Catching an induction motor after a loss power supply of the transistor electricdrive

The solution of the problem of connecting an asynchronous machine with a squirrel-cage rotor to a transistor converter after their disconnection in the absence of a rotor speed sensor is considered. This problem may arise in the drives of pumps, fans, in wind power plants and in other systems, if it is necessary to urgently breaking the mechanism or to ensure its uninterrupted operation. In the article, the problem is solved in relation to the ship's electric propulsion system. When the drive power is lost, the propeller and the rotor of the machine are first slowed down relatively quickly to a speed corresponding to the speed of the vessel. Then braking slows down due to the large inertia of the vessel. The significant duration of the process allows the use of an algorithm for determining the rotor speed, based on testing the machine by feeding the stator of an asynchronous motor from an inverter with low voltages with a frequency that varies within the specified limits. Mathematical and computer models of the system are constructed, numerical experiments are performed confirming the effectiveness of the considered solution.

Authors: A. G. Vorontsov

Direction: Electrical Engineering

Keywords: transistor frequency converters, induction motor, power loss, catching, simulation

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