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What are the Braking Methods of Servo Motor?

Servo motors are also called actuator motors, or control motors. In automatic control system, servo motor is an executive element, its role is to transform the signal (control voltage or phase) into mechanical displacement, that is, to change the received electrical signal into a certain speed or angular displacement of the motor. Its capacity is generally 0.1-100W, commonly used is below 30W. Servo motors are divided into DC servo motor and AC servo motor.

Electric Brake Method:
Dynamic brake (also known as energy braking) consists of a dynamic braking resistor to shorten the mechanical feed distance of the servomotor through energy braking in the event of malfunction, emergency stop, or power failure.

Regenerative braking (also known as feed-back braking) refers to the servo motor in deceleration or stopping the energy generated by braking through the inverter circuit feedback to the DC bus, absorbed by the capacitive resistance circuit.

Mechanical Braking Method:
The electromagnetic brake is a mechanical device that locks the shaft of the motor.

Difference between the three methods:

Regenerative braking must work when the servo is working normally, and it is not possible to brake the motor in case of malfunction, emergency stop, or power failure. Dynamic brake and electromagnetic brake work without power supply.
Regenerative braking is automatic, while dynamic braking and electromagnetic braking require external relay control.
Electromagnetic brake is generally activated after SV OFF, otherwise it may cause amplifier overload. Dynamic brake is generally activated after SV OFF or main circuit power failure, otherwise it may cause dynamic brake resistor overheating.

Notes for selecting accessories:

Some systems such as conveyors, elevators, etc. require the servo motor to stop as soon as possible. And in the fault, emergency stop, power failure servo no regenerative braking can not decelerate the motor. At the same time, the mechanical inertia of the system is large, then you need to choose the dynamic brake dynamic brake selection should be based on the weight of the load, the motor's operating speed.
Some systems to maintain the static position of the mechanical device requires the motor to provide a larger output torque and stop for a longer period of time, if the use of servo self-locking function will often cause motor overheating or amplifier overload. In this case, it is necessary to choose a motor with electromagnetic braking.
Some servos have built-in regenerative braking units, but when the regenerative braking is more frequent, it may cause the DC bus voltage to be too high, and then it is necessary to equip a separate regenerative braking resistor. Whether the regenerative braking resistor needs to be fitted separately and how big the regenerative braking resistor should be fitted can be referred to the instruction of the sample. It should be noted that the number of braking times on the sample list is the data of the motor at no load. The actual selection should be based on the load inertia of the system and the sample motor inertia, calculate the inertia ratio. Then divide the number of braking times on the sample list by (inertia ratio + 1). The data thus obtained is the permissible number of braking times.