Setup and performances of the real-time simulation platform connected to the INELFE control system

• Description of real-time simulation setup for VSC control system testing.
• Solution to get a robust, accurate and fast solution of VSC MMC converters in real-time.
• Technical solution implemented, tested and validated in a real project.

The VSC-based HVDC link between France and Spain (INELFE project: France-Spain ELectrical INterconnection) is currently the most powerful VSC link. This 2000 MW interconnection is composed of two parallel VSC links. For system studies and maintenance purposes, the replicas of the control systems have been acquired by the French (RTE) and the Spanish (REE) Transmission System Operators. This paper describes the hardware and software setup to perform Hardware In the Loop (HIL) simulations with the INELFE control system replicas. The converter and cable models used in the real-time simulation are presented. Modular Multilevel Converters present a major challenge for real-time simulation due to the large number of sub-modules and to the nonlinearities that shall be solved: transformer saturation and nonlinear characteristic of surge arresters that protect cables against switching transients. The paper presents how these issues have been solved in order to be able to test the control system with AC and DC faults. It is shown that iterative methods are used to provide accurate solutions in the presence of nonlinear devices but are not mandatory in this specific case. A complete setup has been developed in order to validate the modeling approach. HIL simulations have been performed with the real-time simulator connected to an external generic control system having the same interface than the replica. Real-time performance and simulation accuracy are fully achieved with the proposed solution. This solution has been used to interface the real-time simulator with the real control cubicles. The converter model is validated with on-site measurements.