电力设备状态评估是状态检修的关键一环。为了解决电力设备健康状态评估结果准确性不高这一问题,该文设计了一种基于最优云熵-灰云证据的中高压断路器健康状态评估方法,该方法以云模型和证据理论为基本理论框架。选取适当的定性和定量...电力设备状态评估是状态检修的关键一环。为了解决电力设备健康状态评估结果准确性不高这一问题,该文设计了一种基于最优云熵-灰云证据的中高压断路器健康状态评估方法,该方法以云模型和证据理论为基本理论框架。选取适当的定性和定量评价指标建立综合评估体系;在灰云模型的基础上引入最优云熵,结合大数定理对所得隶属度进行二次处理最终确定状态区间隶属度,并将其作为证据理论的基本信度分配(Basic Probability Assignment,BPA);利用不确定系数对BPA进行二次更新;通过改进证据融合规则进行证据融合,所得结果转化为相应的健康指数使评估结果更为直观。实例分析表明,该方法能很好地处理评价过程中的模糊性及随机性,具有一定的参考价值。展开更多
故障树分析法(Fault Tree Analysis,FTA),是一种将系统失效形成的原因由总体至部分按树枝状逐级细化的分析方法,可以简化系统结构,降低可靠性及重要度的计算复杂程度。文中以共因失效系统(Common Cause Failure System,CCF)作为研究对象...故障树分析法(Fault Tree Analysis,FTA),是一种将系统失效形成的原因由总体至部分按树枝状逐级细化的分析方法,可以简化系统结构,降低可靠性及重要度的计算复杂程度。文中以共因失效系统(Common Cause Failure System,CCF)作为研究对象,基于FTA方法,给出了系统结构通过各种不同的逻辑门(与门、或门、非门等)转化为故障树的表示方法,并提出了基于故障树的系统可靠性和Birnbaum重要度的隐式替代算法,最后针对串联和并联案例分别进行了系统可靠性及Birnbaum重要度的计算,结果验证了基于故障树方法计算系统可靠性和重要度的可行性。展开更多
A DC to 5GHz series MEMS switch is designed and fabricated for wireless communication applications,and thermal effect and power handling of the series switch are discussed.The switch is made on glass substrate,and gol...A DC to 5GHz series MEMS switch is designed and fabricated for wireless communication applications,and thermal effect and power handling of the series switch are discussed.The switch is made on glass substrate,and gold platinum contact is used to get a stable and little insert loss.From DC to 5GHz,0 6dB insertion loss,30dB isolation,and 30μs delay are demonstrated.Thermal effect of the switch is tested in 85℃ and -55℃ atmosphere separately.From DC to 4GHz,the insert loss of the switch increases 0 2dB in 85℃ and 0 4dB in -55℃,while the isolation holds the same value as that in room temperature.To measure the power handling capability of the switch,we applied a continuous RF power increasing from 10dBm to 35 1dBm with the step of 1 0dBm across the switch at 4GHz.The switch keeps working and shows a decrease of the insert loss for 0 1～0 6dB.The maximum continuous power handling (35 1dBm,about 3 24W) is higer than the reported value of shunt switch (about 420mW),which implies series switches have much better power handling capability.展开更多
文摘电力设备状态评估是状态检修的关键一环。为了解决电力设备健康状态评估结果准确性不高这一问题,该文设计了一种基于最优云熵-灰云证据的中高压断路器健康状态评估方法,该方法以云模型和证据理论为基本理论框架。选取适当的定性和定量评价指标建立综合评估体系;在灰云模型的基础上引入最优云熵,结合大数定理对所得隶属度进行二次处理最终确定状态区间隶属度,并将其作为证据理论的基本信度分配(Basic Probability Assignment,BPA);利用不确定系数对BPA进行二次更新;通过改进证据融合规则进行证据融合,所得结果转化为相应的健康指数使评估结果更为直观。实例分析表明,该方法能很好地处理评价过程中的模糊性及随机性,具有一定的参考价值。
文摘故障树分析法(Fault Tree Analysis,FTA),是一种将系统失效形成的原因由总体至部分按树枝状逐级细化的分析方法,可以简化系统结构,降低可靠性及重要度的计算复杂程度。文中以共因失效系统(Common Cause Failure System,CCF)作为研究对象,基于FTA方法,给出了系统结构通过各种不同的逻辑门(与门、或门、非门等)转化为故障树的表示方法,并提出了基于故障树的系统可靠性和Birnbaum重要度的隐式替代算法,最后针对串联和并联案例分别进行了系统可靠性及Birnbaum重要度的计算,结果验证了基于故障树方法计算系统可靠性和重要度的可行性。
文摘A DC to 5GHz series MEMS switch is designed and fabricated for wireless communication applications,and thermal effect and power handling of the series switch are discussed.The switch is made on glass substrate,and gold platinum contact is used to get a stable and little insert loss.From DC to 5GHz,0 6dB insertion loss,30dB isolation,and 30μs delay are demonstrated.Thermal effect of the switch is tested in 85℃ and -55℃ atmosphere separately.From DC to 4GHz,the insert loss of the switch increases 0 2dB in 85℃ and 0 4dB in -55℃,while the isolation holds the same value as that in room temperature.To measure the power handling capability of the switch,we applied a continuous RF power increasing from 10dBm to 35 1dBm with the step of 1 0dBm across the switch at 4GHz.The switch keeps working and shows a decrease of the insert loss for 0 1～0 6dB.The maximum continuous power handling (35 1dBm,about 3 24W) is higer than the reported value of shunt switch (about 420mW),which implies series switches have much better power handling capability.
