An Adaptive Sliding Mode Control Law for Induction Motors Using Field Oriented Control Theory
Được đăng lên bởi
lenam15
Số trang: 6 trang

Lượt xem: 1992 lần

Lượt tải: 0 lần
Proceedings of the 2006 IEEE International Conference on Control Applications Munich, Germany, October 46, 2006 WeC08.4 An Adaptive Sliding Mode Control Law for Induction Motors Using Field Oriented Control Theory O. Barambones*, A.J. Garrido, F.J. Maseda and P. Alkorta Abstract— In this paper, an indirect ﬁeldoriented induction motor drive with a slidingmode controller is presented. The proposed slidingmode control law incorporates an adaptive switching gain that avoid calculating an upper limit of the system uncertainties. The design also includes rotor speed computation from measured stator terminal voltages and currents. The calculated speed is used as feedback in an indirect vector control system achieving the speed control without the use of shaft mounted transducers. Stability analysis based on Lyapunov theory is also presented, to guarantee the closed loop stability. Finally simulated results show on the one hand that the proposed controller with the proposed estimator provides highperformance dynamic characteristics, and on the other hand that this scheme is robust with respect to plant parameter variations and external load disturbances. I. INTRODUCTION Indirect ﬁeldoriented techniques utilizing microprocessors are now widely used for the control of induction motor servo drive in highperformance applications. With the ﬁeldoriented techniques, the decoupling of torque and ﬂux control commands of the induction motor is guaranteed, and the induction motor can be controlled linearly as a separated excited D.C. motor [2], [6], [13]. However, the control performance of the resulting linear system is still inﬂuenced by the uncertainties, which usually are composed of unpredictable parameter variations, external load disturbances, unmodelled and nonlinear dynamics, etc. Therefore, many studies have been made on the motor drives in order to preserve the performance under these parameter variations and external load disturbances, such as nonlinear control, optimal control, variable structure system control, adaptive control and neural control [7], [8]. Moreover, in an indirect ﬁeldoriented control of induction motors, a knowledge of rotor speed is required in order to orient the injected stator current vector and to establish speed loop feedback control. Although the direct ﬁeld oriented control method with a ﬂux estimator does not need the speed sensor in order to orient the injected stator current vector, this method is not practical. This is ...
An Adaptive Sliding Mode Control Law for Induction Motors Using
Field Oriented Control Theory
O. Barambones*, A.J. Garrido, F.J. Maseda and P. Alkorta
Abstract— In this paper, an indirect ﬁeldoriented induction
motor drive with a slidingmode controller is presented. The
proposed slidingmode control law incorporates an adaptive
switching gain that avoid calculating an upper limit of the
system uncertainties. The design also includes rotor speed
computation from measured stator terminal voltages and cur
rents. The calculated speed is used as feedback in an indirect
vector control system achieving the speed control without the
use of shaft mounted transducers. Stability analysis based on
Lyapunov theory is also presented, to guarantee the closed loop
stability. Finally simulated results show on the one hand that
the proposed controller with the proposed estimator provides
highperformance dynamic characteristics, and on the other
hand that this scheme is robust with respect to plant parameter
variations and external load disturbances.
I. INTRODUCTION
Indirect ﬁeldoriented techniques utilizing microproces
sors are now widely used for the control of induction motor
servo drive in highperformance applications. With the ﬁeld
oriented techniques, the decoupling of torque and ﬂux control
commands of the induction motor is guaranteed, and the
induction motor can be controlled linearly as a separated
excited D.C. motor [2], [6], [13]. However, the control
performance of the resulting linear system is still inﬂuenced
by the uncertainties, which usually are composed of un
predictable parameter variations, external load disturbances,
unmodelled and nonlinear dynamics, etc. Therefore, many
studies have been made on the motor drives in order to
preserve the performance under these parameter variations
and external load disturbances, such as nonlinear control,
optimal control, variable structure system control, adaptive
control and neural control [7], [8].
Moreover, in an indirect ﬁeldoriented control of induction
motors, a knowledge of rotor speed is required in order to
orient the injected stator current vector and to establish speed
loop feedback control. Although the direct ﬁeld oriented
control method with a ﬂux estimator does not need the speed
sensor in order to orient the injected stator current vector, this
method is not practical. This is because the ﬂux estimator
does not work well in a low speed region. The ﬂux estimator
presents a pole on the origin of the S plane (pure integrator),
and therefore it is very sensitive to the offset of the voltage
sensor and the parameter variations.
However, the speed or position sensor of induction motor
still limits its applications in some special environments
because of not only for the difﬁculties of mounting the
*Department of Systems Engineering and Automatic Control. University
of The Basque Country. E.U.I.T.I de Bilbao. Plaza de la Casilla, 48012
Bilbao (Spain).
oscar.barambones@ehu.es
sensor, but also for the need of low cost and reliability
systems [11]. The research and development work on a
sensorless driver for the AC motor is progressing greatly.
Much work has been done by either the ﬁeld oriented based
method or the slip frequency based approach [4], [5], [10],
[14]. In these schemes the speed is obtained based on the
measurement of stator voltages and currents. Nevertheless,
the robustness to parameter variation and load disturbance
still deserves to be further studied and above all needs to be
paid attention during a low speed in a transient state.
To overcome the above system uncertainties, the variable
structure control strategy using the slidingmode has been
focussed on many studies and research for the control of
the AC servo drive system in the past decade [1], [3], [9].
The slidingmode control can offer many good properties,
such as good performance against unmodelled dynamics,
insensitivity to parameter variations, external disturbance
rejection and fast dynamic response [12]. These advantages
of the slidingmode control may be employed in the position
and speed control of an AC servo system.
However the traditional sliding control schemes requires
the prior knowledge of the upper bound for the system uncer
tainties because these bound are employed in the switching
gain calculation. This upper bound should be determined
as precisely as possible, because as higher is the upper
bound higher value should be considered for the sliding
gain, and therefore the control effort will also be high
which is undesirable in a practice. In order to surmount this
drawback, in the present paper it is proposed an adaptive
law to calculate the sliding gain which avoids the necessity
of calculate an upper bound of the system uncertainties.
This paper presents a new sensorless vector control scheme
consisting on the one hand of a speed estimation algorithm
which overcomes the necessity of the speed sensor and on the
other hand of an adaptative novel variable structure control
law with an integral sliding surface that compensates the
uncertainties that are present in the system. The sliding gain
is not calculated previously but it is estimated online in order
to compensate the present system uncertainties.
The closed loop stability of the proposed scheme is
demonstrated using the Lyapunov stability theory, and the
exponential convergence of the controlled speed is also
provided.
This report is organized as follows. The rotor speed
computation is introduced in Section 2. Then, the proposed
robust speed control with adaptative sliding gain is presented
in Section 3. In the Section 4, some simulation results are
presented. Finally some concluding remarks are stated in the
Proceedings of the 2006 IEEE
International Conference on Control Applications
Munich, Germany, October 46, 2006
WeC08.4
0780397967/06/$20.00 ©2006 IEEE 1008
Để xem tài liệu đầy đủ. Xin vui lòng
Đăng nhập
Nếu xem trực tuyến bị lỗi, bạn có thể tải về máy để xem.
An Adaptive Sliding Mode Control Law for Induction Motors Using Field Oriented Control Theory

Người đăng:
lenam15
5
Tài liệu rất hay!
Được đăng lên bởi
Viên Đạn Bạc

1 giờ trước
Đúng là cái mình đang tìm. Rất hay và bổ ích. Cảm ơn bạn!
6
Vietnamese
An Adaptive Sliding Mode Control Law for Induction Motors Using Field Oriented Control Theory
9
10
910