Development and research on integrated protection system based on redundant information analysis

Facing the growth of energy demand and the worldwide interests in renewable energy sources,smart grid has been proposed in order to accommodate the needs of power grid development.In China,digital substations have been widely applied.Moreover,as the worldwide interest and development in smart grid have increased significantly,the digital information availability and communication capability of modern substation have been improved.Different with traditional substation protection configuration based on local information,Integrated Protection(IP)is used to denote the integration of several protective devices for multiple power equipment within the substation into one protective relay,obtaining all the real time information of the substation by communication network.The analysis of sharing information and cooperation among different protection functions helps to realize more reliable and sensitive fault detection.This paper describes several different integrated protection schemes and their respective advantages and disadvantages.The principles and functions applied in integrated protection systems are addressed to provide an overview of the current state of the technology.A new coordinated protection system based on inter-substation information is proposed and simulation study is discussed to verify the improved reliability and sensitivity.

Research on Coordinating Protection and Control System with Redundant Information and Distributed Computing

This paper proposes a distributed computing architecture for protection functions within a digital substation, in order to achieve data redundancy, functional redundancy and functional coordination. This can be realized primarily due to the advances in digital and communications technology within a substation, particularly the process bus which allows data sharing between Intelligent Electronic Devices(IEDs). Results of backup protection investigation, using redundant information both within the substation and on a wide area basis, are then presented. A campus microgrid protection scheme was used as a test case to demonstrate the concept of protection using shared information. Finally, the paper proposes a multi-agent system as a simulation platform, which can be used to further demonstrate some of these concepts.

General medical practice in China:evaluation of urban community health care service functions based on a rough set reduction theory

Objective:This study aims to achieve an empirical evaluation on the functional performances of urban community health care services in fi ve administrative districts of Nanchang city in China.Methods:In order to increase effectiveness,data collected from fi ve administrative districts of Nanchang city were processed to exclude redundant information.Rough set reduction theory was brought in to evaluate the performances of community health care services in these districts through calculating key indices’weighed importance.Results:Comprehensive evaluation showed the score rankings from high to low as Qing-yunpu district,Xihu district,Qingshanhu district,Donghu district,and Wanli district.Conclusion:The objective performance evaluation had actually reflected the general situation(including social-economic status)of community health care services in these administrative districts of Nanchang.Attention and practical works of community health service management were needed to build a more harmonious and uniform community health care service system for residents in these districts of Nanchang.