The CIGRE DLL toolbox enables automatic interfacing with EMTP DLLs created according to the IEEE/CIGRE DLL format developed by the Joint IEEE TASS Task Force and CIGRE B4.82 Working Group, “Use of real-code in EMT models for power system analysis.” This standard has been adopted by most major converter manufacturers in the industry.

It allows the inclusion of user-defined code or controller code replicas (software-in-the-loop) within a control scheme in EMTP. The DLL code is executed based on the sampling time value defined in the DLL. Interpolation is applied if the simulation time-step differs from the DLL sampling time.

A control device linked to the DLL is automatically created with all input and output ports defined in the DLL. A mask with the DLL’s tunable parameters is available. Initialization options are provided to allow “flat-starting” the controller from load-flow results. Snapshot files may also be used.

Multiple instances of the DLL can be invoked in the same simulation. No compiler is required to use this toolbox.

It is recommended to always use this toolbox to interface control codes with EMTP, as it provides a higher level of assurance that the code will remain compatible with future EMTP versions. This interface is also optimized for EMTP solvers and delivers better performance in terms of simulation speed and numerical stability than custom-built interfaces.

Licensing: 

2 licenses are available with this toolbox:

• The Built license which allows to load a DLL and create the associated control device. Thislicense is typically used by original equipment manufacturer to create their controller replica.
• The Read-Only license which only allows to tune the already created device and performed simulations. This option is typically preferred for the end-users of the model. This license is free..

The Renewable energy toolbox license is a prerequisite for both license types.

Example: