Interface EMTP with a control DLL


This toolbox allows you to interface EMTP with DLLs created using the IEEE/Cigre DLL Modeling Standard from the Joint IEEE TASS Task Force and CIGRE B4.82 Working Group “Use of real-code in emt models for power system analysis”.

Once a DLL adhering to this standard is created, this device is used to create all the necessary connections (pins) and provide access to the modifiable parameters of the DLL. The interfacing pins (ports) of this device in EMTPWorks are created automatically based on the information contained in the DLL.

This version of the device participates in control system solutions without any time-step delay.

This device has user and manufacturer functionalities: manufacturer license is required to load DLLs into this device, whereas users can change DLL parameters but cannot load new DLLs.

The DLL computations are called based on the time-step value stored in the DLL.


A typical workflow of using the device is as follows:

1. A manufacturer generates a DLL that adheres to the IEEE/CIGRE real code interface standard.

2. Then “loads” the generated DLL into this device. At this point the device is ready and can be distributed to users along with the DLL.

3. Users can tune the device using GUI:

  • a. Change DLL parameters
  • b. Activate interpolation
  • c. Activate model initialization and provide initial output values
  • d. Use autoinitialization feature

4. Launch simulation.

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Before loading a DLL

Before loading a dll

After loading a DLL

After loading a dll


Features & Benefits 

  • Linear interpolation
  • Allow multiple calls to DLL when model sampling time is smaller than EMTP time-step
  • Phase adjustment
  • Initialization (manual or auto)


Example of control dll of a synchronous machine


A comprehensive documentation is provided with the Toolbox, but we are available to support and guide the users as much as possible.