Three-phase asynchronous motor electric-braking device and control method thereof

Abstract

The invention discloses a three-phase asynchronous motor electric-braking device and a control method thereof. The three-phase asynchronous motor electric-braking device comprises a thyristor voltage regulator, a braking actuator and a control and status monitor. The thyristor voltage regulator is connected with a brake actuator and a three-phase alternating-current power source, the braking actuator is connected with a motor, and the control and status monitor is connected with the braking actuator, the three-phase alternating-current power source and the motor respectively. Besides, the thyristor voltage regulator comprises a bypass contactor and at least one thyristor valve group which are in parallel connection. The braking actuator comprises a forward contactor and a reverse contactor which are in parallel connection. The control and status monitor changes input voltage of the stator of the motor by controlling the thyristor valve group. The electric-braking device is simple in structure, reliable and safe in performance and applicable to quick, accurate and smooth brake stop in a three-phase asynchronous motor driving system.

Description

technical field [0001] The invention relates to a motor braking device and a control method thereof, in particular to an electric braking device applied to a three-phase asynchronous motor and a control method thereof. Background technique [0002] Braking is one of the important issues in the electric drive system. In order to improve efficiency in industrial production, or in special applications such as fire protection, many machines require fast braking to achieve fast braking and accurate parking. There are two types of braking methods: mechanical braking and electrical braking. Mechanical braking mainly achieves the purpose of braking by increasing friction. It has disadvantages such as inconvenient operation, poor reliability, and complicated processing technology, and often fails to meet the requirements of use, while electrical braking overcomes the above shortcomings. Electric braking, also known as electromagnetic braking, causes the motor to generate an electrom...

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Problems solved by technology

[0011] The braking device and braking method used for motor braking in Document 2 adopts super capacitor DC energy-consuming braking technology, which requires a set of DC power supply device, and the equipment cost is high

In addition, when some drag systems use energy-consumption braking to stop, on the one hand, it needs to consider the need for a large braking torque, and on the other hand, it is not possible to overheat the winding due to the excessive current of the stator and rotor circuits. Due to the limitations of the motor, the braking accuracy is relatively poor, and the braking effect is also different due to the different motor power.

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