Introduction: The future power system is going to be highly complex, integrating renewable generation, smart grids, voltage upgrades, increasing usage of long cables and HVDC. Successful implementation will require extensive computer simulations during all the planning and engineering phases. Existing simulation tools have limited accuracy for representing some critical components such as transformers and cables. The project will produce models that are sufficiently accurate and compatible with available circuit simulators, and make use of the models in system simulation studies in order to pinpoint bad configurations. There is also limited understanding of these interactions, such that development project and designers do not know what can cause the problems and how to avoid designing potential problems.

Objectives: A collaborative research group is being established, made up of utilities, manufacturers and research bodies, to investigate the Electromagnetic Transient (EMT) interaction of renewable generation on transmission equipment. The focus of the project will be on the EMT modelling of components (transformers, cables, circuit breakers, instrument transformers etc.) to provide best practice and expert opinion on their interaction with the power system.

System and plant measurements will be carried out to validate the models, which can then be used to simulate and demonstrate the power system interaction phenomena on equipment such as current inrush, harmonic penetration, resonant overvoltages, etc. The work will consider transformer modelling (both in terms of modelling expertise and laboratory facilities), and acquiring cable lengths for the purpose of model validation (complex multi-phase cables with steel armouring). In addition, a number of system studies will be performed in order to highlight special transient phenomena such as how CT/VT saturation may impact on protection performance.

Participants will highlight their interests, for instance, EDF want to compare case studies using PSCAD and EMTP-RV packages, Statkraft would like an activity on modelling oil-filled cables, Vestas is very interested in black-box cable modelling, etc.

In summary, the work will:

• Develop component models to characterise the range of phenomena associated with transient conditions

• Examine the network architecture

• Validate EMT models in different simulation packages

• Disseminate the results and models to the partners.