An analysis of the possibility of applying thermal models of asynchronous motors to assess the thermal state of a doubly fed machine

In the development and operation of an adjustable electric drive, it is important to ensure the optimal temperature of the base electric machine, which is the main factor in the reliability of the system as a whole. Energy-efficient drive control algorithms selected at the design stage and the PWM strategy in the output inverter section of the frequency converter affect the heating of the phase windings of the motor and its elements. To assess this effect, thermal models are needed. Selecting the topology and parameters of the model is a difficult task and depends on the electrical parameters of the engine, the range of operating speeds and loads, and the design features of the electric machine etc. This article discusses the advantages and disadvantages of mathematical models of the thermal state of an induction motor. An assessment is made of the possibility of using such models to analyze the thermal state of a doubly fed machine when implementing energy-efficient control algorithms at a wide range of speeds and shaft loads.