IJSRSET207232 | Accepted : 10 March 2020 | Published : 21 March 2020 | March-April-2020 [ 7 (2) : 98-101] International Journal of Scientific Research in Science, Engineering and Technology (www.ijsrset.com) © 2020 IJSRSET | Volume 7 | Issue 2 | Print ISSN: 2395-1990 | Online ISSN : 2394-4099 DOI : 10.32628/IJSRSET207232 98 Modelling and Analysis of BLDC Motor Using Sliding Mode Control and comparing it with PI Controller T. Santosh Kumar 1 , B. Ramsankar 2 , K. Raviteja 3 , P. Ravi 4 , B. Rambabu 5 ,V. Jagadeesh 6 1 Assistant Professor EEE Department, Raghu Institute of Technology, Visakhapatnam, India 2-6 B.Tech Student EEE Department, Raghu Institute of Technology, Visakhapatnam, India ABSTRACT The sliding mode control technique for brushless DC motor is used to improve its dynamic performance with high accuracy. The proposed novel sliding mode (SM) controller method is used drive at all speed levels. The SM controller is the most attractive and simple in modelling for its insensitivity to parameter variations and external disturbances. The validity of the proposed method is verified through simulation. The BLDC motor is inherently electronically controlled and requires rotor position information for proper commutation of current. An equation based model for closed loop operation of BLDC motor drive is simulated in MATLAB/Simulink. Simulation results show the proposed SM Controller has the advantage of fast response and less steady-state error when compared to that of the conventional PI controller. In this paper the responses of current, speed and torque using SM controller is compared with that of PI controller. Keywords : Brushless DC Motor, Sliding mode controller, PI controller. I. INTRODUCTION The BLDC is essentially configured as a permanent magnet rotating part, a set of current carrying conductors. In this respect, it is equivalent to an inverted DC commutator motor, in that the magnet rotates while the conductors remain stationary. In both cases, the current must reverse polarity every time a magnet pole passes by, in order that the torque is unidirectional. In the DC commutator motor, the commutator and brushes perform the polarity reversal. In the brushless DC motor, the polarity reversal is performed by power MOSFETS, which must be switched in synchronism with the rotor position. The stator is normally 3-phase star connected. Each commutation sequence has one of the windings energized to positive power current entering into the winding and the second winding energized to negative power current exits the winding and third winding non-energized. Torque is produced by the interaction of the magnetic field produced by the permanent magnets and the stator windings. II. PI CONTROLLER PI controller operates the BLDC motor at the set point corresponding to a reference speed. It is important to incorporate a controller in the feedback path. The PI controller contains an outer speed controller and an inner current controller. Accordingly a PI speed controller has been chosen with gain parameters Kp and Ki. The speed of the BLDC motor compared with the reference value and the error in speed is processed by the speed controller. The output of the PI controller at any instant is the reference torque given by