Circuits and Systems, 2016, 7, 726-734 Published Online May 2016 in SciRes. http://www.scirp.org/journal/cs http://dx.doi.org/10.4236/cs.2016.76062 How to cite this paper: Shanmugam, S.K., Ramachandran, M., Kanagaraj, K.K. and Loganathan, A. (2016) Sensorless Control of Four-Switch Inverter for Brushless DC Motor Drive and Its Simulation. Circuits and Systems, 7, 726-734. http://dx.doi.org/10.4236/cs.2016.76062 Sensorless Control of Four-Switch Inverter for Brushless DC Motor Drive and Its Simulation Sathish Kumar Shanmugam 1* , Meenakumari Ramachandran 2 , Krishna Kumar Kanagaraj 1 , Anbarasu Loganathan 3 1 Department of EEE, Jansons Institute of Technology, Coimbatore, India 2 Department of EEE, Kongu Engineering College, Erode, India 3 Department of EEE, Erode Sengunthar Engineering College, Perundurai, India Received 1 March 2016; accepted 9 May 2016; published 12 May 2016 Copyright © 2016 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract The major function of this proposed research is to control the speed of the brushless DC motor with sensor less control for four-switch three phase inverter. This proposed system is simplified the topological structure of the conventional six-switch three phase inverter. In this proposed method, a new structure of four-switch three phase inverter [1] with reduced number of switches for system is introduced to reduce the mechanical commutation, switching losses that occur in the six-switch method. The proposed inverter fed brushless DC motor used in sensorless control schemes which is used for sensing positioning signals. To improve sensor less control perfor- mance, four-switch electronic commutation modes based proportional intergral controller scheme is implemented. In this four-switch three phase inverter reduction of switches, low cost control and saving of hall sensor were incorporated. The feasibility of the proposed sensor less control four-switch three phase inverter fed brushless DC motor drive is implemented, analysed using MATLAB/SIMULINK, effective simulation results have been validated out successfully. Keywords Brushless DC Motor, Four-Switch Three Phase Inverter, Proportional Integral Controller, Sensorless Control * Corresponding author.