Brushless DC motors use electric switches to realize current commutation, and thus continuously
rotate the motor. These electric switches are usually connected in an H-bridge structure for a
single-phase BLDC motor, and a three-phase bridge structure for a three-phase BLDC motor .
Raising the switching frequency increases PWM losses, though lowering the switching frequency
limits the system’s bandwidth and can raise the ripple current pulses to the points where they
become destructive or shut down the BLDC motor driver.
Sensored Motor Drive
A three-phase BLDC motor requires three Hall sensors to detect the rotor’s position. Based on the
physical position of the Hall sensors, there are two types of output: a 60° phase shift and a 120°
phase shift. Combining these three Hall sensor signals can determine the exact communation
sequence.
Mode of control-120 degree BLDC control
A three-phase BLDC motor requires three Hall sensors to detect the rotor’s position. Based on the
physical position of the Hall sensors, there are two types of output: a 60° phase shift and a 120°
phase shift. Combining these three Hall sensor signals can determine the exact communation
sequence
Sensor less Motor Driver
A three-phase BLDC motor measure back emf to detect the rotor’s position. There are
3 type of sensing methods :single shunt ,dual shunt and three shunt.
Mode of control -180 degree BLDC control and 120 degree BLDC control
