High efficiency due to reduced losses, low maintenance
and low rotor inertia of the brushless dc (BLDC) motor
have increased the demand of BLDC motors in high power
servo and robotic applications. Since fuzzy logic with
human like but systematic property can convert the
linguistic control rules based on expert knowledge into
automatic control strategy, it can be well applied to control
the systems with uncertain or unmodelled dynamics. In
view of fuzzy logic merits, this paper proposes three types
of fuzzy logic controllers for BLDC motor drive using
advanced simulation model and presents a comparative
study of performance specifications of classical PI and PID
controllers and three fuzzy logic controllers. The three
fuzzy logic controllers considered are PI-like fuzzy logic
controller (PI-Like FLC), Hybrid fuzzy logic controller
(HFLC) and integrated fuzzy logic controller (IFLC). The
steady state and dynamic characteristics of speed and
torque are effectively monitored and analyzed using the
proposed model. The aim of fuzzy logic controllers is to
obtain improved performance in terms of disturbance
rejection or parameter variation than obtained using
classical controllers. In the HFLC, the proportional term
of the traditional PID controller is replaced with an
incremental fuzzy logic controller. For the PI-Like FLC,
the output of the controller is modified by a rule base with
the error and change of error of the controlled variable as
the inputs. The IFLC is constructed by using Fuzzy logic
controller and PID controller. A performance comparison
of classical and fuzzy logic controllers has been carried out
by several simulations at different speeds and different
load conditions.
Index Terms — BLDC motor, IFLC, HFLC, PI-Like
FLC