PROTECTION DEVICE AGAINST THE ACTION OF THE REVERSE ENERGY FLOW OF AN ASYNCHRONOUS MOTOR TO A FAULT POINT IN THE POWER CABLE Russian patent published in 2023 - IPC H02H3/02 H02H7/08 

FIELD: electrical engineering.

SUBSTANCE: protection device connected to the power circuit of the phase windings of the stator of the asynchronous motor, the first conclusions of which are intended for connection to the phase conductors of the power cable, contains a series connection circuit of the first, second capacitors and a diode connected by the cathode to the grounded metal case of the asynchronous motor, and also connected in parallel to the second capacitor, a resistor and a reacting element, connected by its output to the input of a switching device containing an open power contact, and equipped with a second and third diodes, a second resistor and a closed low-current contact of the switching device, connected by its first output to the second resistor in a series circuit connected in parallel to the first capacitor, and connected to the second output of the first phase winding of the stator of the asynchronous motor, the second output of the closed low-current contact is connected to the cathode of the second diode, the anode of which is connected to the cathode of the third diode and is intended for connection to the second output of the second phase winding of the stator of the asynchronous motor, while the opening power contact of the switching device, the first output is connected to the cathode of the second diode, and the second output is connected to the anode of the third diode, connected to the second output of the third phase winding of the stator of the asynchronous motor.

EFFECT: ability to adapt the protection device against the action of the reverse energy flow of the induction motor into the structure of the induction motor and, thereby, increase the reliability of the protection.

1 cl, 4 dwg