COMMUTATION STRATEGIES OF BLDC MOTOR

Abstract

Improved efficiency and dependability have been resulted from the development of sophisticated motor drives. Conventional drives utilizes AC motors, such as induction motor and DC series motors, which needs frequent maintenance and difficult to control. A Brushless DC (BLDC) motor drives, on the other hand, are more efficient, require less maintenance, and are more expensive. Brush-less DC motors (BLDC) will be used to replace these inefficient motors, resulting in significant energy savings. As a result, a low-cost but effective BLDC motor controller is required. Brushless DC (BLDC) motor is used with hall sensors for many applications like in electric vehicles and robotics. Certain working environments of the motor can affect the functionality of hall sensors and can even cause complete failure. If the hall sensors functionality is affected, it would affect the whole working of system and can make system unstable depending upon the fault that incurred in hall sensors due to their effect on switching pattern timing. So, here hall signals have been deduced, making the operation sensor-less. This paper presents a sensor-less method of BLDC motor operation using 120ᵒ trapezoidal commutation method. Further, a Matlab Simulink model is developed where, the hall equivalent signals are deduced from phase voltages in the proposed method. Finally, simulation analysis is carried out for the proposed method by starting the motor using original hall sensor values and then suddenly shifting to the proposed deduced hall signal method. This work explores the possible application of this method in case of any hall sensor failure also.