UPCommons - E-prints UPC Universitat Politècnica de Catalunya
E-prints UPC cobreix dues finalitats: per una banda, és el dipòsit institucional de la UPC que recull els articles de revista, les comunicacions de congrés i els reports de recerca generats en les activitats de recerca del personal docent i investigador de la universitat; per l'altra, és una eina que permet accelerar la producció científica, allotjant versions de documents prèvies a la publicació en una revista o a les actes d’un congrés.
Hysteresis motor with self sustained rotor for high speed applications - Granados García, Xavier; Márquez, Isabel; Mora Serrano, Javier; Fontcuberta, Josep; Obradors Berenguer, Xavier; Pallarés, J.; Bosch Tous, Ricardo
Pellets of YBCO HTSC have been used to construct a cylindrically shaped rotor. A four poles/four phases stator has been wound in order to build a motor. The motor behaves as an hysteresis motor when it starts and as synchronous in the steady state. The levitation forces associated to the flux inside the rotor region and the flux dispersed at the basal surfaces contribute to maintain the rotor anchored to its cavity in a self-sustained configuration. Power and torque in the synchronous regime, centering forces, static excitation field mapping and field distribution at the HTSC surface have been investigated.
Comparison of the occupational hazards in the Spanish mining sector based on the type of workplace in the period 2003-2012 - Sanmiquel Pera, Lluís; Freijo Álvarez, Modesto; Rossell Garriga, Josep Maria; Bascompta Massanés, Marc
Methods and background: This review has done a comparison of the 3 types of workplace in the Spanish mining sector. The 3 workplaces considered are: mines, quarries and mineral processing plants. The 10 most frequent accidents and deviations have been obtained for each one. It has also been calculated the annual incidence, frequency, average duration and severity indexes as well as the risk index for each one. Besides, the accident distribution has been modelling, based on exponential distribution function of the lost days in the 3 workplaces mentioned. Results: The main sort of accident is due to physical overexertion and...
Workplace accidents in mining of Catalonia in 2012 - Freijo Álvarez, Modesto; Sanmiquel Pera, Lluís; Vintró Sánchez, Carla
Objective: To compare in Catalonia , the incidence of fatal occupational injuries and non-fatal accidents for workers in the mining sector Subterrania workers with open-pit mining in 2012 . Methods : Data from accident injuries came from the Ministry of Labour and Immigration and the Department of Industry , Mines i Energia de la Generalitat de Catalunya. The incidence of fatal and non-fatal injuries was calculated by accident and the Odds Ratio (OR ) in the confidence interval of 95% ( 95 % CI) for mineworkers in Subterrania compared to workers in the mining opencast Results and discussion: the OR...
A hierarchical control structure for multi-terminal VSC-based HVDC grids with GVD characteristics - Rouzbehi, Kumars; Miranian, Arash; Candela García, José Ignacio; Luna Alloza, Álvaro; Rodríguez Cortés, Pedro
This paper presents a hierarchical control structure for Multi terminal HVDC grids. The hierarchical control structure is inspired by the three-layer control structure of largescale AC power systems and it is divided into primary, secondary and tertiary control. This structure permits to create an easy interaction between power dispatch and the lower controllers.
Moreover, a generalized voltage droop (GVD) characteristic is also proposed which facilitates control issues inside the Multi
terminal HVDC grids. In the proposed control structure, the coefficients of the GVD characteristics are set based on the
solution of a DC power flow algorithm, executed in the secondary
Optimized control of multi-terminal DC GridsUsing particle swarm optimization - Rouzbehi, Kumars; Miranian, Arash; Luna Alloza, Álvaro; Rodríguez Cortés, Pedro
This paper addresses the important issue of Multi-Terminal DC (MTDC) grid control strategy based on the particle swarm optimization (PSO) technique. The MTDC grid is controlled by the concept of vector control, in which the AC currents and voltages are transformed into the rotating directquadrature (d-q) reference quantities which are subsequently used for decoupled control of the active and reactive powers as well as the DC and AC voltages. The paper employs an efficient PSO algorithm for optimal tuning of the controllers’ parameters in an MTDC grid. In addition, voltage droop control scheme is utilized to ensure the balance of...
Comprehensive analogy between conventional AC grids and DC grids characteristics - Rouzbehi, Kumars; Gavriluta, Catalin; Candela García, José Ignacio; Luna Alloza, Álvaro; Rodríguez Cortés, Pedro
The high penetration of renewable energy resources, such as wind and photovoltaic, as well as the development of power electronics devices play an important role in the
development of DC grids. However, the evolution of DC-systems from point-to-point connections to ‘Multi-terminal’ DC (MTDC)
networks is not so straight forward. At the current moment there is a large gap in the literature concerning the dynamics, control
and operation of MTDC networks. On the other hand, conventional AC networks have been studied exhaustively in the past decades providing for a rich inspiration source.
In this paper we are going to establish a comprehensive analogy between the...
Adaptive droop for primary control in MTDC networks with energy storage - Gavriluta, Catalin; Candela García, José Ignacio; Luna Alloza, Álvaro; Rocabert Delgado, Joan; Rodríguez Cortés, Pedro
Multi-terminal DC (MTDC) systems are drawing a lot of interest lately in applications related to distributed generation, especially in those that integrate wind or PV systems together with energy storage. This paper proposes an improved strategy for the primary control of MTDC integrating energy storage (ES) units. The concept is based on the combination of a droop control method and dc-bus signaling in order to provide a generic approach to be used as basis for a hierarchical control structure in a multi-point DC-bus system.
The proposed method considers the State of Charge (SoC) of the energy storage system at the primary...
A generalized voltage droop strategy for control of multi-terminal DC grids - Rouzbehi, Kumars; Miranian, Arash; Luna Alloza, Álvaro; Rodríguez Cortés, Pedro
This paper proposes a generalized voltage droop (GVD) control strategy for control and power sharing in voltage source converter (VSC)-based multi-terminal DC (MTDC) grids. In the proposed approach, the conventional voltage droop characteristics of voltage-regulating VSC stations are replaced by the GVD characteristics. The proposed GVD control strategy can be operated in three different control modes including conventional voltage droop control, fixed active power control and fixed DC voltage control by proper adjustment of the GVD characteristics of the voltage-regulating converters. The proposed strategy improves the control and power-sharing capabilities of the conventional voltage droop, and enhances its maneuverability. Simulation...
Decentralized control of MTDC networks with energy storage and distributed generation - Gavriluta, Catalin; Candela García, José Ignacio; Citro, Costantino; Luna Alloza, Álvaro; Rodríguez Cortés, Pedro
Multi-terminal dc (MTDC) networks are drawing a lot of interest lately in applications related to distributed generation, especially in those that integrate energy storage. Several approaches for controlling the operation of such systems have been proposed in the literature; however the existing structures can be significantly enhanced. This paper proposes an improved primary control layer, based on droop and dc-bus signaling to serve as a base framework for implementing a hierarchical control structure in a MTDC system. As it will be further discussed in this work, five operating bands as well as various droop characteristics for different elements connected to...
Magnet shape influence on the performance of AFPMM with demagnetization - Saavedra Ordóñez, Harold; Riba Ruiz, Jordi-Roger; Romeral Martínez, José Luis
In this paper the effect of the magnets shape on the AFPMM performance under a demagnetization fault has been analyzed by means of 3D-FEM simulations. Demagnetization
faults in permanent magnet synchronous motors (PMSMs) may generate specific fault harmonic frequencies in the stator currents, output torque and the zero-sequence voltage component (ZSVC) spectra the ones can affect motor behavior, and so these parameters have been studied and compared, for each magnet
configuration in each condition. These analyses are carried out to find out the more suitable geometry for an operation under
healthy and faulty condition.
Sliding mode control of a single-phase LCL full-bridge rectifier - Biel Solé, Domingo; Dòria Cerezo, Arnau; Fossas Colet, Enric
This paper presents a dynamic analysis and the
control design for a singe-phase full bridge recti¿er with a
LCL ¿lter. The control algorithm is based on the sliding mode
control techniques that provides good tracking performances and
robustness against parameter variations. The control design also
considers the connection to a non ideal power network with a
grid impedance as well as higher harmonics components in the
voltage. The control law has been tested in numerical simulations
with satisfactory results (also in the case of non ideal power grid).
Control en modo deslizante de un rectificador monofásico con un filtro LCL - Biel Solé, Domingo; Dòria Cerezo, Arnau; Fossas Colet, Enric
En este artículo se presenta el análisis dinámico
y el diseño de un controlador para un rectificador monofásico
controlado con un filtro LCL. El algoritmo de control está
basado en las técnicas de modos deslizantes que permiten
unas buenas prestaciones de seguimiento y robustez en los
convertidores de potencia. Durante el diseño se ha considerado
la conexión a una red débil y con fuerte contenido armónico. La
ley de control se ha validado mediante simulaciones numéricas
con resultados satisfactorios incluso en casos de una red no
Exploring the range of impedance conditioning by virtual inductance for grid connected voltage source converters - Suul, Jon Are; Molinas, Marta; Rodríguez Cortés, Pedro
Conditioning of network impedance by insertion of a virtual inductance as an inherent feature of the converter control system has the potential to extend the range of stable operation of the overall system. This paper presents a scenario in which such potential is explored and its range of application is identified. It shows first that implementation of a virtual inductance is naturally suited for combination with Virtual Flux-based control systems, and that it can be extended to the more general case of a virtual reactance. The paper then presents the structure of a control system for operation under unbalanced conditions,...
Analysis and comparison of battery energy storage technologies for grid applications - SAEZ-DE-IBARRA, A.; Milo, Aitor; Gaztañaga, Haizea; Etxeberria Otadui, Ion; Rodríguez Cortés, Pedro; Bacha, Seddik; Debusschere, V.
Battery Energy Storage Systems (BESSs) could
contribute to the generation/consumption balance of the grid
and could provide advanced functionalities at different grid
levels (generation, T&D, end-user and RES integration). In this
paper an analysis and comparison of Battery Energy Storage
(BES) technologies for grid applications is carried out. The
comparison is focused on the most installed technologies in the
recent experimental BESS installations. Furthermore, the paper
presents a new methodology aimed at selecting the most suitable
BES technology for a specific grid application. This
methodology defines a priority level for each technical and
economical characteristic of the BES technologies. Finally, the
proposed methodology is applied for a specific grid application
confirming its contribution...
Design of AC-DC power converters with LCL + tuned trap line filter using Si IGBT and SiC MOSFET modules - Piasecki, S.; Mir Cantarellas, Antonio; Rabkowski, J.; Rodríguez Cortés, Pedro
This paper presents a method for improving the
design procedure of AC-DC power converters for power
generation applications. The proposed methodology is based on
selection of the most convenient configuration, in terms of
switching frequency and design of the line filter, in order to
minimize the overall losses in the system. In this work two types
of semiconductor devices are considered: silicon IGBT and
silicon carbide MOSFET for the design of a 100 kVA system, and
they performance is compared. The AC-DC converter
parameters, the design methodology and preliminary simulation
results for representatives of Si IGBT and SiC MOSFET modules
Grid harmonic detection and system resonances indentification in wave power plant applications - Nisak, Khairul; Mir Cantarellas, Antonio; Luna Alloza, Álvaro; Candela García, José Ignacio; Rodríguez Cortés, Pedro
There is a growing interest in electrical grid
connection of single unit Wave Energy Converters (WECs), as
well as the multiple units based Wave Power Plant (WPP)
applications. Due to the increasing integration of high power
converters in WPP, additional concerns on the harmonic current
mitigation of WEC device arise which requires the grid filter
installation. Furthermore, the identification and appropriate
mitigation of additional harmonics at the WPP level is needed, as
any inductances and capacitors of the WPP can interact with the
resonant frequency of the entire system and lead to detrimental
effects on equipment. The present paper focuses on the potential
harmonic studies of a realistic proposed WPP layout,...
Control of an active rectifier with an inductive-capacitive-inductive filter using a twisting based algorithm - Dòria Cerezo, Arnau; Puleston, Paul; Kunusch, Cristian
This paper presents a novel controller for an
active rectifier with an inductive-capacitive-inductive filter. The
proposed control scheme comprises two levels. The internal
level, is a current controller based on the second order sliding
mode Twisting algorithm, which robustly ensures an unity power
factor at the connection point. The slower external level is a PI
controller in charge of regulating the output DC voltage to a
desired reference. The controller setup also includes a finite-time
observer of the current derivative that can be used to avoid direct
(and sometimes problematic) numerical differentiation. Finally,
simulation results are presented to validate the proposed control