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12 June 2008


Delphi team awarded $5m DOE funding to halve size and cost of electric propulsion inverters

Mobile electronics and transportation system provider Delphi Corp of Kokomo, IN, USA has been awarded $5m by the US Department of Energy (DOE) as lead contractor of an industry-government team to develop next-generation propulsion inverters for hybrid electric vehicles. The partners in the team were originally selected by the DOE in May 2007.

Propulsion inverters provide phased AC power for hybrid vehicle traction motors and generators, as well as auxiliary pumps and drives. They enable precise control over electrical power flow from the battery to the electric motor. One or more electric motors can be combined with another power source like a gasoline or ethanol engine, an engine-generator, or a fuel cell to propel the vehicle at higher efficiency than conventional engine technology.

The new smaller inverter is lower cost and will be used on next-generation high-efficiency hybrid electric vehicles (HEVs) and next ‘plug-in’ hybrids (PHEVs). In the longer-term, the inverter will be used for fuel cell vehicles (FCVs).

The DOE and Delphi view the project as a key element of a strategic, public-private partnership to achieve the lower-cost technologies needed for such hybrid vehicles to become more broadly accepted in the US marketplace.

In addition to the $5m in DOE funding, the Delphi-led research and design team will contribute $3m. The $8m project seeks to reduce the cost and size of the inverter for electric propulsion systems by 50% or more.

“We have assembled a team of highly qualified industry leaders and national laboratories to identify and develop the key technologies needed for an electric propulsion inverter that meets or exceeds the DOE performance and cost targets,” says Thomas Goesch, managing director of Delphi’s Power Electronics PBU.

The primary team members for the project include: Delphi for the inverter design, packaging, thermal management, mechanical integration, build, test and assessment of cost to manufacture; silicon carbide materials supplier Dow Corning Corp of Midland, MI and device maker GeneSiC Semiconductor Inc of Dulles, VA for SiC-on-silicon power semiconductor devices; General Electric for high-temperature thin-film DC buss capacitors; Argonne National Laboratory for ceramic capacitors; and Oak Ridge National Laboratory for the characterization of power semiconductor devices, modeling, simulation and evaluation of alternative inverter topologies, and system testing.

Dow Corning has been developing SiC technology for more than 15 years. In 2003 it acquired SiC substrate maker Sterling Semiconductor Inc and formed Dow Corning Compound Semiconductor Solutions (DCCSS), which in 2004 built a new SiC plant in Auburn, MI. DCCSS is developing the manufacturing of device-quality SiC substrates up to 100mm (4-inches) in diameter (funded by US Office of Naval Research contracts of $3.6m awarded in December 2005 and $4.2m in December 2007). GeneSiC develops SiC-based devices (such as rectifiers, field-effect transistors , and bipolar devices, as well as particle & photonic detectors) for high-temperature, radiation, and power grid applications.

In addition to reducing the cost and size of the inverter system, the Delphi team aims to enable the system to operate at normal engine coolant-loop temperatures of 105-120°C to help reduce other system costs and the space needed to cool existing inverters. “This will result in development of inverter building blocks that will be readily scalable to a wide range of power levels, enabling the necessary economies of scale for lower cost,” says A.J. Lasley, Delphi’s chief engineer for advanced HEV and powertrain electronics.

See related items:

SemiSouth awarded SiC JFET manufacturing patent

Dow Corning wins further Navy funds to develop 4” SiC

SiC electronics market to reach $800m by 2015

Search: Hybrid electric vehicles Dow Corning GeneSiC SiC SiC substrates