Research On Intelligent Generation Technology For Test Scheme Of Relay Protection Device

Relay protection is one of the most important functions of substations and it is the first line of defense for the safety and stability of power systems.With the advancement of construction and renovation projects for smart substation,digital protection devices are widely used in smart substations.Currently,the automatic test system for relay protection devices tends to mature in technology,which can achieve closed-loop automatic testing with high-efficiency.Although the entire test process has a highly efficient closed loop,less manual participation,as well as accurate and reliable test results,there are still deficiencies: a secondary development platform is used for the manual editing and development of the device testing scheme.It requires the testers must be proficient in the function configuration,protection principle,and test principle of different protection devices.Not only does it have a long development and debugging cycle,but it is more likely to cause the missing item risks.The key technologies of the intelligent generation for the whole device test scheme is studied in this paper,and the software platform to realize the intelligentization and automation of the test scheme editing is developed,which has certain theoretical significance and engineering application value.The main content of the paper is as follows:Firstly,the hierarchical structure of the digital protection device data model and the characteristics of the data object are described,and the intelligent analysis method of the device data model is studied.Based on the analysis of the defects of the traditional FMM algorithm,an improved dictionary mechanism for relay protection and an improved FMM algorithm based on the dictionary structure are proposed.On the premise of guaranteeing accuracy of word segmentation,the matching success rate and word segmentation efficiency are improved.The correctness of the improved algorithm is verified by the application examples.The improved algorithm can intelligently analyze the device data model data object of digital relay protection and realize the automatic identification of the protection configuration of the protection device.Secondly,a keyword search algorithm based on breadth-first for test sub-template is proposed.The XML document of the relay protection sub-template library and its directed tree model were established.In view of the structural particularity of the directional tree,a hierarchical coding scheme was used to encode the nodes and extened to the triplet form,and specific coding rules is given in this paper.The keyword sequence of intelligent analysis of the device data model is used as a query condition to complete the automatic retrieval of the test sub-template.Then,a relay protection test sub-template instantiation algorithm based on improved edit distance was studied.Based on the classical Levenshtein algorithm,an improved Levenshtein algorithm is proposed.Word segmentation is performed on the source string and the target string,using improved FMM algorithm.and a dual filtering-verification mechanism using a combination of length filtering and suffix filtering is used to filter out unmatched data objects in the device data model.The automation and intelligence of data matching and value transmission during the instantiation of the protection device test sub-template is realized,the efficiency of the test scheme development is improved furtherly.Finally,the overall design of the intelligent system for test scheme generation is described,including software architecture and the visual interface framework.Based on the concept of modularization design,the specific implementation methods and program interactions of the software modules of the entire system are introduced in detail.Based on the existing automatic testing software,a test scheme intelligent generation system was developed to replace the test scheme development module of the ATS system.The manual secondary development of the test scheme was converted into computer intelligence generation,which improvs the efficiency of automatic testing furtherly.Lastly,the correctness and practicability of the software system is verified by taking the digital bus protection device produced by NR Electric Co.,Ltd.as an example.