Dear experts, regarding the calculation of the starting current of motors for automatic startup during voltage fluctuations
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For a 10 kV, 10,000 kW motor that uses soft starting to initiate operation and is then loaded with its rated load, what is the current at the moment when the system voltage is restored, in the event of a sudden voltage fluctuation (assuming the motor has not stopped operating yet)? How can this current be calculated?
This situation will not reach the full plant short-time delay protection activation value. However, according to experts, if the duration of the voltage fluctuation reaches 0.5 seconds, the motor will lose around 15% of its torque; in such cases it is best to shut down the machine and restart it, otherwise the vibration levels of the motor will exceed acceptable limits.