How is the three-phase asynchronous motor started? The manufacturer of the Dalan motor tells you that the process of increasing the speed from zero to the rated speed from the start of the power supply is called the start-up process. The starting method of the three-phase asynchronous motor is divided into two types: direct start and buck start. 1. Direct start 1 Direct start means that the motor stator winding is directly connected to the power supply at startup, and the voltage applied to the motor is the same as the normal working voltage, so the direct start is also called full voltage start. 2 When the power supply capacity is large enough and the motor capacity is small, direct start is used, and the power supply voltage is not fluctuated greatly by the start of the motor. 3 to determine whether a motor can be directly started, can be determined by the following formula: Ist / IN ≤ 3 / 4 + SN / 4PN. Where Ist is the starting current of the motor, IN is the rated current of the motor, SN is the capacity of the transformer that supplies the motor, and PN is the rated power of the motor, kW. Ist/IN is the motor's starting current multiple and can be found in the motor samples and technical data. If the calculation result does not satisfy the formula, a buck start should be used. 2, buck start 1 in order to prevent the motor starting current is too large, often use the starting device to properly reduce the power supply voltage and then add to the motor stator winding start to limit the motor starting current, when the motor speed rises to close to the rated speed, The voltage on the stator windings of the motor is then restored to its nominal value. This startup process is called buck start. 2 Step-down start must ensure that there is enough starting torque, but also to reduce the starting current, but also to avoid too long startup time. The starting current is typically limited to 2 to 2.5 times the rated current of the motor. At the time of starting, the torque is also greatly reduced due to the reduced voltage, so the step-down start is often performed under the light load condition of the motor. 3 commonly used step-down starting methods are auto-transformer step-down start, Y-△ step-down start. a. Auto-transformer step-down start auto-transformer step-down start-up refers to the use of an autotransformer to reduce the starting voltage applied to the stator winding of the motor when the motor is started. After the motor is started, the motor is disconnected from the autotransformer. , normal operation at full voltage. b, Y-△ step-down start Y-△ step-down start means that when the motor is started, the stator winding is connected to a star shape, and after the motor is started, the motor stator winding is changed to a triangle to make the motor run at full voltage. . The Y-△ step-down starting method is only applicable to the △ wiring motor, and it is connected to the star when starting. The starting current value is one-third of the starting current when the delta connection is directly full-voltage starting, so the motor capacity cannot be large, otherwise It will start to be difficult. To measure the performance of the motor starting, it is mainly evaluated from the following aspects: 1. The starting current should be as small as possible. 2. The starting torque should be large enough to ensure that the motor starts normally. 3. The speed should rise as smoothly as possible. 4. The starting method should be simple and reliable, and the starting equipment should be simple and economical. 5. The motor power consumed during startup should be as small as possible. ----- Responsible Editor: Dalan Oil Pump Motor 02- Purchasing Consultant Copyright http:/(Dalan Motor) Reprint, please indicate the source http://news.chinawj.com.cn Recessed Liner Pool Light,Underwater Recessed Linear Light,Recessed Ip68 Liner Pool Light,Recessed Led Pool Light Shenzhen Poolux Lighting Co., Ltd. , https://www.pooluxled.com