
ThA2 Regular
Session 
C102

Electrical
and Mechanical Systems 


Chair: Dochain, Denis 
Univ. Catholique de Louvain 
CoChair: MunozArias,
Mauricio 
Univ. of Groningen 

10:0010:20, Paper
ThA2.1 

Robustness Analysis of a Position Observer
for SurfaceMount Permanent Magnet Synchronous
Motors VisAVis Rotor Saliency 
Pillai, Harish 
Indian Inst. of Tech. Bombay 
Ortega, Romeo 
Supelec 
Hernandez, Michael 
Schneider Electric 
Devos, Thomas 
Schneider Electric 
Malrait, Francois 
Schneider Toshiba Inverter 
Keywords:
Observability
and Observer Design, Performance
Issues, Robustness
Abstract: A gradient descentbased
nonlinear observer for surfacemount permanent magnet
synchronous motors (PMSMs) with remarkable stability
properties was recently proposed in [7]. A key
assumption for the derivation of the observer is the
absence of rotor saliency, which is the case in
surfacemount PMSMs. A question of great practical
interest is to assess the performance of the observer
in the presence of saliency. This is the topic of
study of the present paper. It is shown that the
robustness of the observer is fully determined by the
sinusoidal steadystate values of the currents,
providing some guidelines for the selection of their
reference values to ensure good position estimation.


10:2010:40, Paper
ThA2.2 

Nonlinear Control for Bidirectional Power
Converter in a Dc Microgrid 
Lenz Cesar, Eduardo 
Federal Univ. of Santa Catarina 
Pagano, Daniel Juan 
Federal Univ. of Santa Catarina 
Keywords:
Stability,
Passivity,
Variable
Structure Control and Sliding Mode
Abstract: Some comparative studies of
several nonlinear control techniques applied to dcdc
power converters are developed in this paper, like for
instance the Immersion & Invariance,
PassivityBased Control, Feedback Linearization and
the SlidingMode Control. All these different control
strategies are used to drive dcdc power converters in
a dc microgrid. The load, modeled as a Constant Power
Load type, is also a major issue of this paper.


10:4011:00, Paper
ThA2.3 

Voltage Balancing in FiveLevel
DiodeClamped Power Converters 
Umbría Jiménez, Francisco 
Univ. of Seville 
GomezEstern, Fabio 
Univ. De Sevilla 
Gordillo, Francisco 
Univ. de Sevilla 
Salas Gómez, Francisco 
Escuela Superior de Ingenieros. Univ. de
Sevilla 
Keywords:
Model
Based Control, Switching
Control, Power
Systems
Abstract: This paper addresses the
voltage imbalance problem of the dclink capacitors in
multilevel power converters. Considering the
fivelevel diodeclamped converter, a mathematical
analysis of the capacitor voltage difference dynamics
is carried out. It leads to a new problem statement
that relates the voltage balancing objective to a
problem of ensuring the practical stability of a
nonlinear system in the presence of disturbances.
Then, exploiting the properties and knowledge of the
disturbance patterns, a novel and simple controller is
presented. Simulation results are included to validate
the performance of the proposed controller.


11:0011:20, Paper
ThA2.4 

A Globally Exponentially Stable Tracking
Controller for Mechanical Systems with Friction
Using Position Feedback 
Romero Velazquez, José
Guadalupe 
Lab. des Signaux et Systčmes, CNRSSUPELEC 
Ortega, Romeo 
Supelec 
Keywords:
Control
of Mechanical, Electrical and Process Systems,
Applications
of Observer Design, Stabilization
Abstract: A solution to the problem
of global exponential tracking without velocity
measurement of mechanical systems with friction and
possibly unbounded inertia matrix is given in the
paper. The proposed controller is obtained combining a
new fullinformation passivitybased controller with
a new immersion and invariance observer. The resulting
closedloop system has, in some suitably defined
coordinates, a portHamiltonian structure with a
desired energy function and a uniformly positive
definite damping matrix. In this way, global
exponential tracking of position and velocity for all
desired reference trajectories is ensured.


11:2011:40, Paper
ThA2.5 

Force Control of a Class of Standard
Mechanical Systems in the PortHamiltonian Framework 
MunozArias, Mauricio 
Univ. of Groningen 
Scherpen, Jacquelien M.A. 
Univ. of Groningen 
Dirksz, Daniel A. 
INCAS3 
Keywords:
Control
of Mechanical, Electrical and Process Systems,
Robotics,
Lyapunov
Methods
Abstract: This work is devoted to a
force control strategy of a class of standard
mechanical systems in the portHamiltonian framework.
First, a coordinate transformation is applied to
equivalently describe the original portHamiltonian
system in a portHamiltonian form which has a constant
massinertia matrix in the Hamiltonian. Then, we show
how to derive an extended portHamiltonian system with
structure preservation which can be used for force
control purposes. Furthermore, we prove that the
closedloop system is asymptotically stable via a
Lyapunov candidate function. Finally, experiments
results are provided to show the advantages of the
force control strategy in presence of external forces.


11:4012:00, Paper
ThA2.6 

A Thermodynamic Approach to the Passive
Boundary Control of Tubular Reactors 
Hoang, Ngoc Ha 
Univ. of Tech. (VNUHCM, Vietnam) and Univ.
Bern 
Dochain, Denis 
Univ. Catholique de Louvain 
Keywords:
Passivity,
Chemical
Process, Lyapunov
Methods
Abstract: This paper proposes a
thermodynamics based approach for the boundary control
of distributed single phase reactive systems in one
spatial dimension. More precisely, this approach is
motivated by the socalled thermodynamic availability
directly derived from the concavity of the entropy
function for homogeneous mixtures. On this basis, a
general connection to the boundary control is
developed for the case of tubular chemical reactors by
selecting an appropriate inputoutput pair. In this
control framework, we shall show that to be (strictly)
passive, a necessary and sucient condition for the
dissipation that is strongly related to the transport
phenomena and chemical reaction has to be fullled.
Consequently, a proportional boundary feedback control
law globally stabilizes the reactor at a desired
stationary prole. For a simple study without
convection, the dissipation condition holds thanks to
the irreversible entropy production.
