The Study On Black Start Path Aided And Decision-making System Of Tianjin Grid

In recent years, there are several consecutive major accidents around the world, causing serious damages to the national economy. The system after power failure, recovering power supply is considered to a complex and time-consuming work.Restoration of a power system after a complete breakout is a very completed issue. At present ,black-start schemes of the domestic grid corpotions are artifical drawn up, which can't reflect the new situation of system and is formed in efficient .Therefore, developing a set of black-start program automatically generation system becomes more urgent.Aiming at these problems, we analyze the law of feasible black-start scheme. By using computer technology, we develop out the black start of a rule-based automatic program generation system, the content of this work and the results are as follows:1. This paper first introduces the basic concepts of black start, and the issue of domestic and international situation and the latest research results. Describing the system startup process in the black staff, the black pneumatic principles should be considered. For example, the path length of black start, the priority of start plant ,the number of transformers, the capacity principles of start. And how to build a path to self-excitation scheme, operating over-voltage and power frequency over voltage, the recovery process of the voltage and frequency control checks to ensure that the resulting solution is feasible and usable.2. Developed an optimized depth-first search algorithm. By the searching of grid, formating the initial path of the program. Compared with other path search algorithm, the search algorithm has been improved in three areas: (1) optimization of the forward search, the first search path of the program without a transformer; (2) The child node set and reset the set of child nodes to ensure complete forward and backward search; (3) the path of the search program, taking into account the important level of the plant which is started.3. Proposed an entropy-based fuzzy comprehensive evaluation model of black-start scheme evaluation methods. This method has a good combination of subjective and objective factors in the process of black-start scheme evaluation, besides it's calculation is simple. This method can not only complete multi-program sorting, but also can make a reasonable evaluation of a single program. This method has been applied to the Black-start candidate schemes of TianJin Power Grid, and which get the optimal scheme, the result demonstrates the feasibility and effectiveness of this method.4. Developed a convenient and practical black-start automatically generation system, which includes a database module, the graphics module and algorithm modules. Graphics module is based on secondary development from VG, which can connect to the database. You can click on the picture to get the components of the data elements to be modified. Algorithm module includes an initial program of black start path generation, self-excitation of the parity, power frequency overvoltage, operation overvoltage, voltage and frequency stability calculations, and the path evaluation and sorting . Database module is based on the Oracle9i database, which include plant, bus, line, transformer and switch data sheet, and the corresponding path data. This system has been applied to practical, according to this system, we can quickly get the black-start paths based the specific circumstance of the power grid, which can greatly reduce the staff strength of dispatchers.