Intelligent Automation and Control Technology Based on Energy Meter Testing and Storage System Construction Model

Transcription

1 Applied Mechanics and Materials Online: ISSN: , Vol. 455, pp doi: / Trans Tech Publications, Switzerland Intelligent Automation and Control Technology Based on Energy Meter Testing and Storage System Construction Model Huai-Ling Shao 1, a, Zhi-Qiang He 1, b, Er-Qiang Xu 1, c,lei Liu 2,d 1 Metrology Centre of Electric Power of Henan.Jinshui Road,Zhengzhou CBD,Henan,China 2 Zhengzhou Power Supply Company Zhengzhou CBD Branch.Hanghai Road, Zhengzhou City,Henan,China a @139.com, b @139.com, c xu_push@163.com, b @139.com Keywords: Automated test, Intelligent storage, Production scheduling platform, Risk prevention and controlt Abstract. Explains smart energy meter testing and storage systems,the background,analysis of the current development of the industry at home and abroad,focusing on Metrology Centre of Electric Power of Henan meter verification and storage systems,the content of the system in key technologies summary,the process of building the proposed risk control measures. Introduction In recent years, along with China s promotion of the smart electric grid, smart electric meters are in great use in the whole nation. According to the slogan Big Marketing of the State Grid Corporation of China, it is necessary to further optimize and integrate the metering resources and construct the provincial centralized metering system. In the traditional mode, it requires a great amount of resources such as manpower, space and equipment for testing, storing, and delivering electric meters, which is apparently not adapted to requirements for energy metering and management in the new situation. In this paper, we summarize the experience of Metering Center of Henan Electric Power Cooperation (MCHEPC) in practice of Automatic Testing, Intelligent Storage and Logistic Delivery, aimed to provide reference in constructing metering centralized systems for other provincial electric power companies. The Research Status at Home and Abroad. Since the 21st century, as automatic control technology is getting mature, the technology of automatic testing, and intelligent storage for the electric meters has made great progress in the field of measuring and verification. Itron Metering System Company in the United States, and Landis+Gyr Company in Switzerland have developed automatic testing line for the factory test of electric meters. In 2005, Flexlink Company in Sweden cooperating with Zhengzhou SMS Electric Company designed a set of three-phase electric meter testing assembly line for DONG Electric Company in Denmark, equipped with functions such as automatic transmission, automatic wiring, automatic checking, automatic assembly, etc, which reflects high degree of automation and advanced design ideas. In China, some manufacturers producing testing devices or electric meters such as SMS, Clou, the New Century, Sida, Aventis, Granville have begun to develop, produce and put into practice the automatic testing assembly line. At the same time, Chinese power companies also tried to develop the system of automatic testing and storage. In the December of 2007, Metering Center of Chongqing State Grid Company built an automatic electric meter stereoscopic warehouse. It achieved the function of automatic out-put and in-put of warehouse and batch testing for electric meters, providing valuable experience for the power companies to carry out intensive management of energy metering devices. In June, 2009, Shaoxing All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, (ID: , Pennsylvania State University, University Park, USA-09/04/16,13:10:04)

2 Applied Mechanics and Materials Vol Power Authority in Zhejiang province built the first automatic single-phase testing lines for electric meters in China. Then the research and development of automatic testing for electric meters began to be carried out. A new system of automatic single-phase testing for smart electric meters was completed and put into trial use by Metering Center of Henan Electric Power Company. The system uses a flexible chain conveyor system as a transportation unit, achieves "seamless joint" with intelligent storage system physically, connected with production scheduling platform in management, and adopts techniques of automatic control and logistics transportation, making the whole process for electric meters (transmission, puncture test, visual inspection, programming, accuracy testing, seals, and labeling, etc) automatic. Construction Contents. The construction contents of MCHEPC mainly include: automatic verification system, intelligent storage system, and production scheduling platform. Automatic Testing System. The system built in MCHEPC is an overall automatic system for smart meter testing. It uses flexible chain conveyor system as a delivery unit, achieves seamless joint with automatic storage and logistics systems physically, and connected with the intelligent production scheduling platform of the metering center in management. It can receive meter testing tasks assigned by the marketing system, coordinate with the production scheduling platform, and finish meter testing automatically. The main processes of the system are as follows: first, the storage system gets meter boxes (stack) out of the warehouse and sends them to the connection place to the testing system through hoists; second, meter boxes are unpacked and conveyed to the feeding unit and feeding robots take the meters and place them to the testing line trays; third, the testing system does puncture test, visual inspection, automatic turning on programming switch, accuracy and versatility test and other tests in turn automatically; finally according to the test results, the system does automatically sorting and distribution. Qualified meters will be automatically sealed, labeled and packed to the next feeding unit for packing, stack and storage. Substandard meters are delivered to the unqualified exit for boxing. The testing system has six testing branch lines (containing 96 meter locations), which share a set of standard meters and a multi-function digital meter source. The main technical indicators of the testing system are given as follows: (1) Accuracy level: 0.1; (2) Measurement range: 220V, (0.05 ~ 100) A; (3) Minimum Output Current: 5mA, the measurement accuracy of current and power is not less than 5%; (4) Standard Meter: Multi-range, accuracy is 0.05, the annual variation 300ppm; (5) Measuring range of standard meter: 220V, (0.05 ~ 100) A; (6) Accuracy of standard frequency meter: 10~8. The automatic testing mode works in the same principle as the traditional testing mode, but in the former mode, the continuous experiments are carried out for a large quantity of meters on multi-locations, thus this results in a higher requirement in many aspects such as the power source capacity of the testing device, and communication etc. Intelligent Storage System. The intelligent storage system designed in MCHPEC is a logistics, warehousing and distribution system. It makes use of three-dimensional shelves, roadway stackers, lift reciprocating conveyors, reciprocating shuttle cars, automatic conveyor systems, conveyor electrical control systems and computer systems to achieve intelligent storage and metering equipment delivery. The intelligent storage system is physically connected seamlessly to the automatic testing system, and connected to the intelligent production scheduling platform of the management center, which enables itself to receive the storage, warehousing, distribution and other

3 404 Mechanical Materials and Manufacturing Engineering III tasks assigned by the marketing system. Coordinated with the production scheduling platform, the intelligent storage system can auto-complete meter storage and transport. The storage system mainly includes a pre-stacking operation zone, an automatic meter-stacking warehouse and a connection place to the testing system. Production Scheduling Platform. This is a production management software system, using J2EE technology, database technology, network technology and other measures to achieve unified management operations. The production scheduling platform achieves business integration and platform management. There are three main aspects in the business functions. First, it is connected to marketing business application systems, ERP systems, RFID asset identification systems, logistics and distribution system and other external systems; Second, it coordinates intelligence storage system and the automatic testing system to realize automatic testing for electric meters. Third, it provides many specific business functions such as production management, production monitoring, production analysis, metrology. Key Technologies Automatic Testing Technology for Electric Meters. The meter testing technology combining automatic control and logistics transportation realizes the automatic whole process of testing electric meters (including transmission, high-voltage test, visual inspection, programming, accuracy testing, seals, and labeling, etc). These new techniques are hardly applied in the field of measuring and testing internationally and it is the first time in China that such a large-scale system making use of these new technologies has been built and applied. The key techniques of automatic control and logistics transportation include the following aspects. Three-Dimensional Flexible Chain Plate Transmission. The testing system uses a flexible chain plate conveyor system as its delivery carrier for electric meters. The main features include: (1) The system can design special climbing, turning, crossing transmission lines meeting the demand of production; (2) The system can give a flexible layout based on ground condition and functional unit requirement; (3) The system also has so good extensibility that the number of testing meter units, the number and the layout of testing lines can be flexibly designed according to the characteristics of ground; (4) The transmission speed of the chain plate can be adjusted in a certain range according to capacity requirements. Active Online Automatic Positioning Wiring. The feature of the wiring mode is: on the testing conveyor line, the electric meters can be wired automatically without leaving the assembly line which is promoted by the wiring sector initiatively after achieving accurate positioning through the automatic positioning mechanism. Having already tested the system at great length, we find that the rate of wiring successfully will be up to 100% when the size of the electric meters meets the standard size. A unit of automatic positioning wiring is shown in Figure 1: Fig.1 Automatic positioning of the active online connection

4 Applied Mechanics and Materials Vol Online Automatic Sealing. On the assembly line, the system adopts the automatic locking type sealing technology which completes the automatic installation of sealing through the automatic feeding equipment and automated assembly equipment. And combined with the laser coding digital identification technology, it seals qualified meters and sorts out unqualified meters automatically. This method prevents unscrewing the sealing screw, so as to preventing others from ruining the seals arbitrary. The lid of the seal is designed coordinately with the base. Once buttoned up, the cover will not be taken unless using destructive means. The two-dimensional identification code under the sealing cover plays an effective role in anti-counterfeiting. Image Recognition Technology. During the testing process, the system uses industrial cameras to capture LCD display screen of electric meters automatically for automatic LCD detection. At the same time, it compares the detecting information with the standard information and correct data stored in the system to complete the visual inspection and charged inspection items for the electric meters. Intelligent Storage Technology for Electric Meters Identification Technology of Electric Meter Assets based on RFID. Arrival receiving RF-door uses advanced RFID (radio frequency identification) technology that uses the space coupling of radio frequency signals for non-contact transmission of information, making the process of device identification batch, accurate, and high-speed. Currently, for the electric meters received or tested qualified by metering center with RFID tags and unique asset number of internal storage, when they are put into and out of the warehouse, the identification rate of the RF-door is up to 100%, and the recognition rate is up to 360 boxes per hour (there are 12 ~ 24 meters in each paper packing box). When electric meters arrive, the system completes the receive process automatically through directly reading RFID information on meter boxes, and with the help of the RF-door and retractable chain plate machines, which greatly reduces the amount of manual handling. For delivering meters, the system reads the RFID information of electric meters (six boxes per stack) on retractable chain plate machines and completes the delivering tasks automatically, which greatly reduces the manual work of transport, lowers labor intensity, illustrates an effective combination of automation and information technology in a modern logistics system. Physical Checking Technology Based on Image Recognition and RFID. Physical Checking Technology combines RFID with the Image Recognition. It confirms the number and direction of electric meters, which eliminates the possibility of human error during packing operations, and fully embodies the information, intelligence of the system. Development and Application of Production Scheduling Platform Seamless Joint of Meter Testing System and Intelligent Storage System The system of testing and the system of intelligent storage for electric meters achieve seamless joint in application through production scheduling platform, and achieve physical seamless joint through the elevator and other transportation equipments. The production scheduling platform provides a variety of interfaces such as WebService, SOCKET, intermediate library, OPC, documents, etc. to control the two systems in real-time and make it work stably, orderly and efficiently. Large-Screen and Digital Signage for Visual Scheduling and Monitoring. The system uses Web split-screen technology, multi-screen display technology and a variety of expert systems to make the real-time business data shown on the screen of the monitoring center and the corresponding part of the electronic bulletin board, thus this achieves real-time monitoring and system control of a comprehensive set of business processes. Construction risk prevention and control In recent years, Henan Electric Power Company has walked in the forefront of the national grid system in the construction of provincial measurement centers. In the construction process, some experience are accumulated and specifically summarized as "Four Cardinal Principles":

5 406 Mechanical Materials and Manufacturing Engineering III Adhere to the goal: "automatic testing, intelligent warehousing, logistics of distribution, overall authorization". A prominent feature of Provincial Metrology Center is gathering upward the business of testing and distribution. In order to remain labor costs relatively balanced, it is necessary to significantly improve verification, warehousing, distribution capacity and efficiency, thus an automatic testing and intelligent storage system becomes an inevitable choice: (1) A supply chain of automatic testing and intelligent storage systems has been formed, which is completed with selective tendering; (2) Many single-phase smart meter automatic testing systems have been successfully applied with technologies and processes maturing gradually. The key technologies on three-phase electric meters, collection terminals, automatic verification system mounted transformer have been achieved breakthroughs, and will achieve product and practicality; (3) The construction of provincial measurement center achieves an optimal allocation of resources, such as measuring and testing equipments, facilities, staff, and measuring instruments, and maximizes social and economic benefits dramatically. The basic philosophy: to adhere to the "plan first, then implementation scientific process. Risks and difficulties. (1) The task of "Big Five" system construction is heavy and time-urgent. To the end of 2013, the State Grid Corporation of system requires full completion. (2) In "Big Five" system construction, the requirement of the testing site of the provincial center construction is the most professional and the most difficult to achieve. Making use of existing venues results in poor adaptability, while new venues faces challenges such as large investment, difficult approval, and long construction period. (3) Some of provincial companies faces the problems of the reform of rural power, the construction scale of testing, warehousing and distribution needs not only to ensure current needs, but also to take into account the future development. (4) Three-phase power meters, collection terminals, and practical devices of low-voltage transformer automatic verification system, are still under improvement, and will be possibly modified in the future. Risk prevention and control ". Overall planning, step-by-step implementation" is the key of risk prevention. Planning should include siting, infrastructure renovation program, various verification of measuring instruments and warehousing construction scale, construction schedule, pipeline forms and so on. To adhere to optimize the design is the key We should follow the "best fit" rule. It includes: (1) Act according to one s ability. Make a good grasp of each system design principles. For example, the automatic testing system design should follow the principles such as "automation, modular, optimization, scalability, interference, reliability, safety, traceability" and so on.. (2) Tact timing calculation and simulation verification is the key. Ensure the continuity of multi-systems and the coincidence of the design capacity and the actual capacity. (3) Measuring centers have to deeply involve the important aspects such as feasibility studies, program design, technical route choice, tender document preparation and evaluation techniques, and have to be careful to being simply "wait-shopping." (4) It is necessary to consider to hire external experts on automation and control, logistics management, information engineering and civil engineering. (5) During the construction, project consulting, construction supervision, etc. should be introduced to ensure project quality and safety. To adhere to the principle of the system reliability is the guaranty. Practice has proved that the operational reliability of the automation system is the most prominent problem. System reliability depends on many factors such as program design, tendering, component selection, installation and commissioning. Our experience shows that: (1) The theoretical design capacity of automatic testing line should have a certain redundancy, generally not less than 10-20% of running capacity.

6 Applied Mechanics and Materials Vol (2) Based on site and the overall test volume, the testing capacity of a single test line should be reasonable planned. In principle, an independent test line capacity should not be more than 1.5 million, otherwise two or more independent test line are recommended to use. (3) The number of buffers need to design according to the batch rotation time and the number of the test units of the system. (4) More buffers can increase the efficiency of the system. Conclusion As the further promotion of "Big Five" system by State Grid Corporation, the provincial metering centers as an important part of the marketing system will play an important role of technical supporters. With the basic construction principles, "Intensive and Efficient, the Provincial Focus," how to choose a safe and efficient construction plan is the critical issue during the constructing process of a system by provincial metering centers. With the creation and application of forefront technologies in the field of measurement and other related fields, metering assets will gradually realize "Centralized Storage, Centralized Testing, Unified Distribution, and Unified Supervision". Then the metering management will achieve "Intensive, Flat, Professional", and will promote metering industry. References [1] Zong Jianhua, Yan Hua, Shi Shudong, etc. Smart meters [M], Beijing: China Electric Power Press.2010 [2] State Grid Corporation. Universal design standard for provincial metering centers [S].2010 [3] Metering Center of Henan Electric Power Cooperation. Reports of automatic testing and intelligent storage for electric meters (projects) [R].2011 [4] SMS Electric Co., Ltd., Zhengzhou. Automatic sealing device for electric meters [P]. Chinese Patent: (been accepted), 2011

7 Mechanical Materials and Manufacturing Engineering III / Intelligent Automation and Control Technology Based on Energy Meter Testing and Storage System Construction Model /