The Correction of the Operation Modes for Frequency-Controlled Induction Motor with Scalar Control under Stator Windings Damage Appearance

wide application in the industry of the regulated electric drives systems allows one to create effective energy saving technology which implementation allows one not only to save electric energy, but also to increase equipments' service life. Nowadays in the mass systems of the industrial regulated electric drive, in the systems of heat and water supply which work, generally, in continuous static modes with a constant loading, systems of the frequency-controlled electric drive with scalar control takes a dominant place. However, the proper operation of the adjustable electric drive depends on the reliable operation of the induction motor, the power unit of the energy converter and the control system, and in the process of operation, each of these components may fail. The paper presents a method for fault-tolerant control of an induction motor which works as a part of a frequency-controlled electric drive system with scalar control for the case of damage in the power circuit of the electric motor stator. The proposed method is based on the reduction of the task signal in the damaged phase in proportion to the asymmetry rate of the active resistances of the motor phases. The study results for the presented system confirm the possibility of improving the dynamic and energy characteristics of the regulated electric drive. The proposed control strategy is easy to implement and does not require the installation of new sensors or changes in the power circuit of the classic system of frequency-controlled electric drive.