Merging Unit Software Design And Implementation In Digital Substation

Merging Unit(MU) which is the core of the digital substation is an important interface between primary equipment and secondary equipment in substation. With the development and promotion of digital substation technology, traction substation with integrated automation system will inevitably transit to digital traction substation. In this paper, MU of traction substation is studied and designed in detail which is of great importance to the realization of digital traction substation.In this paper, the functions of MU are analyzed according to IEC60044-8and IEC61850-9-2, then combined with the actual needs of the high-speed railway traction substation, the configuration scheme of MU is given. On this basis, the overall realization scheme of traction substation MU is given, which is characterized by using field programmable gate array FPGA as the hardware core of MU, making full use of its fast processing speed and short development cycle characteristics. In the overall design of MU, the FPGA program is divided into data acquisition module, data processing module and data transmission module. The numerical integration, re-sampling and data synchronization of data processing module are analyzed in detail, the algorithms of which are optimized according to the characteristics of the FPGA. In this paper, functions of data acquisition, data processing, data transmission module are analyzed, and the detailed design method and realization procedures of each module is given. Each module of MU is simulated and tested using Xilinx ISE14.1software, and the test results show that all the modules of MU designed in this paper can perform their functions well in accordance with the requirements of IEC61850substation automation communication standards. A feasible realization scheme for digital traction substation MU is provided in this paper.