Expansion of the possibilities of providing the control and protection system of asynchronous motors with an electric signal

This article presents a study of the measuring windings that provide a high-quality electrical signal for the control system and protection during the shaving of phases occurring in asynchronous motors. The magnitude of the asynchronous motor stator currents in the form of secondary voltage imposes such requirements as high sensitivity and high rate of change of the sensor elements of the converter, isolation from the primary circuit, efficiency, small size and weight, low cost. To meet these requirements, a three-phase sensitive control and reactive power control element of an asynchronous motor is placed in the space between the main windings and windings on the stator wedges and provides the normative value of the received output signals. At the same time, receiving a signal from a sensitive element that determines the symmetry of the three-phase primary currents of an asynchronous motor and disconnecting the current from a stator can expand the capabilities of this current converter and ensure a normal electrical value at the output, as well as the possibility of using these signals directly in the protection and control systems of an asynchronous motor. The rational choice of the number of windings of the measuring instrument and their placement on the stator wedges when obtaining a normalized output voltage on three-phase current converters of the asynchronous motor protection system was carried out by the recommended methods. The sensing element of the three-phase current converter of the asynchronous motor stator complements the function of the basis for transmitting information to the control, monitoring and protection system. This current-to-voltage converter is a structurally simple and easy-to-manufacture technology that allows you to continuously change and measure the operating state of an asynchronous motor, control system and sew up when a signal is given.