The selection of Brushless DC motor is generally considered from the following dimensions:

　　1. Required motor power

　　2. Required motor torque and speed

　　This is the speed with application demand. The speed demand of the motor can be determined according to the trapezoidal curve of the motor speed. Usually, 10% margin is left in the calculation.

　　3. Voltage used

　　When selecting brushless DC motor products, the correct voltage should be selected. According to the needs of customers, the rated voltage should be selected to select the voltage parameters of the driver. The voltage used should not exceed the range specified by the driver in the process of no-load and full load.

　　4. Test absorptivity K.

　　When the absorption ratio is greater than 1.33, it indicates that the insulation of the motor has not been affected by moisture or the degree of moisture is not serious. In order to compare with the previous data, the absorption ratio measured at any temperature should also be converted to the same temperature.

　　PS: another key point is the requirement of power insulation. In order to ensure the normal operation of the driver, the insulation resistance between the hall line ground wire and the motor winding wire of the motor, and between the hall ground wire winding wire and the housing is greater than 100 megohm 500VDC, which can withstand 600vac / 50 Hz / 1 mA / 1 second without breakdown.

　　5. The speed control of high speed must consider whether the clock resolution of the system is enough to control the time of processing software instructions. In addition, the data access mode of Hall sensor signal change also affects the processor performance and the correctness and real-time performance of judgment. As for the speed control of low speed, especially the low-speed starting, because the return Hall sensor signal changes more slowly, how to capture the signal mode, processing time and properly configure the control parameters according to the motor characteristics are very important.

　　6. The required motor mounting flange size and motor length, etc