Views:1 Author:Site Editor Publish Time: 2019-06-28 Origin:Site
It is very important for a machine start before its starting work.
Because the startup is not good, the work efficiency will be poor. So the correct startup method will also have an impact on the life span of the machine.
Just like a synchronous motor, it is important to start it correctly before working.
There are two methods for starting a synchronous motor. The first is the asynchronous start method: a cage-type start winding is mounted on the main pole pole of the motor.
When starting, the field winding is short-circuited through the resistor, and then the stator winding is connected to the grid.
By relying on the asynchronous electromagnetic torque of the starting winding, the motor is speeded up to the synchronous speed. Then the exciting current is passed into the field winding to establish the main pole magnetic field, and the synchronous motor torque can be used to pull the motor rotor into the synchronous speed.
The second type is the auxiliary motor starting method: this method usually uses the induction motor with the same number of synchronous motors as the auxiliary motor to drag the main unit to the synchronous speed.
Then switches the power supply to the main stator, and the excitation current flows into the excitation winding. Pull the host into the synchronous speed. Synchronous motors also have higher operational stability.
The synchronous motor is generally operated in an overexcited state, and its overload capability is greater than that of the corresponding asynchronous motor.
The torque of an asynchronous motor is proportional to the square of the voltage. The torque of the synchronous motor is determined by the product of the voltage and the internal electromotive force generated by the motor excitation current, that is, only proportional to the primary of the voltage.