Search Results

For fuel cell vehicles to become a commercial reality, a number of challenges must be met including fuel infrastructure, durability, cost, performance, and efficiency. To help address these challenges, hybrid systems that combine fuel cells with an electrical energy storage system such as batteries or ultracapacitors is a potentially important configuration to increase efficiency and extend fuel cell life times by mitigating transient loads. However, the successful implementation of a hybrid fuel cell system requires achieving performance and efficiency benefits that offsets the additional costs, weight, and complexity of the energy storage system. The key to achieving the levels of efficiency required to justify the hybrid system lies in the power management control strategy. To this end, this paper examines the extension of a novel cost based control strategy developed for conventional internal combustion engine hybrid vehicles to a fuel cell platform (Patent WO 02/42110).

This paper follows on from a previous publication [1] and describes the continued development of a generic Integrated Powertrain (IPT) model. Simulation tools have been used for many years in engine and vehicle development programmes, to predict fuel consumption and emissions over various drive cycles. The concept phase of these programmes typically considers the overall layout and sizing of the components, with the detailed control strategies developed later. Today, the increased integration of vehicle sub-systems requires a high degree of overall control early in the programme, firstly, to allow the sub-systems to function, and secondly, to apply a similar quality of system control to each hardware iteration. To address this issue, a control hierarchy has been applied comprising of a supervisor controller and multiple local controllers.

Future demands for very low emissions from diesel engines, without compromising fuel economy or driveability, require Engine Management Systems (EMS) capable of compensating for emissions dispersion caused by production tolerances and component ageing. The Advanced Diesel Engine Control (ADEC) Project, a collaboration between Ricardo and General Motors, is aimed at reducing engine-out emissions dispersion and enabling alternative combustion modes, such as Highly Premixed Cool Combustion (HPCC), in real-world scenarios. This is being achieved by high-level co-ordination of fuel, air and EGR in order to meet the conflicting performance requirements of current and future diesel engines. A sensor feasibility study was undertaken which included a number of new sensing technologies appropriate for future mass production. Two sensor types, namely cylinder pressure and accelerometer sensors, were then selected to demonstrate varying degrees of benefits versus sensor technology cost.