Study On The Networking Of Protective Apparatus In Power System

The electric device is very important in the power system, which occupies 80% electric energy in the system. It is not only the key equipment of safeguarding the production and living electricity, but also is the base of guarantying the safe and reliable service of the distribution network. The modern power system has electronic, informative and networking characteristic. Protective electric apparatus'network, which fuses network, computer, communication and automated control technologies, realizes the distributed control, maintenance and management for the whole system or the local system.The key problems of the protective electric apparatus networking, such as network access, real-time performance, network reliability and so on, are deeply researched after analyzing the development stage of the network design of the protection electric apparatus in the power system in this paper. To take the CAN bus and Profibus-DP as entrance, the methods of the network access of the field bus are studied from view of hardware and the software. However, there are many kinds of field bus. To solve the problem, the common methods of the protocol conversion of the field bus are discussed. Then the CAN/Profibus-DP protocol conversion gateway is designed, which implements the interconnection between two kinds of field bus system. It is summarized and discussed to how to access Ethernet for the understratum electric apparatus. For understratum equipment's directly Ethernet accesses, the interconnection technology between Ethernet and other non-TCP/IP networks is deeply analyzed, including the encapsulation technology, the COM technology and the tunnel technology. Then, the method of fieldbus accesses to Ethernet through the embedded gateway is determined. And the feasibility of the method has proved by designing CAN Ethernet embedded gateway. Therefore, it provides the reference for the understratum equipment access to Ethernet.To the characteristic of the software system of the protected electric apparatus, the real-time operating system is detailed researched on task management, task scheduling, duty correspondence and sharing, store management, exception handling and so on. On the basis, the real-time operating system DSP/BIOS developed by TI Corporation is firstly applied to the intelligent circuit breaker. The real-time requirement of the network is analyzed. For TCP/IP, the prior scheduling mechanism for the exchange Ethernet based on an improved switch structure is proposed, which improves the performance of the industry Ethernet applying to the protection electric apparatus network . The simulated experiments show that the new method can effectively improve the real-time performance of the network control system under certain network throughput.Higher reliability and security of Ethernet are required by the protected electric apparatus in the power system. The network topology based on the improved genetic algorithm is designed through analyzing the main factors effecting the reliability and security of the industry Ethernet and is simulated. The reliability of the method is verified by comparing with the traditional Ethernet. The intrusion detecting system with the immunologic function is used to the safe guard system of the industry Ethernet for the first time. The checking system with the immunologic function is developed. Then the performance and its completeness are validated by the simulation analysis. It has proved that the checking system can meet the performance requirement of the industry Ethernet and has higher detecting ability.