Sensorless speed control of BLDC motors using sliding mode observer

11 SENSORLESS SPEED CONTROL OF BLDC MOTORS USING SLIDING MODE OBSERVER (Phd. Thesis) Mehmet GEDİKPINAR GAZİ UNIVERSITY INSTITUE OF SCD2NCE AND TECHNOLOGY July 2002 ABSTRACT In this thesis, a new sensorless speed control algorithm for Brnshless DC motors has been developed. The algorithm is based on the use of Sliding Mode Observer (SMO) and an identification model. The SMO has been used to estimate both the rotor speed and position. Although the ideal sliding mode techniques are robust in the case of parameter variations, the discrete time implementation of the SMO is sensitive to the large parameter variations. Thus, an identification model of the motor has been employed to estimate the true stator resistance and inductance and to use these estimated parameters in the sliding mode observer. The operation results showing the effectiveness of the proposed method under different speed and load conditions have been presented in the thesis. Science Code : 626.01.01 KeyWords : Permanent magnet synchronous motor, Sliding Mode observer, parameter estimation Page Number : 116 Adviser : Assoc. Prof. Dr. Güngör BAL