A method and system for restarting a motor based on a rapid identification method of shaking power

Abstract

The present invention provides a method and system for restarting a motor based on a method for rapid identification of electric shock. The method for rapid identification of electric shock includes the following steps: Step 1: sampling the voltage loop, updating the sampling value cache; Digital low-pass filtering; Step 3: Calculate the voltage amplitude by the two-point method; Step 4: Determine whether the maximum voltage is less than the voltage loss setting value, if it is less than the voltage loss setting value, set the corresponding position of the undervoltage result cache to 1, otherwise, undervoltage The corresponding position of the result cache is set to 0; Step 5: Determine whether the minimum voltage is greater than the fixed value of the recovery voltage. If it is greater than the fixed value of the recovery voltage, the corresponding position of the voltage recovery result cache is set to 1, otherwise, the corresponding position of the voltage recovery result cache is set to 0. The beneficial effects of the present invention are as follows: the method for quickly judging the electric shock of the present invention can identify the electric shock of 5 ms at the minimum, and through the mutual cooperation of the electric shock starting and the delayed restarting in batches, the motor can run at the fastest speed. resume operation.

Description

technical field [0001] The present invention relates to the field of electric power technology, and in particular, to a method and system for restarting a motor based on a rapid identification method for electric shock. Background technique [0002] In the power supply system of the enterprise, due to line short circuit caused by lightning strike, typhoon, pollution flashover, abnormal input power supply, etc., the system voltage may drop to 10%-90% of the rated voltage instantaneously, and the duration is 0.5 cycles to 1min. This phenomenon It's called "voltage dip", and it's called "shake electricity". The low-voltage motor circuit is basically controlled by an AC contactor. The general requirements for the voltage retention of the AC contactor are: the voltage is not less than 45% or the voltage loss time is not more than 60ms. And the lower the voltage, the shorter the tripping time, after less than the tripping voltage, generally it will trip within 10ms. Therefore, s...

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Problems solved by technology

Therefore, it is easy to cause large-scale power outages and unplanned parking of production equipment, causing heavy losses to production enterprises, and even equipment and personal accidents.

[0003] For the swaying time greater than 30ms, the conventional swaying detection algorithm, such as: FFT, DFT, etc., can also be detected reliably, but for the swaying time below 30ms, it cannot be reliably detected, and missed detection may occur

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