Reliability and Security Study of the Digital Substation System
|School||Huazhong University of Science and Technology|
|Course||Proceedings of the|
|Keywords||Digital substation automation system Functional reliability Structural Reliability Information Security|
With the continuous development of the grid and the deepening of the reform of the electricity market, the increasingly high demand on the grid safe and economic operation and quality of power supply. Substation as an important node in the grid, and more and more to the amount of information required to dispatch control centers, including not only the conventional operation, accident information, and may also include important equipment condition monitoring information; same time the need to achieve the control function is also increasingly The more complex. These prompted substation must be digitized, information technology, and information modeling. Therefore, digital substation system is the development trend of the future substation automation. Compared with traditional substation automation system (SAS), the digital substation automation system (DSAS) has a number of significant advantages. However, as a novel system, at this stage DSAS still exist many problems, such as reliability and safety. Over the years, scholars reliability of SAS has done a lot of research, but DSAS with new features, the traditional method of analysis has been less suitable, and therefore establish the DSAS the reliability analysis model, and adopt new methods of analysis for analysis has important significance. In addition, DSAS dependence on communication technology to be much higher than the SAS, and therefore bring information security risks can not be ignored. Most of the existing substation system safety analysis method to stay in the level of qualitative analysis, or limited to the level of technical analysis, of little significance in the actual production safety management guidance. Looking for a comprehensive quantitative and sexually system safety analysis method, DSAS the safe operation has important significance. Firstly an overview of the features, functionality and architecture of DSAS, and Research DSAS reliability and safety aspects at this stage. Then, starting from the power business users to focus on reliability, proposed the DSAS the reliability analysis both from the functional reliability and structural reliability. This article proposed to DSAS a is the object of study analysis method, different from the traditional method of analysis of the system or apparatus for the study of functional reliability analysis, the goal is to analyze the function sustainable effective time indicators, to avoid traditional analysis gives the overall system reliability index is too general shortcomings. Functional reliability analysis of the characteristics of GO principle for analysis. First introduced the principle of the GO methodology, then digitized to a transmission line protection function, for example, establish its GO functional model to calculate the sustainable and effective function of time, as well as the weak link analysis, and description of this method is effective in functional reliability analysis sex. For structural reliability analysis, this dependence for the DSAS of the communication network, the introduction of a reliability analysis of network structure. Introduced the first the IEC62439 standard parallel redundant network (PRP) program and its future promotion prospects, and then the IEC61850 standard definition T2 transmission substation station level bus example, assume that the use of PRP network. Its network structure analysis through Bayesian network reliability modeling and application of diagnostic reasoning to analyze the weak links of the network structure. This method and fault tree analysis to prove the superiority of the method. Finally, for the DSAS information security risk analysis, the article describes the ISO13335 information security risk model to identify safety risk factors, and a risk assessment index system is established according to the security risk factors. On this basis, the integrated use of fuzzy theory and group decision-making level analysis of risk factors for the three fuzzy assessment measure (probability, impact, uncontrollability). Experts to assess the validity of the results, we propose a combination of the validity of the theory of information entropy analysis method, define a validity coefficient indicators for the results of the assessment to be corrected.