Results for “all-electric” — Page 7

NASA NTRSDate not supplied

Aviary: Open-Source Software Tool for Optimizing Next-Generation Aircraft Designs

Existing aircraft design tools are limited in their ability to provide meaningful trends for hybrid-electric & all-electric aircraft. Aviary is an open-source software tool that modernizes legacy design tools and enables multidisciplinary analysis and optimization of unconventional vehicles like X-66A. Aviary has the potential to revolutionize aircraft analysis by making aircraft conceptual designs more efficient.

Jennifer Gratz↗

NASA NTRS2024

X-57 Maxwell High Lift Motor Controller Electromagnetic Interference Test Results

During research and development for NASA’s X-57 Maxwell all-electric aircraft project, the efficiency and power density requirements of its electric propulsion subsystem components were met, but aspects of integrating its powertrain subsystems proved problematic. Electromagnetic interference (EMI) from the cruise motor controller (CMC) was a significant challenge for the project. This problem was exacerbated by the lack of EMI requirements imposed on subsystem powertrain components. This report presents the results of EMI testing of the X-57 high lift motor controller (HLMC) at the NASA Glenn Research Center’s EMI Laboratory. For reference, the conducted emissions are compared to DO–160G and MIL–STD–61G conducted emissions limits. After the EMI test, mitigation of the conducted emissions using lightweight EMI chokes produced at NASA Glenn was evaluated using the Fast Fourier Transform (FFT) capability of an oscilloscope in the hardware development laboratory. This process can contribute to the rapid prototyping of electric powertrain components and EMI filters and improve the likelihood of successful EMI qualification at the component and system levels.

Silicon carbide↗

NASA NTRSDate not supplied

X-57 Flight Systems Integration Path

The foundation for a safe and successful flight test of the National Aeronautics and Space Administration (NASA) X-57 Maxwell all-electric experimental airplane, or any X-Plane, is comprehensive system testing on the ground. This test campaign includes verification and validation (V&V) that the integrated system operates as designed and expected, as well as understanding how the system reacts and responds to failures that can occur during flight by performing failure modes and effects testing (FMET). The aircraft should be in the final flight configuration for these test activities because any modifications, even those that appear insignificant, could affect test outcomes. Although the plan was to perform V&V and FMET testing once the airplane was in the flight configuration, due to multiple component redesigns, concurrent software development, and other problems with on-aircraft testing, the X-57 Maxwell never made it into a full-flight configuration. As a result, a build-up approach was followed to test software and hardware as they became ready in order to continue making progress wherever possible. Using this approach revealed problems with the hardware and software faster than waiting for a full-flight configuration, allowing solutions to be found more quickly and in parallel with other project tasks. Other than unloaded motor testing in a lab setting, the only other test setup was on the airplane itself. On-aircraft testing was preferrable in order to test things as close to a flight configuration as possible but was time consuming due to the requirements for testing on the airplane. To overcome some of the on-aircraft barriers, off-aircraft test configurations, such as the Systems Integration Laboratory (SIL) and hardware-in-the-loop (HIL) setups, were used, but each of these setups had limitations to be considered. As a result, solutions found in the SIL or HIL configurations did not always work as expected on the airplane, resulting in an iterative process between on- and off-aircraft testing to find the final solution. Having a dedicated test platform such as an iron bird that closely represents the aircraft - without flight hardware - would have been the most effective off-aircraft test setup, which could have allowed the project to save time and money and potentially reach flight. This paper will highlight the V&V and FMET considerations and testing prerequisites, the build-up approaches to both software and system testing, the benefits and drawbacks to different test configurations, as well as battery testing and operations.

Kassidy M. Mclaughlin↗

NASA NTRSDate not supplied

NASA's X-57 High Lift Motor Controller: Detailed Design, Test Results, and Outcomes

NASA's X-57 all-electric aircraft was a research project aimed at investigating lightweight and efficient electric propulsion components. The general approach was to utilize a distributed electric propulsion (DEP) design. An essential component of this design was the High Lift Motor Controller (HLMC), a motor drive which provided power to the High Lift Motors (HLMs) and High Lift Propellers (HLPs) responsible for providing additional thrust for take-off and landing. This paper presents the detailed design, test results, and outcomes from the development of the HLMC, a 14 kW, 1kg, 98.3% efficient, outer mold line (OML) cooled, silicon carbide (SiC) MOSFET-based inverter and controller.

Electric Aircraft↗

NASA NTRSDate not supplied

Development of the X-57 Mod III/IV Piloted Simulator and Discussion of the Resultant Flighting Qualities Predictions

The all-electric X-57 Mod III aircraft was designed to demonstrate wingtip propulsion drag reduction benefits on a high-aspect-ratio wing. The X-57 Mod IV aircraft was designed to expand on the Mod III version and demonstrate the benefits of distributed electric propulsion. This paper discusses the development of theall-electricX-57 Mod III and Mod IV fixed-base pilot-in-the-loop nonlinear simulator. The paper describes the model development and the simulator cockpit construction for uses such as flight training and flying qualities analysis. Results from a stability and flying qualities analysis for both Mod III and Mod IV are presented. These results predict that both Mod III and Mod IV are stable throughout their flight envelopes. Mod III is predicted to have satisfactory flying qualities while Mod IV is predicted to have areas of adequate flying qualities.

Ryan Wallace↗

NASA NTRSDate not supplied

Thin-Film Embedded Sensors for Battery Health Monitoring

Hybrid or all-electric aircraft are being developed as the next generation of aircraft to both allow new forms of aviation and decrease environmental impact. Since these types of aircraft are based on high-capacity battery technology, safe operation of these batteries becomes increasingly important. In particular, the potential for battery failure due to uncontrolled chemical reactions resulting in thermal runaway, catastrophic failure, and battery fires must be addressed in order for such battery technology to have the level of safety needed for standard aviation implementation. Efforts to ensure battery safety often involve engineering solutions that seek to contain rather than prevent such events by early detection. Such approaches increase the system weight and decrease the power per unit mass provided by the battery system. Existing methods for measuring battery parameters to determine the battery state-of-health are limited. These methods include electrical measurements of the cell current and/or voltage output as well as temperature measurements taken externally on the cell surface. Such external temperature measurements are limited in their ability to provide early warning of impending battery failure. In response, an effort to develop sensors operating internal to battery for health monitoring has been ongoing in the NASA Sensor-based Prognostics to Avoid Runaway Reactions & Catastrophic Ignition (SPARRCI) project. The basic approach associated with this sensor work is the deposition of thin film sensors on the battery separator located between the anode and cathode of the battery. These thin film sensors are then monitored to determine changes in battery parameters and health. Microfabrication techniques are employed to minimize the overall impact of the sensors on battery operation through the implementation of sensors with minimal size, weight, and power consumption. The thickness of the films, which are fabricated through physical vapor deposition (sputtering), are on the order of thousands of angstroms and can have minimal surface area. Thin film sensors for system health management have been implemented for a many decades on complex components for aerospace applications. However, the application of thin films of this type on a battery separator for internal battery monitoring applications has not previously been demonstrated to our knowledge. This paper describes the development of sensors for the internal battery monitoring through the use of thin film sensor technology. Thin metal films were successfully deposited on a battery separator polymer material with good adherence and electrical continuity. Multiple types of sensors have been deposited, as well as lead connections from the sensor to the edge of the separator material. The ability of these thin film sensors immersed in electrolyte to perform multiple types of battery parameter measurements has been demonstrated. For example, a multiparameter sensor system measured multiple properties simultaneously inside of a pouch cell over a wide temperature range. Further, real time measurement of interior temperature changes in a battery pouch cell with an integrated interior temperature sensor was demonstrated. These changes include detecting a fault in the battery (shorting) in situ with rapid response time (less than a minute) corresponding to a more limited response by a temperature sensor mounted externally. Other aspects of monitoring battery health were also explored, such as real-time measurement of simulated dendrite growth/metal deposition by sensor on separator material demonstrated. Future efforts will include improvements in the durability of the sensor structure to allow introduction of the approach into standard battery fabrication techniques. Overall, this work is a step forward in providing a method to prevent catastrophic battery failures and provide a foundation for safer, lighter, and higher energy batteries for the electric aircraft industry.

thin film battery health↗

NASA NTRSDate not supplied

Refined Analysis of CO2 Emissions in Urban Air Mobility Networks

In this study, we examine the environmental impact of Urban Air Mobility (UAM) operations as measured via carbon dioxide (CO2) emissions by leveraging a computational model from previous studies that has been refined and expanded. Several scenarios are examined in which total transportation emissions for a representative day in a metro area are distributed differently among vehicle types and transportation modes. Specifically, we investigate the use of electric air vehicles in a UAM network; the increasing presence of electric ground vehicles for ground transportation; the impacts from implementing ridesharing in the UAM mode; and the effects of varying the electricity grid emissions. Results for a case study in the Chicago, IL metro area indicate that incorporating electric ground vehicles and UAM ridesharing can both lead to reduced CO2 emissions. These preliminary results indicate that carbon emissions from a UAM system leveraging ridesharing and all-electric aircraft may not be a practical operational limit on UAM, though further improvements to the modeling are warranted.

advanced air mobility↗

NASA NTRS2024

NASA's X-57 High Lift Motor Controller: Detailed Design, Test Results, and Outcomes

NASA's X-57 all-electric aircraft was a research project aimed at investigating lightweight and efficient electric propulsion components. The general approach was to utilize a distributed electric propulsion (DEP) design. An essential component of this design was the High Lift Motor Controller (HLMC), a motor drive which provided power to the High Lift Motors (HLMs) and High Lift Propellers (HLPs) responsible for providing additional thrust for take-off and landing. This paper presents the detailed design, test results, and outcomes from the development of the HLMC, a 14 kW, 1kg, 98.3% efficient, outer mold line (OML) cooled, silicon carbide (SiC) MOSFET-based inverter and controller.

Electric Aircraft↗

NASA NTRSDate not supplied

Refined Analysis of CO2 Emissions in Urban Air Mobility Networks

In this study, we examine the environmental impact of Urban Air Mobility (UAM) operations as measured via carbon dioxide (CO2) emissions by leveraging a computational model from previous studies that has been refined and expanded. Several scenarios are examined in which total transportation emissions for a representative day in a metro area are distributed differently among vehicle types and transportation modes. Specifically, we investigate the use of electric air vehicles in a UAM network; the increasing presence of electric ground vehicles for ground transportation; the impacts from implementing ridesharing in the UAM mode; and the effects of varying the electricity grid emissions. Results for a case study in the Chicago, IL metro area indicate that incorporating electric ground vehicles and UAM ridesharing can both lead to reduced CO2 emissions. These preliminary results indicate that carbon emissions from a UAM system leveraging ridesharing and all-electric aircraft may not be a practical operational limit on UAM, though further improvements to the modeling are warranted.

advanced air mobility↗

NASA NTRSDate not supplied

X-57 Flight Systems Integration Path

The foundation for a safe and successful flight test of the National Aeronautics and Space Administration (NASA) X-57 Maxwell all-electric experimental airplane, or any X-Plane, is comprehensive system testing on the ground. This test campaign includes verification and validation (V&V) that the integrated system operates as designed and expected, as well as understanding how the system reacts and responds to failures that can occur during flight by performing failure modes and effects testing (FMET). The aircraft should be in the final flight configuration for these test activities because any modifications, even those that appear insignificant, could affect test outcomes. Although the plan was to perform V&V and FMET testing once the airplane was in the flight configuration, due to multiple component redesigns, concurrent software development, and other problems with on-aircraft testing, the X-57 Maxwell never made it into a full-flight configuration. As a result, a build-up approach was followed to test software and hardware as they became ready in order to continue making progress wherever possible. Using this approach revealed problems with the hardware and software faster than waiting for a full-flight configuration, allowing solutions to be found more quickly and in parallel with other project tasks. Other than unloaded motor testing in a lab setting, the only other test setup was on the airplane itself. On-aircraft testing was preferrable in order to test things as close to a flight configuration as possible but was time consuming due to the requirements for testing on the airplane. To overcome some of the on-aircraft barriers, off-aircraft test configurations, such as the Systems Integration Laboratory (SIL) and hardware-in-the-loop (HIL) setups, were used, but each of these setups had limitations to be considered. As a result, solutions found in the SIL or HIL configurations did not always work as expected on the airplane, resulting in an iterative process between on- and off-aircraft testing to find the final solution. Having a dedicated test platform such as an iron bird that closely represents the aircraft - without flight hardware - would have been the most effective off-aircraft test setup, which could have allowed the project to save time and money and potentially reach flight. This paper will highlight the V&V and FMET considerations and testing prerequisites, the build-up approaches to both software and system testing, the benefits and drawbacks to different test configurations, as well as battery testing and operations.

Kassidy McLaughlin↗

NASA NTRSDate not supplied

X-57 Mod III Wing Ground Vibration Test

The X-57 “Maxwell” all-electric experimental aircraft was an electric propulsion demonstrator developed by the National Aeronautics and Space Administration to inform airworthiness standards for electrified aircraft. The development of the X-57 aircraft was separated into configuration modifications culminating in a distributed electric propulsion flight demonstrator named Modification IV (a.k.a., Mod IV). One of these configurations, the X-57 Mod III aircraft, involved flight-testing of a long, slender, high-aspect-ratio wing with two electric motors located at the wingtips. The X-57 Mod III wing ground vibration test was performed in the Flight Loads Laboratory at the National Aeronautics and Space Administration Armstrong Flight Research Center to measure the structural dynamics properties of the newly developed wing, and to confirm airworthiness of the Mod III/IV aircraft. This paper describes the testing performed to acquire the modal data and the subsequent results from the test.

Samson Truong↗

NASA NTRSDate not supplied

Solid-State Architecture Batteries for Enhanced Rechargeability and Safety (SABERS) Beyond Li-Ion: Technology to Enable Next-Generation Sustainable Electric

All-electric vertical take-off and landing vehicles (eVTOL) for urban air mobility (UAM) concepts face numerous challenging technical barriers before their introduction into the consumer marketplace. The primary barrier to overcome is developing an energy storage system that meets rigorous aerospace safety and performance criteria. The performance metrics for eVTOL vehicles are at least two times greater than those of electric ground vehicles. Furthermore, inherently non-flammable batteries are essential for the safe operation of commercial electric aero vehicles. The SABERS concept proposes a battery that meets the critical performance criteria by developing a solid-state architecture battery utilizing a high-capacity sulfur-selenium cathode and lithium metal anode. The combination of sulfur and selenium offers a balanced energy-to-power density ratio, which can be tailored to the specific application by altering the stoichiometric ratios of sulfur to selenium. This hybrid cathode will be developed using NASA-patented holey graphene technology as a highly conductive, ultra-lightweight electrode scaffold. A solid-state electrolyte will be used as a safe, non-flammable replacement for the highly flammable liquid organic electrolytes currently in SOA lithium-ion batteries. This solid-state lithium-sulfur/selenium cell will be designed in a serial stacking configuration to enable the dense packaging of the battery cells. The serial stacking configuration is termed a bipolar stack, which has the advantages of reducing overall cell weight, simplifying the interfaced connections for the cell, and minimizing the cooling requirements. Lastly, the optimization of battery components will occur through a robust and rigorous combination of various computational modeling techniques covering multiple length scales. The expected result will be a fully solid-state battery with operational temperatures up to 150°C, providing the required energy density, discharge rates, and inherent safety to meet the strict aerospace mission performance criteria. The SABERS team employed novel materials development, computational modeling, and design-of-experiments (DOE) optimization studies in their research. This presentation will show the results of these studies and demonstrate a feasible path for solid-state cells with a specific energy greater than 400 Wh/kg to enable electric aircraft.

Computational Modeling↗

NASA NTRSDate not supplied

High-Fidelity Aeropropulsive Optimization of a Mail-Slot Distributed Electric Propulsion System for the SUSAN Electrofan

Hybrid- and all-electric aircraft concepts use electric motors for power rather than a conventional jet engine. Electric propulsors open the door to new ways to synergistically integrate the propulsion system with the airframe. For example, many small electric propulsors can be distributed along the wing to increase the effective bypass ratio for better overall efficiency. Furthermore, these propulsors can be attached to the wing surface for boundary layer ingestion(BLI) to further the efficiency gains. However, these novel methods of aeropropulsive integration also create challenges such as nonuniform inflow and complex nacelle geometries. Here we use gradient-based aerodynamic shape optimization to address the design challenges of the wing-mounted distributed electric propulsion system of the Subsonic Single Aft Engine (SUSAN)concept. In doing so, we aim to more accurately benchmark the flow power of SUSAN’s mail slot propulsors relative to a conventional propulsion system in both an isolated and BLI configuration. Our preliminary results found relative to an optimized podded propulsor the optimized mailslot and BLI mailslot design required 8% and 17% more flow power respectively.The methods and key design insights also apply to other aircraft concepts that utilize distributed electric propulsion and boundary layer ingestion.

CAS↗

DOE OSTI2024

At a Glance: Electric Vehicles (French Translation)

Electric vehicles (EVs) include all-electric vehicles - also referred to as battery electric vehicles (BEVs) - and plug-in hybrid electric vehicles (PHEVs). This is the French translation of NREL/FS-5400-87123 (https://www.nrel.gov/docs/fy23osti/87123.pdf).

ADVANCED PROPULSION SYSTEMS↗

DOE OSTI2024

Development and Testing of an Advanced Cascaded Thermoelectric Residential Heat Pump

Electricity-driven heat pumps using vapor compression cycle are an energy-efficient solution to replace fossil fuel burning and reduce greenhouse gas emissions for space heating in residential buildings. However, heating capacity and Coefficient of Performance (COP) of heat pumps degrade significantly with increasing temperature difference between ambient and indoor environments. Residents and building owners are hence reluctant to fully embrace electric heat pumps. The use of conventional all-electric heat pumps also causes concern for electric utilities due to an increased winter peak demand arising from the use of supplemental electric resistance heaters. Our research is an attempt to alleviate these concerns by designing and laboratory testing a thermoelectric (TE) heat pump cascaded with a vapor compression cycle to enhance heating capacity and COP. TE modules increase the subcooling in the refrigerant liquid of the vapor compression cycle to enlarge the evaporating capacity and works at an efficiency greater than a conventional electric resistance strip. This results in a simple, affordable, efficient and highly controllable solution to adequately meet space heating needs in dwellings. The laboratory testing of the 3-stage cascaded TE heat pump performed in this research has exhibited a higher heating capacity by above 15%, while maintaining a heating COP of 2.0-3.6 in the ambient temperature range of -18˚C to 8˚C (0˚F to 47 ˚F), which represents more than 60% of winter temperatures observed in US. If successfully commercialized, this technology can advance space-heating electrification by overcoming consumer cost barrier of heat pumps.

Shen, Bo↗

DOE OSTI2024

Electrification Analysis: Container Ports' Cargo Handling Equipment

This one-page highlight details the key takeaways from a project that utilized NREL's Fleet Research, Energy Data, and Insights (FleetREDI) data analysis pipeline, the Electrification Analysis of Container Ports' Cargo Handling Equipment project. This project created a scalable solution to model energy demand per shipping container moved (kWh/TEU) for an all-electric cargo handling equipment fleet located at a maritime port. The model allows stakeholders to understand energy demand at each electric vehicle (EV) equipment level and is easily scalable to container demand and EV adoption rate projections.

ADVANCED PROPULSION SYSTEMS↗

DOE OSTI2025

Electric Vehicle Basics (French Translation)

Electric vehicles (EVs) use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. EVs include all-electric vehicles, also referred to as battery electric vehicles (BEVs), and plug-in hybrid electric vehicles (PHEVs). In colloquial references, these vehicles are called electric cars, or simply EVs, even though some of these vehicles still use liquid fuels in conjunction with electricity. EVs are known for providing instant torque and a quiet driver experience. Other types of electric-drive vehicles not covered here include hybrid electric vehicles, which are powered by a conventional engine and an electric motor that uses energy stored in a battery that is charged by regenerative braking, not by plugging in, and fuel cell electric vehicles, which use a propulsion system similar to electric vehicles, where energy stored as hydrogen is converted to electricity by the fuel cell. This is the French translation of NREL/FS-5400-87125.

ADVANCED PROPULSION SYSTEMS,DIRECT ENERGY CONVERSI↗

NASA NTRS2020

Multidisciplinary Systems Analysis of a Six Passenger Quadrotor Urban Air Mobility Vehicle Powertrain

There is a high degree of research interest in the design space for electric vertical takeoff and landing (eVTOL) vehicles, because these vehicles are seen as key enablers for urban air mobility (UAM). This work further explores the eVTOL design space, by presenting analysis of a six-passenger eVTOL quadrotor powertrain, with integrated power, propulsion, and thermal management systems modeled using the Numerical Propulsion System Simulation (NPSS) and the NPSS Power System Library. Four architectures are modeled at the same design point and compared over a design mission. Results from an architecture comparison study show that a hybrid architecture performs best in terms of cruise range, however, the hybrid needs batteries with high specific energy and specific power in order to obtain a benefit vs turboelectric architectures. Sensitivity studies are conducted to show correlations between component parameters and system metrics. This data provides useful indicators for further technological improvement. Lastly, an initial TMS model is presented, and sensitivity studies on TMS design parameters are presented as well, to show high level TMS design trends.

electrified propulsion↗