EMT modelling and simulation of grid following converters in Modelica integrating the IEEE/CIGRE 'Real Code'/DLL modelling guidelines

(EMT) simulations to assess the behaviour of converter-dominated networks. Vendors often protect their intellectual property by distributing controller models as dynamic link libraries

(DLLs), but these are typically tied to specific proprietary tools—leading to high integration costs and limited to no cross-platform re-use. The IEEE/CIGRE DLL interface (ICDMS), described in CIGRE Technical Brochure 958, aims to standardize vendor-validated controller code that can be shared in a tool-independent manner in power system simulators. However, the adoption of this interface has been limited to a small set of commercial EMT tools, making accessibility and re-usability in other simulation solutions a major challenge.

This paper investigates whether such DLL-based controller models can be integrated into models described by the open access and standardized Modelica language and be used with compliant tools to perform EMT simulation. A direct implementation approach is developed using standardized external object capabilities of Modelica, allowing ICDMS-compliant DLLs to be linked and executed natively Modelica-based simulation environments. The approach is validated against the implementation of the ICDMS readily available in proprietary EMT tool

(referred to here as EMT Software-A in compliance with CIGRE publication guidelines).