the goal of stepless speed at high speeds and coordinate with constant torque and constant power loads.

The speed regulation method of three-phase asynchronous wound rotor motor is relatively simple compared to other methods, and can be easily achieved. However, the speed regulation process is not smooth and has different levels. At low speeds, the stability is very poor, and the characteristics are not obvious. At the same time, the consumption of rotor copper is very large, which reduces the efficiency of the motor in operation.

A frequency converter refers to the conversion of voltage and fixed frequency into variable voltage and frequency.

In order to achieve mutual conversion of voltage and frequency on an electric motor, the alternating current of the voltage should first be converted into direct current, and this mechanical process is called rectification.

The process of converting direct electricity into alternating current is called inverter, and the machinery that can convert direct current into alternating current is called inverter.

An inverter whose frequency and voltage can be readjusted is called a frequency converter.

The shape of the wave output from the frequency converter is similar to a sine wave, and its main purpose is to adjust the speed of a three-phase asynchronous motor, so it can also be called a high-speed device.

The speed formula for three-phase asynchronous motors is: n=60f/p (1-s).

From the above equation, it can be seen that changing the power supply frequency f, the number of pole pairs p of the motor, and the slip rate s can achieve the goal of changing the speed.

Zhejiang Jinsu Motor Co., Ltd. is an enterprise that manufactures various types of DC, AC, and three-phase asynchronous motors. The company covers a total area of over 30 acres and currently employs more than 150 employees; Having a modern garden style factory building and introducing excellent and efficient production and testing equipment from both domestic and international sources, we aim to create a sustainable manufacturing enterprise that provides customers with excellent products and services. As a modern enterprise that integrates scientific research, production, sales, and service, we are committed to building a sustainable business.