To see the other types of publications on this topic, follow the link: Modelling of resonant converter.
Dissertations / Theses on the topic 'Modelling of resonant converter'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Modelling of resonant converter.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Panov, Vasil. "LLC resonant converter modelling." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46521.
Full textAbstract:
Many of today's power converters use pulse-width modulation(PWM) techniques to regulate the circulating currents and voltages. A significant problem with most dc-dc converters is the increased power loss during switching. These devices typically operate in hard-switching mode which results in switching losses. Resonant converters have been used to minimize or even eliminate this problem.
Although LLC resonant converters have shown significant gains in terms of efficiency, their modeling is still a challenge. LLC converters are designed to function in a specific mode and region of operation. It has been difficult to design a stable and robust controller with consistent bandwidth and disturbance rejection for every application. The complexity of the control design is magnified when the LLC converters are controlled using embedded digital control techniques. Recent developments in micro-controllers, including processing speed, power, and memory management, make possible the use of innovative non-linear or adaptive control algorithms, in order to produce high performance LLC circuits. Accurate modeling of the hardware is the key to an effective solution.
This thesis presents several modeling techniques of the LLC resonant converter. Previous research is discussed and relevant techniques are used as reference for deriving the models presented here. A new approach will be used to describe the characteristics of the LLC within the operating region. This approach is derived using the method of Least Squares of errors. The method estimates the coefficients of the plant transfer function, which then help to calculate control coefficients in the instantaneous operating condition of the LLC resonant power converter.
2
Kolachina, Srinivasa Kranthi Kiran, and Nishu Reddy. "Modelling and Simulation of a Resonant Converter." Thesis, Blekinge Tekniska Högskola, Institutionen för tillämpad signalbehandling, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-3374.
Full textAbstract:
This thesis is a part of collaborated project between Alstom and Blekinge Institute of Technology. In this thesis a fifth order non- linear Hamilton observer is applied on a series resonant converter. Two models for individual modes are given for a resonant power converter, one is suitable for simulation and other is suitable for simulation and analysis. The circuit is run in eight modes. A switched model of a fifth order DC/DC converter consisting of eight different switching modes has been derived and the performance of the circuit is studied under several conditions by simulation.+917893357437
3
Cheng, Brian Cheak Shing. "Modelling and control of the LLC resonant converter." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43729.
Full textAbstract:
To achieve certain objectives and specifications such as output voltage regulation, any power electronics converter must be coupled with a feedback control system. Therefore, a topic of considerable interest is the design and implementation of control systems for the LLC resonant converter. Additionally, with the current trend of smaller, more cost effective and reliable digital signal processors, the implementation of digital feedback control systems has garnered plenty of interest from academia as well as industry.
Therefore, the scope of this thesis is to develop a digital control algorithm for the LLC resonant converter. For output voltage regulation, the LLC resonant converter varies its switching frequency to manipulate the voltage gain observed at the output. Thus, the plant of the control system is represented by the small signal control-to-output transfer function, and is given by P(s) =V_o/f.
The difficulty in designing compensators for the LLC resonant converter is the lack of known transfer functions which describe the dynamics of the control-to-output transfer function. Thus, the main contribution of this thesis is a novel derivation of the small signal control-to-output transfer function. The derivation model proposes that the inclusion of the third and fifth harmonic frequencies, in addition to the fundamental frequency, is required to fully capture the dynamics of the LLC resonant converter. Additionally, the effect of higher order sideband frequencies is also considered, and included in the model.
In this thesis, a detailed analysis of the control-to-output transfer function is presented, and based on the results, a digital compensator was implemented in MATLAB. The compensator's functionality was then verified in simulation.
A comparison of the derivation model and the prototype model (based on bench measurements) showed that the derivation model is a good approximation of the true system dynamics. It was therefore concluded that both the bench measurement model and the derivation model could be used to design a z-domain digital compensator for a digital negative feedback control system. By using the derivation model, the main advantages are reduced computational power and the requirement for a physical prototype model is diminished.
4
Bansal, Gurvinder Singh. "Modelling and analysis of quasi-resonant and square wave converter topologies." Thesis, University of Brighton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.309174.
Full text
5
Szabo, Adrian. "The modelling of quasi-resonant and multi-resonant boost converters." Thesis, Nottingham Trent University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245100.
Full text
6
Baha, B. "Control and modelling of quasi-resonant converters." Thesis, University of Brighton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343606.
Full text
7
Ang, Yong-Ann. "Modelling, analysis and design of LCLC resonant power converters." Thesis, University of Sheffield, 2006. http://etheses.whiterose.ac.uk/15027/.
Full textAbstract:
The thesis investigates the modelling, analysis, design and control of 4th -order LCLC resonant power converters. Both voltage-output and current-output variants, are considered. Key research outcomes are the derivation of new frequency- and time-domain models of the converters, based on normalised component ratios, and including the effects that parasitic elements have on circuit behaviour, and a detailed account of multi-resonant characteristics; extensions to the use of cyclicmode modelling methods for application to LCLC converters, to provide rapid steady-state analysis, thereby facilitating the use of the derived methodologies as part of an interactive design tool; the formulation of analytical methods to predict the electrical stresses on tank components-an important consideration when designing resonant converters, as they are often higher than for hard-switched converter counterparts; the characterisation of both continuous and discontinuous modes of operation and the boundary conditions that separate them; and a substantial treatment of the modelling, analysis and design of LCLC converters that can provide multiple regulated outputs by the integrated control of both excitation frequency and pulse-width-modulation. The proposed methodologies are employed, for validation purposes, in the realisation of two proof-of concept demonstrator converters. The first, to satisfy the requirements for delivering 65V (rms) to an electrode-less, SW, fluorescent lamp, to improve energy efficiency and lifetime, and operating at a nominal frequency of 2.65 MHz, is used to demonstrate capacitively-coupled operation through the lamp tube, thereby mitigating the normally detrimental effects of excitation via the electrodes. The second prototype considers the realization of an LCLC resonant power supply that can provide multiple regulated outputs without the need for post-regulation circuitry. The two outputs of the supply are independently, closed-loop regulated, to provide asymmetrical output voltage distributions, using a combination of frequency- and duty-control. Although, an analysis of the supply shows that the behaviour is extremely complex, due, in particular, to the highly non-linear interaction between the mUltiple outputs and parasitic inductances, and rectifier, an analysis to provide optimum performance characteristics, is proposed. Moreover, a PICIFPGA-based digital controller is developed that allows control of the transient performance of both outputs under start-up and steady-state conditions.
8
Ghahderijani, Mohammad Moradi. "Dynamic modelling and control schemes for current-source resonant converters." Doctoral thesis, Universitat Politècnica de Catalunya, 2018. http://hdl.handle.net/10803/481978.
Full textAbstract:
This thesis focuses on the control methods applied to current source resonant converters, especially in two different applications of switching power supplies and wire-less power transfer systems. In fact, the existing applications are mostly working with voltage source resonant converters. For voltage-source resonant converters, many control strategies have been analyzed and investigated, turning this into a mature technology nowadays. The current-source resonant converter is an alternative solution as they offer well-known advantages such as non-pulsating input current, low stress for switches, simple driving circuitry, and short circuit protection capabilities.
However, there is an obvious lack of control methods applicable to current-source resonant converters. In addition, obtaining an appropriate dynamic model to be used in control design is the other challenging issue in this field. Hence, the objectives of this thesis are used to fill these gaps. The proposed control schemes are:
- Frequency modulation control scheme applied to a DC/DC current-source parallel resonant converter.
- Sliding mode control scheme with amplitude modulation applied to a DC/DC current-source parallel resonant converter.
- A control scheme for a multiple-output DC/DC current-source parallel resonant converter.
- A communication-less control scheme for a variable air-gap wireless energy transfer system using a current-source resonant converter.Esta tesis doctoral está centrada en los métodos de control aplicados a los convertidores resonantes con fuente de corriente, especialmente en dos aplicaciones distintas como son fuentes de alimentación conmutadas y sistemas de transferencia de energía sin hilos. De hecho, las aplicaciones existentes trabajan principalmente con convertidores alimentados mediante fuentes de tensión. Para los convertidores resonantes con fuente de tensión, se han analizado muchas estrategias de control en la literatura, lo que hace hoy en día que esta sea una tecnología madura. El convertidor resonante con fuente de corriente es una solución alternativa, que ofrece ventajas conocidas como corriente de entrada no pulsante, baja tensión para interruptores, circuitos de conducción sencillos y capacidades de protección contra cortocircuitos. Sin embargo, existe una falta evidente de métodos de control aplicables a los convertidores resonantes con fuente de corriente. Además, otro desafío en este tema es la obtención de modelos dinámicos apropiados para el diseño del control. Por lo tanto, los objetivos de esta tesis se utilizan para llenar estos vacíos. Los esquemas de control propuestos son: - Esquema de control en frecuencia aplicado a un convertidor resonante paralelo con fuente de corriente para reguladores de tensión en continua - Esquema de control en modo de deslizamiento con modulación de amplitud aplicado a un convertidor resonante paralelo con fuente de corriente para reguladores de tensión en continua. - Esquema de control para un convertidor resonante paralelo con fuente de corriente para la regulación de tensión en continua de varias salidas. - Esquema de control sin comunicaciones para un sistema de transferencia de energía sin hilos con un transformador con entrehierro variable basado en un convertidor resonante con fuente de corriente.
9
Nittayarumphong, Sadachai. "Vereinfachte Methoden zur optimalen Regelung resonanter Leistungskonverter." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1231866555971-93803.
Full textAbstract:
Nowadays the developments of power supplies in military, industrial or commercial applications are growing rapidly, not only to achieve the highest efficiency but also to focus on the size and weight minimization which are playing a major role in this area. Therefore, the research trends in dc-dc, ac-dc, dc-ac, ac-ac topologies are still continuously developing into the direction of new topologies, new control concepts, new materials and devices to achieve highest efficiency and smallest size. The cost per unit is also one of the most important points of power supplies. Also, with new control methods and new ways of manufacturing, for example, the cost per unit might be reduced. Also, a simplified control concept might help to avoid discrete circuits, especially, at low power levels. The last mentioned statement is demonstrated, for instance, by the concept of the Link-Switch of the company Power Integration where an extremely small number of components are necessary. With the target of minimization, this research work explores the possibility to replace conventional electromagnetic transformers considered as the most bulky devices in power supplies by piezoelectric transformers (PT) for innovative off-line power supplies. Several control methods for a load resonant converter focusing on class-E topology utilizing PT, were developed in order to investigate and to select an appropriate control method capable of improving the efficiency and reducing the size of the converter. Efficiency should be understood in this way as maximum reliability at minimum power losses. Different controllers were evaluated for optimizing the effect of disturbances of line and load variations. The ZVS condition for a wide input voltage range and a wide output load range can be achieved by a method called duty-cycle tracking. Further, with an improved design of the PT containing an auxiliary tap, the ZVS condition can be obtained by a method called turn-on synchronization. The controlled output voltage, current or power is achieved by a variable frequency control. Further, the dynamic modeling for open loop and closed loop of load resonant converters, focused on the class-E topology, was introduced. The transient behavior of the output voltage of the open loop against perturbations such as the input voltage change, the switching frequency change, and the output load change is treated by replacing the complete circuit of the class-E converter by simple equivalent circuit models. The results from the analysis of the open loop dynamic behavior are applied to modeling the closed loop class-E converter with several control methods. The methods of linearization for exact solution and heuristic approximation for the steady state analysis were purposed. These models of linearization were implemented with the controller in its topologies to investigate the sufficient accuracy of obtained results of the regulation. Besides, the linearization models were used to observe the stability condition of the proposed control loops. Finally, the evaluation of a well-known classical control such P, I, PI, PD, PID and a simplified controller for a fixed load application by matching an appropriate switching frequency according to the input voltage, into the load resonant converter, considering class-E topology, were presented. Also, the optimum design of the controller for a load resonant converter was discussed and derivedDie Entwicklung von Stromversorgungen in militärischen, industriellen und kommerziellen Anwendungen nimmt bis heute tendenziell stark zu. Nicht nur zur Erzielung höchster Wirkungsgrade, sondern auch im Hinblick auf Baugrößen- und Gewichtsminimierung, welche eine vorrangige Rolle spielen, ist diese Tendenz zu verzeichnen. Diesbezüglich gehen die Forschungstrends bei DC-DC, AC-DC, DC-AC und AC-AC Topologien in Richtung neuer Topologien, neuer Regelungskonzepte, sowie neuer Materialien und Bauelemente, um den höchsten Wirkungsgrad bei kleinster Baugröße zu erreichen. Die Gerätekosten sind ebenso ein sehr wichtiger Punkt bei Stromversorgungen. Auch durch neue Regelungsmethoden und durch neue Herstellungsverfahren können die Gerätekosten beispielsweise reduziert werden. Ebenso kann ein vereinfachtes Regelungskonzept dazu verhelfen, dass diskrete Schaltungen, speziell im unteren Leistungsbereich, vermieden werden. Letzteres wird beispielsweise beim Konzept des Link-Switch der Firma Power Integration verdeutlicht, indem extern wenige Bauelemente benötigt werden. Mit dem Ziel der Miniaturisierung wird in dieser Forschungsarbeit die Möglichkeit untersucht, konventionelle elektromagnetische Transformatoren, welche in Stromversorgungen als besonders voluminös gelten, durch piezoelektrische Transformatoren (PT) bei der Herstellung innovativer Netzstromversorgungen zu ersetzen. Verschiedene Regelungsmethoden für Lastresonanzkonverter, mit dem Fokus auf eine Klasse- E-Topologie mit PT, wurden hierzu entwickelt. Dies hatte zum Ziel, ein geeignetes Regelungsverfahren zu erarbeiten und auszuwählen, welches eine verbesserte Effizienz bei reduzierter Konverter-Baugröße aufzuweisen hat. Effizienz soll hierbei verstanden werden als maximale Zuverlässigkeit bei minimalen Leistungsverlusten. Verschiedene Reglertypen wurden entworfen um die Effekte der Störungen durch Netzspannungs-und Lastvariationen regelungstechnisch zu optimieren. Die Nullspannungsschaltungsbedingung (ZVS-Bedingung) über einen weiten Bereich der Eingangspannung und einen weiten Lastbereich kann durch einen sogenannte Duty-Cycle-Nachführung mit der Frequenz erreicht werden. Weiterhin kann durch eine verbesserte Ausführung des PT auf Basis einer Hilfsanzapfung die ZVSBedingung durch eine sogenannte Einschaltsynchronisation erreicht werden. Geregelte Ausgangsspannung, Ausgangsstrom oder Ausgangsleistung werden über eine Frequenzstellung erreicht. Die dynamische Modellierung der offenen und geschlossenen Regelschleife eines Lastresonanzkonverters, wieder im Hinblick auf die Klasse-E, wird im weiteren vorgestellt. Das transiente Verhalten der Ausgangsspannung der offenen Regelschleife gegenüber Störungen durch Eingangsspannungsänderung, durch Schaltfrequenzänderung oder durch Ausgangslaständerung, wird durch den Ersatz der Klasse-E-Schaltung durch einfache Äquivalenzmodelle behandelt. Die Ergebnisse der Analyse des Verhaltens des offenenen Regelkreises werden verwendet, um den Klasse-E-Konverter mit geschlossener Regelschleife unter Verwendung verschiedener vorgestellter Regelungsmethoden zu modellieren. Methoden der Linearisierung für die exakte Lösung und für eine heuristische Approximation der statischen Analyse des eingeschwungenen Zustands werden vorgeschlagen. Diese Methoden der Linearisierung werden zusammen mit den Reglermodellen in deren jeweilige Topologie implementiert um die ausreichende Genauigkeit der erhaltenen Resultate des Regelungsverhaltens zu beurteilen. Weiterhin werden diese Linearisierungsmodelle dazu verwendet, die Stabilitätskriterien der vorgeschlagenen Regelschleife zu überwachen. Schlussendlich wird die Bestimmung der bekannten klassischen Regler (P, I, PI, PD, PID), sowie eines vereinfachten Konstantlaststellers durch geeignete Anpassung der Schaltfrequenz an die Eingangsspannung, für Lastresonanzkonverter, wieder mit Blick auf die Klasse-E, vorgestellt. Außerdem wird der optimierte Reglerentwurf für Lastresonanzkonverter diskutiert und abgeleitet
10
Engström, Jens. "Hydrodynamic Modelling for a Point Absorbing Wave Energy Converter." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-160319.
Full textAbstract:
Surface gravity waves in the world’s oceans contain a renewable source of free power on the order of terawatts that has to this date not been commercially utilized. The division of Electricity at Uppsala University is developing a technology to harvest this energy. The technology is a point absorber type wave energy converter based on a direct-driven linear generator placed on the sea bed connected via a line to a buoy on the surface. The work in this thesis is focused mainly on the energy transport of ocean waves and on increasing the transfer of energy from the waves to the generator and load. Potential linear wave theory is used to describe the ocean waves and to derive the hydrodynamic forces that are exerted on the buoy. Expressions for the energy transport in polychromatic waves travelling over waters of finite depth are derived and extracted from measured time series of wave elevation collected at the Lysekil test site. The results are compared to existing solutions that uses the simpler deep water approximation. A Two-Body system wave energy converter model tuned to resonance in Swedish west coast sea states is developed based on the Lysekil project concept. The first indicative results are derived by using a linear resistive load. The concept is further extended by a coupled hydrodynamic and electromagnetic model with two more realistic non-linear load conditions. Results show that the use of the deep water approximation gives a too low energy transport in the time averaged as well as in the total instantaneous energy transport. Around the resonance frequency, a Two-Body System gives a power capture ratio of up to 80 percent. For more energetic sea states the power capture ratio decreases rapidly, indicating a smoother power output. The currents in the generator when using the Two-Body system is shown to be more evenly distributed compared to the conventional system, indicating a better utilization of the electrical equipment. Although the resonant nature of the system makes it sensitive to the shape of the wave spectrum, results indicate a threefold increase in annual power production compared to the conventional system.
11
Nittayarumphong, Sadachai. "Vereinfachte Methoden zur optimalen Regelung resonanter Leistungskonverter." Doctoral thesis, Technische Universität Dresden, 2008. https://tud.qucosa.de/id/qucosa%3A23833.
Full textAbstract:
Nowadays the developments of power supplies in military, industrial or commercial applications are growing rapidly, not only to achieve the highest efficiency but also to focus on the size and weight minimization which are playing a major role in this area. Therefore, the research trends in dc-dc, ac-dc, dc-ac, ac-ac topologies are still continuously developing into the direction of new topologies, new control concepts, new materials and devices to achieve highest efficiency and smallest size. The cost per unit is also one of the most important points of power supplies. Also, with new control methods and new ways of manufacturing, for example, the cost per unit might be reduced. Also, a simplified control concept might help to avoid discrete circuits, especially, at low power levels. The last mentioned statement is demonstrated, for instance, by the concept of the Link-Switch of the company Power Integration where an extremely small number of components are necessary. With the target of minimization, this research work explores the possibility to replace conventional electromagnetic transformers considered as the most bulky devices in power supplies by piezoelectric transformers (PT) for innovative off-line power supplies. Several control methods for a load resonant converter focusing on class-E topology utilizing PT, were developed in order to investigate and to select an appropriate control method capable of improving the efficiency and reducing the size of the converter. Efficiency should be understood in this way as maximum reliability at minimum power losses. Different controllers were evaluated for optimizing the effect of disturbances of line and load variations. The ZVS condition for a wide input voltage range and a wide output load range can be achieved by a method called duty-cycle tracking. Further, with an improved design of the PT containing an auxiliary tap, the ZVS condition can be obtained by a method called turn-on synchronization. The controlled output voltage, current or power is achieved by a variable frequency control. Further, the dynamic modeling for open loop and closed loop of load resonant converters, focused on the class-E topology, was introduced. The transient behavior of the output voltage of the open loop against perturbations such as the input voltage change, the switching frequency change, and the output load change is treated by replacing the complete circuit of the class-E converter by simple equivalent circuit models. The results from the analysis of the open loop dynamic behavior are applied to modeling the closed loop class-E converter with several control methods. The methods of linearization for exact solution and heuristic approximation for the steady state analysis were purposed. These models of linearization were implemented with the controller in its topologies to investigate the sufficient accuracy of obtained results of the regulation. Besides, the linearization models were used to observe the stability condition of the proposed control loops. Finally, the evaluation of a well-known classical control such P, I, PI, PD, PID and a simplified controller for a fixed load application by matching an appropriate switching frequency according to the input voltage, into the load resonant converter, considering class-E topology, were presented. Also, the optimum design of the controller for a load resonant converter was discussed and derived.Die Entwicklung von Stromversorgungen in militärischen, industriellen und kommerziellen Anwendungen nimmt bis heute tendenziell stark zu. Nicht nur zur Erzielung höchster Wirkungsgrade, sondern auch im Hinblick auf Baugrößen- und Gewichtsminimierung, welche eine vorrangige Rolle spielen, ist diese Tendenz zu verzeichnen. Diesbezüglich gehen die Forschungstrends bei DC-DC, AC-DC, DC-AC und AC-AC Topologien in Richtung neuer Topologien, neuer Regelungskonzepte, sowie neuer Materialien und Bauelemente, um den höchsten Wirkungsgrad bei kleinster Baugröße zu erreichen. Die Gerätekosten sind ebenso ein sehr wichtiger Punkt bei Stromversorgungen. Auch durch neue Regelungsmethoden und durch neue Herstellungsverfahren können die Gerätekosten beispielsweise reduziert werden. Ebenso kann ein vereinfachtes Regelungskonzept dazu verhelfen, dass diskrete Schaltungen, speziell im unteren Leistungsbereich, vermieden werden. Letzteres wird beispielsweise beim Konzept des Link-Switch der Firma Power Integration verdeutlicht, indem extern wenige Bauelemente benötigt werden. Mit dem Ziel der Miniaturisierung wird in dieser Forschungsarbeit die Möglichkeit untersucht, konventionelle elektromagnetische Transformatoren, welche in Stromversorgungen als besonders voluminös gelten, durch piezoelektrische Transformatoren (PT) bei der Herstellung innovativer Netzstromversorgungen zu ersetzen. Verschiedene Regelungsmethoden für Lastresonanzkonverter, mit dem Fokus auf eine Klasse- E-Topologie mit PT, wurden hierzu entwickelt. Dies hatte zum Ziel, ein geeignetes Regelungsverfahren zu erarbeiten und auszuwählen, welches eine verbesserte Effizienz bei reduzierter Konverter-Baugröße aufzuweisen hat. Effizienz soll hierbei verstanden werden als maximale Zuverlässigkeit bei minimalen Leistungsverlusten. Verschiedene Reglertypen wurden entworfen um die Effekte der Störungen durch Netzspannungs-und Lastvariationen regelungstechnisch zu optimieren. Die Nullspannungsschaltungsbedingung (ZVS-Bedingung) über einen weiten Bereich der Eingangspannung und einen weiten Lastbereich kann durch einen sogenannte Duty-Cycle-Nachführung mit der Frequenz erreicht werden. Weiterhin kann durch eine verbesserte Ausführung des PT auf Basis einer Hilfsanzapfung die ZVSBedingung durch eine sogenannte Einschaltsynchronisation erreicht werden. Geregelte Ausgangsspannung, Ausgangsstrom oder Ausgangsleistung werden über eine Frequenzstellung erreicht. Die dynamische Modellierung der offenen und geschlossenen Regelschleife eines Lastresonanzkonverters, wieder im Hinblick auf die Klasse-E, wird im weiteren vorgestellt. Das transiente Verhalten der Ausgangsspannung der offenen Regelschleife gegenüber Störungen durch Eingangsspannungsänderung, durch Schaltfrequenzänderung oder durch Ausgangslaständerung, wird durch den Ersatz der Klasse-E-Schaltung durch einfache Äquivalenzmodelle behandelt. Die Ergebnisse der Analyse des Verhaltens des offenenen Regelkreises werden verwendet, um den Klasse-E-Konverter mit geschlossener Regelschleife unter Verwendung verschiedener vorgestellter Regelungsmethoden zu modellieren. Methoden der Linearisierung für die exakte Lösung und für eine heuristische Approximation der statischen Analyse des eingeschwungenen Zustands werden vorgeschlagen. Diese Methoden der Linearisierung werden zusammen mit den Reglermodellen in deren jeweilige Topologie implementiert um die ausreichende Genauigkeit der erhaltenen Resultate des Regelungsverhaltens zu beurteilen. Weiterhin werden diese Linearisierungsmodelle dazu verwendet, die Stabilitätskriterien der vorgeschlagenen Regelschleife zu überwachen. Schlussendlich wird die Bestimmung der bekannten klassischen Regler (P, I, PI, PD, PID), sowie eines vereinfachten Konstantlaststellers durch geeignete Anpassung der Schaltfrequenz an die Eingangsspannung, für Lastresonanzkonverter, wieder mit Blick auf die Klasse-E, vorgestellt. Außerdem wird der optimierte Reglerentwurf für Lastresonanzkonverter diskutiert und abgeleitet.
12
Horsley, Edward Lewis. "Modelling and analysis of radial mode piezoelectric transformers and inductor-less resonant power converters." Thesis, University of Sheffield, 2011. http://etheses.whiterose.ac.uk/12870/.
Full textAbstract:
Within the electronics industry there is a continual demand for DC-DC power converters that achieve high power density at low cost. Since a piezoelectric transformer (PT) has an electrical equivalent circuit that is similar to several resonant converter topologies, a PT can be used to replace many of the reactive components in these topologies with a single ceramic component, thereby offering potential savings in cost, size, and mass. The first part of this thesis presents a new equivalent circuit model for one of the most promising types of PT, the radial mode Transoner. This model relates the electrical characteristics of the PT to the physical dimensions and material properties. Considerable insight is then gained about how to design these devices to meet a particular set of converter specifications whilst simultaneously maximising PT power density. The second part of this thesis concerns the effect of the rectifier topology on PT power density. Using concepts from material science, together with equivalent circuit models of both the PT and the rectifier topologies, it is shown that a given PT will always achieve a higher thermally limited maximum output power when used in an AC-output topology compared to a DC-output topology. The half-bridge inductor-less PT-based converter topology is particularly attractive because it requires no additional components between the half-bridge and the rectifier. However, it is difficult to achieve zero-voltage-switching (ZVS) without significantly compromising PT power density when using this topology. The third part of this thesis details the development and experimental verification of a new model for the ZVS condition. Using a normalisation scheme and numerical optimisation techniques, the requirements for achieving inductor-less ZVS are accurately quantified for the first time. The impact of these requirements on PT power density is assessed, and design guidelines for maximising PT power density are given.
13
Chen, Haoning (William). "LLC Resonant Current Doubler Converter." Thesis, University of Canterbury. Electrical and Computer Engineering, 2013. http://hdl.handle.net/10092/8492.
Full textAbstract:
The telecommunications market is one of the large rapidly growing fields in today’s power supply industry due to the increasing demand for telecom distributed power supply (DPS) systems. The half-bridge LLC (Inductor-Inductor-Capacitor) resonant converter is currently the most attractive topology for the design and implementation of 24V/48V DC telecom power converters. The current doubler rectifier (CDR) converter topology was invented and described in the early 1950s which can offer the unique characteristic of halving the output voltage while doubling the output current compared to a standard rectifier. In this thesis, the current doubler converter topology with its unique characteristic is evaluated as a complementary solution to improve the LLC resonant converter performance, especially for the low output voltage and high output current telecommunication applications. A novel half-bridge LLC resonant current doubler converter (LLC-CDR) is proposed in this thesis which can offer several performance benefits compared to conventional LLC-standard rectifier design . The unique characteristics of the LLC-CDR topology can offer significant improvements by transformation of a 48V converter into a 24V converter with the same power density. This thesis introduces a new SPICE-based simulation model to analyse the operation of this novel LLC-CDR converter circuit design. This model can be used to define the critical component parameters for the LLC -CDR circuit output inductor values. It can also be used to predict the circuit overall performance under different load conditions. Both time-domain based transient simulation analysis and frequency-domain based AC analysis provided by this simulation model showed favourable results in comparison to bench measurement results on a prototype. The model
provides a valuable insight to reveal some of the unique characteristics of this LLC -CDR topology. It demonstrates a proof of concept that the conventional LLC resonant
converter can be easily redesigned for low voltage, high current applications by using the LLC-CDR topology without requiring a new design for the LLC resonant stage components and the power transformer. A new magnetic integration solution was proposed to significantly improve the overall performance in the LLC-CDR topology that had not been published before. The LLC-CDR converter hardware prototypes with two output inductors coupled and uncoupled configurations were extensively modelled, constructed and bench tested.Test results demonstrated the suitability of an integrated coupled inductors design for the novel LLC-CDR converter application. The integrated coupled inductors design can significantly improve the LLC-CDR converter frequency-domain based AC simulation analysis results. In addition, these results also illustrate the potential benefit of how the magnetic integration design in general could reduce the magnetic component size, cost, and weight compared to the uncoupled inductors design. Finally, a hardware prototype circuit was constructed based on a commercial 1800 W single phase telecom power converter to verify the operation of this novel half bridge LLC-CDR topology. The converter prototype successfully operated at both no load and full load conditions with the nominal output voltage halved from 48VDC to 24VDC, and doubled the output current to match the same output power density. It also demonstrates that the efficiency of this novel half bridge LLC –CDR is 92% compares to 90% of EATON’s commercial 24VDC LLC resonant converter, which can fulfill the research goals.
14
Jong, Owen. "Multi Resonant Switched-Capacitor Converter." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/88019.
Full textAbstract:
This thesis presents a novel Resonant Switched-Capacitor Converter with Multiple Resonant Frequencies, abbreviated as MRSCC for both high density and efficiency non-isolated large step-down Intermediate Bus Converter (IBC). Conventional Resonant Switched-Capacitor Converter (RSCC) proposed by Shoyama and its high voltage conversion ratio derivation such as Switched-Tank Converter (STC) by Jiang and li employ half sinusoidal-current charge transfer method between capacitors to achieve high efficiency and density operation by adding a small resonant inductor in series to pure switched-capacitor converter's (SCC) flying capacitor. By operating switching frequency to be the same as its resonant frequency, RSCC achieves zero-current turn off operation, however, this cause RSCC and its derivation suffer from component variation issue for high-volume adoption. Derived from RSCC, MRSCC adds additional high frequency resonant component, operates only during its dead-time, by adding small capacitor in parallel to RSCC's resonant inductor. By operating switching frequency higher than its main resonant frequency, MRSCC utilizes double chopped half-sinusoidal current charge transfer method between capacitors to further improve efficiency. In addition, operating switching frequency consistently higher than its resonant frequency, MRSCC provides high immunity towards component variation, making it and its derivation viable for high-volume adoption.MS
Following the recent trend, most internet services are moving towards cloud computing. Large data applications and growing popularity of cloud computing require hyperscale data centers and it will continue to grow rapidly in the next few years to keep up with the demand [4]. These cutting-edge data centers will require higher performance multi-core CPU and GPU installations which translates to higher power consumption. From 10MWatts of power, typical data centers deliver only half of this power to the computing load which includes processors, memory and drives. Unfortunately, the rest goes to losses in power conversion, distribution and cooling [5]. Industry members look into increasing backplane voltage from 12V to 48V in order to reduce distribution loss. This thesis proposes a novel Resonant Switched-Capacitor Converter using Multiple Resonant Frequencies to accommodate this increase of backplane voltage.
15
Wong, Siu Chung. "A macromodel for resonant converter circuits." Thesis, University of Southampton, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242683.
Full text
16
Liu, Kwang-Hwa. "High-frequency quasi-resonant converter techniques." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/74737.
Full textAbstract:
Two waveform-shaping techniques to reduce or eliminate the switching stresses and switching losses in switching-mode power conversion circuits are developed: the zero-current switching technique and the zero-voltage switching technique.
Based on these two techniques two new families of quasi-resonant converters are derived. Since the stresses on semiconductor switching devices are significantly alleviated, these quasi-resonant (QRC) converters are suitable for high-frequency operations with much improved performances and equipment power density.
Employing the duality principle, the duality relationship between these two families of quasi-resonant converters are derived. The establishment of the duality relationship provides a framework allowing the knowledge obtained from one converter family to be readily transferred to the other.
Further topological refinements are derived through the utilization of parasitic elements in the devices and the circuit. In particular, the two most significant parasitic elements, the leakage inductance of the transformer and the junction capacitances of the semiconductor switch, are incorporated as part of the resonant-tank circuit required by these quasi-resonant converters. Consequently, the detrimental effects due to these parasitic elements are eliminated, and the converters can be operated at very high frequencies.Ph. D.
17
Feng, Shengli. "Optimal trajectory control of series resonant converter." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ64718.pdf.
Full text
18
Rowley, Anna Kaspartian. "A new zero-voltage-mode resonant converter." Thesis, Brunel University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303182.
Full text
19
Abodhir, Nourdeen Abdulslam. "Resonant power converter control for industrial magnetron." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/39383/.
Full textAbstract:
High voltage DC power supplies have been used in a wide range of applications such as Radio Frequency (RF) tube drives, industrial, military, aerospace, medical, and domestic applications. Recently as a result of advances in power electronics and magnetic materials, development of compact high voltage DC power supplies has become an active area of research, and resonant power converters have been introduced as a promising solution, owing to their potential for high efficiency and high power density. Several resonant converter topologies have been investigated to be used as modulators for supplying RF tubes (i.e. Magnetrons, Klystrons, and Traveling Wave Tubes) for various applications. The main aim of this study is to develop a control methodology for maintaining soft switching of a series resonant series loaded (SRSL) power converter based modulator for driving an industrial magnetron with variable load conditions. This thesis considers the design of a high voltage, high frequency, compact power supply for applications where the load is variable and/or nonlinear. One particular application where this is the case is when driving an industrial magnetron with a variable output RF energy requirement. The magnetron appears to the resonant converter as a variable load which can negatively affect the efficiency of the power conversion unless control of the converter is carefully considered. A compact power supply based on the SRSL resonant converter with an extended combined phase and frequency control is proposed. A novel control method based on three dimensional (3D) lookup tables has been developed, in order to control the load resonant converter whilst maintaining soft switching under variable load conditions. A direct quadrature (DQ) based modelling approach is used to develop a suitable model of the converter for control design. Based on the characteristics of the magnetron, an emulator prototype is also proposed to represent the magnetron load behavior in a low voltage laboratory environment. A detailed design and implementation procedure is presented, including the hardware design and control of the resonant power converter and the magnetron emulator. Simulation and experimental results are provided to validate the approach and in order to demonstrate the feasibility of the proposed converter modelling approach and control strategy. A good correlation between simulation and experimental results is obtained.
20
Chin, Yuan. "Constant-frequency parallel-resonant converter (clamped-mode)." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/104308.
Full text
21
Chang, Yu-kun. "Digital Control of a Series-Loaded Resonant Converter." Thesis, University of Canterbury. Electrical and Computer Engineering, 2006. http://hdl.handle.net/10092/1090.
Full textAbstract:
Primarily because of its low cost and ease of implementation, analogue control has been the dominant control strategy in modern switch-mode power supply designs. The 'on/off' nature of power switches is essentially digital, which makes it tempting for power elec- tronics engineers to combine the emerging capability of digital technologies with existing switch-mode power supply designs. Whereas an analogue controller is usually cheaper to implement, it lacks the flexibility and capacity to implement the complex control func- tions which a digital controller can offer. The research presented in this thesis addresses the practical implementation of a digi- tal controller for a Series-Loaded Resonant Converter (SLR). The resonant frequency of the SLR converter is around 60 kHz, and the switching frequency varies up to around 80 kHz to regulate the 12V dc output voltage across a 100W, variable resistive load, from a variable 46.6V 60.2V input voltage. This provides a fair challenge for digital waveform generators as the digital processor needs to have a high clock rate to produce high speed, high resolution and linearly varying frequency square waves, to regulate the output volt- age with adequate resolution. Digital compensation algorithms also need to be efficient to minimise the phase lag caused by the instruction overhead. In order to completely understand the control needs of the SLR converter, an analogue controller was constructed using a UC3863N. The feedback compensation consists of an error amplifier in an integrator configuration. Digital control is accomplished with a TMS320F2812 Digital Signal Processor (DSP). Its high throughput of 150 MIPS provides sufficient resolution to digitally generate linearly varying frequency switching signals util- ising Direct Digital Synthesis (DDS). Time domain analysis of the switching signals, shows that the DDS generated square iv ABSTRACT waves display evidence of jitter to minute variations in pulse-widths caused by the digi- tisation process, while in the frequency domain, this jitter displays itself as additional sidebands that deteriorate the fundamental frequency of the switching signal. Overall, DDS generated square waves are shown experimentally to be adequate as control signals for the MOSFET power switches. Experiments with step load changes show the digi- tal controller is able to regulate the output voltage properly, with the drawback of the settling time being a little longer than the analogue counterpart, possibly caused by the unpredictable damping effects of switching signal jitter. Variations in input voltage shows that the digital controller excels at operating under noisier conditions, while the analogue controlled output has slightly greater noise as input voltage is increased. As the digital technology continues to improve its speed, size and capacity, as well as becoming more affordable, it will not be long before it becomes the leading form of control circuitry in power supplies.
22
McClusky, Scott Logan. "HIGH VOLTAGE RESONANT SELF-TRACKING CURRENT-FED CONVERTER." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/254.
Full textAbstract:
High voltage power supply design presents unique requirements, combining safety, controllability, high performance, and high efficiencies. A new Resonant Self-Tracking Current-Fed Converter (RST-CFC) is investigated as a proof-of-concept of a high voltage power supply particularly for an X-ray system. These systems require fast voltage rise times and low ripple to yield a clear image.
The proposed converter implements high-frequency resonance among discrete components and transformer parasitics to achieve high voltage gain, and the self-tracking nature ensures operation at maximum gain while power switches achieve zero-voltage switching across the full load range. This converter exhibits an inherent indefinite short-circuit capability. Theoretical results were obtained through simulations and verified by experimental results through a complete test configuration. Converter topology viability was confirmed through hardware testing and characterization.
23
Price, Colin Franklin. "Investigation of a quasi-square parallel-resonant converter." Thesis, University of Edinburgh, 1992. http://hdl.handle.net/1842/12798.
Full textAbstract:
A converter is proposed which is based on parallel-resonant technology, incorporating a capacitive filter. The convertor complies with a high-power, low voltage load specification, and is required to operate with a fixed switching frequency. The topology uses a combination of resonant tanks, and a clamped voltage technique, to maintain the advantages of more standard square-wave converters, whilst exploiting the desirable features of resonant conversion. The purpose of the proposed converter is threefold: 1. -to reduce the converter size by operating without an output filter choke; 2. -to reduce component stresses by clamping internal voltages, and so limiting voltage and current peaks; 3. -to reduce switching losses by limiting the volt-current product during the switching transient. The shape of the internal waveforms define the power transferred and are determined by values of resonant components positioned within a standard bridge circuit. As a result of these resonant components the converter efficiency at full load approaches 93%, and the characteristics of the EMI spectrum are favourable. Low power resonant techniques are well understood, however, operation at higher output powers requires careful construction techniques and consideration of various engineering compromises. An explanation of these is presented and justification for their choice is discussed. Three prototype converters are built and tested, and problems encountered during their development are highlighted. Results of two simulation techniques correlate well with the observed results, and a numerical modelling technique is developed as a design aid. As a result of the work at low output voltages it is shown that the converter is better suited to operation as the front-end of a distributed power power system, converting voltage from 270 V to 48 V.
24
Ho, Kwun-yuan Godwin, and 賀觀元. "A novel integrated synchronous rectifier for LLC resonant converter." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B49618180.
Full textAbstract:
There is ever-increasing demand in telecommunication system, data server and computer equipment for low voltage, high current power supply. LLC resonant converter is a good topology on primary side of the converter because it has soft switching and resonant conversion. However, the passive rectifier in the secondary side has high power dissipation. Synchronous rectifier is a popular method to reduce this rectification loss. Although there are many types of synchronous rectifier for PWM converter, most of them do not function well in LLC resonant converters. It is because the wave form of LLC resonant converter is different from PWM. The objective of this research is to reduce the power dissipation and physical size at the same time.
In this thesis, a novel current driven synchronous rectifier with saturable current transformer and dynamic gate voltage control for LLC resonant Converter is presented. This novel circuit reduces the rectification loss and size of the current transformer in the synchronous rectifier. This synchronous rectifier has several outstanding characteristics compared with generic voltage driven and current driven synchronous rectifier. The saturable feature reduces the current transformer turns. Inherent dynamic gate voltage controlled by saturable current transformer reduces gate loss in the MOSFET. A novel driving circuit is proposed for accurate turn off time. It reduces loss significantly. This synchronous rectifier is completely self-contained which can replace the rectifier diode as a drop in replacement. It is insensitive to parasitic inductance. In order to explain the current transformer saturable, a model of saturable current transformer is proposed. A prototype demonstrates the advantages of the proposed current driven synchronous rectifier.
Furthermore, a novel integrated synchronous rectifier is presented which provides a more compact system. The synchronous rectifier current transformer is integrated with the main transformer which reduces the number of circuit joints in power path. Each soldering joint generates significance loss in power converter. A pair of 0.5mΩ soldering joint in 25A current path produces 0.62W loss. The placement of the integrated current transformer is important. A criterion for the placement of the current transformer within the main transformer is to avoid interference to the current transformer from the magnetic flux of the main transformer. Thus, a placement method to integrate the current transformer into the main transformer is proposed. An integrated current transformer model is suggested to explain the operation of the integrated synchronous rectifier. A prototype demonstrates the advantages of the integrated synchronous rectifier.published_or_final_version
Electrical and Electronic Engineering
Master
Master of Philosophy
25
Cook, D. J. "A direct resonant converter for high power RF applications." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438305.
Full text
26
Goldberg, Andrew Franklin. "A radio frequency DC-to-DC resonant power converter." Thesis, Massachusetts Institute of Technology, 1985. http://hdl.handle.net/1721.1/27944.
Full textAbstract:
Thesis (Elect. E.)--Massachusetts Institute of Technology, Dept. of Electrical Engieering and Computer Science, 1985.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING.
Bibliography: leaves 136-139.
by Andrew Franklin Goldberg.
Elect.E.
27
George, Mark S. "Power factor correction using a boost quasi-resonant converter." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/41901.
Full textAbstract:
A steady-state analysis of a quasi-resonant zero current boost converter is performed in its application to a single-phase power factor correction circuit. The known closed-form expressions are used to design the boost converter and the multiloop control circuit. The operating characteristics are simulated by using PSPICE and are experimentally verified. Considerations for a practical design are based upon hardware operating at a maximum of 1 megahertz, with a 115 VRMS input, 200 VDC and 100 watt output.
Master of Science
28
Lin, Pei-jung, and 林沛蓉. "Modelling and Analysis of an LLC Series Resonant Converter." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/25122516691681194871.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
96
This thesis focuses on derivation and analysis of a LLC series resonant converter model by a 240W single-output and a 340W double-output half-bridge series resonant converter. First of all, the basic operating principle of series resonant converters is discussed in detail. Besides the significant parameters, such as resonant capacitors and inductors, turn ratio and magnetizing inductance, the on-state resistance of MOSFETs, the leakage inductors in the secondary side of the transformers, stray capacitors, line loss and ground plane are considered in the LLC equivalent model. Furthermore, the remaining loss of the secondary side is approximated as a parallel capacitor in the resonant tank. Thus, the output voltage is obtained by MATHCAD with above parameters. According to previous experiments, a revised LLC equivalent model is presented in the thesis. By doing simulation with the revised model, the frequency response of the output voltage gain can be shown in a chart with better accuracy and the operation frequency of converters is clearly predicted. In addition, in the case of verifying this model, a single-output and a double-output LLC-type resonant converter are implemented as following specifications: 12V/20A for the former and 12V/20A and 5V/20A for the latter with 400V input voltage. The deviation between the real output voltage and the simulated one is reduced from 35.0% to 3%. To sum up, the revised LLC equivalent model is proposed and improved with less deviation and much convenience in the LLC SRC convertor design.
29
Lakshminarayanan, Sanjay. "Modelling, Simulation And Design Of A Single Switch Resonant Inverter For Induction Heating." Thesis, 1995. http://etd.iisc.ernet.in/handle/2005/1647.
Full text
30
Yung-Chyang-Wang and 王永強. "LLC Resonant Half Bridge Converter." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/65223932741609639976.
Full text
31
PAN, GUANG-HUA, and 潘光華. "Resonant high voltage DC converter." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/86954567194956024001.
Full text
32
Theron, Philippus Coenraad. "The partial series resonant converter." Thesis, 2014. http://hdl.handle.net/10210/10242.
Full textAbstract:
D.Ing. (Electrical and Electronic Engineering)increased dramatically during the past few years. This progress can mainly be attributed to recent developments in power electronic switching devices. Switching times are reduced, resulting in lower switching power loss, on-state voltage is reduced leading to lower conduction power losses, and higher voltage and current capabilities are possible. These advances are mainly responsible for a reduction in physical size of the converters, especially of the reactive components; an increase in dynamic response; and also, to a lesser extent, have an influence on the converter behaviour. Different applications of DC-DC converters require different characteristic behaviour, and the trend to obtain these different characteristics is usually accomplished by adding additional components to existing DC-DC converters. The disadvantage of such an approach is that it adds to the complexity of the converter topology and controller, and consequently increases the manufacturing cost, and reduces reliability. In this thesis, the objective is to identify a galvanic isolated DC-DC converter having inherent short circuit protection, sinusoidal transformer current, a low number of components and a simple controller. Hard switched DC-DC converters are approached from a fundamental point of view, weighing simplicity against characteristics, and a systematical classification is addressed. In order to address the issue of sinusoidal transformer current and inherent short circuit protection, a systematic classification of simple resonant converters is also addressed. The partial series resonant converter, which is a new converter topology, is identified and analysed. It does not follow the trend of increased converter and controller complexity with different characteristics, and meets all the objectives mentioned above. In addition to these objectives, it has the following characteristics: Output current can be controlled without any current measurement, while obtaining inherent short circuit protection. Switching losses are ultra low due to zero voltage switching at reduced turn-off current, enabling the use of insulated gate bipolar transistors at switching frequencies in excess of 50 kHz, which, among others, benefits dynamic response. The output load line resembles a natural constant output power load line at constant switchingfrequency. The combination of these characteristics is shown to provide major advances in low inductance load applications, such as arc welding and battery charging. Furthermore, all the magnetic components are integrated into one physical structure, which benefits, among others, manufacturability and cooling. The analysis and feasibility of the partial series resonant converter is verified by the construction of multi kilowatt prototypes for both battery charging and arc welding.
33
CAI, DONG-YI, and 蔡東宜. "Constant-Frequency parallel-resonant converter." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/09359324523573623283.
Full text
34
Chen, Jyue-Long, and 陳珏龍. "Design and Implementation of Resonant Capacitor Controlled LLC Resonant Converter." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/uaae3v.
Full textAbstract:
碩士國立中央大學
電機工程學系
106
This thesis focuses on the design and implementation of a half-bridge LLC resonant converter with power factor correction. The traditional LLC resonant converter suffer from the problem of poor light-load efficiency. Burst-mode is usually used to solve this problem, but Burst-mode has problems like large output voltage ripple, acoustic noise, poor dynamic response. This thesis proposes a resonant capacitor controlled LLC resonant converter to improve light-load efficiency. In addition, this control method can be used to extend hold-up time. Finally, this thesis implements a 300W AC/DC power supply. The input voltage range is 90 ~ 264V_ac, the output voltage is 50V_dc, and the output current is 6 A at full-load. The overall average power factor is more than 0.94. The average efficiency is 90%, and the highest efficiency is 93%. Finally, the relevant experimental results verify that the designed resonant capacitor controlled half-bridge LLC resonant converter with power factor correction has the effect of improving light load efficiency and extending the hold-up time.
35
Chen, Song-Cian, and 陳頌謙. "Near Constant-Frequency LLC Resonant Converter." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/80169305727621846036.
Full textAbstract:
碩士建國科技大學
電機工程系暨研究所
99
This study proposed a new LLC resonant converter with near constant-frequency. With the characteristic of soft switching, LLC resonant converters presents the advantages of high conversion efficiency and low electromagnetic interference (EMI) that they are suitable for high-frequency power converters. Nonetheless, LLC resonant converters are operated with variable-frequency control that the designs of EMI filters become more complicated and difficult. Besides, when working in light load, the efficiency conversion is lower and the output voltage ripples are larger. In this case, the LLC resonant converter, which could work in Near Constant-Frequency, is proposed in this study. To achieve the function of Near Constant-Frequency, a frequency-converted Resonant Tank is designed to change the resonant frequency with the change of load. Furthermore, the LLC resonant converter with Near Constant-Frequency remains the characteristic of high efficiency conversion and largely improves the conversion efficiency with light load. The LLC resonant converter with near constant-frequency control is first analyzed; then, chaotic ganetic algorithm is utilized to design the key circuit element parameters of the converter; and finally, the near constant-frequency LLC resonant converter is completed. The experimental results show that the efficiency of the ultra-light load 6W is 78.2%, the efficiency of 18W reaches 89.3%, the maximum efficiency of the circuit presents 94.5%, and the change of the operation frequency 24W~240W appears 1.1kHz.
36
Chun-HsuYang and 楊淳旭. "IC Design for LLC Resonant Converter." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/41940660259405825488.
Full textAbstract:
碩士國立成功大學
電機工程學系碩博士班
101
In this thesis, a controller for a half-bridge LLC resonant DC-DC converter with light-load efficiency improvement is realized. The high switching frequency and circulating current in the resonant tank result the poor efficiency of a LLC resonant converter under light load condition. The light-load efficiency improvement is limited with the conventional burst-mode control. To improve efficiency further, a modified burst-mode control is implemented in the proposed controller. The switching frequency decreases gradually during burst-on time to reduce the number of switching cycles under the same output ripple. Moreover, in burst-on time, the first pulse drives the MOSFET at high side with limited pulse width to suppress the initial current in resonant tank. The last switching cycle in burst-on time must be complete to ensure that initial conditions of each burst cycle are the same. Consequently, the switching losses are reduced by proposed control strategy, and light-load efficiency is improved. This chip is fabricated with TSMC 0.25um CMOS high voltage mixed signal general purpose process.
37
GIU, GUO-ZHEN, and 邱國珍. "High frequency quasi-resonant 'CUK converter." Thesis, 1988. http://ndltd.ncl.edu.tw/handle/16475920676707101656.
Full text
38
Hsu, Steven, and 徐聯芳. "frequency control of series resonant converter." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/51362460146490510678.
Full textAbstract:
碩士中正理工學院
電機工程研究所
86
39
Lin, Wei-Jie, and 林暐捷. "Novel Interleaved Voltage Doubler Resonant Converter." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/sduhgx.
Full textAbstract:
碩士國立雲林科技大學
電機工程系
103
This thesis presents a novel interleaved voltage doubler resonant converter. The circuit architecture of the proposed converter is used on DC-DC converter applications. The primary sides of the converter are two half-bridge LLC resonant converters connected in parallel. However, conventional LLC resonant converters have high current stress and current ripple on the secondary side. In order to reduce the current stress of power switches and decrease current ripple on the output capacitor, the interleaved PWM scheme is used in the proposed converter. Base on the LLC resonant converter features, such as zero voltage switching (ZVS) for power switch and zero current switching (ZCS) for rectifier diodes, the switching losses and the reverse recovery current on power components are reduced. For high voltage output applications, two Geinacher circuits of voltage doubler are connected in parallel at secondary side. Thus, the current stress of the secondary windings and rectifier diodes can be reduced. In the meantime, the envelope detector on the output side can also reduce the output current ripple. Finally, the theoretical analysis of the proposed converter is verified by SIMetris- SIMPLIS simulation and the experiment tests with input voltage 250V~300V and 1200W rated power (400V/3A).
40
HUANG, NIAN-ZHONG, and 黃念中. "Research of LLC Resonant DC Converter." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/n59wwt.
Full textAbstract:
碩士中華科技大學
機電光工程研究所碩士班
106
This thesis mainly discusses the LLC resonant power converter. We uses the characteristics of the resonant converter's soft switching and analyzes the operation principle of the LLC resonant converter. The advantages of the LLC resonant converter are as follows: The switch has Zero voltage switching, secondary side rectification with zero current. The LLC resonant converter has the advantage of a fixed duty cycle. It uses primary transformer primary leakage inductance, magnetizing inductance, parasitic elements of the MOSFET, and resonant capacitors to generate resonance to reduce switching losses and improve efficiency. The half-bridge switching, LLC resonance, and step-down rectification have been simulated by the PSIM software. The waveforms of the transient and steady-state response of the DC-DC converter system have been presented. The zero-voltage switching, frequency of the LLC resonant converter and secondary side rectification with zero current are presented in this thesis. From the results of simulation to verify their effectiveness.
41
Wu, Chia-Hasn, and 吳佳勳. "High-Efficiency D-Type Resonant Converter." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/px77gq.
Full textAbstract:
碩士崑山科技大學
電機工程研究所
102
This paper proposed a high efficiency power converter in which the class D resonant converter as the main structure, with a simple circuit structure, small size, light weight, low switching losses, low cost price advantages.The use of resonant slots are composed of inductance and capacitance to produce resonant voltage and current required by zero voltage or zero current switching to achieve soft switching technique to reduce switching loss caused in the switch,to obtain the desired output voltage and output current. The paper also analyzed the operating characteristics for the circuit theory and circuit model, and finally, to implement the results of verification circuit, the circuit conversion efficiency of 93.5%.
42
Chen, Peng-Ruei, and 陳芃瑞. "Implementation of the LLC Resonant Converter." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/02429844998477385969.
Full textAbstract:
碩士崑山科技大學
電機工程研究所
104
This thesis presents an isolated half-bridge converter for high efficiency battery charger. The power stage uses a resonant LLC topology since it improves efficiency, reduces EMI signature and provides better transformer utilization compared to conventional topologies. In the resonant tank, only one magnetic component is needed, the leakage inductance of transformer is used as resonant inductance. With proper selection of the resonant tank and modulation of the operation switching frequency, the power switches of proposed circuit can achieve zero voltage switching (ZVS), and rectifier diodes are turned off at ZCS if the switching frequency is less than the series resonant frequency. Due to the ZVS and ZCS yielded by the LLC converter, the switching loss is reduced and the system efficiency is enhanced. Finally, a prototype of 150V input and 110W output is constructed. The SPICE simulation and experimental results of the ZVS and ZCS, unique frequency modulation efficiency are presented to prove the feasibility of the designed LLC resonant converter.
43
Rajapandian, A. "A Constant Frequency Resonant Transition Converter." Thesis, 1995. http://etd.iisc.ernet.in/handle/2005/1645.
Full text
44
YANG, JIN-DE, and 楊進德. "High frequency multi-resonant 'Cuk converter." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/48884549100181992421.
Full text
45
Vandelac, Jean-Pierre. "A pulse-width modulated series resonant converter operated at resonant frequency." Thesis, 1988. http://spectrum.library.concordia.ca/4632/1/ML44862.pdf.
Full text
46
Chan, Chih-Hao, and 詹智皓. "Implementation and Study of LLC Resonant Converter." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/50964565994434461961.
Full textAbstract:
碩士建國科技大學
電機工程系暨研究所
97
This thesis conducts Genetic Algorithm and Taguchi method to determine the component values of the resonant circuit. Since LLC resonant converter possesses soft-switching characteristic and has high transfer efficiency and low electromagnetic interference, it is suitable to be used in switching power supplies. Nevertheless, the high output current ripple requiring a larger capacitor is a major drawback that limits the applications of LLC resonant converter. Even though current-shaping technologies have been proposed for overcoming the above-mentioned defect, but there is still no systematic method for the determination of the resonant circuit parameters effectively. Therefore this study develops a novel method to implement a productive resonant circuit for depressing the output current ripple and the experimental results show that there is 20.4% reduction in full-load operation. This thesis first analyzes the operation principles of the LLC resonant converter and the same converter with current-shaping technogy. Afterward MathCAD and Genetic Algorithm are adopted to analyze and determine the resonant circuit parameters for the lowest output current ripple. Also IsSpice software is used for circuit simulations. Besides, the theoretical values obtained from theoretical analysis are confined to the standard specifications of elements, so that proper element specifications cannot be established and the functioning of prototype circuit is far from ideal. Therefore Taguchi method is conducted to achieve optimal design. Eventually, an LLC resonant converter with current shaping is implemented and thus proves the feasibility of the proposed method.
47
Lin, Chien-Chih, and 林建志. "Boost Resonant Converter and Photovoltaic Lighting Application." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/24572477427278687314.
Full textAbstract:
碩士清雲科技大學
電機工程研究所
95
A novel resonant converter---the boost resonant converter is presented in this thesis. The proposed converter is developed and applied as the power conversion unit in a stand-alone photovoltaic lighting system. Based on half bridge structure, the proposed boost resonant converter combines the dc-dc boost converter and the dc-ac resonant inverter to form a single unit, which operates to provide dual outputs, one is the boosted DC output and the other is the high frequency sinusoidal output. Single output can also be achieved with only one load. Under conditions of bidirectional continuous conduction and nductive load, the switches in the boost resonant converter could be turned on with ZVS. In addition, the upper switch of the half bridge is turning on with synchronous effect. The advantages of the proposed boost resonant converter include simple structure, multiple outputs, and high energy efficiency. The solar-powered lighting system developed in this thesis utilizes the boost resonant converter as the power conversion unit and the fluorescent lamp and lead-acid battery as the loads. The maximum power point tracking of the solar cell panel is finished using a DC boost converter operated in hill-climb algorithm with a microcontroller. The photovoltaic system is designed to charges the lead-acid battery in the daytime with a high switching frequency, and the lead-acid battery turns on the fluorescent lamp in the nighttime with a low switching frequency. While the lead-acid battery is charged with constant voltage by modulating the duty ratio, the fluorescent lamp illuminates with constant lamp current by modulating the switching frequency, all with the same set of driver ICs. To implement the solar-powered system, a day-night illumination gauge circuit, a frequency selection circuit, and a voltage-controlled oscillator (VCO) are also included to make the system function as designed. Apart from theoretical analysis, design and computer simulation, an experimental prototype system is constructed. The performance of the prototype circuit loaded with fluorescent lamp of 21W and lead-acid battery of 36V are measured. The measured results are in good agreement with theoretical analysis. The photovoltaic lighting system is also functioned as expected.
48
Yang, Chih-Lung, and 楊志隆. "Analysis and Implementation of LLC Resonant Converter." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/75066414087761942462.
Full textAbstract:
碩士雲林科技大學
電機工程系碩士班
96
Analysis and implementation of an LLC resonant converter with multiple outputs are presented in this thesis. The advantages of resonant converter are high efficiency, high switching frequency and high power density. The LLC converter are suitable for TFT-LCD power supply module. The proposed LLC resonant converter can supply 12V and 24V output voltages at the same time. The front stage of proposed converter is a boost converter with high power factor. The flyback converter is also designed to provide the standby power for the full circuit. The experimental results and the measured values are proved in this thesis.
49
Cheng, Ching-Ming, and 鄭金明. "Analytic Model of the Parallel Resonant Converter." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/95674450820661734360.
Full textAbstract:
碩士國立海洋大學
電子工程學系
83
Parallel resonant converter is a widely used converter. The steady-state analysis of the lossy parallel resonant converter is presented with closed-form expression. The phase difference between the input square-wave voltage and the output square- wave current which excite the resonant tank is used as the parameter to plot the converter output current and voltage characteristic for given damping ratio and switching frequency. The load line can be superimposed on the output characteristic to determine the operating point and the value of the associated parameter (by using linear interpolation) , which can be used to plot the resonant-tank waveforms. The upper bound of the switching frequency can be found as a function of the threshold voltage of the output rectifier and is practically independent of the damping ratio. The damping has a serious effect when the switching frequency is near resonance in that the output characteristic is far from an ideal current source as in the lossless case.
50
Patterson, Oliver Desmond. "Pseudo-resonant full bridge DC/DC converter." 1987. http://catalog.hathitrust.org/api/volumes/oclc/15634707.html.
Full textAbstract:
Thesis (M.S.)--University of Wisconsin--Madison, 1987.Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 77-78).