IEC61850-based Topology Recognition And Dynamic Partition Mechanism Of Active Distribution Network

In recent years,as increasing number of distributed energy resources enter the power network,the number of reactive power control variables in active distribution network increases as well.The application of traditional branch partition method for distribution area division may result in problems of reactive coordination controlling,and the frequent changing in system load data,network topology and DG power may lead to different division results,which,on the other hand,puts forward higher demands for partition algorithm.The introduction of hierarchical and distributed controlling mode in to the distribution network can well avoid the problems proposed above,which can not only simplify the distribution network partition rules,but also help ease the data processing work in main station.However,for the moment when undergo topology updating,most active distribution network under hierarchical and distributed controlling mode still need to configure the topology description information in main station manually,which not only lowers the operating efficiency,but also become more difficult to meet the requirement from the flexible structured smart grid.In this case,the realization of distribution network's automatic partition has become one of the most desperate problems the DMS hope to solve.The main difficulty to realize this mechanism is that most main station DMS is based on CIM information model,which is in lack of the ability to recognize the local topology changing.IEC61850 standard is one of the core standards in the future distribution network information integration.It is equipped with complete equipment self-description modeling rules,and if we can construct the topology description model for area coordinate controller according to the IEC61850 modeling rule,the main station will be able to acquire the newly-added self-control area's topology information,and update the local topology connections and partitions automatically.For the moment,the IEC61850 standard is still confined to the substation automation field,but its development in power system automation,especially the aspects related to distribution automation and DER monitoring and controlling,has become the inexorable trend.Based on IEC61850,the area partition and local topology recognition mechanisim are desighed and analyzed in this paper,which can be divided into the following aspects:The first problem is about the modeling of IEC61850 active distribution network topology.In this paper,the IEC61850 modeling rules are analyzed,together with the hierarchical structure of active distribution network.The logical nodes for self-control area's topology description are abstracted,and the IEC61850-based self-description model for area coordinate controller is built.Finally,a typical piece of self-control area containing controllable PV plants and battery storage piles is taken as an example.In this case,the area's function requirement is analyzed,the IEC61850 logical nodes are selected and extended so as to complete the modeling of specific function-oriented logical devices.The second problem is the construction of distribution network topology's model transformation platform.Based on the IEC61850 information model built above,this part further analyzes the model's difference from CIM static global topology model,and constructs the full set of IEC61850/IEC61968 meta-model mapping rules.Based on the rules,the topology model transformation software is developed based on XSLT language,which can extract the distribution topology information from the IEC61850-based SCD configuration files and transform them into the IEC61968-based static topology messages that can be recognized by the main station.The purpose of the application of this platform is to ensure the output files produced from the IEC61850-based automatic partition mechanism can be well compatible with the CIM-based main station information.We take the same example to test the system's effectiveness.The last problem is about the specific realization of topology recognition and dynamic partition in active distribution network.Main station need to be equipped with the ability to process the configuration files and reorganize the local topology according to the information contained in the files.This paper applies the Depth First Search Algorithm to traversal all the leaf nodes of the main station global topology,and based on the modification to the algorithm,recognizes the local topology part that need to be updated.In addition,full set of updating rules is developed for specific topology modification,which can be used as the data-driven framework for library function operation so as to develop the rule-driven automatic partition mechanism in active distribution network.The breakthrough for the key problems of IEC61850-based active distribution network topology recognition and dyamic partition will lay a foundation for the further application of ADN technology.