锂离子电池可作为后备电源为电力系统的一次设备、二次设备及通信管理等提供不同等级的交直流电,保证核心设备紧急时刻仍然能够正常工作。先串后并的并联型储能系统不仅因并联模组的互为备用具有更高的可靠性,也能够避免传统串联型后备...锂离子电池可作为后备电源为电力系统的一次设备、二次设备及通信管理等提供不同等级的交直流电,保证核心设备紧急时刻仍然能够正常工作。先串后并的并联型储能系统不仅因并联模组的互为备用具有更高的可靠性,也能够避免传统串联型后备电源的木桶效应问题。然而,并联型方案会因模组之间的不一致,使得各模组寿命呈现差异性;串联电池组组内电压分布差异,也会导致电池单体过充或者过放。为此提出了一种针对并联型锂离子电池储能系统的多时间尺度均衡方法。首先,对电池模组组内单体以荷电状态(state of charge,SOC)为指标进行旁路均衡,使电池组在单次充放电循环的短时间尺度达到组内均衡;然后,通过并联电池模组组间的寿命均衡,使系统在寿命衰减的长时间尺度达到平衡。所提均衡方法能够提高并联型储能系统使用过程中模组间的一致性,增强并联模组互为备用的可靠性,降低运维成本,提高锂离子电池的使用效率。为了验证该均衡方法,在电池加速老化实验的基础上,搭建仿真模型验证了所提方法在不同条件下的有效性。展开更多
Energy-efficient data gathering in multi-hop wireless sensor networks was studied,considering that different node produces different amounts of data in realistic environments.A novel dominating set based clustering pr...Energy-efficient data gathering in multi-hop wireless sensor networks was studied,considering that different node produces different amounts of data in realistic environments.A novel dominating set based clustering protocol (DSCP) was proposed to solve the data gathering problem in this scenario.In DSCP,a node evaluates the potential lifetime of the network (from its local point of view) assuming that it acts as the cluster head,and claims to be a tentative cluster head if it maximizes the potential lifetime.When evaluating the potential lifetime of the network,a node considers not only its remaining energy,but also other factors including its traffic load,the number of its neighbors,and the traffic loads of its neighbors.A tentative cluster head becomes a final cluster head with a probability inversely proportional to the number of tentative cluster heads that cover its neighbors.The protocol can terminate in O(n/lg n) steps,and its total message complexity is O(n2/lg n).Simulation results show that DSCP can effectively prolong the lifetime of the network in multi-hop networks with unbalanced traffic load.Compared with EECT,the network lifetime is prolonged by 56.6% in average.展开更多
文摘锂离子电池可作为后备电源为电力系统的一次设备、二次设备及通信管理等提供不同等级的交直流电,保证核心设备紧急时刻仍然能够正常工作。先串后并的并联型储能系统不仅因并联模组的互为备用具有更高的可靠性,也能够避免传统串联型后备电源的木桶效应问题。然而,并联型方案会因模组之间的不一致,使得各模组寿命呈现差异性;串联电池组组内电压分布差异,也会导致电池单体过充或者过放。为此提出了一种针对并联型锂离子电池储能系统的多时间尺度均衡方法。首先,对电池模组组内单体以荷电状态(state of charge,SOC)为指标进行旁路均衡,使电池组在单次充放电循环的短时间尺度达到组内均衡;然后,通过并联电池模组组间的寿命均衡,使系统在寿命衰减的长时间尺度达到平衡。所提均衡方法能够提高并联型储能系统使用过程中模组间的一致性,增强并联模组互为备用的可靠性,降低运维成本,提高锂离子电池的使用效率。为了验证该均衡方法,在电池加速老化实验的基础上,搭建仿真模型验证了所提方法在不同条件下的有效性。
基金Projects(61173169,61103203)supported by the National Natural Science Foundation of ChinaProject(NCET-10-0798)supported by the Program for New Century Excellent Talents in University of ChinaProject supported by the Post-doctoral Program and the Freedom Explore Program of Central South University,China
文摘Energy-efficient data gathering in multi-hop wireless sensor networks was studied,considering that different node produces different amounts of data in realistic environments.A novel dominating set based clustering protocol (DSCP) was proposed to solve the data gathering problem in this scenario.In DSCP,a node evaluates the potential lifetime of the network (from its local point of view) assuming that it acts as the cluster head,and claims to be a tentative cluster head if it maximizes the potential lifetime.When evaluating the potential lifetime of the network,a node considers not only its remaining energy,but also other factors including its traffic load,the number of its neighbors,and the traffic loads of its neighbors.A tentative cluster head becomes a final cluster head with a probability inversely proportional to the number of tentative cluster heads that cover its neighbors.The protocol can terminate in O(n/lg n) steps,and its total message complexity is O(n2/lg n).Simulation results show that DSCP can effectively prolong the lifetime of the network in multi-hop networks with unbalanced traffic load.Compared with EECT,the network lifetime is prolonged by 56.6% in average.
