Research On Digital Substation Practical Technology

The automatization of transformer substation achieved a certain level, for example, the new built substation will adopt integrated substation automation system in Longkou. The widely adoption of substation automation technology improves the dispatching ability of power grid and of transmission distribution. The speed and accurate transmission of information in power systems play a more and more important role in electric power production, especially in power system operation and overhaul. Transformer substation changed from general to integrative automatization. Recently, some problems are found about transformer substation, which take great effect of the development of electric power. Many scientists make great efforts on the academic research and actualization of digital transformer substation all over the world. However, these theories and implementary methods are not enough comprehensive, systemic and material. Therefore, I analyse the theories of digital transformer substation roundly in article. Theoretic analysis also is used of the build of transformer substation practically. In the wake of the development of intelligent electric, especially intelligent switch and the Non Conventional Instrument Transformer, the automatization of transformer substation will be the new stage of digital development.The main content of this thesis which has been focused on analyzing and researching the technology of the digitized substation, mainly includes:(1)Non Conventional Instrument TransformerThe Non Conventional Instrument Transformer is based on modern electronic technology and optical technology, it has been widely used in power engineering because of its high precision, high stability, wide response bandwidth and strong anti-jamming.(2) The intelligent circuit breakerWith the extensive application of micro-electronics technology, computer and network communication technology, rapid development, as well as information transmission technology, sensor technology and artificial intelligence in-depth research and comprehensive application of intelligent controller rapid development emerged in the situation, intelligent control device to promote the continuous development of intelligent circuit breaker functions has been expanded, intelligent circuit breaker will gradually replace the old mechanical body to become a major power switching devices. (3) The standard of IEC61850In the digital substation system to achieve its control, monitoring and protection functions, require different equipment manufacturers to achieve information sharing, interoperability, for which the International Electrotechnical Commission (IEC) developed a substation communication networks and systems within the standard system-IEC61850. The IEC61850 standard in order to speed up the construction of digital substation provides a reference basis and theoretical support. IEC61850 applied cost has been approved all over the world, it is an inevitable trend that IEC61850 will replace traditional communication protocol to become mainstream of substation internal network protocol.(4)Communication NetworkThe development of substation automation brings some new demands on its communication network. The most important thing is that the new and high-powered communication network is used to meet the demand of technology progress. Ethernet has become the preferred network solution for the industry control network because of its ubiquitous application, low cost, high speed and abundant software and hardware resources. The trend of future is that Ethernet will be used for process bus and station bus in the digitized substation.(5)The system architecture and design principles of digitized substation are expounded and the technical fundamentals for the proposed system architectures are analyzed. The solutions for the connecting of conventional devices are put forward in the process level and bay level. Some suggestions in renovating traditional substation were put forward as well. On the basis of describing the simulation principle of optimized network engineering tools (OPNET), the digital communication simulation model of station network was built up. The nodal time delay and data flow rate under different treatment capacity of data packet and different band width were simulated. It was proved that the Ethernet network with bandwidth of 1 OOMb/s could meet the station network's requirement of time delay less than 1 ms, and it was pointed out that the communication processing capability of the node and the bandwidth of the channel were the important factors restricting the network performance. This is the main work to do the current digitized substation technology level and the relevant product and development of equipment, as well as in transformer substation microcomputer automation transformation experience,the design of a 35kV digital substation is also introduced, innovations of this article are to propose a new structured rehabilitation programs, and programs are compared with the general,and proposes the improvement program. In the end, the economic benefit of the digital substation is introduced.