随着电动汽车数量的与日俱增,其充电负荷对配电网的影响变得越来越不可忽视。电动汽车作为一种可延迟负荷,需求响应(demand response,DR)潜力巨大,对其进行合理控制可以辅助配电网安全经济运行。文章建立了单台电动汽车的迟滞充电负荷模...随着电动汽车数量的与日俱增,其充电负荷对配电网的影响变得越来越不可忽视。电动汽车作为一种可延迟负荷,需求响应(demand response,DR)潜力巨大,对其进行合理控制可以辅助配电网安全经济运行。文章建立了单台电动汽车的迟滞充电负荷模型,基于配电网分层控制架构,引入集群电动汽车参与需求响应的最优能量状态调节量控制策略(optimal energy status regulation control strategy,OESRCS),该策略通过对电动汽车能量状态设定点施加最优调节量,实现对集群电动汽车充电过程的实时控制。在此基础上,制定了配电网电压变化百分比和网络损耗百分比这2个指标对需求响应效果进行评估。仿真结果表明,利用OESRCS策略,电动汽车可以精确地跟踪目标功率,同时配电网电压波动和网络损耗均有所减小。展开更多
This research focuses on the electric behavior of a mixed ferrielectric sulflower-like nanostructure.The structure includes a core with spin S_(i)^(Z)-1 atoms and a shell with spin σ_(j)^(Z)-5/2 atoms.The Blume–Cape...This research focuses on the electric behavior of a mixed ferrielectric sulflower-like nanostructure.The structure includes a core with spin S_(i)^(Z)-1 atoms and a shell with spin σ_(j)^(Z)-5/2 atoms.The Blume–Capel model and the Monte Carlo technique(MCt)with the Metropolis algorithm are employed.Diagrams are established for absolute zero,investigating stable spin configurations correlated with various physical parameters.The MCt method explores phase transition behavior and electric hysteresis cycles under different physical parameters.展开更多
The piezoelectric effect and electrostrictive effect are analyzed in detail, and the characteristics of piezoelectric elements are studied theoretically. By adopting PD series piezoelectric driver developed by the aut...The piezoelectric effect and electrostrictive effect are analyzed in detail, and the characteristics of piezoelectric elements are studied theoretically. By adopting PD series piezoelectric driver developed by the authors, some experiments have been done with WTDS-I piezoelectric elements, and a conclusion that the electric polar method can reduce the hysteresis and creep of piezoelectric element is drawn. The hysteresis is reduced by 1%. The displacement of piezoelectric element is linearized.展开更多
The anomalous hysteresis in a perovskite solar cell induced by an asymmetric field is confirmed by a capacitance–voltage measurement. By applying several cycles of alternating reverse and forward scans, this hysteres...The anomalous hysteresis in a perovskite solar cell induced by an asymmetric field is confirmed by a capacitance–voltage measurement. By applying several cycles of alternating reverse and forward scans, this hysteresis phenomenon is obviously alleviated, resulting in a hysteresis-less state in the perovskite solar cell. Meanwhile, the open-circuit voltage and power conversion efficiency of the perovskite solar cell are enhanced by 55.74% and 61.30%, respectively, while the current density and fill factor keep almost invariable. The operation of alleviating hysteresis is essential for further research and is likely to bring in performance gains.展开更多
Pt/Ti bottom electrodes were fabricated on SiO2/Si substrates by magnetron dual-facingtarget sputtering system. Lead zirconate titanate（PZT） thin films were deposited on Pt/Ti/SiO2/Si substrates by radio frequency ...Pt/Ti bottom electrodes were fabricated on SiO2/Si substrates by magnetron dual-facingtarget sputtering system. Lead zirconate titanate（PZT） thin films were deposited on Pt/Ti/SiO2/Si substrates by radio frequency （RF） magnetron sputtering system. The thickness of PZT thin films which were deposited for 5 h was about 800 nm. XRD spectra show that PZT thin films deposited in Ar ambience and rapid-thermal-annealed for 20 min at 700 ℃ have good crystallization behavior and perovskite structure. AFM micrographs show that mean diameter of crystallites is 70 nm and surface structures of PZT thin films are uniform and dense. Raw mean, root mean square roughness and mean roughness of PZT thin films are 34..357 rim, 2. 479 nm and 1. 954 nm respectively. As test frequency is 1 kHz, dielectric constant of PZT thin films is 327.5. Electric hysteresis loop shows that coercive field strength, residual polarization strength and spontaneous polarization strength of PZT thin films are 50 kV/cm, 10μC/cm^2 and 13μC/cm^2 respectively.展开更多
Battery is the key technology to the development of electric vehicles,and most battery models are based on the electric vehicle simulation.In order to accurately study the performance of LiFePO4 batteries,an improved ...Battery is the key technology to the development of electric vehicles,and most battery models are based on the electric vehicle simulation.In order to accurately study the performance of LiFePO4 batteries,an improved equivalent circuit model was established by analyzing the dynamic characteristics and contrasting different-order models of the battery.Compared to the traditional model,the impact of hysteresis voltage was considered,and the third-order resistance-capacitance(RC)network was introduced to better simulate internal battery polarization.The electromotive force,resistance,capacitance and other parameters were calibrated through battery charge and discharge experiments.This model was built by using Modelica,a modeling language for object-oriented multi-domain physical systems.MWorks was used to implement the cycle conditions and vehicle simulation.The results show that the third-order RC battery model with hysteretic voltage well reflects the dynamics of a LiFePO4 battery.The difference between the simulated and measured voltages is small,with a maximum error of 1.78%,average error of 0.23%.The validity and feasibility of the model are verified.It can be used in unified modeling and simulation of subsequent multi-domain systems of electric vehicles.展开更多
基金supported by the High Technology Research and Development Program of Jilin(20130204021GX)the Specialized Research Fund for Graduate Course Identification System Program(Jilin University)of China(450060523183)+2 种基金the National Natural Science Foundation of China(61520106008,U1564207,61503149)the Education Department of Jilin Province of China(2016430)the Graduate Innovation Fund of Jilin University(2016030)
文摘随着电动汽车数量的与日俱增,其充电负荷对配电网的影响变得越来越不可忽视。电动汽车作为一种可延迟负荷,需求响应(demand response,DR)潜力巨大,对其进行合理控制可以辅助配电网安全经济运行。文章建立了单台电动汽车的迟滞充电负荷模型,基于配电网分层控制架构,引入集群电动汽车参与需求响应的最优能量状态调节量控制策略(optimal energy status regulation control strategy,OESRCS),该策略通过对电动汽车能量状态设定点施加最优调节量,实现对集群电动汽车充电过程的实时控制。在此基础上,制定了配电网电压变化百分比和网络损耗百分比这2个指标对需求响应效果进行评估。仿真结果表明,利用OESRCS策略,电动汽车可以精确地跟踪目标功率,同时配电网电压波动和网络损耗均有所减小。
基金supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2020R1I1A3052258)funded by Researcher Supporting Project number (RSP2024R117), King Saud University, Riyadh, Saudi Arabia
文摘This research focuses on the electric behavior of a mixed ferrielectric sulflower-like nanostructure.The structure includes a core with spin S_(i)^(Z)-1 atoms and a shell with spin σ_(j)^(Z)-5/2 atoms.The Blume–Capel model and the Monte Carlo technique(MCt)with the Metropolis algorithm are employed.Diagrams are established for absolute zero,investigating stable spin configurations correlated with various physical parameters.The MCt method explores phase transition behavior and electric hysteresis cycles under different physical parameters.
文摘The piezoelectric effect and electrostrictive effect are analyzed in detail, and the characteristics of piezoelectric elements are studied theoretically. By adopting PD series piezoelectric driver developed by the authors, some experiments have been done with WTDS-I piezoelectric elements, and a conclusion that the electric polar method can reduce the hysteresis and creep of piezoelectric element is drawn. The hysteresis is reduced by 1%. The displacement of piezoelectric element is linearized.
基金supported by the National Natural Science Foundation of China(Grant Nos.11474105 and 51172079)the Science and Technology Program of Guangdong Province,China(Grant Nos.2015B090903078 and 2015B010105011)+1 种基金the Science and Technology Project of Guangzhou City,China(Grant No.201607010246)the Program for Changjiang Scholars and Innovative Research Team in Universities of China(Grant No.IRT13064)
文摘The anomalous hysteresis in a perovskite solar cell induced by an asymmetric field is confirmed by a capacitance–voltage measurement. By applying several cycles of alternating reverse and forward scans, this hysteresis phenomenon is obviously alleviated, resulting in a hysteresis-less state in the perovskite solar cell. Meanwhile, the open-circuit voltage and power conversion efficiency of the perovskite solar cell are enhanced by 55.74% and 61.30%, respectively, while the current density and fill factor keep almost invariable. The operation of alleviating hysteresis is essential for further research and is likely to bring in performance gains.
文摘Pt/Ti bottom electrodes were fabricated on SiO2/Si substrates by magnetron dual-facingtarget sputtering system. Lead zirconate titanate（PZT） thin films were deposited on Pt/Ti/SiO2/Si substrates by radio frequency （RF） magnetron sputtering system. The thickness of PZT thin films which were deposited for 5 h was about 800 nm. XRD spectra show that PZT thin films deposited in Ar ambience and rapid-thermal-annealed for 20 min at 700 ℃ have good crystallization behavior and perovskite structure. AFM micrographs show that mean diameter of crystallites is 70 nm and surface structures of PZT thin films are uniform and dense. Raw mean, root mean square roughness and mean roughness of PZT thin films are 34..357 rim, 2. 479 nm and 1. 954 nm respectively. As test frequency is 1 kHz, dielectric constant of PZT thin films is 327.5. Electric hysteresis loop shows that coercive field strength, residual polarization strength and spontaneous polarization strength of PZT thin films are 50 kV/cm, 10μC/cm^2 and 13μC/cm^2 respectively.
基金This work was supported by the National Key Research and Development Program of China(No.2018YFB0106204-03).
文摘Battery is the key technology to the development of electric vehicles,and most battery models are based on the electric vehicle simulation.In order to accurately study the performance of LiFePO4 batteries,an improved equivalent circuit model was established by analyzing the dynamic characteristics and contrasting different-order models of the battery.Compared to the traditional model,the impact of hysteresis voltage was considered,and the third-order resistance-capacitance(RC)network was introduced to better simulate internal battery polarization.The electromotive force,resistance,capacitance and other parameters were calibrated through battery charge and discharge experiments.This model was built by using Modelica,a modeling language for object-oriented multi-domain physical systems.MWorks was used to implement the cycle conditions and vehicle simulation.The results show that the third-order RC battery model with hysteretic voltage well reflects the dynamics of a LiFePO4 battery.The difference between the simulated and measured voltages is small,with a maximum error of 1.78%,average error of 0.23%.The validity and feasibility of the model are verified.It can be used in unified modeling and simulation of subsequent multi-domain systems of electric vehicles.
