MICROPROCESSOR-BASED DEVICE FOR DIAGNOSING THE INSULATION OF A MOTOR BY EMF SELF-INDUCTION WITH A MEGGER FUNCTION Russian patent published in 2018 - IPC G01R27/26 G01R31/34 

FIELD: electrical measuring equipment.

SUBSTANCE: invention refers to electrical measuring equipment in particular, to devices for monitoring the quality of insulation, characterized by its breakdown voltage, and can be used in means for diagnosing the state of insulation of an induction motor with a squirrel-cage rotor. Microprocessor-based device for diagnosing the insulation of a motor by EMF self-induction with a megger function contains a microcontroller 1, including a pulse width modulator (PWM) and an analog comparator, a voltage divider 2, controlled voltage source 3, first controlled switch 4, converter of interfaces USART/USB 5, DC voltage source 6, diagnosed winding of the motor 7, second key 8, reference inductance 9, semiconductor diode 10, a capacitor 11, and a computer 12. Second terminal of the DC voltage source 6 is connected to the first terminals of the diagnosed winding of the motor 7 and the reference inductance 9, second terminals of the latter are connected to the second terminal of the second switch 8, which can be either in the "lower" position - the diagnosed winding 7 is connected, or in the "upper" - include the reference inductance 9 and the anode of the semiconductor diode 10, cathode of which is connected to the first plate of the capacitor 11. First output of second switch 8 is connected to second outputs of first switch 4 and voltage divider 2. Control output of the first controllable switch 4 is connected to the microcontroller 1, control input of the reference voltage source 3 is connected to the PWM output of the microcontroller 1, Output of voltage source 3 is connected to first input of analogue comparator of microcontroller 1, to the second input of the analog comparator of the microcontroller 1 is connected the middle terminal of the voltage divider 2, first end terminal of which is connected to the first terminals of the first controllable switch 4 and the constant voltage source 6, and also with the second plate of the capacitor 11. Measured insulation resistance is connected to capacitor 11 plates. USART module of the microcontroller 1 is connected to the USART / USB 5 interface converter, which is connected to the USB interface of the computer 12.

EFFECT: technical result achieved in the implementation of the claimed invention is reduced to the expansion of its functionality through the organization of measurement under the control of a computer.

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