Fuzzy Based Sensorless Control of BLDC Motor Using Hystersis

The objective of the book is to control the speed of the BLDC motor using a hysteresis comparator for a sensorless technique. The brushless DC motor is a synchronous electric motor which is powered by DC supply and it has an electronically controlled commutation system, instead of a mechanical commutation system based on brushes. In these motors, the current and torque, voltage and rpm are linearly related. Brushless motors offer several advantages over brushed dc motors, including more torque per weight, more torque per watt (increased efficiency), increased reliability, reduced noise, longer lifetime (no brush and commutators erosion), elimination of ionizing sparks from the commutators and overall reduction of electromagnetic interference (EMI). For proper operation of the drive, the position of the rotor is necessary. However, in sensorless drives, position sensors are not used. Instead, position information is obtained indirectly using hysteresis comparator. Advantages of sensorless drives include increased system reliability, reduced hardware cost, reduced feedback units and decreased system size.