Abstract— This paper presents an advanced simulation model of
Permanent Magnet Synchronous Motor (PMSM). The vector
control scheme of a PMSM drive has been implemented using the
developed simulation model. In the developed model, speed and
torque as well as the voltages and currents of voltage source
inverters components can be effectively monitored and analyzed.
The developed simulation model has been implemented using
Matlab and the dynamic response of PMSM drive has been
analysed for constant speed, varying torque and variable speed
constant torque operation. Also, the simulation results have been
presented. The simulation results of the developed model has
been validated with the circuit simulation using the PMSM block
available in the Matlab/Simulink library. Therefore, it can be
expected that the developed simulation model can be an easy to
design tool for the design and development of PMSM drives for
different control algorithms and topological variations with
reduced computation time and memory size.
Keywords- PMSM; vector control; modeling; closed loop;
constant torque angle control;
I. INTRODUCTION
In recent years, many DC drives were replaced by brushless
AC drives. PMSM gained much attention and has become the
most used drive in machine tool servos and modern speed
control applications. The inherent advantages of the machine
include high efficiency, high power factor, high power density,
easy maintenance, fast dynamic response. PMSM replaces
Induction motor (IM) and Synchronous motor (SM) in several
applications due to its higher efficiency, high power density
and high torque to inertia ratio [1]. Rotor of PMSM is made up
of permanent magnet so there is no need of supplying
magnetizing current through stator to produce airgap flux. SM
requires dc excitation on the rotor, which is supplied by
brushes and slip rings; it leads to rotor losses and requires
regular maintenance [2]. In PMSM rapid torque build up
required by, variable speed and fast dynamic response drives,
could be achieved by stator current control technique.
PMSM is a topic of interest for last twenty years. Vector
control technique is one of the most common closed loop
control technique used in a PMSM drive. Vector control
eliminates oscillating flux, torque responses in inverter fed
induction motor and synchronous motor drives. This method
has further classification, which includes constant torque angle
control, Unity power factor control, constant mutual air gap
flux-linkages control, optimum-torque-per-ampere control and
flux-weakening control. The choice of these methods depends
on mainly on the type of application and the load
characteristics.
Hence, it is always essential to perform a simulation study
prior to designing a PMSM drive for choosing the appropriate
control algorithm for a particular application. The mathematical
model of PMSM as such has been well established in literature
[2] and [3]. Incorporation of PMSM model along with the
inverter model and load characteristics is essential to represent
a complete drive system. Such a simulation model has been
reported for a BLDC drive [4]. Also the modeling of complete
PMSM drive is reported in [2].
This paper proposes a system simulation model for a
complete PMSM drive based on the mathematical model of an
inverter fed PMSM implemented using MATLAB\Simulink,
which could be used for simulating various control algorithms.
In the developed model, speed and torque as well as the
voltages and currents of voltage source inverters components
can be effectively monitored and analyzed.
In this paper, section II discusses about mathematical
modeling of PMSM. Section III discusses about the developed
simulation model of PMSM drive system. The simulation
results of the developed model validated with the circuit
simulation model has been presented in section IV.
II. MATHEMATICAL MODEL OF PMSM
The mathematical model of PMSM available in the existing
literature [1] and [5] has been presented in this section to
provide a basis for the subsequent sections.
The stator of the PMSM and the wound rotor synchronous
motor are similar. The permanent magnets used in the PMSM
are of a modern rare-earth variety with high resistivity, so
induced currents in rotor are negligible. In addition, there is no
difference between the back EMF produced by a permanent
magnet and that produced by an excited coil. Hence the
mathematical model of a PMSM is similar to that of the
wound rotor SM. The rotor reference frame is chosen because
the position of the rotor magnets determines the instantaneous
induced emfs and subsequently the stator currents and torque
of the machine independently of the stator voltages and
currents. The following assumptions are considered in the
derivation.
Trichirappalli, India.
lenin-eee@saranathan.ac.in
Asst. Professor, EEE,
Saranathan College of Engineering,
S. Lenin Prakash
kamalaselvaneee@gmail.com
M.E, Power Electronics and Drives
Saranathan College of Engineering,
Trichirappalli, India.
A. Kamalaselvan
Modeling Simulation and Analysis of Closed Loop
Speed Control of PMSM Drive System
2014 International Conference on Circuit, Power and Computing Technologies [ICCPCT]
692 978-1-4799-2395-3/14/$31.00 ©2014 IEEE