To evaluate the performance of a winding machine, in addition to the working characteristics (such as torque, efficiency, power factor, etc.), the starting characteristics of the winding machine is also an important index. The reliability of winding machine in operation depends on the performance of starting to a large extent.
1. The starting torque must be large enough to enable the winding machine to overcome the resistance torque and start.
2. The starting current should be as small as possible.
3. Starting equipment should be as simple, economical and convenient as possible.
The starting method of winding machine can be divided into direct starting and step-down starting. Direct start is the winding machine directly connected to the rated voltage start, also known as full voltage start. This starting method is mainly used in the grid capacity is large, the winding machine starting current will not cause obvious voltage drop on the grid occasions. Generally, the winding machine with power below 1Okw uses full voltage start. When the power is large and the capacity of the power supply is not allowed, the buck start should be used. The step-down starting method can be divided into Y-A starting method, compensator step-down starting method and extension triangle step-down starting method. The specific method should be based on the nameplate of the motor and the load of the motor.
