Study And Development Of Testing System For Digital Protection Devices Based On Real Time Digital Simulation

With the breakthrough of opto-electrical transducer technology, the publishment and implement of IEC 61850, application of Ethernet network, and development of intelligent breaker, technology of substation automation system is stepping into "digital substation" stage. These new technologies above have brought significant reform to substation automation system, and the protection equipments based on IEC 61850 (called digital protection in this paper) are popularized more and more, which brings new challenges to relay device testing. Therefore it has important practical significance and great applied value to research digital protection testing methods and develop new testing systems.After analyzing the requirement of digital protection test and current testing solutions, this paper first chose the development of real time digital simulation testing system as the research orientation. Simultaneously, this paper introduced the applied technology of digital substation, which includes the contents and characteristics of IEC 61850, the working principle of electronic transducer, Merging Unit and Intelligent Breaker, the communication mechanism and structure of process level in digital substation.Based on above, the paper discussed several ideas to establish an available real time closed-loop testing system based on MATLAB, and then selected the xPC dual system as the basement of the system. Utilizing the real time simulation system of xPC and its Ethernet communication function, the paper built simulation models of Merging Unit and Intelligent Breaker, which helped to realize the real time simulation of power system and digital communication corresponding IEC61850. With the aid of Sampled Values message and GOOSE message, a closed-loop testing system was constructed.Then, based upon the simulation system constructed above, the paper developed a digital relay protection testing system, via introducing the process of building typical testing system, the development of GUI with MFC and MATLAB engine, and the testing flow of using this system.At last, analyzing its function requirements and communication performance ruled by IEC61850, the digital protection testing system was evaluated in the paper, including Merging Unit performance test, GOOSE performance test and integration test. Result of the evaluation showed that the system worked smoothly and the communication performance was corresponding to IEC61850. Eventualy, target of the research topic was achieved.