Key to making hybrid electric and fuel cell vehicles practical is the development of low-cost, high-power integrated power electronics devices. The research conducted at NREL's Advanced Power Electronics Laboratory is intended to improve these devices by developing and testing power management components and systems that significantly reduce cost, weight, and volume, and increase efficiency and reliability.
Advanced Power Electronics Laboratory
The laboratory, located at NREL's Golden, Colorado campus, is designed to allow researchers to effectively perform experiments on power systems, power electronics circuits, electric machines, and control algorithms. The lab houses state-of-the-art power electronics equipment, electric machines*, and measuring equipment (oscilloscopes, power meter, power quality meter, voltmeter, and ammeter). It also has auxiliary equipment such as power supplies, a solder board, as well as the most advanced analysis, simulation, and design software available to the power electronics staff.
Our scientists and engineers at the Advanced Power Electronics Laboratory collaborate with industry to develop and evaluate subsystems and interactions between a vehicle's motor, controller, inverter, load, and energy storage systems. These researchers have extensive expertise in electronic components and control system design and optimization, thermal management, and energy storage and modeling.
The research performed at the lab will help remove technical and cost barriers to enable technology for use in hybrid electric and fuel cell vehicles that meet the goals of DOE's 21st Century Truck and U.S. DRIVE partnerships. The lab supports these goals through a three-pronged approach intended to:
Identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry's recommendations and requirements, then develop the appropriate technical targets for systems, subsystems, and component research and development activities.
Develop and validate individual subsystems and components, including electric motors, battery systems, power electronics, accessories, and devices to reduce parasitic losses.
Determine how well the components and subsystems work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved.
Many tests performed at the laboratory are "proof-of-concept" experiments that include testing of motors/motor controllers with a continuous power rating as high as 55 kW. The length of the experiments varies depending on their details and objectives. Experiments use power circuits and signal circuits.
Thermal Management Capabilities
NREL is working on the integration of motor and power control technologies by focusing on the thermal management of inverters and motors with single- and two-phase cooling technologies. To develop and demonstrate the viability and advantages of two-phase cooling techniques such as spray cooling, jet impingement, pool boiling, two-phase microchannel/minichannel cooling, and surface enhancements, the lab contains:
- Spray and jet impingement cooling testing capability, localized heat sources and total inverter box
- High-speed camera for flow visualization
- Infrared camera for capturing temperature distribution
*Because most electric machines can be operated as motors or as generators, the term "electric machine" is used rather than motor or generator.