Matters needing attention in purchasing industrial brushless motor
Brushless DC motor uses semiconductor switching devices to realize electronic commutation, that is, electronic switching devices are used to replace the traditional contact commutator and brush. It has the advantages of high reliability, no commutation spark and low mechanical noise. It is widely used in high-grade recording stand, video recorder, electronic instruments and automatic office equipment.
Brushless DC motor is composed of permanent magnet rotor, multipole winding stator, position sensor, etc. The position sensor converts the current of the stator winding in a certain order according to the change of the rotor position (that is, detect the position of the rotor magnetic pole relative to the stator winding, generate the position sensing signal at the determined position, control the power switching circuit after being processed by the signal conversion circuit, and switch the winding current according to a certain logical relationship). Operation of stator winding.
What aspects should we start with when purchasing brushless DC motor? What should we pay attention to? Below, demak motor will introduce one or two to you. When purchasing the type selection of DC brushless motor, you might as well compare it to see if it is useful.
1. Pay attention to the voltage of Brushless DC motor
The voltage is supplied by an electronic switch circuit controlled by the position sensor output. When selecting DC brushless motor products, you should first select the correct voltage, select the rated voltage according to the needs of customers to select the driver voltage parameters, and note that the voltage used should not exceed the specified range of the driver during no-load and full load.
2. Pay attention to the current of Brushless DC motor
Let's select the peak current of the driver. The method of selecting the peak current is to have the rated input current IR (a) of the motor, then the peak current IP (a) = 2xir. Otherwise, there is no certain engineering allowance for the output current during the use of the driver. If the rated output power (or maximum output power) pr (W) and driving voltage VR (V) of the motor are known, then the peak current IP (a) ≧ 4xPr/Vr.
3. Pay attention to the service temperature of Brushless DC motor
We can also set the motor according to the parameters, but we need to set the appropriate parameters according to different motors. Of course, we also need to take into account the use range of temperature. The wider the temperature, the higher the price.
4. Pay attention to the resistance of Brushless DC motor
According to the requirements of power insulation, in order to ensure the normal operation of the driver, the insulation resistance between the hall ground wire of the motor and the motor winding wire, and between the hall ground wire winding wire and the casing is greater than 100 megohm 500VDC, which can withstand 600vac / 50Hz / 1mA / 1s withstand voltage without breakdown.
Special attention: the drive brake of Brushless DC motor adopts short-circuit brake at the motor end. The motor has braking force when it is running, and there is no braking force when it is not running. The higher the speed, the greater the braking force. Because the brake current does not pass through the current sensing resistance, the brake current cannot be controlled. Therefore, when braking, the speed shall not exceed the safe braking speed, otherwise the power tube may be burned. Please use this function with caution.