Motor restart controller and control method of motor restart controller

Abstract

The invention relates to a motor restart controller and a control method of the motor restart controller. The motor restart controller is used for controlling the restart of the motor through a frequency converter. A backup power supply module is electrically connected with a logic control module and a reset module. The logic control module is used for judging whether the operation signal normallyopen contact of the frequency converter is disconnected when the instantaneous sag amplitude of the power supply voltage is detected to reach the preset amplitude threshold and blocking the start instruction of the frequency converter and detecting whether the power supply voltage is restored if the judgment result is yes; and if the power supply voltage is not restored when the preset time threshold is up, the connection between the backup power supply module and the reset module is disconnected and the start instruction of the frequency converter is relieved, or the backup power supply module is controlled to supply power to the reset module so as to control the frequency converter to reset. The controller can quickly respond and accurately judge whether shutdown of the frequency converter is really caused by instantaneous "power failure" of the power supply so that false starting of the frequency converter caused by misjudgment can be prevented, continuous production and operationcan be guaranteed and the safety accident can be reduced.

Description

technical field [0001] The invention relates to the field of industrial control, in particular to a motor restart controller and a control method for the motor restart controller. Background technique [0002] With the ring network of the main power grid and the increase of power supply lines of the medium-voltage power grid of the enterprise, and the enterprise does not set up impedance isolation components to reduce power consumption, it is inevitable that when the main network or the adjacent line of the medium-voltage power grid of the enterprise fails Instantaneous loss of voltage or undervoltage (referred to as "shock power"), the time of "shock power" depends on the removal time of adjacent line faults, which is about 200ms or less. For the release of the inverter caused by "shocking electricity", since the voltage acquisition refresh cycle time of the microprocessor is longer than the instantaneous power failure time (such as 200ms), the conventional microprocessor-b...

AI Technical Summary

Problems solved by technology

For the release of the inverter caused by "shocking electricity", since the voltage acquisition refresh cycle time of the microprocessor is longer than the instantaneous power failure time (such as 200ms), the conventional microprocessor-based restart equipment cannot quickly capture and respond to the voltage Instantaneous change, so the "shaking power" can not work for the instantaneous voltage loss of the power supply below 200ms

[0003] Inverters are widely used in the field of industrial control. Due to the perfect protection characteristics of the inverter itself, it has the function of automatic reset and restart for some faults. However, the inverter manufacturers have given warning instructions for the use of this function. It is not recommended to use it. The user is responsible for the possible personal and safety hazards after use, because the inverter itself does not have the ability to judge which faults can be automatically reset and restarted, and which faults cannot be reset or restarted, which requires the user to Judge and use at your own risk

[0004] Therefore, in the daily use of frequency converters, for the problem of low-voltage protection tripping of the frequency converter caused by the instantaneous "shock" of the power supply when the motor is running normally, it is usually necessary to rely on manual re-operation to restore the motor after the power is automatically restored. , resulting in unnecessary shutdown of the motor during operation, interrupting production, which will cause great economic losses to continuous production enterprises such as petroleum, petrochemical, chemical, electric power, and metallurgy, and even lead to safety accidents

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