XIX Sympozjum Srodowiskowe PTZE - materialy.pdf

XIX Sympozjum PTZE, Worliny 2009
PERFORMANCE EVALUATION OF SYNCHRONOUS
RELUCTANCE MOTOR IN BLDC DRIVE
Bojan Štumberger 1 , Viktor Goričan 1 , Gorazd Štumberger 1 ,
Miralem Hadžiselimović 1 , Tine Marčič 2 , Mladen Trlep 1
1
University of Maribor, Faculty of Electrical Engineering and Computer Science,
Smetanova ulica 17, SI-2000 Maribor, Slovenia, e-mail: bojan.stumberger@uni-mb.si
2
TECES, Research and Development Centre for Electric Machines,
Pobreška cesta 20, SI-2000 Maribor, Slovenia
Introduction
While the use of permanent magnet synchronous motors in brushless DC (BLDC) drives and
brushless AC (BLAC) drives is frequent, the use of synchronous reluctance machines (SRM)
is generally limited to application in BLAC drives. In ideal conditions with three-phase
distributed stator windings and sinusoidal excitation, the stator excitation generated revolving
MMF in BLAC drive, while the quasi-rectangular stator excitation produced MMF which
travels in discrete steps in BLDC drive.
The rotor iron core of SRM is usually compounded of high permeability electrical steel and
low permeability flux-barriers, which cause highly anisotropic magnetic behavior of the rotor
iron core according to the rotor position in respect to the direction and level of stator
excitation [1, 2]. The behavior of SRM with rotor flux-barriers and their performance
evaluation in the BLDC drive is not well described in the literature, therefore the goal of this
work is the first attempt to fill the gap in this field.
Method of analysis and results
The BLDC motor drive is actually an integrated system consisting of motor, shaft position
sensor (usually Hall-effect device), switch logic controller and transistor bridge inverter. The
BLDC motor performance characteristic is similar to a separately excited commutator dc
motor, i.e. speed control is implemented by the increase or decrease of armature impressed
voltage [3].
The tested synchronous reluctance motor was made from IEC 56 induction motor stator frame
(stator winding: three-phase distributed winding in Y connection) and four pole rotor with
three-barriers per pole. The motor was equipped on the B-side of the motor with four pole
ring magnet and three 120 electrical degree shifted Hall-effect sensors in order to establish
simple shaft position sensor system. The input supply voltage of the inverter was constant,
while the level of output voltage of the inverter in the 120 electrical degree conducting mode
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