Advanced Materials Research Vols. 1070-1072

Abstract: Smart Grid value-added service is an important approach to utilize the potential of smart grid infrastructure. The scientific and rational commercial mode of smart grid value-added service can promote smart grid integrated projects from the pilot to comprehensive application. In this paper, the definition and content of smart grid value-added services commercial mode were studied. According to commercial model theory and evaluation methods, based on balanced scorecard theory, evaluation indicator system was established, evaluation model was proposed based on TOPSIS combined with Delphi and AHP (DAHP-TOPSIS). Through the example of PFTTH (Power fiber to the home) project, the analysis results show that the indicator system and the evaluation model proposed in this paper is useful for the selection of appropriate commercial mode and promote the rapid development of smart grid new services.

Abstract: The intelligrid-oriented on-line relay settings verification system based on EMS real-time data are discussed, with related software system designed and fulfilled. Firstly, the research background and current situation of on-line relay settings verification system are summarized. Secondly, the on-line relay settings verification system's general principle, hardware and software design are mainly discussed. And this paper shows the designed hardware structure diagram, the software structure diagram. And the flowchart of main procedure is given. Thirdly, the methods of dealing with EMS real-time data of the on-line verification system are discussed in detail. The verifying principles of sensitivity & selectivity of relay protection are given definitely. It is able to simulate two simultaneous faults, faults in network oscillation, and faults during auto-reclosing. It checks reliability & sensitivity of relay settings under these circumstances. Finally, considering substation-area and wide-area relay protections, this paper points out some key problems of on-line relay settings verification system to be resolved, and its application prospect.

Abstract: Microgrid has been considered as a new green and reliable power system technique, especially for remote regions. In recent years, there is a steady increasing in studying optimal microgrid deploying and operation strategies. Multi-objective optimization is the most interesting approach for resolving these issues. The multi-objective optimization includes energy operation cost and emission pollutant cost. Potential benefits of using model predictive control (MPC) strategy for multi-objective dispatch problem in microgrid with fluctuant energy resources, such as solar, wind and alike are also presented by comparing with the strategy of day-ahead programming strategy and normal strategy with no battery energy storage. Simulation results show that the proposed model in this paper could reflect the actual characteristics of microgrid more precisely.

Abstract: The merging unit is used to realize the digitalization and sharing of the data of process and is widely used with the electronic voltage transformer (EVT) and electronic current transformer (ECT). As the construction of smart substation which is presented by the state grid company of china, a serial new requirements and needs about the merging unit are proposed and the merging unit which only sends the sampling value can not meet it. The new demands of the smart substation are analyzed, The design of hardware and the implement of the function are presented. The multifunction which including the model of sampling, the data catenation, the acquisition of status signal through GOOSE , the voltage parallel and switching and the synchronization of device are analyzed in detailed. At the end, the function of intelligent diagnosis and debug is introduced. The device has been used in the project of smart substation and takes good effect.

Abstract: The sampling based on process bus is not widely used in smart substation because there are still some technical problems on synchronization, the design of network architecture and sampling data receiving and processing areas. There are some researches about the problems are carried out, but they only focus on part of them and cannot give the whole solution. In order to improve the reliability of network sampling, a new system method which includes all the segments of the sampling based on process such as the synchronization of data acquisition, data transmission, network optimization and data processing are presented. In the data acquisition segment, the synchronization based on IEEE1588 is provided, In the data transmission segment, a new hardware architecture which is based on FPGA+DSP+VxWorks is described, in the segment of network optimization, the topology structure and virtual LAN are suggested. At last, the automatic resampling is proposed in the data receiving and processing segment. It will be useful to improve the reliability of sampling based on process bus in smart substation.

Abstract: With the construction of smart grid and smart substation, influences of the main electrical connection on the reliability of the entire power gird have become more and more important. Therefore, coordinated development between power grid and substation is a key to the design and optimization of main electrical connection. In this paper, the entire equipment in power grid including the main electrical connection is simulated simultaneously, and then the index of power gird with the main electrical connection optimization by disconnecting circuit breaker is calculated. Optimization schemes are sorted by the method of TOPSIS, realizing the evaluation of main electrical connection based on coordinated development between power grid and substation.

Abstract: With the development of digital and intelligent trend of substation, higher requirements on communication network were put forward. With features of high bandwidth, low cost, high reliability, easy maintenance, EPON has been widely applied in the field of distribution communication network. But precision of time synchronization is insufficient while bearing intelligent substation services by EPON. For providing sub microsecond time synchronization, IEEE 1588v2 can solve this problem. Based on depth study of EPON synchronization technology and IEEE 1588v2 protocol, a novel method to implement high-precision time synchronization based on EPON technology in intelligent substation is proposed. Through test, the proposed scheme has very good time synchronization performance. It can well meet requirements on precise time synchronization in intelligent substation.

Abstract: Data synchronization of electronic instrument transformer is introduced. Synchronization method commonly used are analyzed in aspects of their advantages and disadvantages, such as interpolation synchronization, impulsive synchronization method; Then, a new approach based on Newton interpolation is presented, and the simulation and error analysis are given. The theoretical analysis results show that this method can reach to the same precision with Lagrange interpolation which is accurate in synchronization of harmonic components and obtain the synchronized data fast. Finally this paper sets equal interval sampling and non-equal interval sampling data, and then calculates maximum error in the case of the steady state and transient state respectively by using Matlab. The simulation results proved the feasibility of this method and its engineering practical value.

Abstract: According to the new changes brought out by the smart substation, including disappearance of the traditional concept of terminal and replacement of the original point to point cable connection by optical fiber network, a new design method of GOOSE “virtual terminal” is put forward. The method contains GOOSE “virtual terminal”, virtual terminal logic connection line, GOOSE configuration table and virtual terminal information flow diagram, and solves some problems of digital protection, measurement and control device, such as without contact, no terminal, no wiring etc. of GOOSE information. The design method was applied in the engineering practice of the south of Changshu 500kV smart substation in Suzhou, and the effect of designing was very good.

Abstract: As the new energy resources including scenery storage have been well accessed into power grid, the operation process of power dispatching and distribution involves the massive, multi type, high complex data which contain the real-time data, plan data, warning and monitoring data, environmental data. Nowadays, the application of big data focused on single analysis of structured and semi-structured data. And the deep learning analysis hasn’t been concerned, transforming power gird data into knowledge is the inevitable trend in the development of smart grid. In this paper, the power dispatching and distribution data were analyzed in detail from the data source, data characteristics, the trend of application etc. According to the new requirement of smart grid now and in the future, the potential application with big data technology was studied in the field of smart grid and the reference opinions was provide by intelligent analysis and decision which are accurate, security, economic, comprehensive optimal features. Finally, to meeting requirement of the power dispatching & distribution data analysis, power dispatching and distribution data system architecture was designed which is an integrated software/hardware, storage-computation-communication trinity. And it was proved that power dispatching and distribution data system architecture have strong supporting, service and safety ability.