Study of the Modes of Re-Enable the Asynchronous Electric Drive of a Centrifugal Pump

A study of the dynamic modes of re-enable an induction motor of a centrifugal pump for a given power supply scheme has been carried out. The studies were conducted under the conditions of the specified technical requirements and the availability of technical data on the elements of the power supply system, electric drive and mechanism. The author's mathematical models of induction motors were used based on a generalized machine described in a three-phase fixed coordinate system taking into account the nonlinearities of the motor – iron losses, rotor current displacement effects and saturation along leakage paths and the main magnetic flux. An assessment is given of the qualitative and quantitative indicators of transient processes of the electric drive – currents, voltages, motor torques. The dynamics of voltages and currents in the phases of the engine are analyzed. The influence of non-zero initial electromagnetic conditions on the nature of transient processes is considered. It has been shown that overvoltage that occur when motors are switched on again in a circuit with permanently connected capacitors have an adverse effect on the operating electrical equipment. A solution to the problem is provided – the need to implement separate switching of the motor and capacitor sections, the use of thyristor devices to ensure favorable switching conditions, which allows reducing voltages and currents, minimizing peak torque values and ensuring stable operation of the system and also points out the advantages of using controlled starting devices.