变压器绝缘油以链烷烃(C n H 2 n+2)为主要化学成分,在变压器长期运行过程中因电弧、放电、过热、受潮等原因导致化学键逐步发生断裂,产生与故障有关的故障判别气体(CH_(4),C_(2)H 2,C_(2)H_(4),C_(2)H 6,CO和CO_(2)),因此变压器绝缘油...变压器绝缘油以链烷烃(C n H 2 n+2)为主要化学成分,在变压器长期运行过程中因电弧、放电、过热、受潮等原因导致化学键逐步发生断裂,产生与故障有关的故障判别气体(CH_(4),C_(2)H 2,C_(2)H_(4),C_(2)H 6,CO和CO_(2)),因此变压器绝缘油中会溶解多组分气体,故需要一种多组分气体的在线检测装置,以保证变压器的正常运行。针对电力行业装配需求,研制基于可调谐激光吸收光谱法(TDLAS)多组分气体的在线检测装置。针对6种故障特征气体的近红外吸收波段,分别选取1580,1654,1626和1530 nm四个近红外激光器,使用分时扫描的时分多路技术,实现对多组分气体的分时快速顺序检测并采用波长调制技术,消除背景气体的交叉干扰。主要检测气体为绝缘油化学键断裂所产生的烃类化合物(CH_(4),C_(2)H 2,C_(2)H_(4)和C_(2)H 6)和碳氧化合物(CO和CO_(2))。在线检测,与变压器油气象色谱测量方法进行对比实验,并对其进行工况稳定性测试。实验结果表明:乙炔浓度测量范围为0.5~1000μL·L^(-1),范围小于5μL·L^(-1)时最大测量误差小于0.8,5~1000μL·L^(-1)时最大误差在6μL·L^(-1)以下;甲烷、乙烷、乙烯的浓度测量范围为0.5~1000μL·L^(-1),最大测量误差小于6μL·L^(-1);碳氧化合物(CO和CO_(2))测量范围分别为25~5000,25~15000μL·L^(-1),最大测量误差分别在2与20μL·L^(-1)以下。所设计的近红外TDLAS多组分气体检测装置能够用于变压器油中溶解气体的在线检测,测量的气体浓度满足在线检测要求,能够稳定运行且适应恶劣工况条件,为检测变压器油中溶解气体在线测量提供了有效的实践经验。展开更多
In order to evaluate the imaging quality of COD cameras fully and rapidly, the minimum resolvable contrast （MRC） is presented in this paper and the system of measuring MRC is constructed as well, in which two integr...In order to evaluate the imaging quality of COD cameras fully and rapidly, the minimum resolvable contrast （MRC） is presented in this paper and the system of measuring MRC is constructed as well, in which two integrating spheres are proposed to illuminate two sides of the target respectively. The variable contrast can be obtained by regulating the luminance of integrating spheres. Experimental results indicate that the error of measuring luminance is within ±0.3 cd/m^2 ,MRC rises with the increase of the spatial frequency. The experimental results show that the method proposed is an effective apprcach to evaluate the imaaina aualitv of COD cameras.展开更多
文摘变压器绝缘油以链烷烃(C n H 2 n+2)为主要化学成分,在变压器长期运行过程中因电弧、放电、过热、受潮等原因导致化学键逐步发生断裂,产生与故障有关的故障判别气体(CH_(4),C_(2)H 2,C_(2)H_(4),C_(2)H 6,CO和CO_(2)),因此变压器绝缘油中会溶解多组分气体,故需要一种多组分气体的在线检测装置,以保证变压器的正常运行。针对电力行业装配需求,研制基于可调谐激光吸收光谱法(TDLAS)多组分气体的在线检测装置。针对6种故障特征气体的近红外吸收波段,分别选取1580,1654,1626和1530 nm四个近红外激光器,使用分时扫描的时分多路技术,实现对多组分气体的分时快速顺序检测并采用波长调制技术,消除背景气体的交叉干扰。主要检测气体为绝缘油化学键断裂所产生的烃类化合物(CH_(4),C_(2)H 2,C_(2)H_(4)和C_(2)H 6)和碳氧化合物(CO和CO_(2))。在线检测,与变压器油气象色谱测量方法进行对比实验,并对其进行工况稳定性测试。实验结果表明:乙炔浓度测量范围为0.5~1000μL·L^(-1),范围小于5μL·L^(-1)时最大测量误差小于0.8,5~1000μL·L^(-1)时最大误差在6μL·L^(-1)以下;甲烷、乙烷、乙烯的浓度测量范围为0.5~1000μL·L^(-1),最大测量误差小于6μL·L^(-1);碳氧化合物(CO和CO_(2))测量范围分别为25~5000,25~15000μL·L^(-1),最大测量误差分别在2与20μL·L^(-1)以下。所设计的近红外TDLAS多组分气体检测装置能够用于变压器油中溶解气体的在线检测,测量的气体浓度满足在线检测要求,能够稳定运行且适应恶劣工况条件,为检测变压器油中溶解气体在线测量提供了有效的实践经验。
基金Supported by Science and Technology Research Project of Educa-tion Department of Heilongjiang Province(10051065)
文摘In order to evaluate the imaging quality of COD cameras fully and rapidly, the minimum resolvable contrast （MRC） is presented in this paper and the system of measuring MRC is constructed as well, in which two integrating spheres are proposed to illuminate two sides of the target respectively. The variable contrast can be obtained by regulating the luminance of integrating spheres. Experimental results indicate that the error of measuring luminance is within ±0.3 cd/m^2 ,MRC rises with the increase of the spatial frequency. The experimental results show that the method proposed is an effective apprcach to evaluate the imaaina aualitv of COD cameras.
