Kulik M. Asynchronous electric drive with digital system of discrete-phase control

The dissertation is devoted to solving an urgent scientific problem of creating a new principle of control of the rotor speed of an induction motor, which retains the advantages of the vector control method, but at the same time is fundamentally different from purely scalar and purely vector methods and provides for the development of a control system that does not use a cumbersome algorithm of coordinate transformations and ensures maximum correspondence of the operating modes of the asynchronous motor to the algorithm specified by the operator. A discrete-phase method for controlling an asynchronous electric drive has been developed and it has been proven that such a system makes it possible to form the output voltage of the frequency converter according to the algorithm specified by the operator, ensures the continuity of the phase incursion for any changes in the engine operating modes while maintaining the condition of the ratio of the effective value of the output voltage to the rotor speed. A new system of energy recovery with discrete-phase control has been developed, which does not contain a separate rectifier with a pulse-width-modulated signal generating unit, and automatically monitors the current phases of the power supply. For the first time, a triple frequency converter protection system was proposed, based on measuring the input capacity of the IGBT with the protective interval. Keywords: asynchronous electric drive, asynchronous motor control system, phase control, discrete control, frequency converter, multiphase and multilevel systems, energy recovery, multi-stage protection of the power module, IGBT modules.