Components and Systems
The Advanced Heavy Hybrid Propulsion Systems team works on developing and validating cost-effective, advanced next-generation heavy hybrid components and systems, which at the vehicle level could provide, contribute to, or enable a powertrain efficiency increase as high as 100% relative to today's conventional powertrain technology. Researchers use a variety of cross-cutting research and development technologies, systems, and evaluation tools, such as:
- Advanced and novel engine prime power concepts
- Low-cost and lightweight power electronics
- Advanced energy conversion and energy storage technologies and systems
- Advanced transmission and powertrain components and systems
- Advanced computerized powertrain algorithms
- Advanced thermal and fluid management systems
- Advanced materials for hybrid powertrains and vehicle systems
- Advanced computer modeling
- Engine and exhaust aftertreatment optimization
Advanced and Novel Engine Prime Power Concepts
Advanced and novel engine prime power concepts with fundamentally increased fuel efficiency and lower emissions are required to meet future advanced vehicle requirements. Novel concepts to optimize in-cylinder combustion and heat transfer characteristics to increase thermal efficiency, while maintaining or reducing in-cylinder emissions, will be beneficial to achieving program goals.
Topical R&D
Advanced and novel concepts in the areas of advanced hybrid diesel engine concepts, advanced diesel engine concepts that support and facilitate hybridization, advanced fuel-injection systems, combustion- and emission-control technologies, and other novel hybrid diesel engine concepts with the potential of increased fuel efficiency and reduced emissions consistent with the goals of this program.
Low-Cost and Lightweight Power Electronics
Heavy hybrid vehicles will require inexpensive, lightweight, and simplified power electronics that can be easily integrated into heavy hybrid approaches and systems. In particular, small-volume power electronics with higher durability and reliability are needed to control voltage, frequency, switching timing, and state-of-charge conditions and manage system power outputs from the prime mover, electric motors, and auxiliary power units.
Topical R&D
Advanced DC-DC converters, DC-AC inverters, advanced switching electronics, electronic modularization concepts, electromagnetic actuators, advanced capacitors and magnetic devices, and other advanced, novel power electronics to support and realize the heavy hybrid propulsion program mission.
Advanced Energy Conversion and Energy Storage Technologies and Systems
Such technologies and systems are required for auxiliary power, energy storage, and energy/power management in advanced vehicles.
Topical R&D:
Advanced and novel concepts in heavy vehicle-integrated thermoelectric systems and other advanced energy conversion technologies integrated into systems that can supply 5-10 kW or more of auxiliary truck power. Other areas of interest are advanced battery systems, ultracapacitors, and flywheels to support heavy vehicle hybridization.
Advanced Transmission and Powertrain Components and Systems
The transmission systems and other powertrain components are critical to efficiently transfer energy to the vehicle wheels. Continuously variable transmissions (CVTs) hold promising benefits to heavy vehicles, and their integration into heavy hybrid applications should be researched. Vehicle systems modeled to simulate CVT functionality and potential synergies that foster the development of such technology. Advanced transmission systems for heavy hybrid propulsion must be integrated with the vehicle prime power to minimize energy losses and create high-efficiency energy transfer.
Topical R&D
Advanced, next-generation transmissions, CVTs, and powertrain components and systems that are effectively integrated with vehicle prime power to enhance fuel economy enhancement and reduce emissions.
Advanced Computerized Powertrain Algorithms
On-board vehicle computer algorithms will be required to control, manage, and maximize vehicle system energy use. Advanced algorithms must accurately account for all energy use and management, including interrelated, coupled effects, throughout the vehicle.
Topical R&D
Computer technologies and algorithms that combine the effects of aerodynamic drag, rolling resistance, road grade, geographic positioning, weight, weather conditions (e.g., wind speed and direction), system thermal performance, and system electrical performance to help control vehicle motion and response as they relate to energy management.
Advanced Thermal and Fluid Management Systems
Auxiliary load, fuel and lubrication, and cooling systems are integral to any truck. They contribute to the overall design, energy use, and energy management of a truck.
Topical R&D
Advanced heat exchanger technologies, heat pipe/two-phase flow systems, advanced pumps and compressors, and other advanced thermal and fluid management concepts to improve electric powertrain cooling, enhance drivetrain performance, reduce energy use, improve system energy management, and reduce component and system weight, volume, and aerodynamic drag in hybrid powertrains and hybrid vehicle systems.
Advanced Materials for Hybrid Powertrains and Vehicle Systems
Material properties, performance, and optimization will have a tremendous impact on all truck systems and on energy use and management.
Topical R&D
Advanced high-temperature materials, carbon-fiber composites, porous materials, electronic materials, magnesium- and titanium-based alloys, low-friction materials, and other novel advanced materials that lead to enhanced energy use and management, reduced component and system weight and volume, aerodynamic drag reduction, and enhanced drive train performance in hybrid powertrains and vehicle propulsion systems.
Advanced Computer Modeling
NREL's vehicle systems work uses ADVISOR simulation software to show that many vehicle energy-saving techniques and methodologies can only be identified and implemented through a complete vehicle system modeling and design approach that encompasses all the interrelated, coupled energy use and management effects throughout the vehicle.
Topical R&D
Advanced computer modeling of powertrain, components, and complete hybrid powertrain concepts, and advanced vehicle systems design optimization and evaluation, to leverage and extend the capabilities demonstrated in ADVISOR.
Engine and Exhaust Aftertreatment Optimization
Aftertreatment systems should be integrated with advanced and novel engine concepts to produce engine systems with lower emissions, particularly NOx, particulate matter, and non-methane hydrocarbons. Specifically, better systems integration is required to allow aftertreatment subsystems to operate more effectively.
Topical R&D
Programs to optimize exhaust gas recirculation systems to reduce NOx, improve NOx absorber catalysts, develop advanced selective catalytic reduction, develop advanced diesel particulate filters, develop and integrate novel exhaust heat recovery systems, and create advanced sensor systems with higher reliability and durability, lower poison resistance, and faster response (< 15 ms). Other novel aftertreatment systems (e.g., plasma-based systems) are also of interest.
Other related research is being conducted to develop essential power systems and truck electrification to more efficiently manage electrical, mechanical, and thermal power on trucks. These activities are providing a pathway for future truck electrification that complements the AH2PS project.
