Research On Several Key Techniques Of Digital Substation

The substation automation system is going into new development stages with advancement of the technology of non-conventional transducers, the implementation of IEC61850 standard, the application of Ethernet and the development of intelligent breakers. The digital substation is becoming the tendency of future substation automation systems, in which information is collected, transmitted and processed via digital signal processing technology. This paper focuses on certain research topics associated with digital substation technologies, including the effect of digital substation technology on substation automation systems and different application modes of digital substations. The main research results are summarized as follows.1. The foundation for systematical analysis of technological features of digital substation automation systems has been laid, based on a critical review and thorough analysis of the development of conventional substation automation systems and the relevant technical background and key supporting technologies.2. The architecture of digital substation systems, the effects on substation secondary circuits and eight most important technical features of the system were presented and analyzed.3. The information model of digital substation was studied. The information flow and a four-layer architecture of substations were presented that realizes the IEC61850 mode building based on the UML. Furthermore, the information integrated mode and three different information application modes were proposed, which proves practicality of the information security solution based on peer to peer communication scheme.4. The reliability model of digital substation automation systems was established, which allows quantitative analysis of the reliability of digital protection systems based on the importance of different components.5. Applications of advanced technologies, such as GPS, SNTP and IEEE1588 standards were studied, taking into account the information synchronization technology. Simulation tests on different network structures of multi-bays via OPNET were conducted, based on these results it can be concluded that the real time issue of digital protection has been resolved.6. Different application modes of digital substations were analyzed, the main problems in developing modes of digital substation automations were identified.