A5043348919- Advanced DC-DC Converters
- Multilevel Inverters and Converters
- Silicon Carbide Semiconductor Technologies
- Microgrid Control and Optimization
- Wireless Power Transfer Systems
- Advanced Battery Technologies Research
- Photovoltaic System Optimization Techniques
- solar cell performance optimization
- Electromagnetic Compatibility and Noise Suppression
- Low-power high-performance VLSI design
- Semiconductor materials and devices
- HVDC Systems and Fault Protection
- Innovative Energy Harvesting Technologies
- GaN-based semiconductor devices and materials
- Analog and Mixed-Signal Circuit Design
- Energy Harvesting in Wireless Networks
- Solar Thermal and Photovoltaic Systems
- Advancements in Battery Materials
- Parallel Computing and Optimization Techniques
- Thermal Radiation and Cooling Technologies
- Thermal properties of materials
- 3D IC and TSV technologies
- Heat Transfer and Optimization
- Induction Heating and Inverter Technology
- Interconnection Networks and Systems
University of California, Berkeley
2018-2025
Massachusetts Institute of Technology
2007-2024
Rose–Hulman Institute of Technology
2024
Power Standards Lab (United States)
2021
National Taiwan University of Science and Technology
2020
University of Illinois Urbana-Champaign
2012-2019
University of California, San Diego
2018
University of Illinois System
2017
Sandia National Laboratories California
2017
Sandia National Laboratories
2016
Abstract Ultrawide‐bandgap (UWBG) semiconductors, with bandgaps significantly wider than the 3.4 eV of GaN, represent an exciting and challenging new area research in semiconductor materials, physics, devices, applications. Because many figures‐of‐merit for device performance scale nonlinearly bandgap, these semiconductors have long been known to compelling potential advantages over their narrower‐bandgap cousins high‐power RF electronics, as well deep‐UV optoelectronics, quantum...
THIS paper explores opportunities and challenges in power conversion the VHF frequency range of 30-300 MHz. The scaling magnetic component size with is investigated, it shown that substantial miniaturization possible increased frequencies even considering material heat transfer limitations. Likewise, dramatic increases are existing emerging semiconductor devices, but necessitate circuit designs either compensate for or utilize device parasitics. We outline characteristics topologies control...
This paper explores the benefits of distributed power electronics in solar photovoltaic applications through use submodule integrated maximum point trackers (MPPT). We propose a system architecture that provides substantial increase captured energy during partial shading conditions, while at same time enabling significant overall cost reductions. is achieved direct integration miniature MPPT converters into existing junction boxes. describe design and implementation high-efficiency (>;98%)...
High-efficiency and compact single-phase inverters are desirable in many applications such as solar energy harvesting electric vehicle chargers. This paper presents a 2-kW, 60-Hz, 450-VDC-to-240-VAC power inverter, designed tested subject to the specifications of Google/IEEE Little Box Challenge. The inverter features seven-level flying capacitor multilevel converter, with low-voltage GaN switches operating at 120 kHz. also includes an active buffer for twice-line-frequency pulsation...
Traditionally, switched-capacitor (SC) converters have suffered from high transient currents, which limit both the efficiency and power density of such converters. Soft-charging operation can be employed to eliminate current transients greatly improve SC In this approach, a second-stage magnetic converter is cascaded with stage act as controlled load. Another approach use resonant zero-current switching. This paper shows that soft-charging operations are closely related, technique will...
This paper presents a resonant boost topology suitable for very-high-frequency (VHF, 30-300 MHz) DC-DC power conversion. The proposed design features low device voltage stress, high efficiency over wide load range, and excellent transient performance. Two experimental prototypes have been built evaluated. One is 110-MHz, 23-W converter that uses high-performance RF lateral DMOSFET. achieves higher than 87% at nominal input output voltages, maintains good down to 5% of full load. second...
This paper presents a two-stage architecture that combines large step-down switched-capacitor transformation stage with high-bandwidth magnetic regulation stage. The proposed design is particularly well-suited for an integrated CMOS process, as it makes use of the available on-die device characteristics. In such presented offers high efficiency, power density, and high- bandwidth regulation. We show by merging in specific manner, further performance improvements can be attained. When...
The challenging problem of ultra-high-energy-density, high-efficiency, and small-scale portable power generation is addressed here using a distinctive thermophotovoltaic energy conversion mechanism chip-based system design, which we name the microthermophotovoltaic (μTPV) generator. approach predicted to be capable up 32% efficient heat-to-electricity within millimeter-scale form factor. Although considerable technological barriers need overcome reach full performance, have performed robust...
In this paper, we introduce a merged two-stage dc-dc power converter for low-voltage delivery. By separating the transformation and regulation function of into two stages, both large voltage high switching frequency can be achieved. We show how switched-capacitor stage operate under soft charging conditions by suitable control integration (merging) stages. This mode operation enables improved efficiency and/or density in stage. A 5-to-1 V, 0.8 W integrated has been developed 180 nm CMOS. The...
A high-efficiency, high-power-density buffer architecture is proposed for power pulsation decoupling in conversion between dc and single-phase ac. We present an active solution that yields improved efficiency reduced circuit complexity compared to existing solutions. In the architecture, main energy storage capacitor connected series with converter across bus. The series-stacked blocks majority of bus voltage reduce stress on converter, such fast, low-voltage transistors can be employed...
This paper presents the theory and implementation of a distributed algorithm for controlling differential power processing converters in photovoltaic (PV) applications. achieves true maximum point tracking series-connected PV submodules by relying only on local voltage measurements neighbor-to-neighbor communication between converters. Compared to previous solutions, proposed reduced number perturbations at each step potentially faster without adding extra hardware; all these features make...
Switched-capacitor (SC) converters are gaining popularity due to their high power density and suitability for on-chip integration. Soft-charging resonant techniques can be used eliminate the current transient during switching instances, improve efficiency of SC converters. In this paper, we propose a split-phase control scheme that enables Dickson converter achieve complete soft-charging (or resonant) operation, which is not possible using conventional two-phase control. An analytical method...
This paper investigates the use of multilevel conversion in dc-dc applications that require a large voltage ratio. A quantitative method can serve as guide to compare and design topologies for ratio is presented. The proposed keeps conduction loss switching constant across different converters employs passive component volume single performance metric. As examples, flying capacitor hybrid switched-capacitor (SC) are compared conventional two-level buck converters, shown analytically have...
Differential power processing (DPP) is a electronics system architecture that configures dc-dc converters in parallel with the PV string to improve its yield. The nature of DPP brings number benefits, such as low converter rating and losses, all which make especially suitable for submodule-level maximum point tracking (MPPT). Meanwhile, microinverters typically perform only module-level MPPT do not address losses due uncompensated submodule mismatch. In this paper, we introduce into...
Resonant switched-capacitor (ReSC) converters have efficient utilization of both active and passive components, hold the potential to achieve higher efficiency power density than conventional (SC) magnetic-based converters. This article presents a new hybrid/resonant SC converter topology, comprising two cascaded 2-to-1 ReSC converters, address high-conversion-ratio applications. The proposed resonant has simple structure operation principle can one best overall metrics among popular...
Multilevel inverters such as the flying capacitor multilevel inverter (FCML) hold large potential benefit in applications where size and weight of is constrained. This article presents design implementation an module that incorporates two individual nine-level FCML single-phase interleaved design. Each utilizes GaN field-effect transistors (FETs) switching at 100 kHz for effective inductor ripple frequency 800 kHz. The features innovative dual-sided integrated cell layout, which decreases...
Demand for enhanced cooling technologies within various commercial and consumer applications has increased in recent decades due to electronic devices becoming more energy dense. This study demonstrates jumping-droplet based electric-field-enhanced (EFE) condensation as a potential method achieve active hot spot devices. To test the viability of EFE condensation, we developed an experimental setup remove heat via droplet evaporation from single multiple high power gallium nitride (GaN)...
High efficiency and compact single phase inverters are desirable in many applications such as solar energy harvesting household appliances. This paper presents a 2 kW, 60 Hz, 450 VDC to 240 VRMS power inverter, designed tested subject the specifications of Google/IEEE Little Box Challenge. The inverter features 7-level flying capacitor multilevel converter, with low-voltage GaN switches operating at 120 kHz, highest switching frequency date this level. also includes an active buffer for...
One of the challenges utilizing flying capacitor multi-level (FCML) converters is balancing. Poorly balanced capacitors increase switch voltage stress, which detrimental to performance and device rating requirements. Previously, valley current detection was shown as a potential method balance capacitors, but suffers from poor balancing at light load. Here, we investigate load conditions that lead propose new method, constant effective duty cycle (CEDC) compensation, provides active for full...
Capacitor voltage natural balancing is an attractive feature of flying capacitor multilevel (FCML) converters. However, with the commonly used phase-shifted pulsewidth modulation, voltages still can deviate, and active often required. Although mechanism its dynamics have been extensively studied in existing literature, some sources that are responsible for imbalance engineering practice unclear. This article experimentally investigates origins practical implementations such It presents...
Hybrid and resonant switched-capacitor (SC) convertersenable efficient utilization of both active passive components, have the potential to achieve higher efficiency power density than conventional SC magnetic-based converters. One or more added inductors offer an additional degree freedom in design space. It is great interest understand tradeoffsbetween capacitor inductor size volume allocation. In this article, we analyze reactive energy processed by components use it calculate total...
More energy-efficient and power-dense solutions to 48 V point-of-load (PoL) power conversion are required for modern future data center delivery. This paper proposes a Dickson-squared hybrid switched-capacitor (SC) con-verter direct V-to-PoL with high efficiency density. The proposed topology comprises 9-to-1 SC stage that can be viewed as two 3-to-1 Dickson converters combined together nine-phase interleaved buck stage. achieve complete soft-charging operation simple control, ensure...