Research On Interoperability And Interaction Analysis Of Intelligent Electronic Devices In Substation

Interoperability of intelligent electronic equipment (IED) is an important basis of the realization of smart substation. At present, there are the following problems:(1) The IED with private protocols in substation can not connect to the IEC61850 system,and cannot realize data communication interoperability. (2) In the function interoperability of multi IED, there are the following problems:interactive function in distributed system is reachable or not, whether the real-time performance can meet the requirements of the application, whether there is a weak link of reliability, analysis methods of these problems remain to be further researched. So, this thesis carry out research on the above problems.In order to realize data communication interoperability, connect the IED with private protocols to the IEC61850 system is necessary. After studding the composition characteristics of private protocols, Modbus-TCP, and the mapping relations between them, a protocol conversion method is proposed. Then, a mapping method of multi-to-one between large waveform data and Modbus-TCP address is designed. At last, the methods are verified by examples. The results show that these methods can provide guidance for IED with private protocol to realize data communication interoperability.To verify the logical rationality of the structure of distributed system, an interaction processes modeling and reachability analysis method based on behavior trees (BT) is proposed. Firstly, a new BT model is given, the BT modeling method of a device and system is put forward. Secondly, the mapping method of BT model and communication sequential process(CSP) model is given, and the reachability analysis method based on process analysis toolkits(PAT) is presented. Finally, the feasibility of the method is verified through an example. The results show that this method is beneficial to the interaction logic design of multi IED.In order to calculate the theoretical completion time of the functions in distributed system and analyze the time out of distributed tasks, a multi IED interactive real-time modeling and analysis method based on BT is proposed. The concept of delay, time out and concurrency in real-time system model is introduced into BT model to form a new timed BT model. Then time computation and time out analysis of the interaction process in distributed system are completed after modeling the system by timed BT. The delay model of wide area network based on BT is proposed, the modeling and simulation of the wide area backup protection system are completed. At last, the real-time verification of specific IED in interactive process is finished. The results show that this method can provide guidance for the interactive real-time design of multi IED.To evaluate the dynamic interaction reliability of multi IED quantitatively, and find out the weak links of the system, the reliability modeling and analysis method of interaction process of single IED and distributed system is proposed. After the expansion of reliability decoration nodes, this thesis completed the reliability modeling on a single IED and the distributed system. The reliability quantitative calculation method of distributed system is given, and the calculation for the reliability of single IED and the distributed system is completed, the reliability weak links of single IED and distributed system are found out at last. The results show that this method can provide guidance for the interactive reliability design of multi IED.In order to extend the applicability of the method for interactive analysis in this thesis, the concept of generalized interoperability is proposed, and the modeling and solving method of the generalized interoperability problem based on BT is proposed then. The applicability of the method is verified by the example of protection setting sequences calculation in multiloop networks.