Sep 14, 2020
Electrical Paper: Analysis and Discussion of Motor Soft Start Technology
During the start of the motor, the cooperation of multiple components inside the motor is required. Therefore, there are many places that need to be paid attention to and optimized when the motor is started. The soft start of the motor requires braking, starting mode, energy saving and emission reduction, etc. Various aspects are optimized to achieve the best results. A high level of technology is required to start a motor with alternating current, and high-tech products need to be used to ensure the normal start of the motor. The following is a systematic description of the function, structure and start-up related technologies of the soft-start motor.
The motor needs a lot of electric energy when it works. Generally, the current required by the motor when starting is much larger than the rated current, which is about 6 times the rated current. Under such a current, the motor will receive a greater impact than during normal operation. Such an impact will increase the loss of the motor, reduce the life of the motor, and even cause damage to other parts inside the machine when the current is too large. Under such circumstances, people began to pay attention to the research on the soft start of the motor, hoping to enable the motor to start smoothly and smoothly through related technologies.
1 Principle of motor soft start
In the prior art, the research on the soft start of the motor is mainly to control the start of the three-phase AC asynchronous motor. The soft start of the motor is realized by using the three-phase AC asynchronous motor to provide protection for the start and stop of the motor. Such technology is widely used in the industrial field. The industry uses this technology to replace the traditional Y/△ start, and has achieved good results.
The three-phase parallel thyristor (SCR) can adjust the voltage of the soft starter. It is the voltage regulator of the soft starter. When the three-phase parallel thyristor is connected to the circuit, it acts as a connection between the power supply and the motor stator. When you click to start, the voltage inside the thyristor gradually rises, and the motor will slowly accelerate under the action of the voltage. When the running speed reaches the required speed, the thyristor will achieve full conduction. At this time, click The voltage is the same as the rated voltage, which can not only realize the soft start of the motor, but also conform to the mechanical performance of the machine. This start makes the whole process run smoothly. In this case, the motor runs normally under the protection of the thyristor, so that the motor is subject to less impact and loss, which can significantly increase the service life of the motor and keep the motor in good working condition.
2 Soft start technology of asynchronous motor Soft start
2.1 Soft start of thyristor AC voltage regulation
The soft start of thyristor AC voltage regulation is mainly through changing the connection mode of the thyristor, and the traditional connection method is connected to the three-phase winding, thus realizing the power supply to the thyristor in parallel. The thyristor soft starter has strong adjustability, so users can make appropriate adjustments to the motor according to their different needs, and make the starting method of the motor more suitable for their needs through corresponding changes.