Hella KGaA Hueck & Co. Rixbecker Straße 75 D-59552 Lippstadt/GermanyFon +49294138-0Fax +49294138-7133www.hella.com

Energy Management

Technical Information

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Ideas today forthe cars of tomorrow

Ideas today forthe cars of tomorrow

To manage successfully means todelegate efficientlyMore power, greater comfort, improvedsafety – these are mandates and goalsthat are met time and again thanks toinnovations in the field of automotiveengineering. Added to these are regulatorydemands for lower CO2 emissions as wellas specific requirements for safety criticalsystems. The result is a complex structureof the most diverse mechatronic and electronic loads whose energy supply has to be not simply ensured but balancedout reliably. This takes place through consistent monitoring and strategic controls, which occurs in the interest ofefficiency and exactly the way the driverlikes it.

These are high demands, and Hella canoffer intelligent solutions to meet them:energy management that reliably and efficiently coordinates the vehicle electricsystem. This specifically includes the regulation of the power flow of the alter-nator, loads, power stores and converterswhich ensure the starting ability and the availability of the vehicle functions.Naturally, aspects such as power savingoperation and comfort requirements are

being taken into consideration in this context and processed in a coordinatedregulation strategy to generate specifi-cations for the operation of the vehicle.

The goal is clear: to ascertain completeavailability of electrical power for all operat-ing states. This is needed not only withinthe usual vehicle electric systems but alsofor new power supply systems with morethan one power generator and powerstore. Hella power management supportsthe attainment of this goal and takes onthe best possible coordination betweenavailable and needed capacities. This

Energy Management

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The basis has to be correctThe Intelligent Battery Sensor (IBS) takeson a key functionality in successful powermanagement. The sensor systems thatascertain the necessary battery state vari-ables provide the vehicle battery’s precisepower, voltage, and temperature values.Without this data, power managementcannot adequately control and monitor thesystem's energy budget.

With the information supplied by the IBS,the system can efficiently generate theexact amount of electrical energy neededat any time, distribute it intelligently, andultimately store it in the best possible way.This ascertains a maximum availability and reliability of the vehicle’s functionalityand makes sure that sufficient power isavailable the next time the engine is started.

The IBS collects the data with resolutionaccuracies of < 1mV for voltage measure-ments and a maximum of 1% for the entiremeasuring range when measuring the current. Based on these measurements,the ASIC (Application Specific IntegratedCircuit) computes the current service capability based on battery parameterssuch as State of Charge (SoC), State ofHealth (SoH) and State of Function (SoF)of the battery state detection.

The IBS’s sensory system is integrated intothe battery clamp on the negative terminal.This compact mechanical assembly en-ables a perfect fit into the terminal recessof any standard vehicle battery. The core ofthe assembly located on the circuit boardis the ASIC. With its two independent 16 bit A/D converters, an internal currentreference of generally 5 ppm/ºC and corresponding mechanisms for offset compensation, the required accuracy andresolution are reached while measuringvoltage and current at the same time.

Hella’s Intelligent Battery Sensorensures maximum capacity and the highest level of accuracy with the help of an ASIC specifically developed for Hellatakes on central functions in the auto-motive production, operation and service based on its extensive and accurate battery diagnosis increases the quality of the vehicle power system through continuous monitoring of the quiescent current as early as during vehicle productionsupplies detailed information on the charge and aging state of the vehicle electric system’s battery and increases the battery’s lifespan by charging and discharging it gentlysupports quick and safe detection of defective control units within the vehicle

reduces vehicle consumption values through precise battery monitoring and captures the actual state of the control circuits of the vehicle electric system management (especially alternator control); together with a load control allows for adhering to more stringent emission requirements (CO2 emission)presents the most cost-effective solution for precise battery manage-ment based on its high degree of integration and has proved its value as part of several vehicle platforms of different manufacturers since 2003ensures the vehicle’s ability to start with excellent battery management, thus creating higher customer satisfactionis one of many Hella products that have convinced consumers for years as professional and flexible solutions for all kinds of customer requirements.

Intelligent Battery Sensor

takes place in particular through in-depthanalysis, development and optimization ofall crucial components of successful powermanagement in vehicles.

Besides the system components of powermanagement available today, Hella is currently also working on tailored solutionsfor future alternator and starter generationswhich offer additional means for inter-vening in the power management and forreducing vehicle fuel consumption due toacceleration support, start and stop func-tionality and recirculation of the brakingenergy.

Intelligent Battery Sensor (IBS)

Vehicle electric system architecture

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For correct voltageAutomotive electronics are becomingincreasingly complex, and the equipmentrate increases. This makes the vehiclessafer, more economical and better for theenvironment. With an increase in the num-ber of loads, more than one level of volt-age needs to be supplied with the vehicleelectric system. The solution is either adual vehicle electric system or the use of a modern high performance vehicle electric system.

The use of voltage converters in vehiclesembedded in the respective vehicle electric system structures enables newapproaches to reducing fuel consumption.This goal takes the environment into consideration, in particular with an eye on federal regulations. It focuses on thespeedy introduction of measures to increase power efficiency in vehicles on the basis of the existing vehicle electricsystem. But it also mitigates the effect ofincreasing fuel prices for the driver andenables new, innovative applications.

Hella develops and provides the following for the requirement related supply of various vehicle electric systemarchitectures:

voltage convertersvoltage stabilizerscharge convertersequalizers.

Voltage convertersVoltage converters are needed whereverthe electric power source in the vehiclesupplies a higher vehicle voltage than thestandard loads. In vehicles with differentvoltage situations, these converters trans-fer power from the higher to a lower powerlevel and vice versa. The supply of this voltage can thus originate from a 12 Vvehicle electric system, an alternator, a fuelcell or a high voltage battery.

Hella developed the bi-directional voltageconverter specifically for applications withan output capacity of 1000 W and an efficiency of 93% for a maximum input voltage of up to 60 V.

Voltage stabilizersVoltage stabilizers enable the operation of voltage critical loads in vehicles with ahigh voltage dynamic. The stabilizersbalance out voltage fluctuations in themain network and function as boost converters when drops in vehicle electricsystem power occur. The sensitive loadtherefore has a constant output voltageavailable at all times. This is particularlyuseful for vehicles where the internal combustion engine is turned off duringidling in the start and stop operation, since in these cases the supply of the audiosystem or a constant level of lighting canbe ensured even during voltage drops.Hella can provide the correct voltage stabilizer with a load power between 70 W and 350 W.

Charge convertersThe use of charge converters is advisablein vehicles with different or the same voltage levels. On the one hand, chargeconverters support a redundant powersupply. On the other hand, the charge ofthe power stores is optimized and their lifespan and the system availability areenhanced. This will ensure the vehicle’sability to start at all times.

If desired, the charge converters can becombined in one unit with vehicle electriccontrol units or power stores. This will savenot only space, but also money.

Hella's converter portfolioproven products from an established manufacturerintegration in existing vehicle electric systemsreliable unit concepts for future vehicle electric systemspower density thanks to innovative converter topologycan be used for several different applications optimal use of energy storage capabilitieseffective contribution to reducing fuel consumption and CO2 emissionsapplication across platforms.

EqualizersEqualizers create a balance of chargesbetween several storage cells and batteries. This solves the problem ofhaving different charge amounts in individual cells which are caused whenstorage cells are connected in series due to the great cyclical strains, such as in hybrid applications. The chargeequalization ensures not only the func-tionality and the storage ability of the cells,however. In a 24 V vehicle electric systemof commercial vehicles or busses, theequalizer also enhances the lifespan of the12 V batteries connected in series, while at the same time making a 12 V partialelectric grid for selected loads available.

Voltage stabilizer Charge converter from Hella in a vehicle electric control system unitDC/DC converter

Integrated enhanced safetyThe energy management control unit kicks in as an additional safety device insituations where the power supply of primary loads is in danger. This can occurin excess load situations, for example,where the targeted separation of individualload branches from the battery is neededin order to ensure steady supply. Specialpower semiconductors and electromag-netic switches within the control unit carryout the separation reversibly. In addition,pyrotechnical disconnecting elements can be used to protect high-current paths.The selection of protection methods enables flexible vehicle electric systemdesigns.

Hella’s energy management control units

offer additional safety for driver and vehicle in accidents are based on a current sensor system that operates independently from physical characteristics of conventional fuses.enable an individual adaptation of the switch-off strategy to the vehicle electric system components together with software algorithms stored in the control unit.

The automotive parts supplier developsand manufactures components andsystems for lighting technology and electronics for the automotive industry. In addition, joint venture companies alsoproduce complete vehicle modules, airconditioning systems and vehicle electricsystems. Hella has one of the largest aftermarket organizations in the world forautomotive parts and accessories, with its own sales companies and partners inmore than 100 countries. Hella is one ofthe top 50 automotive parts suppliers inthe world and one of the 100 largest industrial companies in Germany. Morethan 25,000 people work in 70 manufac-turing facilities, production subsidiaries andjoint ventures all over the world. Almost3,000 engineers and technicians work inresearch and development throughout thecompany group. Customers include all leading vehicle and system manufacturers,as well as the automotive parts aftermarket.

Network creates added valueCooperation rather than concentration: In line with this aim, Hella enters project-related co-operations and works in jointventures with independent suppliers, enabling the company to offer vehiclemanufacturers an attractive alternative to mega suppliers in terms of innovativeability and global presence.

Hella’s decades of know-how in the field of body electronics links favorably for auto-makers with the vehicle-electric-systemcompetence of Leoni. Thus, from manyyears of cooperation, the joint venture Intedis in Würzburg (Integrated ElectronicDistribution Systems) arose. The aim of the cooperation is to offer automakerscomplete solutions for the vehicle electricsystem of the future. Here, through integralconsideration of the system, consisting of control units, harnesses and lighting, the aim of cost and weight reduction (for example through fewer interfaces) ispursued while keeping functionality reliableand at a high level.

Energy management control unit Hella KGaA Hueck & Co., Lippstadt:

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Hella cooperates with the Japanese supplier Stanley and the Korean supplierSL (formerly Samlip), in the field of lightingtechnology for example. HBPO GmbH is the only joint venture of its kind in the world and is extremely successful in the area of design, develop-ment, production and logistics for complete front-end modules with the suppliers Behr, Stuttgart/Germany, andPlastic Omnium, France.

These examples demonstrate how Helladefines the term “customer benefit”: Expertknowledge is linked and brought togetherin lean organizations with short decisionpaths. Hella is always open for new orextended partnerships, to be able to offervehicle manufacturers optimum solutionswith just the right partners.

Control unit