Sensorless brushless dc motor control - inductive method

  electric motor 20hp aluminum body 
Specifications
1. 20 years manufacturing experience
2. competitive price,high quality
3. Brand Name: FUJIAN DONGFENG MACHINERY ELECTRICAL LIABILITY CO., LTD

 Inductive method has two forms: one kind is used for salient pole permanent magnet brushless dc motor, another kind is used in the embedded magnetic steel structure of the permanent magnet brushless dc motor. The first inductive method mainly through applying detection in the process of starting the www.facebook.com/guohong.trading motor winding voltage to judge its inductance changes, it is used in "the potential laws" a starting technology. Because in a salient pole machine, winding, the self inductance L said into the axis of the winding and the rotor can be direct axis Angle between H times cosine function, by detecting the change electric motor fan cover of L, can determine the approximate location of the rotor axis, and then based on the change trend of iron core saturation degree determine its polarity, thus eventually get correct position signal. This method for implementation is difficult, and can only be applied to the salient pole machine, so the application is less now. 


Y series totally enclosed protect Asynchronous motor

Specifications
1. 20 years manufacturing experience 
2. 12 months guarantee 
3. low noise and temperature rise 
4. high starting torque 

5. AC Voltage: 220V/380V, 380V/660V,400V/690V,220V/400V

Compared with the first, the second form is the true sense of the inductive method. In an embedded type permanent magnet brushless dc motor, the winding inductance would occur because of the change of rotor position and corresponding change, by detecting the change, after a certain calculation again, can get the rotor position signal. When y connection of the three-phase winding inductance changes, including point potential V n will change. Assume in figure 3 a + T, T, b - conduction, when So, lamination detection of L b = L a moment, can detect the ec passing zero moment. This method put forward by foreign first, and on the air conditioning compressor control application, speed range might reach 500 ~ 7, 500 r/min. This method of detection precision, error is small, but the difficulty is bigger also, it needs to continuously the real-time detection of the winding inductance.