Attenuating saturated-regulator operation effect of brushless DC motors through genetic-based fuzzy logic estimator

Authors: EMRE ÇELİK, NİHAT ÖZTÜRK

Abstract: As brushless DC motor (BLDCM) speed approaches base speed, current regulators gradually saturate and lose their ability to perform their regulating task, which causes a dramatic fall in the phase currents and motor power. To control the current to a greater extent and avoid power decline, a new reference current generation technique based on a simple fuzzy logic estimator (FLE) is introduced in this paper. According to motor speed and current command, the developed FLE decides the proper commutation angle $\alpha $, which is the angle relative to normal commutation instant used for setting the current slew rate during commutation. In this sense, current references are obtained with the same slew rates of commutated phases all the time, ensuring the noncommutation phase current is constant. The validity of the study is widely verified using DSP of TMS320F28335 and it is concluded that promising performance and simplicity are important advantages of our proposal that render it convenient for a BLDCM drive system that requires boosted power in high-speed ranges.

Keywords: Brushless DC motor, commutation angle, genetic algorithm, fuzzy logic estimator, saturated-regulator operation

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