1. mechanical braking
①. Mechanical brake combined with brake electromagnetic lock, such as crane brake system.
②. Motor braking is generally divided into reverse braking, energy consumption braking (DC braking) and regenerative braking three ways. The principles and precautions of these braking modes are briefly introduced below.
③. At present, the electric hoist motor is a special motor. The rotor of the motor is conical and can move horizontally. When the motor is energized, the air gap between the stators rotates at the same time, and the positive displacement of the rotor eliminates the air gap lock under the action of the spring in the event of a power outage, which is called mechanical braking.
2. electric braking
(1). Reverse braking refers to changing the phase sequence of the power supply.
①. Reverse braking principle: after the motor is disconnected from the power supply, in order to make the motor stop quickly, the reverse power supply is added to the power supply of the motor by the control method. At this time, the rotation direction of the motor rotor is opposite to that of the rotating magnetic field of the motor. At this time, the electromagnetic torque generated by the motor is the braking torque, which accelerates the deceleration of the motor.
②. Reverse braking has a major disadvantage, that is, when the motor speed is 0, if the reverse power supply is not removed in time, then the power will be reversed.
(2). Dynamic braking is the direct power of the stator.
Energy consumption braking principle: stator winding adopts direct current to generate fixed magnetic field. At this time, the rotor cuts the magnetic wire in the direction of rotation, thereby generating a braking torque. Because this braking mode is different from regenerative braking, the energy generated during braking is fed back to the grid, and the kinetic energy is consumed by the motor alone, so it is called energy consumption braking. Because the stator winding adopts DC braking, the energy consumption braking is also called DC injection braking
