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Analysis for the Defect of Chromatogram in 35kv Oil-immersed Electric Reactor

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Energy and Power Engineering 2013年第4期5卷 838-841页

作者： Yongdong Li Qingda Meng Zheyuan Zhao Po Yang Yuzheng Wang maintenance of northern Hebei Province Electric Power Co. Ltd Substation maintenance center Beijing China

A defect of chromatogram in a 35kV oil-immersed three-phase one-piece electric reactor in a 500kV substation。The initial analysis suggests that the defect is caused by the loose connection of the iron core magnet shield (magnet shield layer of iron core or earthling top). Examination of winding DC resistance, DGA and other relevant examinations were carried out to investigate the defect reasons., which is demonstrated by the dismantlement. In-depth study is taken and corresponding prevention measures are put forward in the paper.

关键词： Oil-immersed Electric Reactor Chromatogram Defect Magnet Shield Layer Partial Discharge

IEC61850 standard-based harmonic blocking scheme for power transformers

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Protection and Control of Modern Power Systems 2019年第1期4卷 123-137页

作者： Senthil Krishnamurthy Bwandakassy Elenga Baningobera center for substation Automation and Energy Management Systems(CSAEMS) DEECECape Peninsula University of TechnologyPO BOX 1906Bellville 7535South Africa

Transformer Differential and overcurrent schemes are traditionally used as main and backup protection respectively. The differential protection relay (SEL487E) has dedicated harmonic restraint function which blocks the relay tripping during the transformer magnetizing inrush conditions. However, the backup overcurrent relay (SEL751A) applied to the transformer protection does not have harmonic restraint element and trip the overcurrent relay during the inrush conditions. Therefore, major contribution of this research work is the developed harmonic blocking scheme for transformer which uses element (87HB) of the transformer differential relay (SEL487E) to send an IEC61850 GOOSE-based harmonic blocking signal to the backup overcurrent relay (SEL751A) to inhibit from tripping during the transformer magnetizing inrush current conditions. The simulation results proved that IEC61850 standard-based protection scheme is faster than the hardwired signals. Therefore, the speed and reliability of the transformer scheme are improved using the IEC61850 standard-based GOOSE applications.

关键词： Transformer protection Overcurrent protection Digital protection scheme Current differential protection Transformer magnetizing inrush current Harmonic blocking IEC 61850 GOOSE message

The Discussion of 500kv Centralized Monitoring System For Large Operation and Large maintenance Mode

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Engineering（科研） 2013年第1期5卷 127-131页

作者： lingling Shuai Xiaojiang Liu Jun Li Jiangxi Electric Power Co. maintenance Branch Nanchang China

The establishment of a centralized monitoring system is an effective means to achieve the goal that no or fewer people are on duty. The function of the current 500kV centralized monitoring system is not enough mature to meet the requirement of the large-scale operation and large-scale maintenance model proposed by the State Grid. In order to fully utilizing the function of the centralized monitoring system, an improved design scheme is presented for the current 500kV centralized monitoring of the Jiangxi Power Grid. The improved centralized monitoring system is divided into three layers: monitoring center layer, operating team layer, and substation layer, which not only has the advantages of high security, high reliability, and easy maintenance, but also realizes the management model of regional control. So it can perfectly meet anti-misoperation requirement in the large operation and large maintenance mode, which can provide reference and guidance for the design of the 500kV centralized monitoring system of Jiangxi Power Grid.

关键词： Centralized monitoring system substation Anti-misoperation system Five-prevention system

Prognostic significance of the hemoglobin A1c level in non-diabetic patients undergoing percutaneous coronary intervention: a meta-analysis

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Chinese Medical Journal 2020年第18期133卷 2229-2235页

作者： Yan Li Xiao-Wen Li Yin-Hua Zhang Lei-Min Zhang Qing-Qing Wu Zhao-Run Bai Jin Si Xue-Bing Zuo Ning Shi Jing Li Xi Chu Department of Cardiology Xuanwu HospitalCapital Medical UniversityBeijing 100053China Department of Emergency Aerospace Center HospitalBeijing 100049China Department of Internal Medicine Qinghe Substation Hospital of Beijing Municipal Administration of PrisonsBeijing 300481China Department of Cardiology Beijing Luhe HospitalCapital Medical UniversityBeijing 101149China Health Management center Xuanwu HospitalCapital Medical UniversityBeijing 100053China

Background:The predictive value of hemoglobin A1c(HbA1c)levels in non-diabetic patients with myocardial infarction undergoing percutaneous coronary intervention(PCI)is still *** study aimed to evaluate whether HbA1c levels were independently associated with adverse clinical outcomes in non-diabetic patients with coronary artery disease(CAD)who had undergone PCI by performing a meta-analysis of cohort ***:This meta-analysis included non-diabetic patients with CAD who had undergone PCI.A systematic search for publications listed in the PubMed,Embase,and Cochrane Library databases from commencement to December 2018 was *** evaluating the adverse clinical outcomes according to abnormal HbA1c levels in non-diabetic patients diagnosed with CAD who had undergone PCI were *** primary outcomes were long-term all-cause deaths and long-term major adverse cardiac events,and the secondary outcome was short-term all-cause *** meta-analysis was conducted with RevMan 5.3 and Stata software *** ratios(ORs)were pooled using a random or fixed-effects model,depending on the heterogeneity of the included ***-group analysis or sensitivity analysis was conducted to explore potential sources of heterogeneity,when ***:Six prospective cohort studies involving 10,721 patients met the inclusion *** the pooled analysis,abnormal HbA1c levels were associated with increased risk for long-term all-cause death(OR 1.39,95%confidence interval[CI]1.16-1.68,P=0.001,I2=45%).Sub-group analysis suggested that abnormal HbA1c levels between 6.0%and 6.5%predicted higher long-term major adverse cardiac event(including all-cause deaths,non-fatal myocardial infarction,target lesion revascularization,target vessel revascularization,recurrent acute myocardial infarction,heart failure requiring hospitalization,and stent thrombosis)risk(OR 2.05,95%CI 1.46-2.87,P<0.001,I2=0).Contrarily,elevated HbA1c levels were not associa

关键词： Acute myocardial infarction Hemoglobin A1c Percutaneous coronary intervention Pre-diabetes

Function Analysis of the Enterprise Skills Training center in the Engineering Education Field

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Function Analysis of the Enterprise Skills Training Center i...

Relationship between serum homocysteine levels and long-term outcomes in patients with ST-segment elevation myocardial infarction

2013年教育技术与管理科学国际会议

作者： Guihua Lin Tao Wang Grid maintenance training department State Grid of China Technology College

The excellent engineer education and cultivation program carried out by the Ministry of Education aims to cultivate a large number of superior technical talents of superb innovation ability and of high adaptability to the needs of economic and social development. Especially in the program "full-time professional master" launched in 2009, the cultivation of superior talents of engineering research ability and application ability was highly accentuated. This essay, aiming at some problems existing in the current engineering education field and based on the engineering education cooperation and practice of substation secondary equipment maintenance of State Grid of China Technology College-State Grid Corporation of China skills training centre and Shandong university, explores the function of enterprise skills training center in the engineering education and the combination model of production, study and research. Moreover, this essay brings forward the feasible scheme for the next cooperation mode in the combination model of production and research of universities and enterprise skills training center and the engineering education development mode.

关键词： engineering education production, study and research combination state-owned enterprise skills training center

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Chinese Medical Journal 2019年第9期132卷 1028-1036页

作者： Jin Si Xue-Wen Li Yang Wang Ying-Hua Zhang Qing-Qing Wu Lei-Min Zhang Xue-Bing Zuo Jing Gao Jing Li Department of Cardiology Xuanwu HospitalCapital Medical UniversityBeijing 100053China Department of Cardiology Tianjin Medical UniversityTianjin 300070China Cadre's Ward Characteristic Medical Center of Chinese People's Armed Police ForceTianjin 300162China Medical Research & Biometrics center National Center for Cardiovascular DiseasesFuwai HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100037China Department of Cardiology Beijing Luhe HospitalCapital Medical UniversityBeijing 101149China Department of Cardiology Qinghe Substation Hospital of Beijing Municipal Administration of PrisonsTianjin 300481China

Background:The mortality of cardiovascular disease is constantly rising,and novel biomarkers help us predict residual *** study aimed to evaluate the predictive value of serum homocysteine (HCY) levels on prognosis in patients with ST-segment elevation myocardial infarction (STEMI).Methods:The 419 consecutive patients with STEMI,treated at one medical center,from March 2010 to December 2015 were retrospectively *** blood samples were obtained within 24 h of admission and HCY concentrations were measured using an enzymatic cycling *** patients were divided into high HCY level (H-HCY) and low HCY level (L-HCY) ***- and long-term outcomes were compared,as were age-based subgroups (patients aged 60 years and younger *** older than 60 years).Statistical analyses were mainly conducted by Student t-test,Chi-squared test,logistic regression,and Cox proportional-hazards ***:The H-HCY group had more males (84.6% vs.75.4%,P=0.018),and a lower prevalence of diabetes (20.2% vs.35.5%,P<0.001),compared with the L-HCY *** hospitalization,there were seven mortalities in the L-HCY group and 10 in the H-HCY group (3.3% vs.4.8%,P= 0.440).During the median follow-up period of 35.8 (26.9–46.1) months,33 (16.2%) patients in the L-HCY group and 48 (24.2%) in the H-HCY group experienced major adverse cardiovascular and cerebrovascular events (MACCE)(P=0.120).History of hypertension (hazard ratio [HR]:1.881,95% confidence interval [CI]:1.178–3.005,P=0.008) and higher Killip class (HR:1.923,95% CI:1.419–2.607,P<0.001),but not HCY levels (HR:1.007,95% CI:0.987–1.027,P=0.507),were significantly associated with long-term ***,the subgroup analysis indicated that in older patients,HCY levels were significantly associated with long-term outcomes (HR:1.036,95% CI:1.011–1.062,P=0.005).Conclusion:Serum HCY levels did not independently predict in-hospital or long-term outcomes in patients with STEMI;however,among elderly

关键词： Homocysteine Acute ST-segment elevation myocardial infarction Percutaneous coronary intervention Clinical outcome

Automatic infrared image recognition method for substation equipment based on a deep self-attention network and multi-factor similarity calculation

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Global Energy Interconnection 2022年第4期5卷 397-408页

作者： Yaocheng Li Yongpeng Xu Mingkai Xu Siyuan Wang Zhicheng Xie Zhe Li Xiuchen Jiang School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University200240 ShanghaiP.R.China State Grid Shandong Electric Power Company Jinan Power Supply Company 250001 ShandongP.R.China maintenance&Test center of EHV power Transmission Company China Southern Power Grid510000 GuangdongP.R.China

Infrared image recognition plays an important role in the inspection of power *** technologies dedicated to this purpose often require manually selected features,which are not transferable and interpretable,and have limited training *** address these limitations,this paper proposes an automatic infrared image recognition framework,which includes an object recognition module based on a deep self-attention network and a temperature distribution identification module based on a multi-factor similarity ***,the features of an input image are extracted and embedded using a multi-head attention encoding-decoding ***,the embedded features are used to predict the equipment component category and *** the located area,preliminary segmentation is ***,similar areas are gradually merged,and the temperature distribution of the equipment is obtained to identify a *** experiments indicate that the proposed method demonstrates significantly improved accuracy compared with other related methods and,hence,provides a good reference for the automation of power equipment inspection.

关键词： substation equipment Infrared image intelligent recognition Deep self-attention network Multi-factor similarity calculation

A quantitative research on the level of disturbance to secondary signal ports of electronic voltage transformers under the operation of gas‐insulated switchgear

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High Voltage 2022年第1期7卷 165-175页

作者： Qi Wang Chao Fu Fanwu Chu Yue Tong Xiaozhou Wang Guoxiong Ye Xiong Wu Power Industry Electrical Equipment Quality Inspection and Testing center China Electric Power Research InstituteWuhanChina

The collectors of electronic transformers has the problem of electromagnetic in-compatibility under the operation of disconnecting switches,which limits their wide application in smart *** evaluate the maximum level of disturbance that collectors are able to withstand in the stochastic process of switching operation,this work in-troduces a quantitative approach based on limited test measurements,which can quantify the level of disturbance in the signal acquisition ports of electronic voltage transformers(EVT)in different gas‐insulated switchgears(GIS).Based on large numbers of experi-mental statistical data of the true type simulation experimental platform,the Spearman rank correlation coefficient is used to prove that the amplitude of the disturbance voltage pulse at the secondary side port and the breakdown voltage between the primary side fracture approximately satisfy a linear ***,the quantile regression model is used to quantify and verify the maximum disturbance level of the secondary side ***,a solution is proposed to tackle the difficulty in obtaining the breakdown voltage at breaks in the GIS substation field applicatvion,under which the quantified maximum disturbance voltage deviation of secondary ports is only−4.34%by *** research work can further explore the practical value of the measured data in a few tests under GIS substation field conditions and provide references for the sub-sequent revision of EVT‐related standards.

关键词： disturbance operation electronic

Integrated Wide Area Protection and Control for Power Grid Security

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CSEE Journal of Power and Energy Systems 2019年第2期5卷 206-214页

作者： Qingping Wang Zhiqian Bo Yingke Zhao Xiaowei Ma Ming Zhang Hao Zheng Lin Wang Corporate R&D center XJ Group CorporationState Grid Corporation of ChinaBeijingChina

The traditional“three defense lines”for power systems are based on local information and static protection&control strategy,which are not suitable to modern large-scale power *** order to improve the security of UHV hybrid power grids,the Integrated Wide Area Protection&Control(IWAPC)is proposed in this paper by applying the new technologies of synchronized high-speed communication,which integrates“three defense lines”and promotes existing wide area protection only for security *** IWAPC is the hierarchical protection and control system which provides the protection and control for wide area power networks to improve their reliability and *** is divided into three levels,the local bay level,the substation integrated protection level and the wide area protection *** wide area real-time protection and control information platform is the most important part of the IWAPC,which is based on a synchronized wide area communication *** key technologies and new development trends include network topology analysis,wide area backup protection,wide area intelligent reclosing,wide area load shedding,wide area auto-switching,overload cutoff and transfer,transmission section protection,intelligent system splitting and dynamic stability *** cannot only integrate three lines of defense for power system protection and control,but also improve security of the power grid.

关键词： Digital substation power grid security control system protection wide area protection&control