The cascade synchronous–asynchronous motor

This paper describes the mechanism and the principle of operation of a cascade asynchronous-synchronous motor. The history of their creation, and the main advantages are given. The analysis of operation of the cascade system under load is carried out, the scheme of substitution is given. It is determined that when the motor is under load the lag in the phase of the magnetic field created by the rotor current of the second stage leads to an increase in its torque as in a conventional synchronous motor. The torque of the asynchronous converter, which also grows with the growth of currents in its stator and rotor, is added to this moment. The load characteristics of the cascade asynchronous-synchronous motor are not much different from those of the synchronous motor. There is a maximum moment, the excess of which can take the cascade out of sync. The created protopit of cascade synchronous-asynchronous motors is described, the passport data of the electric machines included in its composition are given. The experimental setup consists of two crane asynchronous motors with a phase-rotor of the DMTF series - 011-041 IP44, and a P-42 type DC motor as a load. The experimental study confirmed the possibility of creating a cascade combining the advantages of synchronous and induction machines.