Impedance control network resonant dc-dc converter for wide-range high-efficiency operation

This paper introduces a new resonant converter architecture that utilizes multiple inverters and a lossless impedance control network (ICN) to maintain zero voltage switching (ZVS) and near zero current switching (ZCS) across wide operating ranges. Hence, the ICN converter is able to operate at fixed frequency and maintain high efficiency across wide ranges in input and output voltages and output power. The ICN converter architecture enables increase in switching frequency (hence reducing size and mass) while achieving very high efficiency. A prototype 200 W, 500 kHz ICN resonant converter designed to operate over an input voltage range of 25 V to 40 V and output voltage range of 250 V to 400 V is built and tested. The prototype ICN converter achieves a peak efficiency of 97.2%, maintains greater than 96.2% full power efficiency at 250 V output voltage across the nearly 2:1 input voltage range, and maintains full power efficiency above 94.6% across its full input and output voltage range. It also maintains efficiency above 93.4% over a 10:1 output power range across its full input and output voltage range owing to the use of burst-mode control.National Science Foundation (U.S.) (Award 1307699

Design and evaluation of a reconfigurable stacked active bridge dc/dc converter for efficient wide load-range operation

This paper presents the design and implementation of a large-step-down soft-switched dc-dc converter based on the active bridge technique which overcomes some of the limitations of the conventional Dual Active Bridge (DAB) converter. The topology comprises a double stacked-bridge inverter coupled to a reconfigurable rectifier through a special three-winding leakage transformer. This particular combination of stages enable the converter to run in an additional low-power mode that greatly increases light-load efficiency by reducing core loss and extending the zero-voltage switching (ZVS) range. The converter is implemented with a single compact magnetic component, providing power combining, voltage transformation, isolation, and energy transfer inductance. A 175 kHz, 300 W, 380 V to 12 V GaN-based prototype converter achieves 95.9% efficiency at full load, a peak efficiency of 97.0%, an efficiency above 92.7% down to 10% load and an efficiency above 79.8% down to 3.3% load.National Science Foundation (U.S.) (Award Number 1307699)MIT Skoltech Initiativ

Impedance Control Network Resonant Step-Down DC-DC Converter Architecture

In this paper, we introduce a step-down resonant dc-dc converter architecture based on the newly-proposed concept of an Impedance Control Network (ICN). The ICN architecture is designed to provide zero-voltage and near-zero-current switching of the power devices, and the proposed approach further uses inverter stacking techniques to reduce the voltages of individual devices. The proposed architecture is suitable for large-step-down, wide-input-range applications such as dc-dc converters for dc distribution in data centers. We demonstrate a first-generation prototype ICN resonant dc-dc converter that can deliver 330 W from a wide input voltage range of 260 V – 410 V to an output voltage of 12 V.MIT Skoltech InitiativeMIT Energy InitiativeNational Science Foundation (U.S.) (Award 1307699)Texas Instruments Incorporated (Graduate Women's Fellowship for Leadership in Microelectronics

E-Mobility -- Advancements and Challenges

Mobile platforms cover a broad range of applications from small portable electric devices, drones, and robots to electric transportation, which influence the quality of modern life. The end-to-end energy systems of these platforms are moving toward more electrification. Despite their wide range of power ratings and diverse applications, the electrification of these systems shares several technical requirements. Electrified mobile energy systems have minimal or no access to the power grid, and thus, to achieve long operating time, ultrafast charging or charging during motion as well as advanced battery technologies are needed. Mobile platforms are space-, shape-, and weight-constrained, and therefore, their onboard energy technologies such as the power electronic converters and magnetic components must be compact and lightweight. These systems should also demonstrate improved efficiency and cost-effectiveness compared to traditional designs. This paper discusses some technical challenges that the industry currently faces moving toward more electrification of energy conversion systems in mobile platforms, herein referred to as E-Mobility, and reviews the recent advancements reported in literature

Electromagnetic Wave Theory and Applications

Contains table of contents for Section 3 and reports on seven research projects.Joint Services Electronics Program Contract DAAL03-89-C-0001National Science Foundation Contract ECS 86-20029Schlumberger- Doll ResearchU.S. Army Research Office Contract DAAL03 88-K-0057National Aeronautics and Space Administration Contract NAGW-1617U.S. Navy - Office of Naval Research Contract N00014-89-J-1107National Aeronautics and Space Administration Contract NAGW-1272National Aeronautics and Space Administration Contract 958461Simulation Technologies Contract DAAH01-87-C-0679U.S. Army Corp of Engineers Contract DACA39-87-K-0022WaveTracer, Inc.U.S. Navy - Office of Naval Research Contract N00014-89-J-1019U.S. Air Force Systems - Electronic Systems Division Contract F19628-88-K-0013Digital Equipment CorporationInternational Business Machines CorporationU.S. Department of Transportation Contract DTRS-57-88-C-0007

Variable frequency multiplier technique for high efficiency conversion over a wide operating range

This paper presents a variable frequency multiplier (VFX) technique that enables the design of converters for wide input and/or output voltage ranges while preserving high efficiency. The technique is applied to an LLC converter to demonstrate its effectiveness for converters having a wide input voltage variation such as universal input power supplies. This technique compresses the effective operating range required of a resonant converter by switching the inverter and/or the rectifier operation between processing energy at a fundamental frequency and one or more harmonic frequencies. The implemented converter operates over an input voltage range of 85-340 V, but the resonant tank and conversion ratio have only been designed for half this range; a VFX mode of the inverter is used to enhance this to the full range. The experimental results from a 50-W converter show an efficiency of 94.9%-96.6% across the entire input voltage range, demonstrating the advantage of using this technique in such applications