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Implementing and optimizing the sustainability of vehicles that contain embedded electrochemical energy storage have recently been afforded more attention in research due to legislative requirements and cited benefits from circular economy activities. The State-of-Health (SoH) for a traction battery system that prematurely failed can be restored through circular economy activities such as remanufacturing. To enable these circular economy activities, the ability to introduce a new or graded cell or module into a series string to replace the weakest cell or module in a battery module or pack is vital. However, very little is understood about the optimal strategy that will lead to maximizing the lifetime of the most aged cell or module in the new string and predict the expected lifetime of the repaired or remanufactured battery system.

Automotive electronic control systems are expected to respond to input demands in real-time (circa: milliseconds) to ensure occupant and road user safety and comfort. System complexity and real-time computing requirements create significant challenges in proving the robustness of control systems; here robustness is the degree to which a system can function correctly in the presence of unexpected inputs. Evidence shows that faults still escape to customers incurring large warranty costs. Existing test methods can be ineffective in testing robustness with the primary focus being on requirements validation. Evidence from other industries such as IT and medical suggests faults that are difficult to find, manifest due to complex interactions and sequences of events. Research in model based software design, test optimization and formal methods - mathematical based approaches to prove robustness, is abundant in literature.

Increasingly international academic and industrial communities desire to better understand, implement and improve the sustainability of vehicles that contain embedded electrochemical energy storage. Underpinning a number of studies that evaluate different circular economy strategies for the electric vehicle (EV) battery system are implicit assumptions about the retained capacity or State-of-Health (SoH) of the battery. International standards and best-practice guides exist that address the performance evaluation of both EV and HEV battery systems. However, a common theme in performance testing is that the test duration can be excessive and last for a number of hours. The aim of this research is to assess whether energy capacity and internal resistance measurements of Li-ion based modules can be optimized, reducing the test duration to a value that may facilitate further End-of-Life (EoL) options.

While a number of publications have addressed the high-level requirements of remanufacturing to ensure its commercial and environmental sustainability, considerably less attention has been given to the technical data and associated test strategies needed for any evidence-based decision as to whether a vehicle energy storage system should be remanufactured - extending its in-vehicle life, redeployed for second-life (such as domestic or grid storage) or decommissioned for recycling. The aim of this paper is to critically review the strategic requirements for data at the different stages of the battery value-chain that is pertinent to an Electric Vehicle (EV) battery remanufacturing strategy. Discussed within the paper is the derivation of a feasible remanufacturing test strategy for the vehicle battery system.

The power demand of air conditioning in PHEVs is known to have a significant impact on the vehicle’s fuel economy and performance. Besides the cooling power associated to the passenger cabin, in many PHEVs, the air conditioning system provides power to cool the high voltage battery. Calculating the cooling power demands of the cabin and battery and their impact on the vehicle performance can help with developing optimum system design and energy management strategies. In this paper, a representative vehicle model is used to calculate these cooling requirements over a 24-hour duty cycle. A number of pre-cooling and after-run cooling strategies are studied and effect of each strategy on the performance of the vehicle including, energy efficiency, battery degradation and passenger thermal comfort are calculated. Results show that after-run cooling of the battery should be considered as it can lead to significant reductions in battery degradation.

Among the auxiliary systems on electric and hybrid electric vehicles the electric air conditioning (eAC) system causes the largest load on the high voltage battery and can significantly impact the energy efficiency and performance of the vehicle. New methods are being investigated for effective management of air conditioning loads through their integration into vehicle level energy management strategies. For this purpose, a fully integrated vehicle model is developed for a commercially available hybrid vehicle and used to develop energy management algorithms. In this paper, details of the eAC model of this vehicle are discussed, including steady state component validation against rig data. Also results of simulating the cabin pull-down are included.

Testing real-time vehicular systems challenges the tester to design test cases for concurrent and sequential input events, emulating unexpected user and usage profiles. The vehicle response should be robust to unexpected user actions. Sequence Covering Arrays (SCA) offer an approach which can emulate such unexpected user actions by generating an optimized set of test vectors which cover all possible t-way sequences of events. The objective of this research was to find an efficient nonfunctional sequence testing (NFST) strategy for testing the robustness of real-time automotive embedded systems measured by their ability to recover (prove-out test) after applying sequences of user and usage patterns generated by combinatorial test algorithms, considered as “noisy” inputs. The method was validated with a case study of an automotive embedded system tested at Hardware-In-the-Loop (HIL) level. The random sequences were able to alter the system functionality observed at the prove-out test.

This paper aims to indicate the advantages and any drawbacks of high frequency alternating current (HFAC) power for vehicle auxiliary electrical systems. Generally, benefits of HFAC include efficient power distribution and transformation, space and weight saving and load galvanic isolation. In addition, HFAC bus topologies are distributed to the point of use, lending the system to easy fault detection. The paper is structured as follows: first, the main findings of the most relevant automotive HFAC studies are outlined. Next, an HFAC architecture is proposed which is compared to the existing 14V and proposed 42V centralised DC networks in terms of power distribution efficiency and wiring harness weight saving. For this analysis, the case study of a medium-sized passenger vehicle is considered, and a group of intermittent and continuous auxiliary loads with a cumulative power of 2.8kW.

With the increased interest in hybrid vehicle technology there is a need to investigate vast amounts of different hybrid vehicle topologies. Modelling and simulation plays an important role in this investigation process. In particular, modelling for controller development can quickly lead to model management and maintenance issues due to the variety of models required. The use of object oriented modelling languages can aid in plant model management by providing flexibility to different levels of users as well as reducing the number of separate plant models required for controller development. Two case studies are presented that illustrate some of the benefits gained from the object oriented modelling approach.

The quantitative assessment and comparison of different hybrid vehicle options has traditionally been done on the basis of measuring or estimating the vehicle's fuel economy over predefined drive-cycles. In general, little or no consideration has been given to the more subjective and difficult to quantify vehicle requirements, such as trying to understand which derivative will be the most “fun” vehicle to drive. A lack of understanding in this area of vehicle performance sufficiently early within the development life-cycle so as to be in a position to influence the vehicle design, can lead to a compromised powertrain architecture which will ultimately increase the risk of product failure. The work presented within this paper constitutes part of the overall design activities associated with the LIFECar programme. The aim of the LIFECar consortium is to manufacture a lightweight, fuel cell hybrid electric sports vehicle.