P-MART wiki - User contributions [en]

User:GarfieldKraus526

2012-05-08T07:29:54Z

GarfieldKraus526: Created page with 'The [http://www.china-bldcmotor.com/ brushless DC (BLDC) motor] can be envisioned as a brush DC motor turned inside out, where the permanent magnets are on the rotor, and the win…'

The [http://www.china-bldcmotor.com/ brushless DC (BLDC) motor] can be envisioned as a brush DC motor turned inside out, where the permanent magnets are on the rotor, and the windings are on the stator. As a result, there are no brushes and commutators in this motor, and all of the disadvantages associated with the sparking of brush DC motors are eliminated.
This motor is referred to as a "DC" motor because its coils are driven by a DC power source which is applied to the various stator coils in a predetermined sequential pattern. This process is known as commutation. However, "BLDC" is really a misnomer, since the motor is effectively an AC motor. The current in each coil alternates from positive to negative during each electrical cycle. The stator is typically a salient pole structure which is designed to produce a trapezoidal back-EMF waveshape which matches the applied commutated voltage waveform as closely as possible. However, this is very hard to do in practice, and the resulting back-EMF waveform often looks more sinusoidal than trapezoidal. For this reason, many of the control techniques used with a PMSM motor (such as Field Oriented Control) can equally be applied to a [http://zh.netlog.com/majing900103/blog/blogid=376069#blog BLDC motor].

GarfieldKraus526

2012-05-08T07:29:25Z