In 2011, CIGRE B4 study committee initiated several Working Groups (WG) to study the potential future introduction of dc grid. In order to organize the discussions among the groups it was decided to develop a VSC based DC Grid test system with ac and dc systems with all input data. This test system has been developed by WG B4-57 (Guide for the development of models for HVDC converters in a HVDC grid) and B4-58 (Load flow control and direct voltage control in a meshed HVDC Grid) and shared among all the DC Grids WGs. It is used to analyse performances of dc grid systems (protections, load-flow dispatching, transient stability, reliability...). This test system includes mainly: loads, ac and dc cables, ac and dc overhead lines, ac grid, wind farms and VSC station based on the Modular Multilevel Converter (MMC) technology. The test system has been developed and simulated in EMTP-RV. Nevertheless, required data to model the test system in another tool (offline and real-time) are provided in the B4-57 technical brochure (CIGRE Brochure #604). The test system includes 16 MMC converters which complicate the simulations in EMT program. As a consequence, special attention is made to converters modeling in order to get accurate results in a reasonable amount of computation time. CIGRE B4-57has used EMTP-RV to develop and simulate the DC grid test case. The full test system is now available to every EMTP users.
• Sebastien Dennetière, RTE - National Center for Grid Expertise - Substation Department
• Hani Saad, RTE - National Center for Grid Expertise - Substation Department