The main advantage of the frequency control of the speed of rotation of asynchronous motors is the possibility of ensuring smooth control of the speed of rotation of these engines in a fairly wide range, for example, 1:10, while maintaining the overload capacity of the engine as one of the most important indicators of its operation. With frequency control of the speed of rotation of the asynchronous motor, it is necessary to change both the effective value of the phase voltage and its frequency at the same time, but in a certain ratio depending on the type of mechanical characteristics of the drive. Unfortunately, currently in practice an approximate expression for the optimal regulation law is used, which does not take into account the active resistance of the stator winding, and which can be used only for a narrow range of speed control, no more than 1:1.2 In a wider range of regulation, the condition of preserving the overload capacity of the engine is not fulfilled. This article proposes a formulation for the optimal control law that takes into account all the parameters of the asynchronous motor and ensures the constancy of its overload capacity for the three modes of operation of the drive in relation to the left range of speed control.

Authors: M. A. Vaganov, I. A. Babskаy

Direction: Electrical Engineering

Keywords: Asynchronous motor with squirrel-cage rotor, frequency control, modesofoperation, active resistance of stator winding, overload capacity, wher exhibition ratio, the algorithm for determining the frequency, the maximum electromagnetic torque

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