Geographically Distributed Simulation of Complex Offshore Grids

  distributed Simulation Copyright: © RWTH Aachen Geographically distributed simulation.

In this project we develop a geographically distributed simulation platform to operate two remote real-time digital simulators, in particular OPAL-RT (located at SINTEF, Norway) and RTDS (located at ACS, Germany). This new methodology for numerical simulation of large-scale power systems integrates remote simulation resources to meet demanding computational requirements. Furthermore, it enables remote testing of devices by integrating (power) hardware in the loop in this platform. Simulation of an offshore wind farm interacting with the main grid will be the main demonstrator.

ProOfGrids project (Protection and Fault Handling in Offshore HVDC Grids), coordinated by SINTEF Energy Research, is focused on developing tools and guidelines for the design of multi-terminal offshore HVDC grids. Numerical simulation is an essential tool for feasibility study and design of a multi-terminal offshore HVDC grid interconnected with onshore AC networks. Detailed real-time simulation of such complex power system requires large computational resources. To this aim, ACS is developing an Internet-distributed simulation platform that integrates two real-time digital simulators, OPAL-RT (located at SINTEF, Norway) and RTDS (located at ACS, Germany).

Challenges and solutions

Internet-distributed simulation refers to the concept of separating a power system model into subsystem models that are simulated concurrently on simulators located at geographically dispersed locations. Data exchange between simulators is performed by utilizing Internet whose inherent characteristics, such as time delay, jitter and packet loss, affect simulation accuracy and stability. Fidelity of an Internet-distributed simulation is highly dependent on a design of simulator-to-simulator interface. One of the main objectives of the project is to design a simulator-to-simulator interface that enforces conservation of energy between the subsystems while ensuring its transparency. To address this challenge, in the project we develop and implement local predictive algorithms to compensate the effects of communication disturbances and improve stability and fidelity of the distributed simulation.

The new Internet-distributed simulation platform will be utilized in the last stage of the project for studies of potential interactions of the control concepts implemented in the AC grid generators and control strategies of HVDC converters and offshore wind farms.

This work received financial support from the KPN project "ProOfGrids (ref. n. 215942/E20)" financed by the Research Council of Norway's RENERGI program and industry partners (EDF, NationalGrid, Siemens, Statkraft, Statnett, Statoil.