CIRCUIT FOR PROTECTION OF THREE-PHASE INDUCTION ENGINES AGAINST DISSYMMETRICAL OPERATION

摘要

A circuit for protecting three-phase induction motors from asymmetric operation, consisting of: two three-phase voltage asymmetry sensors connected before and after the motor, inverters, and relay-control transistor, characterized in that between the output of one three-phase voltage asymmetry sensor (CZ1) connected before the motor switch-on relay an the relay control transistor base (T), inverter (NOT1) and resistor (R1) are connected in series, whereas between the output of one three-phase voltage asymmetry sensor (CZ2) connected after the motor switch-on relay an the relay control transistor base (T), inverter (NOT2) and diode (D1) are connected in series, whereas to the inverter (NOT2) output, the inverter (NOT3) input is connected, whereas the inverter (NOT3) output is connected via the resistor (R2) and diode (D2) with the inverter (NOT2) input, and diode (D3) is connected between the inverter (NOT2) input and the inverter (NOT1) output.IMAGE