The effect of external constraints on Li diffusion in high-capacity Li-ion battery electrodes is investigated using a coupled finite deformation theory. It is found that thinfilm electrodes on rigid substrates experie...The effect of external constraints on Li diffusion in high-capacity Li-ion battery electrodes is investigated using a coupled finite deformation theory. It is found that thinfilm electrodes on rigid substrates experience much slower diffusion rates compared with free-standing films with the same material properties and geometric dimensions. More importantly, the study reveals that mechanical driving forces tend to retard diffusion in highly-constrained thin films when lithiation-induced softening is considered, in contrast to the fact that mechanical driving forces always enhance diffusion when deformation is fully elastic. The results provide further proof that nano-particles are a better design option for nextgeneration alloy-based electrodes compared with thin films.展开更多
To simplify the transient stability analysis of a large-scale power system and realize real-time emergency control,a fast transient stability simulation algorithm based on real-time dynamic equivalence is proposed.Gen...To simplify the transient stability analysis of a large-scale power system and realize real-time emergency control,a fast transient stability simulation algorithm based on real-time dynamic equivalence is proposed.Generator models are grouped and aggregated according to a fast numerical integration.A fast calculation method of the admittance matrix is then proposed to calculate the parameters of an equivalent system,and numerical integration is performed using the obtained equivalent system.Then,based on integral sensitivity,a new fast emergency control strategy is proposed for the equivalent system.The final emergency control strategy is obtained by mapping the control strategy for the equivalent system back to the original system.The results of a simulation on an East China Power System that includes 496 generators and 5075 buses show that the suggested algorithm can output an accurate transient stability simulation result and form an effective emergency control strategy.The proposed algorithm is much faster than the existing solutions and has the potential to be used for online pre-decision.展开更多
基金supported by the National Research Foundation of Korea through WCU(R31-2009-000-10083-0)
文摘The effect of external constraints on Li diffusion in high-capacity Li-ion battery electrodes is investigated using a coupled finite deformation theory. It is found that thinfilm electrodes on rigid substrates experience much slower diffusion rates compared with free-standing films with the same material properties and geometric dimensions. More importantly, the study reveals that mechanical driving forces tend to retard diffusion in highly-constrained thin films when lithiation-induced softening is considered, in contrast to the fact that mechanical driving forces always enhance diffusion when deformation is fully elastic. The results provide further proof that nano-particles are a better design option for nextgeneration alloy-based electrodes compared with thin films.
文摘To simplify the transient stability analysis of a large-scale power system and realize real-time emergency control,a fast transient stability simulation algorithm based on real-time dynamic equivalence is proposed.Generator models are grouped and aggregated according to a fast numerical integration.A fast calculation method of the admittance matrix is then proposed to calculate the parameters of an equivalent system,and numerical integration is performed using the obtained equivalent system.Then,based on integral sensitivity,a new fast emergency control strategy is proposed for the equivalent system.The final emergency control strategy is obtained by mapping the control strategy for the equivalent system back to the original system.The results of a simulation on an East China Power System that includes 496 generators and 5075 buses show that the suggested algorithm can output an accurate transient stability simulation result and form an effective emergency control strategy.The proposed algorithm is much faster than the existing solutions and has the potential to be used for online pre-decision.
