Eastern Green Link 4 AC Digital Models Study

the Employer is looking to appoint a Study Contractor. The Study Contractor will in a First Stage, develop the AC network models, and in a Second Stage, will work with an HVDC Contractor to test the EGL4 HVDC Link control system.

Below is a brief description of the scope. In the First Stage, the Employer will provide the Study Contractor with AC network model information in DIgSILENT PowerFactory and PSCAD software.

By March 2028, the Study Contractor shall: • Perform multi-infeed interaction factor (MIIF) and unit interaction factor (UIF) studies, identify the AC network nodes remote from the EGL4 converter stations which can be reduced to network equivalents, and prepare PowerFactory and PSCAD models of AC network as viewed from the EGL4 converter stations. • Replace confidential AC network plant models in PowerFactory and PSCAD networks with generic plant models. The generic plant models shall be designed and parameterised to replicate the confidential plant model performance, and this will be evidenced by a validation report for the approval of both the Employer and the HVDC Contractor. • Be responsible for obtaining the Non-Disclosure Agreements where required from third-party plant owners.

The HVDC Contractor will design and develop the EGL4 HVDC Link specific models, based on the AC network models containing equivalenced plant models received from the Study Contractor. The HVDC Contractor will then share the EGL4 HVDC Link specific models with the Study Contractor. In the Second Stage, the Study Contractor shall: • Test the EGL4 HVDC Link specific models after integrating them into the PowerFactory and PSCAD network models developed in the First Stage. • Work with the HVDC Contractor to resolve any further issues related to dynamic performance and tuning of the EGL4 HVDC Link control system.