Research Of Embedded Merging Unit Based On IEC61850

As the study on ECT,EVT developed rapidly, the products has stepped into practical stage.With the presentation of IEC61850 standard,Merging Unit(MU) as the interface of ET resolves the problem of digital interface between primary equipments and secondary equipments, containing protection, measurement devices. The research of it is of great significance in both the popularization of electronic transformers (ET) and the practice of IEC61850.This paper firstly summarizes the background and meaning of the research,analyzes the present research status in the domestic and abroad, and makes clear the research contents in the paper.In connection with the characteristics and definition of IEC61850, the data modeling and communication mapping of MU is discussed. Through comparing IEC61850-9-1 with IEC61850-9-2, differences and similarities between them are illustrated. Through the analysis, the functions of MU in the whole digital substation have been well confirmed. Secondly, According to the system requirements, the overall scheme of accomplishing MU is then presented, which is based on AT91RM9200 micro processor and embedded technology, in order to study and design the MU based on IEC61850-9-2. The paper analyzez the hardware structure of the embedded MU and the implements of the specific function modules , and brings in the embedded OS (operating system) to stablish the software development platform.At last, the method of testing MU'main performance is introduced, the result of which proves that the hardware and software system designed in this paper can absolutely realize the functions of MU in IEC61850-9-1.And the paper analyzes the data frame format and the technology required to realize the IEC61850-9-2 protocol .The feasibility demonstration on the realization of Manufacturing Message Specification (MMS) and TCP/IP protocol on embedded platform provide the theory support to the realize of the IEC61850-9-2 protocol .