Navigation path

Decrease textIncrease textDividerPrint versionRSSDivider

High Density Power Electronics for FC- and ICE-Hybrid Electric Vehicle Powertrains

In order to increase the fuel economy of vehicles, efficient electric drivetrains are needed for conventional or fuel cell-based hybrid cars. Affordable high-density power electronics are a precondition. HOPE has two approaches: a low-cost solution and a more advanced high-temperature solution without liquid cooling.

Tags: Road


Since the invention of cars, urban traffic has grown exponentially, and one of its main consequences is pollution. In the past internal combustion engines were improved by e.g. exhaust gas treatment and optimised combustion. To get to even lower emissions levels, other concepts are needed: e.g. fuel cell and hybrid electric cars. These cars include an electric drive which improves the overall efficiency and reduces CO2. Several Japanese car manufacturers have brought HEV to the markets. In order to bring European hybrid technology successfully to the market, two elements are crucial beside the fuel cell: High performance batteries and highly efficient and reliable power electronics. HOPE addresses the power electronics challenge, with the aim of reducing costs and increasing power density, while ensuring reliability and driving performance.

The results of HOPE are relevant from a business perspective because they improve the competitiveness of European products. On the other hand they help in meeting the environmental targets and therefore HOPE is relevant for the whole European society.


The general objectives of HOPE are:

  • cost reduction
  • meeting reliability requirements
  • reduction of volume and weight.

These are a necessity to make the FC- and ICE-hybrid vehicles a success.

The overall target is to reduce fuel consumption because it will then correlate with CO2 emissions. The ultimate solution is the fuel cell (FC) which requires only hydrogen. But FC cars will not be in large-scale series production before 2015. In the meantime, ICE- (internal combustion engine) hybrid cars will emerge like the various Toyota, Honda, Lexus and Ford models.

It is obvious that there is a need for different power ratings because of the great variety of

cars and their level of electrification. If one assumed that there would be an individual power electronics for every car manufacturer and model, it is obvious that this would lead to high costs. Therefore a standardisation is needed that is based on ‘power electronics building blocks’ (PEBB) with a certain rated power, shape and terminal geometry. These PEBBs will then be a mass product, which can be manufactured at a reasonably low price.

Description of work

Work Package (WP) 1 defines common OEM specifications for FC- and ICE-hybrid vehicle drive systems; identifies common key parameters (power, voltage, size) that allows consequent standardisation; developes a scalability matrix for PEBBs. The power ranges will be much higher than those of, for example, considered in the HIMRATE project and will go beyond 100 kW electric power.

WP2 develops one reference mission profile which will be taken as the basis for the very extensive reliability tests that are planned.

WP3 investigates key technologies for PEBBs in every respect: materials, components (active Si- and SiC switches, passive devices and sensors), new solders and alternative joinings, cooling and EMI shielding.

In WP4, two PEBBs are developed: an IML (power mechatronics module), which is based on a lead-frame technology and a SiC-PEBB inverter.

WP5 develops a control unit for high-temperature control electronics for the SiC-PEBBs.

Finally WP6 works on integrating the new technologies invented in HOPE into powertrain systems and carries out benchmark tests.

It is clear from the start that many innovations are necessary to meet the overall goals of HOPE. An IP management group will be formed as well as a reliability-testing group and standardisation group, which will make contact with different organisations. Contact will be made with the EU project HYSYS concerning the integration.


The project has the following deliverables:

  • Common specifications from OEMs including key parameter ranges for FC-hybrid and ICE-hybrid vehicles drive system
  • Scalability matrix (assessment of OEMs needs covered by the technologies developed)
  • Reference mission profile for FC- and ICE-hybrid electric vehicles
  • Load patterns and lifetime requirements defined by OEMs for three different power ratings
  • Applicable test procedures for power electronic systems
  • Results of APCT, AMPCT and subsystem tests
  • Synthesis of the reliability testing at high temperatures: failure modes and lifetime prognosis
  • WP2 requirements; power partitioning for power modules
  • Sensor evaluation
  • HT-joining technologies
  • Cooling concepts and verification
  • Results of environmental and reliability tests
  • Design of the first mechatronic test vehicles
  • Final assessment on the new IML mechatronic power technology for automotive applications, including its compliance for scalability, comparison of different joining technologies and comparison of the performances of Si- and SiC-based power modules
  • Low parasitic commutation cell concepts for extremely fast switching SiC devices
  • First prototype SiC-driver and demonstrators/subsystems
  • Requirements for SiC inverter control board
  • SiC-control board
  • HT – SiC-control board
  • Specification of FC-hybrid/ICE-hybrid powertrain units
  • Specification of modelling and simulation of powertrain units
  • Impacts of implemented technologies on inverter integration
  • Benchmark study