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Abstract—The aim of this paper is to present the study of
various speed control techniques using permanent magnet
synchronous motor (PMSM). The PMSM is increasingly used in
high performance applications in industry. Such applications
require speed controllers with high accuracy, high performance
and flexibility and efficiency in the design process and
implementation. The several speed control techniques are
available, and these control techniques vary from the type of
controller used for PMSM to the type of software/hardware
implementation. A review of various control techniques is
highlighted in this paper with respect to speed control &
implementation of a speed controller
Index Terms—PMSM, Speed control, Sensorless control,
Neurofuzzy
I. INTRODUCTION
ITH the development of power electronics technology,
microelectronic technology, digital control technology
and control theory, the dynamic and static characteristics of AC
drive system can be compared with DC drive system. AC drive
system has been widely used. AC drive has replaced DC drive.
Become a reality.
Since the AC motor is essentially a nonlinear, multivariable,
strongly coupled, time-varying, large-interference complex
object, its effective control has always been a hot issue at home
and abroad, and various control strategies and methods have
been proposed. Classical linear control can`t overcome the
impact of load, large-scale variation of model parameters and
nonlinear factors, and control performance is not high; vector
control, direct torque control also has some problems; in recent
years, with the theory of modern control and intelligent control
Development, advanced control algorithms are applied to AC
motor control and achieve certain results
Each of these methods has its own characteristics. In
practical applications, it is necessary to properly select
according to specific requirements in order to achieve the best
results. Therefore, it is important to have a comprehensive
understanding of the various control strategies. This paper will
comprehensively analyze and compare the current common
control strategies of AC motors, give them their advantages and
disadvantages, and point out the development direction.
II. CONTROL METHOD BASED ON AC MOTOR DYNAMIC MODEL
To achieve higher dynamic performance, the control law
must be designed based on the dynamic mathematical model of
the AC motor. The dynamic mathematical model of AC motors
is nonlinear and multivariable. The input variables are stator
voltage and frequency, and the output variables are speed and
flux linkage. The most mature control methods currently
available are vector control and direct torque control.
A. Vector control of PMSM
The advantages of this method: the decoupling of flux
linkage and torque is realized, and they can be independently
controlled, which significantly improves the control
performance.
Disadvantages:
1. The dependence on the e motor parameters is large, and
the motor parameters are degenerated in the presence of the
parameters, it is difficult to achieve the desired control effect;
2. Even if the motor parameters and flux linkage can be
accurately measured, decoupling can only be achieved when
the steady state is stable, and the coupling still exists during the
weak magnetic field;
3. It should be assumed that there is only the fundamental
positive magnetic potential in the motor, which is too
theoretical and not completely consistent with the actual
situation;
4. If the decoupled control loop uses an ordinary PI
regulator, its performance is seriously affected by parameter
changes and various uncertainties.
Despite this, vector control has been widely used in AC motor
control.
B. Direct torque control of PMS Motor
No complicated transformation and calculation are required,
and the motor and inverter are regarded as a whole. The space
voltage vector analysis method is used to analyze the
mathematical model of the AC motor in the stator coordinate
system, calculate the stator flux and torque, and pass the PWM
inverter. The switch state directly controls the torque.
The advantages of this method:
1. the system structure is simple, no need to decouple the
stator current, and the static and dynamic performance are
excellent;
2. Using the stator flux linkage for magnetic field orientation,
as long as the stator resistance is known, it can be observed to