Low-voltage frequency converter with rotate speed tracking start

Abstract

The invention discloses a low-voltage frequency converter with a rotate speed tracking start. The low-voltage frequency converter comprises a main control module and a motor output detection circuit connected with the main control module, wherein the motor output detection circuit is used for detecting the operation frequency of the motor in real time and outputting a detection result to the main control module; the main control module is used for controlling the low-voltage frequency converter to output a driving frequency consistent with the detection result. Since the motor output detection circuit is arranged on the low-voltage frequency converter, the operation frequency of the motor can be detected in real time; when the frequency converter is instantly powered on or powered off and the motor is in operation, the main control module of the low-voltage frequency converter is used for controlling the low-voltage frequency converter to output the frequency consistent with the operation frequency of the motor without waiting for the completely stopping of the motor, the time is saved; meanwhile, the output frequency of the frequency converter is consistent with the operation frequency of the motor, the motor is steadily operated and free from damaging.

Description

technical field [0001] The invention relates to a low-voltage frequency converter, in particular to a low-voltage frequency converter with rotational speed tracking start. Background technique [0002] With the rapid development of modern power electronics technology and computer control technology, the technological revolution of electric transmission has been promoted. It has become a development trend that AC speed regulation replaces DC speed regulation, and computer digital control replaces analog control. AC motor frequency conversion speed regulation is a major means of saving electric energy, improving production process, improving product quality, and improving the operating environment. Frequency conversion speed regulation is recognized as the most promising speed regulation method at home and abroad because of its high efficiency, high power factor, and excellent speed regulation and braking performance. [0003] The frequency converter (VFD) came into being wi...

AI Technical Summary

Problems solved by technology

During the process of the motor slowly stopping, its operating frequency gradually decreases until the rotational speed of the motor shaft is zero. If the inverter re-supplies power when the motor is powered off until the rotational speed of the motor shaft decreases to zero, the prior art Because the low-voltage inverter does not track the running state of the motor in real time, it cannot judge the running frequency of the motor. It can only re-control the frequency and amplitude of the working power supply of the motor after the motor has completely stopped, which is a serious waste of time and is not conducive to production.

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