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At least 811 records · Page 45

Damping Selection Strategy for Maximum Energy on Wave Energy Power Converters

An optimal damping selection strategy on the power electronics in wave energy application is introduced to increase the total energy produced from the power converter in a wave energy converter (WEC) system. A damping map for maximum energy is built for the selection. The map is based on an irregular wave-towire simulation and reliability analysis on the IGBT module. From the yearly wave mission profile, the damping selection strategy is proved to provide 40% more energy than the conventional optimal power with passive damping selection in the WEC power converter.

16 TIDAL AND WAVE POWER↗

An intelligent energy router for managing behind-the-meter resources and assets

With increase in distributed energy resources (DERs) and smart loads, each energy resource and load need a separate power conversion system leading to complex coordination and interaction, reduced energy conversion efficiency, coordinating compliance to grid standards (IEEE 1547) from multiple sources, reduced security. Also, multiple vendors with legacy system designs and proprietary communications interfaces result in redundancy and increase in cost of power electronics systems. This paper presents an energy router concept for buildings applications which provides autonomous power flow between sources and loads with a novel agent-based software interface.

Chinthavali, Madhu Sudhan↗

Universal Battery Supercharger

During the course of the UBS project a dc-fast charger was developed to be used in off board high power charging stations. High efficiency is targeted to reduce the charging price for the consumer while reducing the charge time. In the meantime, the size of the converter is minimized so that it could be used in small spaces and potentially urban areas. The topology is modular, and the power level can be expanded for charging higher power vehicles like trucks and buses. During the course of this research several key technologies was developed in LESES that improve the performance of the power electronics system used in EV charger. Integrated magnetics was developed for DMCR to improve the power density as well as efficiency of the magnetic components which is one of the main bottlenecks of EV development. Triangular mode EV current conduction mode is using to perform soft switching (increase efficiency) without adding any new components to the existing topology. Passive and active damping are developed to suppress the interaction between grid and converter, stabilizing the control system. Further numerous other technical problems have been solved to pave the way for even higher performance converters in the future.

25 ENERGY STORAGE↗

Nano-Magnets and Additive Manufacturing for Electric Motors

High power density is required for application of electric motors in hybrid electric propulsion. Potential path to achieve high power density in electric motors include advanced materials, lightweight thermal management, lightweight structural concepts, high power density power electronics, and advanced manufacturing. This presentation will focus on two key technologies for achieving high power density, advanced magnets and additive manufacturing. The maximum energy product in current magnets is reaching their theoretical limits as a result of material and process improvements. Future improvements in the maximum energy product for magnets can be achieved through development of nanocomposite magnets combining the hard magnetic phase and soft magnetic phase at the nanoscale level. The presentation will provide an overview of the current state of development for nanocomposite magnets and the future path for doubling the maximum energy product. The other part of the presentation will focus on the role of additive manufacturing in fabrication of high power density electric motors. The presentation will highlight the potential opportunities for applying additive manufacturing to fabricate electric motors.

materials↗

A Novel Reconfigurable GaN Based Fully Solid-State Microwave Power Module for Communications/Radar Applications

In this paper, we present as a proof-of-concept (POC) the design, integration, and performance of a novel reconfigurable GaN based fully solid-state MPM. The module synergistically integrates diplexers, pre-amplifiers, multistage medium power amplifiers (MPAs), SPDT switches, and CW/Pulsed high power amplifiers (HPAs) with a voltage sequencer, a DC blanking controller, and a low voltage electronic power conditioner. The POC SSMPM operates at both S-band and X-band to serve multiple roles. The SSMPM can be reconfigured to deliver Psat of 39 dBm (8 W CW) at S-band, Psat of 46 dBm (40 W CW) at X-band, and Psat of >50 dBm (>100 W Pulsed) at X-band. Lastly, our link budget calculations indicate that the SSMPM with Psat = 40 W when coupled to a 10 cm X-band transmit antenna on a low Earth orbiting (900 km) satellite can close a 1 Gbps (QPSK) data downlink to a 1 m receive antenna on ground with 3 dB margin.

Simons, Rainee N.↗

X-57 Electromagnetic Interference Design, Integration, and Test Consideration

X-57 is NASA’s first all electric aircraft that utilizes existing airframe of Tecnam 2006P GA aircraft integrated with new all electric power train. The objective of the project was to deliver high performing distributed electric propulsion system while developing US industry in the area of EAP. The project was divided into three distinct flight mods, each serving as a risk reduction efforts to final mod where full distributed power train with highly modified wing structure would be tested in flight. Flight weight, efficient power electronics are enablers for distributed, electric aircraft propulsion systems, and GRC team has developed high power and highly efficient SiC based converters for both cruise and high lift systems on the aircraft. Both controller’s development efforts demonstrate a means to achieve an in-the-nacelle controller with purely passive cooling while maintaining high efficiency. This paper describes the lessons learned on design, integration, and testing challenges that X-57 faced while developing these novel technologies.

Power Train↗

EVSE Cybersecurity and Resilience

Consequence-driven Cybersecurity Analysis for Extreme Fast Charging Electric Vehicle Infrastructure Electric vehicle (EV) development and associated charging infrastructure are expected to advance rapidly. Thirty percent of all global vehicle sales may be EVs and hybrid EVs by 2025, and they will rely on increasingly sophisticated strategies for grid integration. Next-generation EV charging infrastructure is expected to include interconnected renewable resources, such as photovoltaic (PV) arrays and battery storage systems, along with grid-edge devices. Although distributed energy resources (DERs) are useful in several ways, such as peak shaving at high demand times and backup supply for added resilience, the integration of vehicle charging and DERs could create more avenues for cyberattack. Physical and/or remote access to EV charging station components, including charge ports, power electronics, controllers, and local generation (e.g., PV and energy storage) could be paths to cause power fluctuations, leading to altered operations at the charging station, escalated privileges to administrative systems, exfiltration of financial information (including personally identifiable information), and reduced grid stability. One compromised EV supply equipment component can open the door to a variety of exploitable vulnerabilities. Cloud computing and mobile application control have the potential to expand the threat surface to non-repudiation and firmware integrity challenges. Vendor clouds have access to hundreds of chargers, and if compromised, can scale the attack surface exponentially. The high power and voltage levels of xFC infrastructure (e.g., 400 kW at 1000- V DC) increase the hazards and ability to impact the grid and vehicles more than lower-power charging systems. Legacy communications systems and protocols could also put EV infrastructure at risk of cyberattacks requiring a robust patch management process. Communications networks link EVs and chargers to several stakeholders - including charging station operators, grid operators, vendors/manufacturers, and aggregators - who have both physical and network access to share information for control, monitoring, and analytics. Information in these networks that is vulnerable to compromise includes the state of charge, charging duration, payment information, electricity price, and load control. Analyzing and prioritizing these interconnections risks could help address cybersecurity related to data leakage and manipulation.

charging↗

Transient Photocurrent From High-Voltage Vertical GaN Diodes Irradiated With Electrons: Experiments and Simulations

Radiation-hard high-voltage vertical GaN p-n diodes are being developed for use in power electronics subjected to ionizing radiation. Here, we present a comparison of the measured and simulated photocurrent response of diodes exposed to ionizing irradiation with 70 keV and 20 MeV electrons at dose rates in the range of 1.4x10 7 - 5.0x10 8 rad(GaN)/s. The simulations correctly predict the trend in measured steady-state photocurrent and agree with experimental results within a factor of 2. Furthermore, simulations of the transient photocurrent response to dose rates with uniform and non-uniform ionization depth profiles uncover the physical processes involved that cannot be otherwise experimentally observed due to orders of magnitude larger RC time constant of the test circuit. The simulations were performed using an Exploratory Physics Development code developed at Sandia National Laboratories. The code offers the capability to include defect physics under more general conditions, not included in commercially available software packages, extending the applicability of the simulations to different types of radiation environments.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Spacelab's interface to payload experiments

The Spacelab Payload Standard Modular Electronics (SPSME) program has been designed to provide a standardized set of space-qualified low-power electronic modules from which an experimenter may economically implement a command and data management system. SPSME is based on the Computer Automated Measurement and Control (CAMAC) interface standards. To the system of CAMAC, SPSME adds Spacelab interface modules, a flight qualified system crate, and an efficient light-weight power supply to produce a system compatible with the Spacelab environments, the Spacelab Command and Data Management System interface, and any experiment.

Golemon, W. F.↗

First High-Gradient Results of UED/UEM SRF Gun at Cryogenic Temperatures

Benefiting from the rapid progress on RF photogun technologies in the past two decades, the development of MeV range ultrafast electron diffraction/microscopy (UED and UEM) has been identified as an enabling instrumentation. UEM or UED use low power electron beams with modest energies of a few MeV to study ultrafast phenomena in a variety of novel and exotic materials. SRF photoguns become a promising candidate to produce highly stable electrons for UEM/UED applications because of the ultrahigh shot-to-shot stability compared to room temperature RF photoguns. SRF technology was prohibitively expensive for industrial use until two recent advancements: Nb₃Sn and conduction cooling. The use of Nb₃Sn allows to operate SRF cavities at higher temperatures (4K) with low power dissipation which is within the reach of commercially available closed-cycle cryocoolers. Euclid is developing a continuous wave (CW), 1.5-cell, MeV-scale SRF conduction cooled photogun operating at 1.3 GHz. In this paper, we present first high gradient results of the gun conducted in liquid helium.

43 PARTICLE ACCELERATORS↗

Hamiltonian methods of modeling and control of AC microgrids with spinning machines and inverters

This study presents a novel approach to the modeling and control of AC microgrids that contain spinning machines, power electronic inverters and energy storage devices. The inverters in the system can adjust their frequencies and power angles very quickly, so the modeling focuses on establishing a common reference frequency and angle in the microgrid based on the spinning machines. From this dynamic model, nonlinear Hamiltonian surface shaping and power flow control method is applied and shown to stabilize. From this approach the energy flow in the system is used to show the energy storage device requirements and limitations for the system. This paper first describes the model for a single bus AC microgrid with a Hamiltonian control, then extends this model and control to a more general class of multiple bus AC microgrids. Finally, simulation results demonstrate the efficacy of the approach in stabilizing and optimization of the microgrid.

24 POWER TRANSMISSION AND DISTRIBUTION↗

High conductivity coherently strained quantum well XHEMT heterostructures on AlN substrates with delta doping

Polarization-induced two-dimensional electron gases (2DEGs) in AlN/GaN/AlN quantum well high-electron-mobility transistors on ultrawide bandgap AlN substrates offer a promising route to advance microwave and power electronics with nitride semiconductors. The electron mobility in thin GaN quantum wells embedded in AlN is limited by high internal electric field and the presence of undesired polarization-induced two-dimensional hole gases (2DHGs). To enhance the electron mobility in such heterostructures on AlN, previous efforts have resorted to thick, relaxed GaN channels with dislocations. In this work, we introduce n-type compensation δ-doping in a coherently strained single-crystal (Xtal) AlN/GaN/AlN heterostructure to counter the 2DHG formation at the GaN/AlN interface, and simultaneously lower the internal electric field in the well. This approach yields a δ-doped XHEMT structure with a high 2DEG density of ∼3.2×1013 cm−2 and a room temperature (RT) mobility of ∼855 cm2/Vs, resulting in the lowest RT sheet resistance 226.7 Ω/□ reported to date in coherently strained AlN/GaN/AlN HEMT heterostructures on the AlN platform.

Physics↗

Converter-Based Emulation of Battery Energy Storage Systems (BESS) for Grid Applications

Battery energy storage systems (BESSs) tend to be too costly, restrictive, and require high maintenance for experimental use, but power system tests often need their representation. As a solution, we propose an all-in-one, reconfigurable BESS emulation tool for grid applications that only requires one three-phase voltage-source converter. This emulator provides chemistry-specific battery behavior like previous work, but it also includes the BESS's power electronics interface and control as well as automatic frequency and voltage support functions for the attached power system. Thus, it allows simple, plug-and-play BESS emulation for grid applications. Here, this paper details the construction, verification, and use of the BESS emulator in an existing grid testbed and concludes that it provides an inexpensive, easy-to-use alternative to using real BESSs in power system experiments.

25 ENERGY STORAGE↗

Modeling and Characterization of Surface Discharges in Insulating Material for Spacers: Electrode Shape, Discharge Mode, and Revision of the Creepage Concept

In the design of MV AC and DC spacers, the predominant factors are surface and interface conditions. Design is generally carried out on specifications and standards which are based on long-term experience and lab testing. However, the diffusion of power electronics with a trend to increase electric field, switching frequency, and rise time to achieve higher power density calls for an innovative, global approach to optimized insulation system design. A new methodology, based on field simulation, discharge modeling, and partial discharge inception measurements, called the three-leg approach, can form the basis to optimize insulation design for any type of supply voltage waveform. This paper focuses on the influence of the type of electrode on the inception and phenomenology of surface discharges and, as a consequence, on the interpretation of the results used for application of the three-leg approach. It is demonstrated that a typical electrode system used for insulating material testing can generate both gas and surface discharges at the triple point, when the electrodes have a smooth profile that is used to avoid corona or flashover. Hence, testing partial discharge may not provide a straightforward indication of the surface discharge inception and, thus, be partially misleading for insulation design. Another takeover is that such analysis must benefit from PD testing tools endowed with analytics able to provide automatic identification of the type of defect generating PD, i.e., internal, surface, and corona, since design and remedy actions can be taken, and adequate insulating materials developed, only knowing the type of source generating PD. Hence, testing partial discharge may not provide a straightforward indication of surface discharge inception and, thus, be partially misleading for insulation design. In addition to the importance of the three-leg approach to favor reliable and optimized design of insulation systems, there is a clear need to have a PD testing tool endowed with analytics. It should preferably be able to provide automatic identification of the type of defect generating PD, i.e., internal, surface, and corona.

36 MATERIALS SCIENCE↗

Research on spacecraft electrical power conversion

The history of spacecraft electrical power conversion in literature, research and practice is reviewed. It is noted that the design techniques, analyses and understanding which were developed make today's contribution to power computers and communication installations. New applications which require more power, improved dynamic response, greater reliability, and lower cost are outlined. The switching mode approach in electronic power conditioning is discussed. Technical aspects of the research are summarized.

Wilson, T. G.↗

Multi-Kilowatt Power Module for High-Power Hall Thrusters

Future NASA missions will require high-performance electric propulsion systems. Hall thrusters are being developed at NASA Glenn for high-power, high-specific impulse operation. These thrusters operate at power levels up to 50 kW of power and discharge voltages in excess of 600 V. A parallel effort is being conducted to develop power electronics for these thrusters that push the technology beyond the 5kW state-of-the-art power level. A 10 kW power module was designed to produce an output of 500 V and 20 A from a nominal 100 V input. Resistive load tests revealed efficiencies in excess of 96 percent. Load current share and phase synchronization circuits were designed and tested that will allow connecting multiple modules in parallel to process higher power.

Pinero, Luis R.↗

Advanced Electrical Materials and Components Development: An Update

The primary means to develop advanced electrical components is to develop new and improved materials for magnetic components (transformers, inductors, etc.), capacitors, and semiconductor switches and diodes. This paper will give an update of the Advanced Power Electronics and Components Technology being developed by the NASA Glenn Research Center for use in future Power Management and Distribution subsystems used in space power systems for spacecraft and lunar and planetary surface power. The initial description and status of this technology program was presented two years ago at the First International Energy Conversion Engineering Conference held at Portsmouth, Virginia, August 2003. The present paper will give a brief background of the previous work reported and a summary of research performed the past several years on soft magnetic materials characterization, dielectric materials and capacitor developments, high quality silicon carbide atomically smooth substrates, and SiC static and dynamic device characterization under elevated temperature conditions. The rationale for and the benefits of developing advanced electrical materials and components for the PMAD subsystem and also for the total power system will also be briefly discussed.

Schwarze, Gene E.↗

Silicon Carbide (SiC) Power Processing Unit (PPU) for Hall Effect Thrusters

Arkansas Power Electronics International (APEI), Inc., is developing a high-efficiency, radiation-hardened 3.8-kW SiC power supply for the PPU of Hall effect thrusters. This project specifically targets the design of a PPU for the high-voltage Hall accelerator (HiVHAC) thruster, with target specifications of 80- to 160-V input, 200- to 700-V/5A output, efficiency greater than 96 percent, and peak power density in excess of 2.5 kW/kg. The PPU under development uses SiC junction field-effect transistor power switches, components that APEI, Inc., has irradiated under total ionizing dose conditions to greater than 3 MRad with little to no change in device performance.

Reese, Bradley↗