Hella will have on display at the SAE Convergence 2012 conference in Detroit Oct. 16-17 what it calls a new Enhanced Stop-Start Demonstrator featuring advanced hybrid vehicle technology solutions.
The company says stop-start is one among a new generation of Hella electronic system solutions to help vehicle manufacturers address increasingly rigorous fuel-economy and greenhouse-gas requirements.
The demonstrator constitutes something more than a 3-D simulator, a Hella spokesperson told AEI. It will provide a virtual technology experience and a real-world analysis of innovative electronic products for enhanced stop-start, vehicle coasting, and regenerative braking and creeping. The overall goal is to virtually address the challenges facing OEMs regarding the next steps for electronic solutions in advanced hybrid technologies.
Enhanced stop-start and coasting applications help boost fuel economy by up to 4 mpg, according to Hella. Stop-start technologies are enabled by turning the internal-combustion engine off when power for acceleration is not needed. While the engine is off, it is decoupled from the wheels via a clutch and no longer rotates, thereby reducing drag. The alternator does not deliver electrical power, but the vehicle remains in motion. The entire electrical system or dedicated loads must still be supported.
For a 12-V system, additional power is required to ensure the vehicle has a sustainable supply. Used to connect the energy-storage element to the power system is dc/dc power electronics. Energy storage and electronics can be integrated into a technology known as an “energy storage module.”
Regenerative braking harvests additional energy from the kinetic deceleration of the car by converting the braking energy into electrical energy via the alternator. This available energy can be used to reduce the fuel consumption by up to about 2.5 mpg, according to Hella. Up to 10 kW of alternator power is recommended for achieving this level of efficiency, which covers elevated power peaks during braking.
Corresponding voltage needs to be increased to sustain an appropriate power level. This involves a technology known as a dual low-voltage power system. This system offers a more attractive benefit-to-cost ratio compared to the current high-voltage solutions for hybrids.
In Europe, many OEMs are pursuing a 48-V system for this application. However, in the U.S. a variety of different voltage levels with diverse architectures are either in development or being considered. A high-power alternator can also be used as an electrical motor to power the vehicle at low speeds, during traffic conditions (i.e., creeping), etc., without the use of the engine for power.
Hella has expertise in the development of adaptive and modular solutions for energy management. Its components provide a flexible dc/dc converter platform in combination with a variety of energy-storage technologies, from lead-acid batteries and double-layer capacitors to lithium-ion battery cells.
The company claims it is one of the market leaders in intelligent battery management. Its core competency in electronics is energy storage management and high-powered dc/dc converters for dual low-voltage power systems.
The stop-start demonstrator to be highlighted at Convergence virtually displays all the performance benefits of Hella technologies under different driving scenarios. Each “test ride” will generate an analysis of the company’s latest energy management product benefits based on individual driving behavior.
Martin Fischer, head of Hella’s electronics division in the America’s, said at a press briefing in April that sales for the company’s electronics division will exceed those of its lighting division within a year or two. An article covering that press briefing can be viewed on the AEI website at http://www.sae.org/mags/aei/10988.