Frequency converter stopping device

Abstract

The invention discloses a frequency converter stopping device, which comprises at least two buffers and at least two manual switch units, wherein the buffers are connected between a logic control circuit of a frequency converter and an inverter drive circuit after being connected in series; the enabling end of each buffer is connected to a first voltage source by a first resistor; each manual switch unit is connected to a joint of a corresponding buffer and a corresponding resistor; the manual switch units are interlocked; and levels output to the enabling ends of the buffers by the first voltage source are converted by the switching of the manual switch units to control the enabling validity of the buffers. The frequency converter stopping device is provided with at least two hardware control channels for controlling the stoppage of the frequency converter, and can reliably switch a switching device of an inverter off to stop running the frequency converter under the condition of not switching power off to effectively prevent the abnormal starting of a motor and ensure the personal safety of an operator.

Description

technical field [0001] The invention belongs to the technical field of frequency converters, in particular to a device for stopping the operation of frequency converters. Background technique [0002] In the working process of production equipment such as cutting machines, CNC machine tools, and assembly lines, it is often necessary to stop the inverter set on it to stop the operation of the production equipment for the staff to perform operations such as feeding . Commonly, the stop / start command of the inverter is given by the input devices such as the inverter keyboard and the user's external switch in software through a single channel, which has the following defects: after the motor stops, the output terminal of the inverter and the motor still exist Electrical connection, because the electromagnetic environment of the inverter is relatively harsh, the operation command of the inverter may be interfered by the surrounding electrical equipment, resulting in the sudden s...

AI Technical Summary

Problems solved by technology

Commonly, the stop / start command of the inverter is given by the input devices such as the inverter keyboard and the user's external switch in software through a single channel, which has the following defects: after the motor stops, the output terminal of the inverter and the motor still exist Electrical connection, because the electromagnetic environment of the inverter is relatively harsh, the operation command of the inverter may be interfered by the surrounding electrical equipment, resulting in the sudden start of the motor, which may injure the staff

[0003] In order to overcome the above defects, the power of the inverter can be cut off at the same time after the inverter is stopped to ensure the personal safety of the staff, but frequent power-off / power-on operations will affect the production efficiency and the service life of the inverter

[0004] In addition, on the brake device of some production equipment (such as cutting machine), the programmable output relay of the frequency converter is usually used, which is controlled by a single channel in software. When the software enters an endless loop or a device in the control channel is damaged, The possibility of brake control failure is greatly increased

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