固态功率控制器SSPC(solid-state power controller)中功率管的结温监测对SSPC的可靠性有至关重要的作用,热模型法因其无需直接接触测量且方法简单而被广泛使用。然而,功率芯片的老化会导致热路径的退化,器件的结壳热阻抗增加,使实际结...固态功率控制器SSPC(solid-state power controller)中功率管的结温监测对SSPC的可靠性有至关重要的作用,热模型法因其无需直接接触测量且方法简单而被广泛使用。然而,功率芯片的老化会导致热路径的退化,器件的结壳热阻抗增加,使实际结温远远超过热网络模型的估计值,导致对器件健康状态的乐观估计。焊料层疲劳失效被认为是SSPC功率管老化失效的主要原因之一。因此,在SSPC的寿命周期中实时监测器件的老化状态,并对功率管的热模型进行自适应在线修正,通过测量不受焊料层退化影响的热敏参数来计算热阻作为更新依据,将热阻信息关联焊料层老化状态来更新热模型。所提方法可在不影响SSPC正常工作的前提下,实时修正热模型,实验结果验证了方法的有效性。展开更多
Although disintegrated dolomite,widely distributed across the globe,has conventionally been a focus of research in underground engineering,the issue of slope stability issues in disintegrated dolomite strata is gainin...Although disintegrated dolomite,widely distributed across the globe,has conventionally been a focus of research in underground engineering,the issue of slope stability issues in disintegrated dolomite strata is gaining increasing prominence.This is primarily due to their unique properties,including low strength and loose structure.Current methods for evaluating slope stability,such as basic quality(BQ)and slope stability probability classification(SSPC),do not adequately account for the poor integrity and structural fragmentation characteristic of disintegrated dolomite.To address this challenge,an analysis of the applicability of the limit equilibrium method(LEM),BQ,and SSPC methods was conducted on eight disintegrated dolomite slopes located in Baoshan,Southwest China.However,conflicting results were obtained.Therefore,this paper introduces a novel method,SMRDDS,to provide rapid and accurate assessment of disintegrated dolomite slope stability.This method incorporates parameters such as disintegrated grade,joint state,groundwater conditions,and excavation methods.The findings reveal that six slopes exhibit stability,while two are considered partially unstable.Notably,the proposed method demonstrates a closer match with the actual conditions and is more time-efficient compared with the BQ and SSPC methods.However,due to the limited research on disintegrated dolomite slopes,the results of the SMRDDS method tend to be conservative as a safety precaution.In conclusion,the SMRDDS method can quickly evaluate the current situation of disintegrated dolomite slopes in the field.This contributes significantly to disaster risk reduction for disintegrated dolomite slopes.展开更多
随着电动飞机的发展,固态功率控制器(SSPC)作为关键器件,逐渐成为国内外研究的热点。由于SSPC结构复杂且需要频繁调试,所以准确的仿真模型可以为产品设计提供较大帮助。主要使用Ansys Q3D Extractor等软件,对第三代CREE SiC MOSFET组成...随着电动飞机的发展,固态功率控制器(SSPC)作为关键器件,逐渐成为国内外研究的热点。由于SSPC结构复杂且需要频繁调试,所以准确的仿真模型可以为产品设计提供较大帮助。主要使用Ansys Q3D Extractor等软件,对第三代CREE SiC MOSFET组成的SSPC进行基于产品结构的寄生参数提取,并建立SSPC单路和整体电学等效模型。对SSPC的阻性负载开关特性进行了仿真分析,发现波形中并无明显振荡现象。最后得出了寄生参数的影响基本可以忽略的结论。展开更多
The preparation of lead-free thick-film resistors are reported:using RuO 2 and ruthenates as conductive particles,glass powders composed of B 2 O 3,SiO 2,CaO and Al2 O 3 as insulating phase,adding organic matter which...The preparation of lead-free thick-film resistors are reported:using RuO 2 and ruthenates as conductive particles,glass powders composed of B 2 O 3,SiO 2,CaO and Al2 O 3 as insulating phase,adding organic matter which mainly consists of ethyl cellulose and terpineol to form printable pastes.Resistors were fabricated and sintered by conventional screen-printing on 96%Al 2 O 3 substrates,and then sintering in a belt furnace.X-ray diffraction(XRD) and electron scanning microscopy(SEM) have been used to characterize the conductive particles.The resistors exhibit good refiring stability and low temperature coefficient of resistance.Sheet resistance spans from about 80Ω/□ to 600Ω/□.The resistors prepared are qualified for common use.展开更多
文摘固态功率控制器SSPC(solid-state power controller)中功率管的结温监测对SSPC的可靠性有至关重要的作用,热模型法因其无需直接接触测量且方法简单而被广泛使用。然而,功率芯片的老化会导致热路径的退化,器件的结壳热阻抗增加,使实际结温远远超过热网络模型的估计值,导致对器件健康状态的乐观估计。焊料层疲劳失效被认为是SSPC功率管老化失效的主要原因之一。因此,在SSPC的寿命周期中实时监测器件的老化状态,并对功率管的热模型进行自适应在线修正,通过测量不受焊料层退化影响的热敏参数来计算热阻作为更新依据,将热阻信息关联焊料层老化状态来更新热模型。所提方法可在不影响SSPC正常工作的前提下,实时修正热模型,实验结果验证了方法的有效性。
基金supported by the National Natural Science Foundation of China(Grant No.42162026)the Applied Basic Research Foundation of Yunnan Province(Grant No.202201AT070083).
文摘Although disintegrated dolomite,widely distributed across the globe,has conventionally been a focus of research in underground engineering,the issue of slope stability issues in disintegrated dolomite strata is gaining increasing prominence.This is primarily due to their unique properties,including low strength and loose structure.Current methods for evaluating slope stability,such as basic quality(BQ)and slope stability probability classification(SSPC),do not adequately account for the poor integrity and structural fragmentation characteristic of disintegrated dolomite.To address this challenge,an analysis of the applicability of the limit equilibrium method(LEM),BQ,and SSPC methods was conducted on eight disintegrated dolomite slopes located in Baoshan,Southwest China.However,conflicting results were obtained.Therefore,this paper introduces a novel method,SMRDDS,to provide rapid and accurate assessment of disintegrated dolomite slope stability.This method incorporates parameters such as disintegrated grade,joint state,groundwater conditions,and excavation methods.The findings reveal that six slopes exhibit stability,while two are considered partially unstable.Notably,the proposed method demonstrates a closer match with the actual conditions and is more time-efficient compared with the BQ and SSPC methods.However,due to the limited research on disintegrated dolomite slopes,the results of the SMRDDS method tend to be conservative as a safety precaution.In conclusion,the SMRDDS method can quickly evaluate the current situation of disintegrated dolomite slopes in the field.This contributes significantly to disaster risk reduction for disintegrated dolomite slopes.
文摘随着电动飞机的发展,固态功率控制器(SSPC)作为关键器件,逐渐成为国内外研究的热点。由于SSPC结构复杂且需要频繁调试,所以准确的仿真模型可以为产品设计提供较大帮助。主要使用Ansys Q3D Extractor等软件,对第三代CREE SiC MOSFET组成的SSPC进行基于产品结构的寄生参数提取,并建立SSPC单路和整体电学等效模型。对SSPC的阻性负载开关特性进行了仿真分析,发现波形中并无明显振荡现象。最后得出了寄生参数的影响基本可以忽略的结论。
文摘The preparation of lead-free thick-film resistors are reported:using RuO 2 and ruthenates as conductive particles,glass powders composed of B 2 O 3,SiO 2,CaO and Al2 O 3 as insulating phase,adding organic matter which mainly consists of ethyl cellulose and terpineol to form printable pastes.Resistors were fabricated and sintered by conventional screen-printing on 96%Al 2 O 3 substrates,and then sintering in a belt furnace.X-ray diffraction(XRD) and electron scanning microscopy(SEM) have been used to characterize the conductive particles.The resistors exhibit good refiring stability and low temperature coefficient of resistance.Sheet resistance spans from about 80Ω/□ to 600Ω/□.The resistors prepared are qualified for common use.
