Optimum design and novel control techniques for isolated, resonant and quasi-resonant, DCDC converters Escudero Rodríguez, Manuel Morales Santos, Diego Pedro Rodríguez Santiago, Noel Universidad de Granada. Programa de Doctorado en Tecnologías de la Información y la Comunicación Técnicas de control Control techniques Convertidores DCDC DCDC converters Resonant The power supplies or power converters are required in many applications to convert between the AC of the distribution grid to AC or DC at different voltage and current levels required by the electric loads. Each application may include different conversion steps and at different voltage levels. In every conversion step part of the energy is lost and dissipated in the form of unwanted heat. The conversion efficiency in every step is the result of dividing the utilized output power by the total input power in the converter. The total efficiency of the system is the result of multiplying the individual efficiencies of the stages, and will always be necessarily lower than the minimum of the individual efficiencies in the conversion chain. Traditional linear power supplies have been extensively replaced by the more efficient and smaller Switched Mode Power Supplies (SMPS). SMPS makes use of semiconductor switches commutating at a relatively high frequency and reactive circuit elements (inductors and capacitors) to perform the power conversion. The semiconductor switches in SMPS alternate between their on state, where their voltage drop is minimal, and their off state, where they don’t conduct current. However, during the switches turn-on transition and turn-off transition, there is certain overlap of voltage and current which causes switching losses. For the currently available semiconductor power switching devices the resonant and quasi-resonant converters are the most attractive options for achieving high efficiency, high power density or a combination of both at a reasonable cost. The key advantage of the resonant and quasi-resonant converters is the reduction of the switching losses. The switching losses can be reduced achieving Zero Voltage Switching (ZVS) for the turn-on transition and Zero Current Switching (ZCS) for the turn-off transition. Among the isolated, resonant and quasi-resonant DCDC converter topologies, the most common ones in medium- high power and high-voltage applications are the series-parallel resonant converter (LLC), the Phase Shifted Full Bridge (PSFB) and the Dual Active Bridge (DAB) due to their simplicity and high efficiencies. Among those topologies each one has its own advantages and disadvantages, which makes each of them best suited for different applications, power and voltage ranges. This thesis is focused in the study of the LLC and the PSFB. Both of this topologies are very promising and well suited for any of the available power switch semiconductor technologies in the market, and more specifically for Si Super Junction (SJ) MOSFETs, which are the most mature devices and the most competitive in cost currently and in the foreseeable future. The general objective of this thesis is the optimization, improved reliability and functionality of the LLC and the PSFB converters maintaining as much as possible the simplicity of the standard circuit configuration. Therefore, this thesis comprises the design and construction of several DCDC converters with similar specifications and similar magnetic structures to study the achievable performance of the two main topologies objective of this work: LLC and PSFB. More specifically, the fundamental research objectives of this thesis include: The development of very high-efficiency DCDC converters for server applications, including the design optimization of quasi-resonant converters experimentally demonstrated with a 1.4 kW PSFB converter from 400 V to 12 V. The development of very high-efficiency DCDC converters for telecommunitation applications, including the design optimization of quasi-resonant converters, experimentally demonstrated with a 3.3 kW PSFB converter from 380 V to 54.5 V, and the design optimization of resonant converters, experimentally demostrated with a 3.3 kW half-bridge LLC converter from 400 V to 52 V. The development of bidirectional DCDC converters for Electrical Energy Storage (EES) applications, including the bidirectional operation of traditionally considered non-bidirectional PSFB converters, experimentally demonstrated with a 3.3 kW bidirectional PSFB from 380 V to 54 V and from 50 V to 400 V. The integration of a very high-efficiency DCDC converter in a complete two-stage off-line Power Supply Unit (PSU) for server applications, experimentally demonstrated with a 3 kW totem-pole ACDC converter followed by a 3 kW half-bridge LLC DCDC converter from 400 V to 50 V. Once the objectives have been outlined and after the previous brief theoretical background, in the following we summarize the several contributions of this thesis together with the most relevant results obtained and the conclusions that could be derived from them. 2021-11-26T07:52:43Z 2021-11-26T07:52:43Z 2021 2021-11-19 info:eu-repo/semantics/doctoralThesis Escudero Rodríguez, Manuel. Optimum design and novel control techniques for isolated, resonant and quasi-resonant, DCDC converters. Granada: Universidad de Granada, 2021. [http://hdl.handle.net/10481/71760] 978-84-1117-142-7 http://hdl.handle.net/10481/71760 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ info:eu-repo/semantics/openAccess Atribución-NoComercial-SinDerivadas 3.0 España Universidad de Granada