What are the features of BLDC motor?
COMPOSITION AND VARIATIONS OF BRUSHLESS DC (BLDC) MOTORS
|Permanent magnet brushless DC motordesign||Essentially linear torque/speed curve (neglecting iron losses), with torque proportional to current and speed proportional to voltage||Ease of speed and position control|
Are BLDC motors AC or DC?
The BLDC unit is designed to operate from DC which is switched as required by the motor. AC motors tend to be large, steady state, single speed style of motors powered by mains electricity. BLDCs are a lot better at handling different speeds (in very general terms). An AC motor is defined from the AC supply.
Why are BLDC motors so expensive?
Instead of an armature it has coils arranged around the inside of the stator. Due to the restricted space, the windings on most small in-runners have to be installed by hand. This is a difficult and time-consuming and job, which makes them more expensive than machine wound brushed motors.
What is the difference between BLDC motor and DC motor?
Like a brushed motor, a brushless motor works by alternating the polarity of windings inside the motor. It is essentially an inside out brushed motor, which eliminates the need for brushes. In a brushless DC motor, the permanent magnets are fitted to the rotor, with the electromagnets on the stator.
How efficient are BLDC motors?
BLDC motors do not have brushes and require less maintenance and system down time. Yet these motors require electronic controllers that range from simple to complex. The motors typically have efficiency of over 80%, and the controllers in the 95% range.
What is BLDC motor advantages and disadvantages?
They are also compact in size and provides high torque with better speed control and efficiency. On the other hand, it also has a few disadvantages like higher cost, resonance issue, and complex wiring setup due to the involvement of electronic control.
What is the disadvantage of the BLDC sensorless control?
There is one major disadvantage to sensorless BLDC motor control; when the motor is stationary, no back EMF is generated, depriving the MCU of information about the stator and rotor position. The solution is to start the motor in an open loop configuration by energizing the coils in a pre-determined sequence.
What are limitations of BLDC?
İt has harmonic content in back EMF so some torque ripple will occur at motor torque. İt is expensive because of the permanent magnets. Demagnetization possibility also limits the input current of BLDC.