DC-Link Neutral Point Control for 3L-NPC Converters Utilizing Selective Harmonic Elimination PWM

Selective harmonic elimination–pulsewidth modulation (SHE–PWM) is a modulation technique widely used to improve the efficiency and harmonic content in medium-voltage high-power converters. Among these converters, the three-level neutral-point-clamped (3L-NPC) converter is one of the most utilized topologies. However, the 3L-NPC converter requires a proper balancing of dc-link capacitor voltages. This article presents a control technique, based on pulse shifting method, to regulate the neutral point voltage when SHE-PWM is utilized. The proposed technique performs well with any power factor and it can also be directly applied to T-type converters and easily extrapolated to other multilevel topologies. The proposed method is experimentally validated in a scaled-down power converter and a full-scale medium-voltage 3L-NPC converter

Judt, Tony. Algo va mal. Madrid, España, Taurus, 2010 (220 p.). ISBN 9788430607969

Judt, Tony. Algo va mal. Madrid, España, Taurus, 2010 (220 p.). ISBN 978843060796

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Depto. de Análisis Matemático y Matemática AplicadaFac. de Ciencias MatemáticasTRUEunpu

La Vida musical en el Monasterio de Santa Maria de Jonqueres en los siglos XVI y XVII: Agraïda i Eugènia Grimau

En aquest article es du a terme una aproximació a la vida musical del monestir de monges de Santa Maria de Jonqueres, un dels monestirs fundats al segle xii per allotjar les filles i esposes dels cavallers de l'orde de sant Jaume mentre aquests lluitaven a la guerra o quan morien. Ubicat a la ciutat de Barcelona des de finals d'aquell segle, passà a estar habitat principalment per dones nobles o de l'alta burgesia, i la institució no era tant un «convent estricte» com «un pensionat de luxe», habitat per «dames» més que per «monges», segons ha descrit Maria Mercè Costa. Aquest article analitza la relació del monestir amb el seu entorn urbà a través d'activitats musicals, amb especial atenció a les fundacions de celebracions litúrgiques post mortem. El cas concret de les germanes Agraïda/Graida i Eugènia Grimau, dues monges que van exercir de cabiscoles a final del segle XVI i començament del segle XVII, s'estudia en detall a través de l'anàlisi de diversa documentació expedients de proves de sang, llibres de visites, literatura, testaments, llibres de cerimònies, llibres d'aniversaris i llibres de comptes preservada principalment a l'Arxiu de la Corona d'Aragó a Barcelona i a l'Arxiu Històric Nacional a Madrid.This article takes a look at the musical life in Santa Maria de Jonqueres Monastery. It was one of the monasteries founded in the 12th century to accommodate the daughters and wives of the knights of the Order of Santiago while they were fighting wars or when they died. It was located in the city of Barcelona from the end of that century and it was inhabited mainly by women from the nobility or upper classes instead. In fact, the institution was more like a luxury boarding house than a strict convent because it was inhabited by ladies rather than nuns, according to a description by Maria Mercè Costa. This article analyses the monasterys relationship with its urban environment through musical activities, with a particular focus on the foundations of post-mortem liturgical celebrations. The specific case of the sisters Agraïda/Graida and Eugènia Grimau, two nuns serving as cantors in the late 16th and early 17th centuries, is studied in detail by analysing a variety of documents blood sample files, visitor books, literature, wills, ceremony books, anniversary books and ledgers preserved mainly in the Archive of the Crown of Aragon in Barcelona and the National Historical Archive in Madrid.En este artículo se lleva a cabo una aproximación a la vida musical del monasterio de monjas de Santa Maria de Jonqueres, uno de los monasterios fundados en el siglo xii para alojar a las hijas y esposas de los caballeros de la Orden de Santiago mientras éstos luchaban en la guerra o cuando morían. Ubicado en la ciudad de Barcelona desde finales de ese siglo, pasó a estar habitado principalmente por mujeres nobles o de la alta burguesía, y la institución no era tanto un «convento estricto» como «un pensionado de lujo», habitado por «damas» más que por «monjas», según ha descrito Maria Mercè Costa. Este artículo analiza la relación del monasterio con su entorno urbano a través de actividades musicales, con especial atención a las fundaciones de celebraciones litúrgicas post mórtem. El caso concreto de las hermanas Agraïda/Graida y Eugènia Grimau, dos monjas que ejercieron como capiscolas a finales del siglo XVI e inicios del siglo XVII, se estudia en detalle a través del análisis de diversa documentación expedientes de pruebas de sangre, libros de visitas, literatura, testamentos, libros de ceremonias, libros de aniversarios y libros de cuentas preservada principalmente en el Arxiu de la Corona dAragó en Barcelona y en el Archivo Histórico Nacional en Madrid

DC-link Voltage Balancing Strategy based on SVM and Reactive Power Exchange for a 5L-MPC Back-to-Back Converter for Medium Voltage Drives

The reduced capability of multilevel converters with more than one intermediate node to balance the dc-link capacitors voltage, as well as the lack of standard modulation methods to improve their balancing performance, makes these converter topologies unattractive for real power applications. This is especially true when the load demands active power. One of these topologies is the five-level multipoint clamped (5L-MPC) converter. The back-to-back (B2B) configuration of two 5L-MPC converters and the use of a space vector modulation (SVM) that exploits the voltage balancing capability of the redundant switching vectors extend the operation conditions range in which a proper voltage balance can be achieved. However, if practical modulation restrictions are considered (limitation of voltage steps, dead times, switching losses, etc.), the voltage balance cannot be achieved for all operation conditions. In this paper, an SVM which takes into account practical restrictions is proposed. In order to guarantee the voltage balance at any operation condition, the grid-side rectifier exchanges reactive power with the grid-side LCL filter. Thus, the voltage balance of the dc-link is guaranteed while a unity grid-side power factor is achieved. The proposed modulation scheme and the voltage balancing strategy are experimentally validated in a 6.6 kV 1.5 MW 5L-MPC B2B converter

Simple voltage balancing method to protect series-connected devices experimentally verified in a 5L-MPC converter

This paper presents a solution for the voltage balance problem of the series-connected devices that can be applied to multilevel converters in which the series-connected devices need to block twice their switched voltage. The solution is based on two ideas, the control of the switching commands to achieve proper switching losses balance and the use of additional circuitry to achieve proper voltage balance during their blocking state. The proposed strategy is experimentally validated into a 5-level multipoint clamped full-scale converter. However, it can be used in any other converter topology in which the devices need to block twice their switched voltage

Comprehensive analysis of voltage balancing techniques for 5L NPC converters

The reduced capability of the 5L-NPC Inverter to balance the voltages of the four DC-bus capacitors makes this converter unattractive for real power applications. This is especially true if the load demands active power. The Back-to-Back (B2B) configuration of two 5L-NPC converters and the use of a Space Vector Modulation (SVM) that exploits the voltage balancing capabilities of the redundant switching vectors, extend the operating conditions range in which a proper voltage balance can be achieved. However, if practical modulation restrictions are considered (limitation of voltage steps, dead times, switching losses, etc.) the voltage balance cannot be achieved for all operation conditions. This paper introduces the main restrictions that should be considered for the 5L-NPC modulation strategy. The voltage balancing limits of the proposed SVM scheme are shown and additional considerations to improve the voltage balancing capability are proposed and evaluated

La vida musical en el monasterio de Santa Maria de Jonqueres en los siglos XVI y XVII: Agraïda y Eugènia Grimau

This article takes a look at the musical life in Santa Maria de Jonqueres Monastery. It was one of the monasteries founded in the 12th century to accommodate the daughters and wives of the knights of the Order of Santiago while they were fighting wars or when they died. It was located in the city of Barcelona from the end of that century and it was inhabited mainly by women from the nobility or upper classes instead. In fact, the institution was more like a luxury “boarding house” than a “strict convent” because it was inhabited by “ladies” rather than “nuns”, according to a description by Maria Mercè Costa. This article analyses the monastery’s relationship with its urban environment through musical activities, with a particular focus on the foundations of post-mortem liturgical celebrations. The specific case of the sisters Agraïda/Graida and Eugènia Grimau, two nuns serving as cantors in the late 16th and early 17th centuries, is studied in detail by analysing a variety of documents –blood sample files, visitor books, literature, wills, ceremony books, anniversary books and ledgers– preserved mainly in the Archive of the Crown of Aragon in Barcelona and the National Historical Archive in Madrid

La educación musical en la España del siglo XVI a través del Arte de canto llano (Sevilla, 1530) de Juan Martínez

[ES]El Arte de canto llano (Sevilla, 1530) de Juan Martínez, maestro de los mozos de coro de la Catedral de Sevilla, emerge como el tratado de música del mundo hispánico más difundido geográfica y cronológicamente en los siglos xvi y xvii, pero del que casi nada se sabía. El libro fue reeditado durante casi un siglo en los reinos de Castilla, Aragón y Portugal (traducido al portugués), y tuvo una enorme difusión en la Península Ibérica y en el mercado con el Nuevo Mundo. En esta comunicación trazaré la historia del tratado y analizaré sus características didácticas basándome en una transcripción del texto completo en español que he realizado a partir de ejemplares incompletos correspondientes a diferentes reediciones