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Li-Ion battery is attractive for HEVs and FCEVs because of its high power density and lack of memory effect. However, high battery temperatures during operation result in a short battery lifespan and degraded performance. To address this issue, battery manufacturers and OEMs have used different pre-set cooling strategies. Unlike the pre-set cooling strategy this thermal model forecasts battery temperatures, allows a better usage of the battery system, responds to battery power demand and maintains battery temperature limits. This paper discusses the real-time control of the battery cooling including battery stress analysis. The authors present a dynamic thermal model for the Li-Ion battery system using the finite-volume method and discuss transient battery thermal characteristics and real-time battery cooling control under various battery duty cycles. Validation results of the model are presented in this paper.

Ford's H2RV is a Hydrogen engine propelled Hybrid Electric concept Vehicle that was unveiled and driven at Ford's Centennial Show in June 2003. This vehicle is an industry first by an OEM that demonstrates the concept and the marriage of a HEV powertrain with a supercharged Hydrogen ICE that propels the vehicle. Just as Model T was the car of the 20th century, Model U is the vehicle for the 21st century. The powertrain utilizes compressed gaseous hydrogen as fuel, a supercharged 2.3L internal combustion engine, a 25 kW traction motor drive, the electric converterless transmission, regenerative braking, an advanced lithium ion battery, electric power assist steering, electronic throttle and Vehicle System Controller (VSC). The vehicle could deliver a projected fuel economy of 45 mpg and near zero emissions without compromise to performance.

In recent times, the development of alternate-fuel vehicles, including those fueled by hydrogen, has become relatively common. While there are potential safety related issues with any combustible fuel, these have been resolved over the last 100+ years. The comfort level with gasoline fuel has resulted from the widespread application of simple safety procedures followed at every stage of gasoline refinement and handling. It is important to have analogous procedures for handling hydrogen-fueled vehicles safely and with confidence. The characteristics of hydrogen, including: a) wide flammability range, b) very low ignition energy, c) odorless and difficult to detect, d) high diffusion rate, e) high buoyancy, f) invisible flame, etc., bolster the need for safe practices and procedures.

Ford's Hydrogen Hybrid Research Vehicle (H2RV) is an industry first parallel hybrid vehicle utilizing a hydrogen internal combustion engine. The goal of this drivable concept vehicle is to marry Ford's extensive hybrid powertrain experience with its hydrogen internal combustion engine technology to produce a low emission, fuel-efficient vehicle. This vehicle is seen as a possible bridge from the petroleum fueled vehicles of today to the fuel cell vehicles envisioned for tomorrow. A multi-layered hydrogen management strategy was developed for the H2RV. All aspects of the vehicle including the design of the fuel and electrical systems, placement of high-voltage subsystems, and testing, service, and storage procedures were examined to ensure the safe operation of the vehicle. The results of these reviews led to the design of the hydrogen sensing and mitigation system for the H2RV vehicle.

Today, Hybrid Electric Vehicles (HEVs) are synonymous to vehicles that offer a greater fuel economy and lower emissions when compared to their conventional production platforms. The development of an affordable hybrid technology faces challenges on several forefronts. Challenges include, but are not limited to, their technical content and development, corporate challenges, government regulations, program challenges, selecting technology partners and producing a hybrid vehicle that customers find fun to drive. As technologists, our goal is to ensure that the consumer understands that HEVs go that extra mile and provide far more than better fuel economy and lower emissions. HEVs are attractive and fun to drive because they offer multiple attributes and features to that consumers want. Hybrids offer all-wheel drive capability, traction control, regenerative braking, zero emissions, active air conditioning at vehicle stops, silent re-starts.

Hybrid Electric Vehicle (HEV) prototypes are based off production platforms. Several new systems are added to the vehicle, either to perform hybrid functions or to support them and enhance vehicle performance and fuel economy. All these systems are electrically connected in the vehicle with overlay wiring harnesses. Architecture of overlay wiring harness for the HEV requires identification of new systems and working out their electrical connectivity requirements. This dictates the level of changes required in the vehicle electrical system. Harnesses are built based on the circuit design and location of these systems in the vehicle. EMI requirements, routing and packaging challenges are resolved during the overlay process and testing of the prototype. This paper presents the process of harness design, its architecture and integration challenges in the vehicle.

Increased cooling demands in Hybrid Electric Vehicles (HEVs), compactness of engine compartment, and the additional hardware under the hood make it challenging to provide an effective cooling system that has least impact on fuel economy, cabin comfort and cost. Typically HEVs tend to have a dedicated cooling system for the hybrid components due to the different coolant temperatures and coolant flow rates. The additional cooling system doubles the hardware, maintenance, cost, weight and affects vehicle fuel economy. In addition to the cooling hardware, there are several harnesses and electronics that need air cooling under the hood. This additional hardware causes airflow restriction affecting the convective heat transfer under the hood. It also affects the radiation heat transfer due to the proximity of hardware close to the major heat sources like the exhaust pipe.