No abstract

In any given collaboration, information needs to flow from one participant to another. While participants may be interested in sharing information with one another, it is often necessary for them to establish the impact of sharing certain kinds of information. This is because certain information could have detrimental effects when it ends up in wrong hands. For this reason, any would-be participant in a collaboration may need to establish the guarantees that the collaboration provides, in terms of protecting sensitive information, before joining the collaboration as well as evaluating the impact of sharing a given piece of information with a given set of entities. The concept of a trust domains aims at managing trust-related issues in information sharing. It is essential for enabling efficient collaborations. Therefore, this research attempts to develop a taxonomy for trust domains with measurable trust characteristics, which provides security-enhanced, distributed containers for the next generation of composite electronic services for supporting collaboration and data exchange within and across multiple organisations. Then the developed taxonomy is applied to a possible scenario, in which the concept of trust domains could be useful.

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Lithium-ion batteries on electric vehicles have been increasingly deployed for the enhancement of grid reliability and integration of renewable energy, while users are concerned about extra battery degradation caused by vehicle-to-grid (V2G) operations. This paper details a multi-year cycling study of commercial 24 Ah pouch batteries with Li(NiMnCo)O2 (NCM) cathode, varying the average state of charge (SOC), depth of discharge (DOD), and charging rate by 33 groups of experiment matrix. Based on the reduced freedom voltage parameter reconstruction (RF-VPR), a more efficient non-intrusive diagnosis is combined with incremental capacity (IC) analysis to evaluate the aging mechanisms including loss of lithium-ion inventory and loss of active material on the cathode and anode. By analyzing the evolution of indicator parameters and the cumulative degradation function (CDF) of the battery capacity, a non-linear degradation model with calendar and cyclic aging is established to evaluate the battery aging cost under different unmanaged charging (V0G) and V2G scenarios. The result shows that, although the extra energy throughput would cause cyclic degradation, discharging from SOC 90 to 65% by V2G will surprisingly alleviate the battery decaying by 0.95% compared to the EV charged within 90–100% SOC, due to the improvement of calendar life. By optimal charging strategies, the connection to the smart grid can potentially extend the EV battery life beyond the scenarios without V2G.

Battery inconsistency in electric vehicles is an important factor causing battery capacity degradation and safety problems. Therefore, battery equalization technology plays an important role in improving the performance and safety of battery packs. Among the existing equalization technologies, passive equalization is inefficient and active equalization is expensive and complex. Most of the active equalization algorithms only consider the balance of the cells within the battery module, but the balance between modules are not involved. However, battery packs for electric vehicles often consist of multiple modules, cooperative equalization between modules are essentially required to improve the balance efficiency. A novel cooperative equalization system for multi-modules in the battery pack is proposed in this paper. The system combines active and passive equalization, and also includes a fast discharge function for balancing modules by a power resistor. An equalization algorithm aiming at the optimal equalization time is studied. Finally, the equalization system is verified in simulation and experiment. The experimental results show that the proposed equalizer demonstrates good performance in different consistency cases using the proposed control strategy and optimization equalization algorithm.