High voltage direct current (HVDC) transmission, with the help of cutting-edge power electronic technological advancements, is envisioned to be the leading mode of transmission of electric power, superseding the traditional alternating current (AC) transmission. HVDC transmission allows for the transmission of large amounts of power over much longer distances in a more efficient and environmentally friendly way than AC transmission. Moreover, HVDC technology paves the way for the integration of renewable energy sources (RES) into the electric power grid. The main attractive feature possessed by HVDC systems that allows for the integration of RESs into the electric power grid is the ability to connect two unsynchronized AC networks. This allows for a seamless transition to renewable energy power generation as opposed to traditional generation methods. HVDC systems will inevitably be responsible for the expansion of power systems in a more controlled and stable way. When it comes to the design and implementation of HVDC systems, several factors must be taken into account; namely, the architecture of the HVDC system (point-to-point or multi-terminal networks), the converter technology (voltage source converter, line commutated converter, hybrid VSC-LCC, etc.), and the VSC converter topology (2-level, 3-level, or multi-level converter topology). The main focus of this thesis revolves around the converter controls. It has been seen in several commissioned HVDC projects that interoperability plays a massive role in the successful operation of multivendor HVDC systems. Moreover, in multivendor HVDC systems, the converter control software pertaining to each vendor is kept closed. This inaccessibility of vendor-specific converter information leads to inefficient methods of handling interoperability issues. This thesis aims to propose a partially open converter control software that is hypothesized to ease investigations into converter control interactions, interoperability, and system stability issues. Functional models of the control systems are designed with the help of the software Modelio using the systems engineering language known as SysML in order to provide a higher-level perspective of the system, aiding in the understanding and proper navigation of complex HVDC converter control elementsObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.b - Per a 2030, ampliar la infraestructura i millorar la tecnologia per tal d’oferir serveis d’energia moderns i sostenibles per a tots els països en desenvolupament, en particular els països menys avançats, els petits estats insulars en desenvolupament i els països en desenvolupament sense litoral, d’acord amb els programes de suport respectiu
