Study The Reliability Of The Wide Area Protection Communication System

Wide Area Protection System(WAPS) which acquire multi-point information of the power system by means of modern measurement and communication technologies and identify the disturbance which possible serious consequences to the power system and take appropriate control measures to eliminate or mitigate the consequences is a power system control and protection system. Wide area protection is based on communication technology, constrained by the level of communication technology. In order to realize real-time control the power system, wide-area protection communication system require high real-time and high reliability. The real-time of the wide area protection communication system is achieved by development of modern communication technology. The reliability of the wide area protection communication system is an important factor which impact the wide area protection's reliable operation. Study on the reliability of the communication system in order to provide a theoretical basis for design and maintenance the system. This paper which analyze from the wide-area protection function divides the wide area protection communication system into substation communication systems and wide area communications systems.Substation automation has entered the digital age. The paper analyze the reliability of the digital substation communication system first, establish star and ring topologies digital substations'reliability model. Compare the two topologies substations'reliability and find the weak links of the system's reliability. According to the results of the digital substation communication system's reliability, establish the substation communication under the wide area protection reliability models. In digital substation, the reliability of protection operation is affected by the reliability of the digital protection communication system. Reliability models for two structures which one of structure is the protection components and circuit breakers and sever are redundant and one of structure is double configuration are established through three types of data services which are sample value signal transmission and tripping signal transmission and file data transmission. Study the reliability of the communication system and find the weakness of the system and the components'probability importance of the system and the subsystem. This paper analyzes the structure features of the wide area protection communication system. The communication system is divided into the system protection center, backbone networks and regional communications systems which is divided into regional protection center, regional networks and substation system. Analyze the reliability of three commonly fiber optic rings. Reliability model of each subsystem were established. An example of IEEE 14 bus system, calculating the reliability of various subsystem and overall system.In this paper, Bayesian networks as the method of reliability assessment, which not any compute the indices but also find the weakness of the system by the advantage of the unique reverse reasoning.