Detecting the free-wheeling diode conduction in the open phase gives the zero-crossing point of the back EMF

51 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Pvt. Ltd.  Abstract— The development of advanced motor drive has been increases rapidly, because of their higher performance and reliability. The Sensorless control of permanent magnet brushless DC motor is presented in this paper. The fuzzy PI controller is developed for controlling the speed of the PMBLDC motor drive. Here the Sensorless control is obtained based on indirect back EMF detection which was justified by the observation that the position sensing is obtained indirectly from zero crossings of terminal voltages. Closed loop speed control is made with estimated speed from the stator voltage, so the drive proposed without any shaft mounted devices like position sensor and speed sensors. The performances of the proposed fuzzy logic controller based PMBLDC motor drive were investigated and the results are compared with conventional PI controller. Also the sensorless result scheme is compared with sensor control. In this Sensorless technique the cost of mechanical components such as sensors and cables are eliminated. The simulated results of conventional and fuzzy controller is compared and results illustrates that the FLC gives better dynamic performance also it is more robust for industrial speed control drive applications.