Long resistive cables used in the operation of remote instrumentation impose fundamental limits on the amount of power delivered and create difficulties in voltage regulation at the remote-end (voltage at the end of the cable) with changing load conditions. This type of power delivery is used in many engineering systems such as in the operation of underwater remotely-operated vehicles, in oil drilling and mining industries, and in highly distributed systems (aircraft, submarines, and space stations, etc.). The focus of this research is to develop new approaches for power delivery in systems that have considerable voltage drops between the local and remote-ends.Two novel methods of power delivery based on state feedback control and parallel operation of switching and linear regulators to enhance stability and increase the power delivered at the remote-end are developed and validated experimentally.A system-level approach is developed to control the remote-end voltage for changing load conditions through the usage of a model inversion technique at the local-end along with a feedback of the local-end variables.

This thesis presents the simulation, design, and hardware implementation of a modified multiphase boost converter. Converter design must consider noise imposed on input and output nodes which connect to and influence the operation of other devices. Excessive noise introduces EMI which can damage sensitive circuits or impede their operation. High ripple current degrades battery lifetime and reduces operating efficiency in connected systems such as PV arrays. Converters with high ripple current also experience greater peak conduction loss and require larger components. A two-phase implementation of a modified boost converter demonstrates the input current filtering benefits of the modified topology with increased power capacity. In a 12V to 19V 95W design, the modified multiphase design exhibits a reduced input current ripple of 1.103% compared to the 9.096% of the standard multiphase design while imposing minimal detriment to overall converter efficiency. The modified topology uses two inductors and one feedback capacitance per phase. Larger value inductors generally exhibit lower current ratings as well as larger size. The split inductance of the modified multiphase topology can be designed for occupation of less total volume than the single inductance of the standard multiphase topology.

Uno de los campos más importantes de la Electrónica de Potencia es el de los convertidores de potencia conmutados, que debido a sus características de alto rendimiento energético, reducido tamaño, posibilidades de regulación del factor de potencia y de elevación de tensión, etc., están presentes en un gran número de las etapas de alimentación de los equipos electrónicos actuales.Las mejoras tecnológicas en ámbitos como el de la integración de circuitos han permitido importantes reducciones en el tamaño de los equipos (por ejemplo en los ordenadores). Sin embargo, este proceso de reducción de tamaño que, además, suele venir unido a unas especificaciones más rígidas en cuanto a costes, rendimiento, seguridad y prestaciones en general, no se ha producido en igual medida en las etapas de alimentación. El estudio de los convertidores conmutados es por lo tanto un campo necesitado de esfuerzos de investigación y desarrollo.Para potencias superiores a 25 W, y especialmente en potencias superiores a 150 W, una de las estrategias utilizadas para mejorar las prestaciones de los convertidores es el uso del denominado "interleaving" o entrelazado , definido como la puesta en paralelo de N convertidores idénticos desfasando sus señales de control de forma uniforme a lo largo del periodo de conmutación.Con el objetivo principal de reducir al máximo los rizados de la tensión de salida y de la corriente de entrada, en esta tesis se estudian casos particulares de "interleaving" en estructuras convertidoras continua-continua que utilizan el convertidor elevador ("boost") como célula básica y cuyas tensiones de salida son, idealmente y operando en modo de conducción continua, múltiplos enteros positivos de la tensión de entrada, de ahí la denominación de multiplicadores de tensión que aparece en el título de tesis propuesto. Posteriormente se analizan las posibilidades de regulación de tensión que presentan algunos de los casos de estudio, a costa de incrementar los rizados.

No description available.

Les contrôleurs industriels font l’objet de changements de paramètres, de modifications, d’améliorations en permanence. Ils subissent les évolutions technologiques aussi bien matérielles que logicielles (librairies, système d’exploitation, loi de commande...). Malgré ces contraintes, ces contrôleurs doivent obligatoirement assurer toutes les fonctionnalités recouvrant le séquentiel, les protections, l’interface homme machine et la stabilité du système à contrôler. Ces fonctionnalités doivent être couvertes pour une large gamme d’applications. Chaque modification (matérielle ou logicielle) quoique mineure est risquée. Le debogage, l’analyse et la programmation sur site sont énormément coûteux surtout pour des sites de type offshore ou marine. Les conditions de travail sont difficiles et les tests sont réduits au strict minimum. Cette thèse propose deux niveaux de validation en plateforme d’expérimentation : un niveau de validation algorithmique que l’on appelle Validation par Interface Logicielle (VIL) traitée au chapitre 2 ; un niveau de validation physique que l’on appelle Validation par Interface Matérielle (VIM) traitée au chapitre 3. La VIL valide uniquement l’aspect algorithme, la loi de commande et la conformité des références au niveau calcul sans prendre en compte les signaux de commande physiques et les signaux de retour gérés par l’Unité de Gestion des Entrées/Sorties (UGES). Un exemple de validation d’un contrôleur industriel d’un ensemble convertisseur trois niveaux et machine asynchrone est traité dans le deuxième chapitre avec une modélisation particulièrement adaptée à la VIL. Le dernier chapitre traite la VIM sur différentes bases matérielles (Field Programmable Gate Array (FPGA), processeurs). Cette validation prend en compte l’aspect algorithme et les signaux de commande physique ainsi que les signaux de retour. On y présente plusieurs approches de modélisation, choisies selon la base matérielle d’implémentation du simulateur temps réel. Ces travaux ont contribué aujourd’hui à au processus de validation des contrôleurs dédiés aux applications Oil and Gaz et Marine de General Electric - Power Conversion © (GE-PC) / Industrial controllers are always subjected to parameters change, modifications and permanent improvements. They have to follow off-the-shelf technologies as well as hardware than software (libraries, operating system, control regulations ...). Apart from these primary necessities, additional aspects concerning the system operation that includes sequential, protections, human machine interface and system stability have to be implemented and interfaced correctly. In addition, these functions should be generically structured to be used in common for wide range of applications. All modifications (hardware or software) even slight ones are risky. In the absence of a prior validation system, these modifications are potentially a source of system instability or damage. On-site debugging and modification are not only extremely expensive but can be highly risky, cumulate expenditure and reduce productivity. This concerns all major industrial applications, Oil & Gas installations and Marine applications. Working conditions are difficult and the amount of tests that can be done is strictly limited to the mandatory ones. This thesis proposes two levels of industrial controller validation which can be done in experimental test platform : an algorithm validation level called Software In the Loop (SIL) treated in the second chapter ; a physical hardware validation called Hardware In the Loop (HIL) treated in the third chapter. The SIL validates only the control algorithm, the control law and the computed references without taking into account neither the actual physical commands nor the physical input feedbacks managed by the Input/Output boards. SIL validation of the system where industrial asynchronous motor is fed and regulated by a three level Variable Speed Drive with a three level voltage source converter is treated in the second chapter with a particular modeling approach adapted to such validation. The last chapter presents the HIL validation with various hardware implementations (Field Programmable Gate Array (FPGA), processors). Such validation checks both the control algorithm and the actual physical Input/Output signals generated by the dedicated boards. Each time, the modeling approach is chosen according to the hardware implementation. Currently this work has contributed to the system validation used by General Electric - Power Conversion © (GE-PC) as part of their validation phase that is mandatory for Oil & Gas projects and Marine applications

Switched mode power supplies (SMPS) have found wide spread acceptance in all power processing applications. The design demand is moving towards higher power densities. For reduction in size and weight, it is imperative to process the power at a higher switching frequency. High switching frequency requires soft switching techniques to reduce the switching losses. Several families of soft switching converters have emerged in the past two decades. Analysis and modelling methods have been proposed in relation with these topologies. Active clamp converters are the recently introduced soft switching topologies. Steady state analysis and model of these converters have been reported in literature. This thesis presents a unified equivalent circuit oriented model for the family of active clamp converters. Analytical expressions for DC conversion ratio in terms of pole current and throw voltage are derived for all the DC-DC converters with active clamp. The special feature is that, the conversion ratio exhibits a load dependent drop (IRd), where I is the pole current and Rd is the damping resistance. The damping resistance Rd is a mathematical artifact to represent the voltage loss on account of delay in the turn-on of the active switch. There is no energy loss associated with this load dependent drop. This is conveniently expressed as an appropriate lossless resistance in the equivalent circuit model. The proposed equivalent circuit models are valid for both steady-state and dynamic performance. A spread sheet based design is presented for the basic DC-DC converters with active clamp. A prototype design following the spreadsheet is made. The performance of the same is validated and verified by simulation and measurements. Steady state and dynamic results are presented. The stability criterion for the active clamp converters under current programming is investigated. The same is verified through simulation and validated on a current programmed active clamp converter prototype. The active clamp converters suffer from a few disadvantages: Higher VA ratings of switches, load dependent ZVS performance and increased component count. Several soft switching topologies have been reported in literature. Efficiency improvement and increase in switching frequency are obtained to different degrees. This thesis proposes a new family of soft switching converters. This family of converters switch at constant frequency and maintains the advantages of traditional PWM converters. The proposed topology employs an auxiliary circuit to achieve soft switching. The auxiliary circuit consists of a dependent voltage source, an auxiliary switch, a series diode and a set of resonant elements (Inductor and capacitor). The switching transitions of both the active switch and the auxiliary switch are lossless. The novelty in the proposed circuit is the method of generating the dependent source required to enable zero current switching of the auxiliary switch. The dependent source is realized by a coupled winding in the energy storage inductor or tapped from the energy transfer transformer of non-isolated and isolated converters respectively. The proposed topology is applicable to most of the isolated and non-isolated DC-DC converters. The circuit equations governing the sub-intervals of the converter are expressed in terms of pole current and throw voltage. With such a definition, performance results and the design equations are identical for all types of DC-DC converters. Equivalent circuit models are obtained for the whole family of DC-DC converters. The proposed model is valid for steady state and dynamic performance. Analytical expressions of DC conversion ratio for all topologies, in terms of pole current and throw voltage are derived. The special feature is that, the conversion ratio exhibits a load dependent drop (IRd), where I is the pole current and Rd is the damping resistance. The damping resistance Rd is a mathematical artifact to represent the voltage loss on account of delay in the turn-on of the active switch. There is no energy loss associated with this load dependent drop. This is conveniently expressed as an appropriate lossless resistance in the equivalent circuit model. Design guidelines are established for the whole family of proposed converters; the same are validated through prototype converters.

No description available.

Experience Mapping based Prediction Control (EMPC) is a new type of controller presented in literature, which is based on the concept of Human Motor Control (HMC). During the developmental phase, called the initial learning phase, the controller records the experience in a knowledge base, through online interactions with the system to be controlled. This knowledge base created using the experience maps is termed as Experience Mapped Knowledge Base (EMK). The controller envisages the development of EMK only through interaction with the system, without the need for knowledge of the detailed plant model. The EMPC controls the system through prediction of actions based on the mapped experiences of EMK. Depending on the nature of control required for the system chosen, various strategies can be used to achieve control using the EMK. The above controller has previously been utilized for motion control applications. In the present work an effort has been made to study the suitability of the EMPC for the voltage regulation of switching converters. The plant chosen for the control study is a discontinuous conduction mode (DCM) buck converter. The parameter to be monitored for the purpose of control is the load voltage. The control input from the EMPC to the converter is a duty ratio value based pulse-width modulated (PWM) signal. Two strategies of control have been proposed: steady state control and transient control. Steady state control action maintains the steady state output voltage at the required value for a given load. The transient control action is used to improve the transient performance of the system. Iterative predictive action and iterative transient actions are used to facilitate convergence of the output voltage to within the required range in presence of non-linearities and uncertainties in the system. Impulse action is introduced to further improve the transient performance of the system. The EMPC is compared a proportional-integral (PI) controller for the given DCM buck system.