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1
Pollock, Helen Geraldine Phyllis. "A series-parallel load-resonant converter for a controlled-current arc-welding power supply." Thesis, University of Warwick, 1996. http://wrap.warwick.ac.uk/4191/.
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A power supply incorporating a series-parallel load-resonant converter, capable of very efficient operation over a wide range of output power is presented. The series-parallel load-resonant converter is shown to have three pairs of resonant frequencies. Operation of the circuit at each of these resonant frequencies maintains zero current switching and high frequency operation. Design mathematics is developed which allow series-parallel load-resonant converters to be designed with specific resonant frequencies and circuit resistances. A new method of power control for series-parallel load-resonant converters is presented; the power delivered to the circuit and hence the load is shown to var substantially depending on which resonant frequency the circuit is excited at. Two series-parallel load-resonant converters are designed simulated, constructed and tested. There is good agreement between the simulation and experimental results. One of the circuits produces an output current of 200 A while the second demonstrates the new power control technique pulsing between 55 A and 145 A while running at frequencies of 63 kHz and 100 kHz. The new power supply is particularly suited to arc-welding. It contains an active rectifier and draws near unity power factor.
2
Tao, Junbing [Verfasser]. "Half-cycle-sampled discrete model of series-parallel resonant converter with optimized modulation and its control design / Junbing Tao." Paderborn : Universitätsbibliothek, 2018. http://d-nb.info/1155236297/34.
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Drda, Václav. "Vícefázový serio-paralelní LLC rezonanční měnič." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218812.
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The project deals with the design of a switch-mode power supply (SMPS) with a medium and high power output. The power supply uses multiphase control switching. Electric energy is converted through a series parallel LLC resonant circuit to reach the maximum efficiency with a small size and cost efficiency of the designed power supply. The semiconductor switches use ZVS (Zero Voltage Switching) on the primary side and ZCS (Zero Current Switching) on the secondary side of the converter. The design of the converter is based on the knowledge of the high power output converters (types of switching, art topologies) and resonant topologies (series resonant circuit – SRC, parallel resonant circuit – PRC and series parallel circuit –SPRC). The design of the converter was done theoreticaly and tested by using simulation program. The simulation and partial tests served to build prototype the Interleaves Converter (ILLC). The function of the converter was tested in laboratory. The laboratory results have been compared with the theoretical and the simulation results.
4
Xie, Ji. "Modeling, analysis and design of fixed-frequency series-parallel resonant dc/dc converters using the extended describing function method." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0016/MQ54973.pdf.
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Chin, Yuan. "Constant-frequency parallel-resonant converter (clamped-mode)." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/104308.
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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.
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Price, Colin Franklin. "Investigation of a quasi-square parallel-resonant converter." Thesis, University of Edinburgh, 1992. http://hdl.handle.net/1842/12798.
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A converter is proposed which is based on <i>parallel-resonant</i> 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 <i>distributed power</i> power system, converting voltage from 270 V to 48 V.
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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.
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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.
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Paolucci, Jonathan David. "NOVEL CURRENT-FED BOUNDARY-MODE PARALLEL-RESONANT PUSH-PULL CONVERTER." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/112.
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The inherent difficulty in designing high voltage power supplies is often compounded by demands of high reliability, high performance, and safe functionality. A proposed high step-up ratio DC-DC converter meets the exacting requirements of applications such as uninterruptible power systems, radar, and pulsed power systems. The proposed DC-DC converter topology combines a multi-phase buck input stage with a novel self-tracking zero-voltage-switching (ZVS) resonant output stage. Traditionally, the inclusion of multiple power processing stages within a power supply topology severely degrades the overall converter efficiency. Due to the inherent high efficiency per stage, however, this effect is minimized. The self-tracking switching scheme ensures that ZVS occurs across the full range of load variation. Furthermore, the switching scheme allows significantly increased flexibility in component tolerances compared to traditional resonant converter designs. The converter also demonstrates indefinite short-circuit protection and true ZVS during transient processes. Computer simulation and hardware analysis verify the efficacy of the topology as a rugged and efficient converter.
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Vulovic, Marko. "Digital Control of a High Frequency Parallel Resonant DC-DC Converter." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/35934.
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A brief analysis of the nonresonant-coupled parallel resonant converter is performed. The converter is modeled and a reference classical analog controller is designed and simulated. Infrastructure required for digital control of the converter (including anti-aliasing filters and a modulator) is designed and a classical digital controller is designed and simulated, yielding a ~30% degradation in control bandwidth at the worst-case operating point as compared with the analog controller. Based on the strong relationship observed between low-frequency converter gain and operating point, a gain-scheduled digital controller is proposed, designed, and simulated, showing 4:1 improved worst-case control bandwidth as compared with the analog controller. A complete prototype is designed and built which experimentally validates the results of the gain-scheduled controller simulation with good correlation. The three approaches that were investigated are compared and conclusions are drawn. Suggestions for further research are presented.<br>Master of Science
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Mangat, Simmi. "A modified asymmetrical pulse-width modulated series resonant DC/DC converter." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0016/MQ47828.pdf.
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Lebel, Richard B. "Modeling and analysis of a constant power series-loaded resonant converter." Thesis, Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/5717.
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Approved for public release; distribution is unlimited.<br>Future Naval systems and ships are being designed with pulse-power loads and hybrid electrical systems. There is a demand for efficient, reliable, and durable compact power converters to bridge pulse-power systems with the electrical plants of the future. This thesis presents modeling and analysis of a constant power Series Loaded Resonant (SLR) converter. The modeling work presented was successfully implemented in Simulink and then prototyped in a small-scale application in the laboratory. The Simulink model and prototype were tested under various conditions and may be used to reduce the risk in the design of future large-scale applications.
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Bodegård, Andreas. "Design of a planar transformer for a series loaded resonant converter." Thesis, Uppsala universitet, Elektricitetslära, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-414921.
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This report presents a project that has been made to present the design of a planar transformer as a part of a series loaded resonant DC/DC converter in a power unit. The design is based on an existing transformer that is not planar and so the characteristics of the transformer is translated into a planar version. A multilayer printed circuit board (PCB) design was made to fit a chosen magnetic ferrite core that was chosen based on the magnetic characteristics of the old core. Calculations were made for the loss of both core and windings and the final results show that it is possible to design a planar transformer from a traditional transformer.
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Zhao, Xiaonan. "A High-efficiency Isolated Hybrid Series Resonant Microconverter for Photovoltaic Applications." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/78312.
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Solar energy as one type of the renewable energy becomes more and more popular which has led to increase the photovoltaic (PV) installations recently. One of the PV installations is the power conditioning system which is to convert the maximum available power output of the PV modules to the utility grid. Single-phase microinverters are commonly used to integrate the power to utility grid in modular power conditioning system. In the two-stage microinverter, each PV module is connected with a power converter which can transfer higher output power due to the tracking maximum power point (MPP) capability. However, it also has the disadvantages of lower power conversion efficiency due to the increased number of power electronics converters. The primary objective of this thesis is to develop a high-efficiency microconverter to increase the output power capability of the modular power conditioning systems.
A topology with hybrid modes of operation are proposed to achieve wide-input regulation while achieving high efficiency. Two operating modes are introduced in details. Under high-input conditions, the converter acts like a buck converter, whereas the converter behaves as a boost converter under low-input conditions. The converter operates as the series resonant converter with normal-input voltage to achieve the highest efficiency. With this topology, the converter can achieve zero-voltage switching (ZVS) and/or zero-current switching (ZCS) of the primary side MOSFETs, ZCS and/or ZVS of the secondary side MOSFETs and ZCS of output diodes under all operational conditions. The experimental results based on a 300 W prototype are given with 98.1% of peak power stage efficiency and 97.6% of weighted California Energy Commission (CEC) efficiency including all auxiliary and control power under the normal-input voltage condition.<br>Master of Science
15
Sheng, Honggang. "A High Power Density Three-level Parallel Resonant Converter for Capacitor Charging." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/37667.
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This dissertation proposes a high-power, high-frequency and high-density three-level parallel resonant converter for capacitor charging. DC-DC pulsed power converters are widely used in military and medical systems, where the power density requirement is often stringent. The primary means for reducing the power converter size has been to reduce loss for reduced cooling systems and to increase the frequency for reduced passive components. Three-level resonant converters, which combine the merits of the three-level structure and resonant converters, are an attractive topology for these applications. The three-level configuration allows for the use of lower-voltage-rating and faster devices, while the resonant converter reduces switching loss and enhances switching capability.
This dissertation begins with an analysis of the influence of variations in the structure of the resonant tank on the transformer volume, with the aim of achieving a high power density three-level DC-DC converter. As one of the most bulky and expensive components in the power converter, the different positions of the transformer within the resonant tank cause significant differences in the transformerâ s volume and the voltage and current stress on the resonant elements. While it does not change the resonant converter design or performance, the improper selection of the resonant tank structure in regard to the transformer will offset the benefits gained by increasing the switching frequency, sometimes even making the power density even worse than the power density when using a low switching frequency. A methodology based on different structural variations is proposed for a high-density design, as well as an optimized charging profile for transformer volume reduction.
The optimal charging profile cannot be perfectly achieved by a traditional output-voltage based variable switching frequency control, which either needs excess margin to guarantee ZVS, or delivers maximum power with the danger of losing ZVS. Moreover, it cannot work for widely varied input voltages. The PLL is introduced to overcome these issues. With PLL charging control, the power can be improved by 10% with a narrow frequency range.
The three-level structure in particular suffers unbalanced voltage stress in some abnormal conditions, and a fault could easily destroy the system due to minimized margin. Based on thoroughly analysis on the three-level behaviors for unbalanced voltage stress phenomena and fault conditions, a novel protection scheme based on monitoring the flying capacitor voltage is proposed for the three-level structure, as well as solutions to some abnormal conditions for unbalanced voltage stresses. A protection circuit is designed to achieve the protection scheme.
A final prototype, built with a custom-packed MOSFET module, a SiC Schottky diode, a nanocrystalline core transformer with an integrated resonant inductor, and a custom-designed oil-cooled mica capacitor, achieves a breakthrough power density of 140W/in3 far beyond the highest-end power density reported (<100 W/in3) in power converter applications.<br>Ph. D.
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Dai, Chaobo. "A non-resonantly coupled parallel resonant converter for residential renewable energy conversion." Thesis, University of Birmingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433433.
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After the review of single-phase converter topologies and detailed examination of several candidates, a non-resonantly coupled parallel resonant DCIDC converter is identified as being the most appropriate high frequency linked topology. The steady-state characteristics of the chosen converter with both variable frequency and phase shift control have been examined using state-plane analysis. These theoretical predictions are confirmed with time-domain simulation and comprehensive measurements from a 3.0 kVA prototype. The power losses resulted from real devices and components account for the discrepancies. Hybrid control has been employed for stand-alone applications. By contrast, phase-shift control only at a reduced switching frequency provides better output performance and higher conversion efficiency. Under light loads, a look-up correction table has been developed to improve the output performance further. The prototype efficiency is measured to be 94% under full load. Integral compensator and phase shift control only have been utilized for grid-connected applications. A damping resistor has been added to damp the resonant oscillation of the output filter. Similarly, a correction table is introduced under light load. An additional compensator, increased DC gains and phase margin compensation have been introduced to improve the output performance further. The impact of the grid-connected converter on the grid voltage is also examined.
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Glaser, John Stanley 1964. "Analysis and design of a constant frequency diode-clamped series resonant converter." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/278060.
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A constant frequency diode-clamped series resonant power converter (CFCSRC) is proposed as a solution to problems associated with frequency-controlled resonant converters. This converter has two resonant frequencies, and control is achieved by varying the relative time per switching cycle spent at each resonant frequency. Two zero-current-switching (ZCS) modes are examined and plotted in the output plane. Operating and mode boundaries are found and also plotted in the output plane. The output equation for the main mode is shown to be hyperbolic. Peak voltages are shown to be less than or equal to the input voltage, and peak currents are shown to be less than those of the frequency-controlled diode-clamped series resonant converter over a large operating range. A design procedure is given in the form of a design example. Data from a prototype converter is plotted with theoretical data in the output plane and good agreement with the theoretical model is obtained.
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Yanqi, Yu. "A series resonant converter for voltage equalization of series connected supercapacitor. ultracapacitor or lithium battery cells." Thesis, University of British Columbia, 2015. http://hdl.handle.net/2429/54090.
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Supercapacitors are energy storage devices with great potential in many industrial applications. Although they are not as energy dense as batteries, they have much higher power density. This unique feature enables them to be used to provide bursts of energy in electric vehicle applications. They can be connected in parallel with batteries to source and sink dynamic energy which increases the lifetime of the expensive lithium batteries.
Typically, the maximum voltage of a single supercapacitor unit is low, e.g. 2.5 V. In many applications, manufacturers need much higher voltages, e.g. 400 V, so it is necessary to connect supercapacitors in series. A series connection of supercapacitor cells can result in voltage imbalance between cells, since individual supercapacitors have different tolerances. Voltage imbalance can lead to damage of the individual supercapacitors and even the failure of the total energy storage system. Cell voltage equalization is a strategy to maintain the reliability of the supercapacitor pack.
A single series inductor-capacitor (LC) resonant tank is proposed in this thesis for the voltage equalization of series connected energy storage elements. The circuit can be used for lithium battery cells, or supercapacitors, but the focus of the work targets supercapacitors. The circuit includes two levels of source connected MOSFET switches for the connection between resonant tank converter and each supercapacitor cell. A controller arranges supercapacitor voltages in descending order and makes a decision based on whether switches associated with the corresponding supercapacitors should be operated. If the voltage difference is higher than the pre-determined allowable value, the microcontroller sends pulse width modulation signals to gate drivers which control the on-off time of the MOSFET switches.
Simulation results are presented using PSIM and demonstrate that voltage differences among supercapacitors can be removed fast. Experimental results show that the prototype of the proposed circuit can reduce a voltage deviation of 527 mV down to 10 mV in 15 minutes. The circuit is small in size, achieves a relatively short voltage equalization time and has minimal loss, therefore largely alleviating the problems inherent to existing voltage equalization converters.<br>Applied Science, Faculty of<br>Engineering, School of (Okanagan)<br>Graduate
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Hsieh, Yi-Hsun. "Accurate Small-Signal Modeling for Resonant Converters." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/100941.
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In comparison with PWM converters, resonant converters are gaining increasing popularity for cases in which efficiency and power density are at a premium. However, the lack of an accurate small-signal model has become an impediment to performance optimization. Many modeling attempts have been made to date. Besides the discrete time-domain modeling, most continuous-time modeling approaches are based on fundamental approximation, and are thus unable to provide sufficient accuracy for practical use. An equivalent circuit model was proposed by Yang, which works well for series resonant converters (SRCs) with high Q (quality factor), but which is inadequate for LLC resonant converters. Furthermore, the model is rather complicated, with system orders that are as high as five and seven for the SRC and LLC converter, respectively.
The crux of the modeling difficulty is due to the underlying assumption based on the use of a band-pass filter for the resonant tank in conjunction with a low-pass output filter, which is not the case for most practical applications. The matter is further complicated by the presence of a rectifier, which is a nonlinearity that mixes and matches the original modulation frequency. Thus, the modulation signal becomes intractable when using a frequency-domain modeling approach.
This dissertation proposes an extended describing function modeling that is based on a Fourier analysis on the continuous-time-domain waveforms. Therefore, all important contributions from harmonics are taken into account. This modeling approach is demonstrated on the frequency-controlled SRC and LLC converters. The modeling is further extended to, with great accuracy, a charge-controlled LLC converter.
In the case of frequency control, a simple third-order equivalent circuit model is provided with high accuracy up to half of the switching frequency. The simplified low-frequency model consists of a double pole and a pair of right-half-plane (RHP) zeros. The double pole, when operated at a high switching frequency, manifests the property of a well-known beat frequency between the switching frequency and the resonant frequency. As the switching frequency approaches the resonant frequency of the tank, a new pair of poles is formed, representing the interaction of the resonant tank and the output filter. The pair of RHP zeros, which contributes to additional phase delay, was not recognized in earlier modeling attempts.
In the case of charge control, a simple second-order equivalent circuit model is provided. With capacitor voltage feedback, the order of the system is reduced. Consequently, the resonant tank behaves as an equivalent current source and the tank property is characterized by a single pole. The other low-frequency pole represents the output capacitor and the load. However, the capacitor voltage feedback cannot eliminate the high-frequency poles and the RHP zeros.
These RHP zeros may be an impediment for high-bandwidth design if not properly treated. Based on the proposed model, these unwanted RHP zeros can be mitigated by either changing the resonant tank design or by proper feedback compensation. The accurate model is essential for a high-performance high-bandwidth LLC converter.<br>Doctor of Philosophy<br>For high-frequency power conversion, resonant converters are increasingly popular. However, the lack of an accurate small-signal model has become an impediment to performance optimization. The existing equivalent circuit model and its simplified circuit were based on fundamental approximation, where the resonant tank was deemed a good band-pass filter. These models work well for series resonant converters (SRCs) with high Q (quality factor), but are inadequate for LLC resonant converters.
The crux of the modeling difficulty is due to the fact that the operation of this type of resonant converter is based on the use of a band-pass filter in conjunction with a low-pass filter. The matter is further complicated by the presence of a rectifier, which is a nonlinearity that mixes and matches the original modulation frequency. Thus, the modulation signal becomes intractable when using a frequency-domain modeling approach.
This dissertation proposes an extended describing function modeling that is based on a Fourier analysis on the continuous-time-domain waveforms. Therefore, all important contributions from harmonics are taken into account. This modeling approach is demonstrated on the frequency-controlled SRC, frequency-controlled LLC converter, and charge-controlled LLC converter, and the resulting models are proven to be accurate at all frequencies.
A simple equivalent circuit model is provided that targets the frequency range below the switching frequency. This simple, accurate model is able to predict the small-signal behaviors of the LLC converter with high accuracy at half of the switching frequency.
At high modulation frequencies, the resonant converter behaves like a non-minimum phase system, which was neither recognized nor characterized before. This property can be represented by RHP zeros, and these RHP zeros may be an impediment for high-bandwidth design if not properly treated. Based on the proposed model, these unwanted RHP zeros can be mitigated by either changing the resonant tank design or by proper feedback compensation. Accurate modeling is essential for a high-performance high-bandwidth LLC converter.
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Sabaté, Juan A. "Clamped-mode fixed frequency series resonant converter: off- line application, analysis and implementation." Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/45181.
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The performance of the clamped-mode series resonant converter operating
at a fixed frequency is studied for off line applications. A new set of characteristics for the converter operating above and below resonant frequency has been
developed by including the effect of losses in the analysis.<p>
Based on the analytical results, design guidelines are established and two
prototypes were built to operate below and above resonant frequency respectively. The advantages and limitations of the two breadboards are assessed and
their major sources of loss identified.<br>Master of Science
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Reyes-Moraga, Eduardo Felipe. "Predictive control of a direct series resonant converter with active output voltage compensation." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/31263/.
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Modern high power supplies are based on resonant converters in order to use high frequency reactive elements (for reduced size) without sacrificing converter efficiency. In an effort to achieve compact high power supplies, direct power converter topologies have been considered, since these are mainly characterised by their high power density. A direct resonant converter topology combines matrix converters with conventional resonant converters. This work focused on achieving high quality input/output power and high efficiency. Thus, this thesis presents the research on the control of a direct series resonant converter. Since the resonant converter allows a sinusoidal high frequency output current to be generated, zero current switching (ZCS) was considered to reduce the power losses. Hence, since the converter is switched at every zero crossing of the output current (fixed period), model predictive control was considered. Different predictive approaches for controlling the input and output currents were developed and analysed, however, owing to the characteristics of the topology, these strategies resulted in a suboptimal control. Therefore, in order to improve the input and output qualities (reduce distortion), an output voltage compensation strategy was proposed. This compensation approach is based on adding an H-bridge converter in series between the matrix converter and the resonant tank. This converter improves the voltage applied to the resonant tank, thus, reducing the distortion at the output and, as a consequence, also the distortion at the input. The H-bridge converter utilises only a small capacitor on the dc side in comparison with conventional resonant converters and operates at a low voltage. Simulations were carried out using MATLAB/Simulink and an experimental prototype was built to validate the strategies proposed, achieving a reduction of the input current THD from 4.4% to 2.7%, a reduction of the output current distortion of approximately 40% and an analytically derived efficiency of 89.5%.
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Chen, Yu-Min, and 陳育民. "Battery Chargers with Series-Parallel Resonant Converter." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/7q585s.
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碩士<br>崑山科技大學<br>電機工程研究所<br>97<br>Due to the rapidly growing number of battery-powered equipment and operations, the technique of efficient charging methods is getting a more and more urgent. Resonant converters are very attractive in practice because they have high efficiency, small size, light weight, fast dynamic response, low component stresses, and low noise. One of the most popular resonant converters is the series-parallel resonant converter. The topology of the series-parallel resonant converter combines the advantageous properties of both the series resonant converter and the parallel resonant converter. Accordingly, a battery charger with half-bridge series-parallel resonant converter is proposed in this thesis. This resonant circuit behaves differently compared to the conventional linear-mode battery charger. There are three possible modes of operation based on the ratio of switching frequency to the resonant frequency. By controlling the switching frequency of the series-parallel resonant converter for battery chargers, the charging current can be regulated at a desired value. This thesis focuses on a comprehensive steady-state analysis and design treatment of a half-bridge series-parallel converter operating in continuous-conduction mode (CCM) and discontinuous-conduction mode (DCM) to satisfy the requirements of high efficiency battery chargers. Finally, a 12Volt and 48Ampere-hour battery is chosen as a design example for all three different operating modes and is implemented to verify the theoretical predictions.
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Klement, Kathryn. "A Series-parallel Resonant Converter for Electrochemical Wastewater Treatment." Thesis, 2009. http://hdl.handle.net/1807/25706.
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Advantages of electrochemical wastewater treatment over conventional wastewater treatment include its smaller footprint, modularity, and ability to meet increasingly stringent government regulations. A power supply that can be packaged with an electrochemical stack could make electrochemical wastewater treatment more cost-effective and scalable. For this application, the series and series-parallel resonant converters are suitable power converter candidates. With an output current specification of 100A, the series-parallel resonant converter (SPRC) is superior due to its simpler output stage. The thesis presents the design of a 500W SPRC for a wastewater treatment cell stack. A rudimentary cell model is derived experimentally. The closed loop analysis, controller design and simulation results are presented. The output voltage and current are estimated using sensed quantities extracted from the high voltage, low current primary side. Low voltage experimental results verify the operation of the power stage and voltage estimation circuitry in open loop pulsed operation.
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Cai, Shang-Jhe, and 蔡尚哲. "Battery Chargers with Series-Parallel Resonant Converter for Photovoltaic Modules." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/w887xz.
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碩士<br>崑山科技大學<br>電機工程研究所<br>96<br>Due to the price of crude oil is continuously increased, the price of raw material in the national economy and the people’s livelihood is rised. Traffic rate, charges for water and electricity, gas price and so on are also going up. Solar energy, one of renewable energies, is become the best plan for treating the continuous increasing price of crude oil. This thesis realizes a solar energy battery charger with series-parallel resonant converter. The circuit parameters are designed from the derived circuit equations. Experimental results have demonstrated the theoretical effectiveness of the proposed battery charger circuit. The practical mean charging efficiency of the developed battery charger is 89.6%.
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Hsiao, Ho-Kai, and 蕭合凱. "A Novel Single-Switch Current-Fed Series-Parallel Loaded Resonant Converter." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/24207582855704802393.
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碩士<br>崑山科技大學<br>電機工程研究所<br>98<br>The new type of single-switch current-fed series-parallel loaded resonant converter, that is addressed in this study solved the problems in high-frequency switch from traditional PWM converter and conduction loss from the voltage/ current produced by resonant power electronic converter.
Therefore, this study put soft-switching technique in use of the above mentioned resonant converter to adjust the frequency up to more than resonance frequency From resonant inductance and resonant capacitor in resonance trough by means of a frequency change-over from variable-power switch to enable the automatic switch on converter from turn-on switching to stop that made zero by the resonance at two-sides of switch current and then switch to reduce switching loss and improve the efficiency of converting.
To compare with traditional class-d resonant converter which is in need of two power switch, the converter that is addressed in this study caused from that it only need one power switch and input voltage so that it had advantage for loss down and cost down.
Eventually, base on the performance new class-e converter which is designed in accordance with the specifications of component to prove the correctness for theoretical analysis and model deduction by the experimental result and computer simulation, the experimental result is quite satisfied. The entire efficiency reaches 85% above.
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Guo, You-Ruei, and 郭祐睿. "Single-Switch Zero-Current-Switching Topology with Series-Parallel Resonant Converter." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/70503089748845205460.
Full textAbstract:
碩士<br>崑山科技大學<br>電機工程研究所<br>99<br>Because of the advantages of small circuit size, light weight, low switching loss and high efficiency, resonant converters have now been widely used in various kinds of high-frequency switching converters to replace traditional hard-switching ones. The different combinations of the capacitance and inductance in resonant tank can produce different resonant effects and patterns. Besides, a resonant converter can also achieve ZCS (Zero Current Switching) or ZVS (Zero Voltage Switching) at the time of switching, which can reduce switching losses and enhance the efficiency of converters.
Different from traditional class-D resonant converters that require two power switches, the class-E single-switch, ZCS, series-parallel resonant converter presented in this study used only a single switch to lower switching losses to significantly improve overall circuit efficiency.
In this study an class-E converter was made based on the operation principle of converters, and the results of experiment and computer simulation analysis were satisfactory. The conversion efficiency of the converter could
reach up to 92%.
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Ming-Hong, Chang, and 張明宏. "Analysis and Implementation of A Series-Parallel Resonant Converter with Postregulators." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/40574548298243694247.
Full textAbstract:
碩士<br>大同工學院<br>電機工程研究所<br>81<br>In this thesis, a half-bridge series-parallel resonant
converter with and without postregulators is investigated for
discontinuous conduction mode operation. The compre- hensive
analysis of the SPRC is presented. The SPRC is superior to the
pure series and pure parallel converters by removing their main
disadvantages and taking on the desirable characteristics. The
SPRC with a magnetic amplifier, which blocks the rising edge of
the secondary voltage, can undergo analysis Modified
topological modes and steady-state analysis are proposed.
According to the steady-state analysis, the selection of
resonant components is derived and the computer simulation is
given in the normalization system. The experiment results show
that SPRC with postregulators has good cross-regulation. A
100KHz SPRC with magamp post-regulators is designed to compare
with SPRC.
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Xu, Kai. "A SERIES-PARALLEL RESONANT TOPOLOGY AND NEW GATE DRIVE CIRCUITS FOR LOW VOLTAGE DC TO DC CONVERTER." Thesis, 2008. http://hdl.handle.net/1974/1008.
Full textAbstract:
With rapid progress in microelectronics technology, high-performance Integrated Circuits (ICs) bring huge challenge to design the power supplies. Fast loop response is required to handle the high transient current of devices. Power solution size is demanded to reduce due to the size reduction of integrated circuits. The best way to meet these harsh requirements is to increase switching frequency of power supplies. Along with the benefits of increasing switching frequency, the power supplies will suffer from high switching loss and high gate charge loss as these losses are frequency dependant losses.
This thesis investigates the best topology to minimize the switching loss. The Series-Parallel Resonant Converter (SPRC) with current-doubler is mainly analyzed for high frequency low voltage high current application. The advantages and disadvantages of SPRC with current-doubler are presented. A new adaptive synchronous rectifiers timing control scheme is also proposed. The proposed timing control scheme demonstrates it can minimize body diode conduction loss of synchronous rectifiers and therefore improve the efficiency of the converter.
This thesis also proposes two families of new resonant gate drive circuits. The circuits recover a portion of gate drive energy that is total lost in conventional gate drive circuit. In addition to reducing gate charge loss, it also reduces the switching losses of the power switches. Detail operation principle, loss analysis and design guideline of the proposed drive circuits are provided. Simulation and experimental results are also presented.<br>Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2008-01-29 22:37:09.812
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Liu, Chien-Hung, and 劉建宏. "Design and Implementation of Interleaved Resonant Converter with Series-Parallel Transformers Connection." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/03003579777400907500.
Full textAbstract:
碩士<br>國立雲林科技大學<br>電機工程系碩士班<br>100<br>This paper presents an interleaved pulse-width modulation (PWM) LLC resonant converter with series-parallel connected application. The secondary windings of isolated transformers are connected in series-parallel. Thus the leakage inductance currents at the primary sides and the diode currents at the secondary sides are forced to be balanced. Based on the resonant behavior by the output capacitance of MOSFETs and the leakage inductance of transformers, active switches can be turned on at zero voltage switching (ZVS) and recitifier diodes can be turned off at zero current switching (ZCS) during the transition interval. The benefit of the interleaved pwm scheme can reduce the input/output current ripples, decrease the current stress of all semiconductor components and minimize the electro-magnetic interference (EMI).
Finally, the simulation and measured results are presented to confirm the effectiveness of the proposed converter.
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Lee, Yao-Chou, and 李曜州. "Design of PC Power Supply Using Half Bridge LCC Series-Parallel Resonant Converter." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/26040721141831367291.
Full textAbstract:
碩士<br>逢甲大學<br>電機工程所<br>94<br>This thesis introduces all kinds of resonance converters, and explains the basic principle of the resonance converter. The circuit characteristic of half bridge LCC series-parallel resonance converter is presented. A half bridge LCC series-parallel resonant converter for PC power supply is proposed. The voltage regulation using variable frequency control is investigated for 12V, 5V and 3.3V under different load conditions. The proposed converter is carried out by simulations using IsSpice. The validity of this converter is guaranteed by the obtained results. Finally, the converter of 3.3V output voltage is established to validate the characteristics of the proposed converter.
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TU, MING-YU, and 涂明瑜. "Implementation of Full-Bridge LLC Resonant Converter with Series-Input/Parallel-Output Transformer." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/dzftvt.
Full textAbstract:
碩士<br>南臺科技大學<br>電機工程系<br>107<br>This thesis proposed a full-bridge LLC resonant converter with series-input/parallel-output transformer. Series resonant converter (SRC) is capable to achieve the converter's switches are operating in zero voltage switching (ZVS). Architecture of this proposed thesis is adopt a dual transformer, which is primary side is series connection as well as secondary side is parallel connection to obtain quite higher current. In this thesis, the converter will be detailed description in operation principle and state analysis. Otherwise, the operating range of converter will be designed which is depend on the analysis result and ensure the switches of converter are operating in ZVS to reduce the conduction loss. The dual transformer divides the output load current evenly, decrease the transformer bulk, and it will be result in high power application more easily. At last, a full-bridge LLC resonant converter with series-input/parallel-output transformer of 80 to 120 V, output voltage of 24 V and output power of 200 W are realized. The experimental results verify the feasibility of the proposed resonant converter.
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Belaguli, Vijayakumar. "Series-parallel and parallel-series resonant converters operating on the utility line - analysis, design, simulation and experimental results." Thesis, 1995. https://dspace.library.uvic.ca//handle/1828/9445.
Full textAbstract:
High performance ac-to-dc converters are required to meet the regulation standards to suit wide variety of applications. This thesis presents the steady state analysis, design and operation of high frequency (HF) transformer isolated resonant converters on the single phase utility line as a low harmonic controlled rectifier. Two resonant converter configurations of third order have been studied namely the LCC-type parallel resonant converter also popularly known as series-parallel resonant converter (SPRC) and the hybrid parallel-series resonant converter bridge (HPSRCB). These converters are operated at HF using variable frequency as well as fixed frequency control and they operate in different modes depending on the choice of switching frequency and load.
The variable frequency SPRC is operated in discontinuous current mode (DCM), to obtain low line current total harmonic distortion (T.H.D.) and high power factor (pf), without using active control. State space analysis has been presented for one of the predominant circuit modes encountered during its operation in DCM. The various design constraints for operating the resonant converter on the utility line for high pf operation have been stated for different control schemes. In addition, steady state analysis, design optimization carried out for dc-dc converter have been presented. The effect of resonant capacitor ratio on the converter performance characteristics have been studied. SPICE3 simulations and experimental results obtained from a 150 W converter are presented to verify the theory.
Continuous current mode (CCM) operation of the SPRC, and its effect on the line current T.H.D. and pf are studied. Both fixed and variable frequency control schemes have been used to control the SPRC. Complex ac circuit analysis method has been considered as the design tool to get the design curves and design of the SPRC operating on the utility line. SPICE3 simulation results for open loop operation and experimental results for both open as well as closed loop operations (active control), for two capacitance ratio's have been presented to verify the converter performance. It is shown that nearly sinusoidal line current operation at unity pf can be obtained with closed loop operation.
A HPSRCB has been proposed and operated at very high pf on the utility line as a controlled rectifier. Some of the predominant operating modes of the fixed and variable frequency HPSRCB have been identified. The steady state analysis using state space modeling presented for a dc-to-dc converter has been extended to analyze the ac-to-dc converter. Using the large signal discrete time domain model, the time variation of line current and line pf have been predicted using PROMATLAB for both fixed and variable frequency operations of HPSRCB on the utility line. SPICE3 simulation results without active control and experimental results obtained from the bread board model for both open as well as closed loop fixed and variable frequency operations have been presented to verify the theory and design performance.<br>Graduate
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CHIANG, MIN-CHENG, and 江旻整. "Current Sharing Parallel Digitally-Controlled Half-Bridge Series Resonant Converters." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/34431553719345761684.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>電子工程系<br>103<br>This thesis proposes current sharing parallel digitally-controlled half-bridge series resonant converters. The primary-side switches can be turned-on with zero-voltage switching (ZVS) to reduce the switching losses. The parallel converters system is suitable for server power supplies demanding high output currents and high flexibility. In this study, current-sharing technique is used to ensure that load current can be equally distributed. Digital control and current-sharing technique are realized by using Texas Instruments DSP chip TMS320F28035.
Two 650-W half-bridge series resonant converter prototypes with current-sharing are implemented. The output voltage is 12 V, the output current is 54 A. From experimental results, the current-sharing error can be within ±5% at full load condition and voltage regulation within 3% by the developed automatic master-slave current-sharing control. The experimental waveforms during load transient are shown to verify the performance of the studied current-sharing control.
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Chen, Chun-Hung, and 陳俊宏. "Implementation of a Novel Single-Switch Series-Parallel Loaded Resonant Converter with Zero-Voltage-Switching Approach." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/n8xfc3.
Full textAbstract:
碩士<br>崑山科技大學<br>電機工程研究所<br>101<br>A resonant converter is able to transform direct current into alternating current. The direct current runs through switch into the resonant trough which is made of inductances and capacitors, transforms into alternating current by resonant. The resonant modes and effects may be different due to the connection to loads. By choose proper parameters to enable the power switch work under high frequency and operate at zero-voltage switching (ZVS) or zero-current switching (ZCS), the converter efficiency could be improved.
Presented in this paper is a novel method of single switch series-parallel loaded resonant converter with zero-voltage switching. Instead of the traditional two switch series-parallel loaded resonant converter, the mentioned converter uses only single power switch. Therefore minimize the size and weight of the converter and reduce the loss. Also, with power switch works under high frequency environment, adjust the working cycle and frequency to achieve soft-switching reduces the loss and improves the efficiency as well.
This novel method has been performed on a 20W experiment circuit and received a high converting efficiency more than 92%. As a result, this paper presents the availability and efficiency of the converter.
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Xie, Ji. "Modeling, analysis and design of fixed frequency series-parallel resonant DC/DC converters using the extended describing function method /." 1999.
Find full text
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CAI, DONG-YI, and 蔡東宜. "Constant-Frequency parallel-resonant converter." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/09359324523573623283.
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Theron, Philippus Coenraad. "The partial series resonant converter." Thesis, 2014. http://hdl.handle.net/10210/10242.
Full textAbstract:
D.Ing. (Electrical and Electronic Engineering)<br>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.
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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<br>中正理工學院<br>電機工程研究所<br>86<br><Abstract>
To control DC/DC power conversion, usually, the switching mode
power processing circuits based on PWM (pulse-width modulation) is used.
However, the high frequency harmonic components produce high levels of
EMI (electromagnetic inter-ference). To counter this effect the VFC
(voltage frequency control) method can be used with resonant converters.
In resonant converters, high operating frequency is allowable due to the
sinusoid behavior of the capacitor voltage and current waveforms.
This paper is based on the QFT (quantitative feedback theory) to
design a robust controller for a series resonant DC/DC converter. In order
to analyze the stability, a small signal model of series resonant converters is
adopted. Simulation results illustrate that the required performances.
The VFC mode IC GP605, produced by the Gennum company to
design a 50 watts resonant converter, is used to support load variations. By
using the VFC mothod based on QFT, Through this practice the converter's
weigth and size are cut in about 50% and the EMI are reduced also.
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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<br>國立海洋大學<br>電子工程學系<br>83<br>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.
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HSU, WEI-CHIH, and 徐瑋志. "1 MHz Series-Resonant DC-DC Converter." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/27912275460932833783.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>電子工程系<br>104<br>The requirement for power density becomes higher and higher to fit the market demand of power supplies. The current trend is towards high-frequency design and operation because Gallium-nitride (GaN) transistors bring a new breakthrough in high-frequency applications. Due to the steady development of GaN technology, the device reliability is highly increasing. More device specifications are also available for various applications. This thesis aims to study the GaN transistors applied to a series resonant converter for switching loss reduction under high-frequency operation. A buck converter is added as the post-stage circuit to regulate output voltage. A planar transformer is designed to replace the conventional transformer for realizing low-profile converter. A 1 MHz/ 500 W half-bridge series resonant converter is implemented and tested. The experimental results are shown to verify theoretical analysis.
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Chu, Chen-Yen, and 朱辰諺. "Three-Level Bi-Directional Half-Bridge Series-Series Resonant Converter." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/q99c92.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>電子工程系<br>106<br>This thesis aims to develop a Three-Level Bi-Directional Half-Bridge Series-series Resonant Converter for DC micro-grid. Using dual resonant tanks, all components at the primary and secondary sides are the same. The clamped diode and capacitor with three-level circuit architecture can provide an appropriate current path to achieve zero-voltage switching on power switches. By using digital control method, both voltage across the primary side and the secondary side of the resonant tanks approach three-step square wave. In other words, the voltage stress of transformers, resonant tanks, power switches, and other components can be equalized to half of the input voltage and half of the output voltage.
The dual resonant tanks designed according to the specifications of Three-Level Bi-Directional Half-Bridge Series-series Resonant Converter, that can operate in Region-1 and Region-2, ranges up to 380V input voltage, can adjust output voltage from 300V to 400V and can output at a constant 5A current. In order to verify that this architecture can reduce voltage stress, the voltage rating of the power switches is selected only 300V. This thesis also discusses about the voltage equalization capability of the three-level architectures. A digital signal processor (DSP) chip is used as the digital controller of this converter. The measured efficiency can be up to 95% under different load conditions.
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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.
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Cho, Hsueh-Yu, and 卓學郁. "Half-bridge Series Resonant Converter with Integrated Transformer." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/fdn2x4.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>電子工程系<br>105<br>Series resonant converter usually uses a transformer which has primary side and secondary side. Leakage inductance and exciting inductance make sure that series resonant converter work correctly. This thesis applies integrated transformer which combined with three transformers. Proper core design can resist the magnet flux. It can also decrease the exciting inductance. Therefore, the transformer doesn’t need additional air gap. Lower exciting inductance value can make sure the converter reaching zero-voltage switching. Because the transformer has three center-tapped winding which is parallel-connected to secondary sides, the converter can share the secondary current. Consequently, the components can be chosen with smaller current stress. Synchronous rectification switches effectively reduce the conduction loss. This thesis uses integrated transformer to obtain lower exciting inductance and conduction loss. In addition, a plane transformer takes the place of winding transformer.
A half-bridge series resonant converter operated at 300 kHz is implemented to perform the conversion of 380 V to 12 V with rated power of 700 W. The experimental results show that the efficiency can be up to 97.5%.
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TSAI, PEI-SAN, and 蔡佩珊. "Digital Controlled Interleaved Half-Bridge Series Resonant Converter." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/48175742968165323071.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>電子工程系<br>103<br>This thesis focuses on the study and implementation of a digital controlled interleaved DC-DC converter which is composed of two paralleled half-bridge series resonant converters. The circuit specifications are 380 V input voltage/ 12 V output voltage and 54 V output current. High switching frequency and low switching losses can be achieved by the half-bridge series resonant converter circuit. The phase-shift between two gate driver signals is 90˚, thus the output current ripple can be reduced. The output capacitor size can be smaller, and the device stresses can be decreased.
Finally, a 650 W prototype circuit of an interleaved half-bridge series resonant converter was implemented. The digital control was realized by using Texas Instruments DSP chip TMS320F28035. Theoretical analyses are verified with the experimental results.
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Hsieh, Pei-Hua, and 謝佩樺. "A 1 MHz Series-Resonant DC-DC Converter." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/07381216673256676404.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>電子工程系<br>104<br>Gallium-nitride high-electron-mobility transistors (GaN HEMT) are gradually developed prosperously these years. Besides the more steady behavior, they are available in different specifications for various applications. GaN HEMTs outperform Si-transistors in many ways, and allow the circuit to be operated at higher switching frequency.
This thesis applies GaN HEMT transistors on a soft-switched series resonant converter in order to reduce its switching loss at higher switching frequency. Synchronous rectifier is utilized on the secondary side to minimize the conduction loss resulted from the high output current. In addition, a planar transformer takes the place of the usually applied winding transformer. A half-bridge series resonant converter operated at 1 MHz is implemented to perform the conversion of 380 V to 12V with rated power of 500 W. The experimental results show that the power efficiency can be as high as 93%.
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Hsu, Tzu-Yu, and 徐梓育. "250W Push-pull Series Resonant Converter with a Secondary-Side Resonant Tank." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/54848053965787211808.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>電子工程系<br>98<br>This thesis focuses on the study and implementation of a 250-W series resonant converter (SRC) with a secondary-side resonant tank. In general, a half-bridge SRC with primary-side resonant tank is adopted for the applications with high input voltages and low output voltages. When it is applied on the system with a low input voltage and high output voltage, the equivalent output load reflected from the secondary to the primary will be very small. If the quality factor is designed to be low, the characteristic impedance, which is equal to the gain of the quality factor and the reflected output load, will also be small. This causes difficulty in designing the resonant tank elements. The series resonant converter with secondary-side resonant tank can solve the design problem of resonant elements in this thesis. When the SRC with secondary-side resonant tank is suitable for low input voltage and high output voltage applications. The zero current switching can be easy to achieve because the primary switch current is high. When the SRC is operated at light load condition, its output voltage can’t be regulated well because the switching frequency is always less than the resonant frequency. This thesis aims to analyze the operating principle and derive the mathematic model for the studied series resonant converter with a secondary-side resonant tank. By using the simulation software Mathcad, the relationship between gain functions and quality factor is analyzed and discussed. A frequency modulation strategy is also used to regulate the output voltage. Finally, a laboratory prototype with 12V input, 200V output and 0.25A to 1.25A output current was built and tested to verify the feasibility of the proposed scheme, a commercial IC CM6900 with a simple auxiliary circuit was used to realize the studied control strategy. Good voltage regulation feature can be achieved according to the experimental results of the prototype circuit.
Keywords: series resonant converter with a secondary-side resonant tank, zero current switching, switching frequency, resonant frequency, quality factor.
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Lin, Chih-Jung, and 林志融. "Implementation of Parallel Resonant Half-Bridge DC-DC Converter." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/19336853258899885985.
Full textAbstract:
碩士<br>國立臺北科技大學<br>電機工程系碩士班<br>91<br>The objective of this thesis is to design and implement parallel resonant half-bridge converters to reduce the Electro-Magnetic Interference (EMI) and switching losses. The design specifications include: 155 V for input, 19 V for output, 90 W and 300 kHz for switching frequency. The load resonance is achieved by either varying the operation frequency or value of inductance of resonant tank.
The resonant converters are analyzed by using the so-called “approximation analysis” method, which takes only fundamental component into consideration. Then the circuits are designed based upon the theoretical results. The designed circuits are implemented to verify the design process. Measured results demonstrate that 88% of efficiency for variable-inductor topology and 87.6% for variable-inductor plus variable-frequency topology can be achieved by the implemented converters, confirming the design and implementation.
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Chien, Kuo-Syun, and 簡國訓. "High Frequency Time-division Multi-phase Series-series Resonant Coreless Power Converter." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/sn6xfq.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>電子工程系<br>106<br>This thesis presents a high frequency time-division multi-phase series – series power converter, and using coreless planar transformer as the main structure of transmission power that achieve the purpose of thinning size. Explain how to choose the best planar coils and optimize overall circuit efficiency. In order to reduce its switching loss at high frequency, primary side switches achieve Zero-Voltage-Switching(ZVS). Synchronous rectifier is utilized on the secondary side to minimize the conduction loss. Gallium Nitride devices are used both at primary and secondary switches to reduce the converter volume and switching losses to achieve high power density. Based on the planar transformer design, analyze the geometric shape of coils through Maxwell to obtain higher quality factor coils. Reducing copper loss of primary and secondary side, and increase the coupling coefficient to improve transmission efficiency by changing the winding configuration. Eventually, analyze the effect of coils with different turns-ratio for resonant tank current and element loss to select optimal planar transformer. According to the experimental result, the maximum output power of overall systems is 100W and the highest power transmission efficiency can be up to 87.8%, and verify effect of the coils parameter for overall loss.
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Ke, Po-Jen, and 柯柏任. "Design and Implementation of Interleaved LLC Series Resonant Converter." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/3z75g8.
Full textAbstract:
碩士<br>國立臺北科技大學<br>電機工程系研究所<br>97<br>The main theme of this thesis is to design and implement an interleaved LLC series resonant converter which is very promising for high power and current applications, e.g. power for server and personal computer. Since the output current of LLC converter is sinusoidal in each half cycle which results in the increase of both current rating of components and conduction losses of converter. Its output current is usually less than 25A.
This thesis presents an interleaved LLC series resonant converter. The presented interleaved LLC series resonant converter provides higher output power and has the characteristics of fixed phase angle and phase interleaved. Therefore, the output current ripple can be cancelled and transient response is improved.
The designed interleaved LLC series resonant converter is 480 W. It is confirmed by both theoretical analysis and experimental results that the implemented converter has several advantages, including reduction of output voltage and current ripples, output capacitor loss, output capacitance and design cost, and increase of converter efficiency.
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CHEN, CHUN-LIN, and 陳俊霖. "Series Resonant Converter with Volume Optimization and Efficiency Balance." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/63925247887804145077.
Full textAbstract:
碩士<br>國立臺灣科技大學<br>電子工程系<br>102<br>This thesis presents a series resonant converter (SRC) with volume optimization and efficiency balance. The front stage is a CCM buck converter. The output voltage of the post-stage SRC is sensed and can be regulated under full-range load conditions by adjusting the duty cycle of the buck converter. The SRC is operated around the first resonant frequency to reduce the volume of the magnetic components. Zero-voltage switching and synchronous rectification are adopted to improve the efficiency and increase the power density. In addition, a novel feedback controller is proposed in this thesis to lower the switching frequency at light loads, while raise the switching frequency at heavy loads.
A DC-DC power converter with an input voltage of 380 V, an output voltage of 12 V, and rated output current of 25 A is implemented. The switching loss at light load can be reduced with the presented control scheme. The load regulation is within 1%. Also the experimental results are provided to confirm the theoretical analysis.