Modeling and analysis of large dc grids with emtp – new cigre benchmark with mixed vsc - lcc technologies

<h6 class="text-black" style="padding-bottom: 30px; padding-top: 30px; text-align: justify;">Speaker: <strong>Sébastien DENNETIERE</strong>, <em>RTE – Centre National d’Expertise Réseaux</em></h6> <p class="text-black">A high voltage direct current (HVDC) grid is a power transmission system which consists of multiple HVDC terminals interconnected through DC lines. The advantages of a DC grid are increasing system flexibility and reliability and providing redundancy at a lower cost by sharing resources, resulting in lower power losses. In order to test and compare technical solutions that can be applied on a realistic DC grid, CIGRE B4 Study committee decided to propose a VSC based DC Grid test system with ac and dc parts with all input data suitable for EMT simulation. This first benchmark has been developed in 2014 in EMTP and different simulation tools in order to validate the completeness of data provided in the Technical Brochure #604. The test system has 11 AC/DC VSC converters, 2 DC/DC converters and 2 DC voltage levels (±400kV and ±200kV).<br><br> The main purpose of the test system is to provide a common basis for all CIGRE SC B4 WGs that work on the research of DC grids. This benchmark model generated a high interest. Some limitations on this benchmark (topology, equipment included…) have been identified so far. In order to provide common study platforms to meet the most different HVDC grid study purposes and needs, seven HVDC grid test models have been established by the B4-72 CIGRE WG. These models have been designed to cover most HVDC grid applications including collection, integration and transmissions of onshore/offshore renewable power generation over long distance, LCC-HVDC grids, LCC-VSC hybrid HVDC grids, AC system interconnections for different types of studies with appropriate and applicable sizes. The presentation will address the issues related to the modeling of the largest DC grid test system proposed by this WG. This grid model includes 22 VSC converter stations, 4 LCC converter stations, PV and wind generations. </p>