Asynchronous motor soft starter and control method thereof

Abstract

The invention relates to an asynchronous motor soft starter and a control method thereof. The value of an actual current signal and a maximum current value permitted by a preset motor are compared through a current detection circuit, the comparison information is outputted to a controller, a control signal is outputted through operation processing, a synchronization voltage signal and a control signal acquired by a voltage zero cross detection circuit from a power grid line voltage are inputted to a six-path triggering pulse generator for generateing triggering pulse, a motor input voltage is controlled in real time through triggering pulse control on a three-phase thyristor voltage regulation circuit, so a start current of a motor is controlled in real time, and the motor is made to realize stable start. The method is advantaged in that 1, relatively good control quality is realized, and excellent anti-interference capability and high-speed high-precision control especially in the severe environment are realized; and 2, the active-disturbance-rejection control technology is utilized, small overshooting and the short transition process are realized, adaptation to change of an object model and the surrounding environment can be realized in a relatively large scope, control quality of a controller is not influenced, and excellent robustness is realized.

Description

technical field [0001] The present invention is an asynchronous motor soft starter and its control method, especially a new type of motor soft starter which applies the active disturbance rejection control technology to the controller. Advanced soft starter. Background technique [0002] With the continuous advancement of industrialization and urbanization, and the continuous in-depth development of economy and society, energy shortage and environmental pollution have become common problems faced by mankind. [0003] In recent years, with the development of the economy, our requirements for products have become higher and higher. High-quality products require higher production processes. How to make equipment work in a more stable and smooth environment with optimal efficiency , has gradually become a problem of widespread concern. [0004] As the most widely used motor, asynchronous motors are widely used in daily life, especially in industrial production, due to their ad...

AI Technical Summary

Problems solved by technology

However, the starting characteristics of the motor have not been ideal, and there are many defects in the starting and stopping braking methods of the traditional motor.

As we all know, the starting current of a motor is generally 4-8 times the rated current, up to 15 times the rated current, which will cause a huge impact on the power grid, load machinery and the motor, and affect the service life of the motor and its driving equipment Causes a sudden drop in grid voltage, which directly affects the normal operation of other electrical equipment in the grid

Such a large current not only increases the load on the incoming line, the power supply network and the switching devices in front of the motor, but also the huge torque impact that occurs at the same time will cause the motor to send out violent shocks, and it is also used as an auxiliary force for power transmission. Equipment (such as V-belts, speed change mechanisms) and mechanical equipment that do work will bring inevitable mechanical shocks

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