Design and Analysis of Asynchronous Motor Driven by VSD

In recent years, the development and application of frequency conversion speed regulation technology has become more and more extensive, and people have paid more and more attention to the performance of asynchronous motors under the state of frequency conversion speed regulation. The variable frequency power supply is different from the traditional grid power supply. In the state of variable frequency power supply, there will be high harmonics in the current and voltage, which will affect the power factor and efficiency of the asynchronous motor. In the previous design of asynchronous motors, low power harmonics were rarely considered. Therefore, although traditional asynchronous motors can achieve good energy-saving effects under variable frequency conditions, they cannot achieve ideal operating performance. Therefore, the inverter-driven The design and analysis of asynchronous motor has great practical guiding significance for the perfection of asynchronous motor design.

Overview of asynchronous motors driven by frequency converters

Frequency conversion speed regulation technology has become the research focus of electric transmission, because of its many advantages such as: excellent speed regulation and braking performance, high efficiency, remarkable energy saving effect, wide application, etc., it is considered by experts and scholars at home and abroad to be the most promising electric appliance transmission technology. Frequency conversion speed regulation technology organically combines various high and new technologies, and is widely used in machinery, metallurgy, chemical industry and other industries.

The advantages of asynchronous motors driven by frequency converters are as follows:

1. Easy to manufacture. Because the rotor in the asynchronous motor driven by the frequency converter does not need to be wound, compared with the traditional asynchronous motor, the asynchronous motor with variable frequency speed regulation saves equipment such as brushes and collector rings, and has a simple structure and is easy to manufacture and maintain. Very convenient.
2. Stable performance. Because the excellent starting and braking performance of the asynchronous motor driven by the frequency converter greatly promotes the stability of the AC speed control system, the asynchronous motor driven by the frequency converter realizes the stepless smooth speed regulation of the motor, the speed regulation effect is very good, and the performance Also more stable.
3. Good starting characteristics. The asynchronous motor driven by the frequency converter is powered by a variable-voltage variable-frequency power supply. When the motor is started, the starting torque is large and the starting current is low, which ensures its good starting performance.
4. Significant energy saving effect. The asynchronous motor driven by the frequency converter can automatically and smoothly adjust the speed according to the change of the load, which greatly improves the work efficiency and achieves the purpose of energy saving. Generally speaking, the wider the speed range of the asynchronous motor, the more significant the effect of energy saving.

Although the design and manufacturing process of asynchronous motors driven by frequency converters are not fully mature, the rapid development of semiconductor technology and the power electronics industry has led to a rapid increase in the demand for asynchronous motors driven by frequency converters. The asynchronous motor driven by the drive has been actively explored, and has achieved the purpose of adapting to the development of modern industry.

Development trend of asynchronous motor driven by frequency converter

In the middle of the 20th century, electric transmission set off an important technological revolution, and the asynchronous motor driven by the frequency converter will replace the complicated and expensive DC motor. This revolution has achieved gratifying results in today’s rapid development of semiconductor devices and electronic power. With the emergence of thyristor components, the development space of AC transmission technology has been further expanded, and the technology of AC frequency conversion speed regulation has risen rapidly and achieved considerable development. The frequency conversion speed regulation technology makes the performance of the asynchronous motor change greatly after being driven by the frequency converter, and the asynchronous motor is more energy-saving. Various countries have actively developed and developed asynchronous motors driven by frequency converters with high reliability, and achieved good results. In order to adapt to different usage occasions, various series of variable frequency motors have been launched successively, such as: low-voltage variable frequency motors with a power of 0.37-630 kW suitable for water pumps and fan loads, suitable for cranes, metallurgy, etc. that require frequent starting and braking. Yes, the frequency converter with a power of 1.1-1250 kilowatts. The development trend of frequency conversion speed regulation technology shows that the asynchronous motor driven by the frequency converter is completely comparable to the motor of the DC drive, and shows vigorous vitality. The development of frequency converter has brought new life to the design of asynchronous motor.