Advanced Materials Research Vols. 614-615

Abstract: With the development of smart grid, the requirements of high speed, low delay and better coverage have motivated a electric power wireless network that bridge the communication gaps between the transmission system and the load. In this paper, we introduce a new electric power wireless communication network, and give a general overview of studies on the major characters of communication such as wide coverage, a lot of measurement points in distribution networks as well. In order to improve the communication performance, the paper proposes a modified proportional fair algorithm, which allocates the radio resources by introducing a Quality-of-Service (QoS) scale factor. By comparing with the proportional fair algorithm, we get the conclusion that the modified algorithm is more suitable for the electric power wireless private network.

Abstract: Islanded microgrid is an independent micro power system. The system has different kinds of distributed generations with different characteristics. The islanded microgrid makes its frequence control more difficult than the conventional grids. This presents a multi-agent based frequency control approach for islanded microgrid and discusses the characteristics of agents. The hierarchical multi-agent control framework is also proposed. The simulation results show that even in emergency conditions, the proposed frequency control approach based multi-agent system can maintain the frequency stability of islanded microgrid.

Abstract: This article aims to make a design of the power supply for an isolated island that has difficulty in realizing the connection with the mainland power grid. An independent hybrid power system consisting of varieties of renewable power sources including solar power, wind power, wave energy and batteries are introduced. This system is dedicated to make the forecast of the electricity load of the island according to the environmental factors and the electricity demand of the island. Then it builds the basic framework and models of hybrid power system on the basis of the forecast and finds out the appropriate method to optimize the power supply.

Abstract: With the development of smart grid, smart power distribution and utilization park (hereinafter referred to as Park) is also accelerating the building. Distributed energy storage system (DESS）as important energy system of Park, the development has an important impact on the construction of Park. This article briefly introduces both of DESS and Park, focuses on the use of DESS in Park and analyzes the deficiencies in the use of DESS at home and abroad.

Abstract: Because of the fact that the availability of renewable energy sources is determined by the weather and can hardly or not be affected, new functions of electricity networks are required. Smart grid is inevitable in the development of the renewable energy. In this paper a detailed survey of the smart grid techniques about wind power and integration of wind power was provided. An attempt was also made to identify development trend of the future. This survey will also be helpful for the wind farm and grid owner to understand the current smart grid technologies and will give them an idea that technologies will be suitable for the development of the future.

Abstract: This paper analysis the characteristics of two-machine equivalent system in out of step state. According to variation in the out of step state, study the out of step criterion of .Use change area to determine whether the system is out of step, The criterion is simple and clear, and the concept is clear. It can distinguish the acceleration step and deceleration of step, and automatically adapt to system changes in the structure and Operation mode. The minimum voltage amplitude of the device installed is used for capture the oscillation center .The 2012 East China Power Grid, region A fleet out of step mode is simulated analyzed, It is verify that the criterion of accuracy and adaptability in the East China Power Grid.

Abstract: Currently in the smart substation, the traceability method of the digital metering system is a sub-component traceability method, which means that the electronic transformer and the digital power meter are calibrated separately. However, the calibrations of the electronic transformer and the digital power meter have been the problem of measuring department, its traceability having been unable to be a good solution. In this situation, this paper proposes a new digital metering system calibration method, and the overall error of the digital metering system can be calibrated. An on-site calibration of digital metering system was carried out on the heihe xigangzi substation. The result showed that this digital metering system error was 1.013%, which is consistent with the theoretical value.

Abstract: In order to solve the present situation that auxiliary facilities in substation separate from each other and unable to achieve intelligent interactive features, this paper presents the smart substation auxiliary control system based on the IoT (Internet of Things). The system monitors and controls the production auxiliary system of substation, and in the background using IEC61850 communication protocol to achieve the auxiliary production system internal and mutual coordination linkage and information remote transmission. The system integrates all the substation auxiliary facilities, including video monitoring subsystem, security subsystem, lighting subsystem, power supply subsystem and auxiliary system optimal control subsystem, providing smart substation of informatization, automation and interaction auxiliary support.

Abstract: In the application of distributed generation technologies, different building have its own heat-to-power ratio, therefore equipment selection is a key point to determine the energy saving ratio. This study analyzes some devices of four different types, from two basic managements, heat-tracking and electricity-tracking. Result shows the optimal heat-to-power ratio of some certain devices and the changing trends were also given out. The energy saving ratio were also calculated.

Abstract: Demand response (DR) has become an important part of smart grid, mainly for modulating load curve, emergency treatment, balancing the demand and supply of power system. The features of smart grid-self healing and interactive-give the new meaning to DR. In smart grid, the promotion strategies of ISO/RTO in energy and auxiliary service markets implement DR programs in the project of auxiliary services and can reduce energy consumption. This paper summarizes the global related researches and practices, including the classification, progress of each subclass, the future development potential and DR program outlook in China, and puts forward the following two ideas: 1) The DR for single market cannot satisfy the needs of smart grid, advanced measurement and remote sensing technologies shall be made to implement the DR programs combining with multiple markets; 2) The service agency of DR on transmission and distribution shall be conducted and supervised by the government departments.