YZR crane motor reverse braking characteristics: The motor is energized in the ascending direction and operates stably in the 4th quadrant; The speed of the motor is negative in the opposite direction to the synchronous speed; The electromagnetic torque of the motor is the braking torque; Slip is positive, generally between infinity and 1; The load torque must be greater than the starting torque to perform reverse braking.
The energy consumption braking of YZR crane motor is to connect the stator winding of the motor to the DC power supply. At this time, if the motor is driven by a load with kinetic energy or potential energy, the motor enters the energy consumption braking state. The stator winding of the motor is connected with a DC power supply, and the motor has kinetic energy or potential energy.
The electromagnetic torque is braking torque, the external resistance in the rotor is large, the electromagnetic torque is small, and the stable operation speed is large under the same load torque. Excitation current is large, braking torque is large, the same load torque, stable running speed is small. The mechanical characteristic curve passes through the zero point, and the rotor current negative feedback does not pass through the zero point; Overspeed protection shall be set for hoisting mechanism.
YZR crane motor is allowed to be started twice continuously under actual cold state, natural shutdown shall be conducted between two starts, and it shall be started once under hot state. After the above starting, the additional restart of motor shall be conducted after 4 hours of shutdown. The moment of inertia of rotating part of driven mechanical equipment shall not exceed the value of "load moment of inertia jext" item in technical data sheet.
The terminal voltage of YZR crane motor shall not be lower than 80% of rated voltage during starting of user's power grid. The resistance torque characteristics of the driven machinery are those of compressors, fans and pumps. At rated speed, the resistance torque converted to motor end shall not be greater than 40% of rated torque of motor.
