Ontology-based Communication Protocol Mapping And Its Application In Wide Area Protection

With the increasingly rapid pace of technological innovation in smart grid, power network structure is becoming more and more complex, and new ICT(information and communication technology) and automation technology are widely used. Safety operation of power network under new conditions needs higher requirements. Smart grid concludes more automatic control equipment and transmission measuring equipment, which needs to be protected based on the outcome of processing large data. Distributed computation and control have the efficient data processing ability and have been widely used in the area of artificial intelligence. Multi-agent system technology has the characteristics of distributed computation and control, which can handle the problem the grid faced very well. The technology can integrate intelligent system existed in the substation, work on its own intelligent characteristics, promote the fault diagnose and the protection of power grid. However, when wide-area protection multi-agent system is operating online, the real-time operation information from the substation devices needs to be captured, and the system should be able to analyze the information message from local area network of substation. It cannot just rely on traditional SCADA system when the power grid fault diagnose and verification is already in progress, it also needs more data sources. To solve these problem, the paper has been studied from following aspects:Taking the FIPA standards as reference,the IPEDA system is proposed and a protection setting provider(PSP) agent is designed,which is utilized to communicate with protective and measuring equipments in substation with MMS, get the MMS message concluding the latest protection setting information.In order to implement the protection validation function of the IPEDA system, the paper divides the PVD agent in PEDA system into protection verification(PV) agent and protection diagnosis(PD) agent according its fouctions, and riches data sources of IPEDA by integrating the existing wide area measurement system(WAMS).In order to let PSP agent comprehend MMS message from substation devices easily, the paper has designed its internal module in detail, utilize MMS message receiving module to analyze the message to IEC 61850 ACSI information module, utilize the mapping module to convert it to FIPA ACL ontology element.In order to convert the IEC 61850 ACSI information and service to FIPA ACL, the mutual mapping among IEC 61850 ACSI service, MMS service and FIPA ACL service has been proposed, using the method of ontology mapping to implement the mapping from protection setting information to FIPA ACL ontology element.In order to ensure the integrity and consistency of the mapping, the DISA_Map mapping verification algorithm based on the study of various existing algorithms are proposed. Taking the public benchmark testing data set as ontology sample,the paper has made the mapping experiments to verify the high precision of this algorithm. The paper loads the DISA_Map mapping verification algorithm to transfer unit in PSP agent of IPEDA system,to ensure correct conversions of setting information.Finally, the paper has designed experiments of communication simulation based on JADE platform to verify the communication function of IPEDA system. Ontology mapping tool is developed to verify the function of the conversion unit in PSP agent. As demonstrated in the experiments, IPEDA system can works normally.