Three-phase motor self-excited braking circuit

As shown in the figure, during the free braking process, a resistor-capacitor element is connected to the stator winding to form a self-excited braking circuit. When KM1 is open and 2KM is closed, the stator residual magnetization induction potential will generate a capacitive current through the resistance-capacitance circuit. The magnetic field it establishes will strengthen the rotor residual magnetism, generate braking torque, and brake the motor quickly. The connection method of the resistance-capacitance circuit should be determined according to the connection method of the stator winding of the three-phase motor. Tests have shown that Y-connection RC circuits are suitable for Y-connection motors; △-connection RC circuits are suitable for Y or △-connection motors.