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Zhang H.,Zhejiang Electrical Power Corporation | Yue L.-P.,Zhejiang Electrical Power Corporation | Wei F.-X.,China Three Gorges University | Gong H.,State Grid Electric Power Research Institute of China
Applied Mechanics and Materials | Year: 2013

An online monitoring system of main insulation and outer sheath of power cable is designed in this paper. The system can monitor the insulation of the power cable without change the normal power cable wiring and grid structure. Changes of the main insulation and outer sheath of power cable can be monitor and recorded. Alarm of given when the insulation of the power cable is abnormal. System managers arrange outage maintenance depends on the status of the power cable. © (2013) Trans Tech Publications, Switzerland.

Yue L.-P.,Zhejiang Electrical Power Corporation | Zhang H.,Zhejiang Electrical Power Corporation | Gong H.,State Grid Electric Power Research Institute of China | Wei F.-X.,China Three Gorges University
Applied Mechanics and Materials | Year: 2013

This paper describes the detail of design and implementation of cable condition monitoring system, including accessing and sharing of monitoring data, visualization, query, analysis and device management. © (2013) Trans Tech Publications, Switzerland.

Hu S.,CAS Institute of Computing Technology | Liu W.,CAS Institute of Computing Technology | Rabl T.,University of Toronto | Huang S.,CAS Institute of Computing Technology | And 5 more authors.
Proceedings - International Conference on Data Engineering | Year: 2015

Hive is the most mature and prevalent data warehouse tool providing SQL-like interface in the Hadoop ecosystem. It is successfully used in many Internet companies and shows its value for big data processing in traditional industries. However, enterprise big data processing systems as in Smart Grid applications usually require complicated business logics and involve many data manipulation operations like updates and deletes. Hive cannot offer sufficient support for these while preserving high query performance. Hive using the Hadoop Distributed File System (HDFS) for storage cannot implement data manipulation efficiently and Hive on HBase suffers from poor query performance even though it can support faster data manipulation. There is a project based on Hive issue Hive-5317 to support update operations, but it has not been finished in Hive's latest version. Since this ACID compliant extension adopts same data storage format on HDFS, the update performance problem is not solved. In this paper, we propose a hybrid storage model called DualTable, which combines the efficient streaming reads of HDFS and the random write capability of HBase. Hive on DualTable provides better data manipulation support and preserves query performance at the same time. Experiments on a TPC-H data set and on a real smart grid data set show that Hive on DualTable is up to 10 times faster than Hive when executing update and delete operations. © 2015 IEEE.

Liao R.-J.,Chongqing University | Sun H.-G.,ABB | Gong J.,Zhejiang Electrical Power Corporation | Li W.,Bishan Power Supply Bureau of Chongqing Electrical Power Corporation | And 2 more authors.
Gaodianya Jishu/High Voltage Engineering | Year: 2011

Using #25 transformer oil and ordinary kraft paper as raw materials, we simulated the actual transformer production process, in which the initial moisture contents of the oil-paper samples were set to be 1%, 3%, and 5%, and were aged at 90°C, 110°C, and 130°C. Moreover, we analyzed the polymerization degree of insulation paper in ageing process and cellulose degradation kinetic model in terms of DP. The main conclusions can be drawn as follows: the higher temperature and the more moisture contents are, the faster the degree of polymerization will decline, and more rapidly the oil-paper insulation will age. The insulation ageing rate is not constant but decreases with ageing time. The cellulose degradation kinetic model in terms of the DP loss accumulation is able to explain the real experimental data of cellulose ageing in mineral oil under different temperature and moisture contents. The apparent activation energy for kraft paper ageing in mineral oil is Ea=(101±15) kJ/mol. The oil-paper insulation life prediction model is thus established based on time-temperature superposition theory and DP loss accumulation kinetic model.

Zhou Q.,Accenture | Hou F.,Accenture | Huang Y.,Zhejiang Electrical Power Corporation
Proceedings of the 2013 IEEE 7th International Power Engineering and Optimization Conference, PEOCO 2013 | Year: 2013

This paper presents a new solution for load management of a power grid to address the ever growing supply shortage problem. It profiles customers' load behavior data provided by the advanced metering infrastructure and divides the power customers into groups based on their usage characteristics. The possible load management strategy for each of the group(s) was developed to guide the customer's participation in the system load shaving process. An optimization model is developed to perform the load shaving analysis subject to the constraints of the customer participation strategies for each of the group(s) and other load management constraints. The optimization solution provides a recommended load management decision for each of the power customers in order to optimally reduce the system peak load and increase the valley load such that the predicted system peak hour supply shortage could be avoided. The developed load shaving optimization model was solved utilizing the Mixed Integer Linear Programming technique. © 2013 IEEE.

Zhang X.,Dalian Maritime University | An J.,Dalian Maritime University | Chen F.,Zhejiang Electrical Power Corporation
Proceedings - 2010 2nd WRI Global Congress on Intelligent Systems, GCIS 2010 | Year: 2010

In this paper, a new method of insulator fault detection by texture feature sequence is proposed. Morphology, Hough transform line detection and statistic texture feature are applied to this method. Because there are some noises during image shooting, it is necessary that the insulator image should be preprocessed and corrected. The preprocessing includes image grayness, image enhancement and morphological processing. The insulator tilt correction is based on Hough transform line detection. Then, the processed insulator image is separated into ten parts. Each part of ten parts is featured by seven texture values. The matrix is constructed by ten columns which represent ten parts and seven rows which represent seven texture features. Each row of the matrix is defined as a sequence. According to the analysis of seven feature sequence curves, three feature sequence curves are selected because they are active. A fault feature formula that is named CMV is made of the three features. Insulator fault is detected by CMV curve. The position of fault is located by the biggest vale of CMV curve. Experimental results indicate the proper morphological processing improves the precision of Hough transform line detection and the insulator fault is detected and the position of fault is located by the proposed method accurately. © 2010 IEEE.

Liu X.,Huazhong University of Science and Technology | Tao L.,Zhejiang Electrical Power Company | Jiang S.,Huazhong University of Science and Technology | Cheng Y.,Hubei Electric Power Company
Huazhong Keji Daxue Xuebao (Ziran Kexue Ban)/Journal of Huazhong University of Science and Technology (Natural Science Edition) | Year: 2014

The large impulse current generator was delivered to the site, and large simulation lightning current was injected into actual grounding devices of transmission line tower. The potential rise and impulse grounding resistance were measured, and the impulse characteristic parameters of the transmission line tower grounding were obtained. A simulation model of grounding was presented, and the simulation was taken by the ATP-EMTP (ATP-electromagnetic transients program) following the field tests. Comparison between the results of tests and simulation also is completed, and the consistency is good.

Wang Y.,CAS Institute of Computing Technology | Wang Y.,University of Chinese Academy of Sciences | Xu Y.,CAS Institute of Computing Technology | Xu Y.,University of Chinese Academy of Sciences | And 5 more authors.
Proceedings of the ACM SIGMOD International Conference on Management of Data | Year: 2015

Apache Hive has been widely used by Internet companies for big data analytics applications. It can provide the capability of compiling high-level languages into efficient MapReduce workflows, which frees users from complicated and time consuming programming. The popularity of Hive and its HiveQL-compatible systems like Impala and Shark attracts attentions from traditional enterprises as well. However, enterprise big data processing systems such as Smart Grid applications often have to migrate their RDBMS-based legacy applications to Hive rather than directly writing new logic in HiveQL. Considering their differences in syntax and cost model, manual translation from SQL in RDBMS to HiveQL is very difficult, error-prone, and often leads to poor performance. In this paper, we propose QMapper, a tool for automatically translating SQL into proper HiveQL. QMapper consists of a rule-based rewriter and a cost-based optimizer. The experiments based on the TPC-H benchmark demonstrate that, compared to manually rewritten Hive queries provided by Hive contributors, QMapper dramatically reduces the query latency on average. Our real world Smart Grid application also shows its efficiency. Copyright © 2015 ACM.

Zhejiang Electrical Power Corporation | Date: 2011-11-25

A full-automatic detecting system and method for a transformer. The system comprises a material delivery line; a feed device; a detection delivery line; insulating test devices; error detecting devices; a laser marking device; a discharge device; and a detection management system. The insulating test devices, the error detecting devices, and the laser marking device are sequentially arranged beside the detection delivery line. The material delivery line, the detection delivery line, and the devices work in coordination, to realize full-automatic detection of the transformer, avoid manual detection errors and improve the sorting accuracy.

ZHEJIANG Electrical POWER CORPORATION | Date: 2011-11-28

A fully-automatic verification system for intelligent electric energy meters comprises a plurality of verification units for automatic verification of the electric energy meters, main transport lines for connecting the verification units, and a verification management system for coordinating the work of the verification units. The main transport lines comprise upper transport lines for transporting boxes carrying electric energy meters to be verified to the verification units and lower transport lines for transporting the boxes carrying the electric energy meters back to the warehouse. The verification system for electric energy meters can implement fully-automatic verification, thus enhancing the efficiency and the verification accuracy.

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