Citation
Hafz Nour, Mutasim Ibrahim
(2008)
Sensorless Adaptive Fuzzy Logic Control Of Permanent Magnet Synchronous Motor.
PhD thesis, Universiti Putra Malaysia.
Abstract
Permanent Magnet Synchronous Motors (PMSM) require an electromechanical rotor
position sensor to operate. The rotor position sensor has disadvantages, such as
reliability, size, higher cost, and increased electrical connections. PMSM is used in
many speed and position control industrial applications. Proportional integral (PI)
and proportional integral derivative (PID) controllers have been widely utilised as
speed controllers in PMSM drives. However, these controllers are very sensitive to
step change of command speed, parameter variations and load disturbance.
In this work, an adaptive fuzzy logic speed controller is proposed. The main features
of the proposed controller are; quick recovery of motor’s speed from load
disturbances and insensitivity to parameter variation over a wide speed range.
The proposed controller is a hybrid model reference adaptive speed controller
(HMRASC) which mainly consists of two functional blocks. The first block is a
direct FLC that has the error and the change of error as inputs. The error signal is
measured between the actual motor speed and the desired speed and the output is the change in the torque command. The second block implements a model reference
adaptive controller. In the proposed system, the output speed of the reference model
is compared with the actual speed of the motor and the resulted speed error is applied
to a PI controller. The output signal of the PI controller is added to the direct FLC
output to compensate any deviations in the motor speed from the reference speed due
to parameters variation and disturbances in the load.
The design and optimisation of the FLC are carried out using an adaptive fuzzy
inference system network that uses the backpropagation, least square and gradient
algorithms. The fuzzy inference system is trained and designed using an adaptive
network. The rules and the implication method used are also optimised and
minimised in order to shorten the computation time. In addition, the effect of
different types and distributions of the membership functions were investigated and
presented.
This work also presents the estimation of the rotor position, which works effectively
with nearly zero estimation error over wide speed range, to replace the
electrometrical rotor position sensor. An estimation method based on the back EMF
and flux estimation is presented to calculate the rotor position for medium to high
speed. At low speed, the rotor position is calculated using signal injection where a
high frequency low voltage signal is injected on the stator winding. In the proposed
method, the measured motor’s current and the estimated motor’s voltage are
processed through a signal processing block and a PI regulator to calculate the angle
of the rotor position.Finally the performance of the HMRASC and the rotor position angle estimation
algorithms are evaluated by simulation and verified experimentally for two motors
using MCK2407 kit and IMDM15 board which are based on the TMS320LF2407
fixed point Digital Signal Processor (DSP) for different operating conditions. The
first motor is rated at 50W and the second is rated at 380W. Both experimental and
simulation results obtained from the HMRASC and the position angle estimation
algorithms showed superior results compared to other methods presented in the
literature.
Download File
Additional Metadata
Actions (login required)
![View Item View Item](/style/images/action_view.png) |
View Item |