МАТЕМАТИЧНЕ МОДЕЛЮВАННЯ РЕЖИМІВ ПЕРЕМИКАННЯ НАРЕЗЕРВНЕ ЖИВЛЕННЯ АСИНХРОННИХ ДВИГУНІВ

Abstract

Purpose. Simulation of transient and steady state modes of induction motor for analysis of processes of switching to backup power by means of mathematical model. Method. The methods of linear algebra, numerical optimization methods, methods of modeling and analysis of established and transient modes are used. Results. A mathematical model is proposed in the form of a circuit diagram of an induction motor with a double-circuit rotor, which allows to take into account the effect of displacement of current and saturation of the steel of the motor magnetic circuit. A technique for determining the parameters of the induction circuit of an induction motor is proposed, which allowsto improve the accuracy of modeling in steady state and transient modes. The mathematical model isreduced to a three-phase coordinate system a, b, c. The results of mathematical modeling have shown that the induction motor asynchronous activation, which takes place in the case of automatic input of the reserve and in other cases, leads to dangerous values of the shock currents and shock torque of the induction motor. Shock currents can also be dangerous to other power supply equipment. Thus, induction motors, when the rotor's own field has not yet gone out, require synchronization before being connected to the network, as well as synchronous machines. Scientific novelty. The mathematical model of the asynchronous motor was improved, taking into account the displacement of current and saturation of the magnetic circuit, the method of determining the parameters of the mathematical model was improved, which allowed to increase the accuracy of the simulation and the reliability of the simulation results. The modes of switching to backup power are simulated and the values of shock current and shock torque of the engine are obtained. Practical meaning. The mathematical model of an induction motor allows to analyze the behavior of induction motors in interaction in the power supply system and to identify the dangerous states of asynchronous motors. The proposed model allows to improve the accuracy of determination of the limits of dangerous states and to increase the reliability of operation of induction motors and power supply systems