Due to the much needed energy transition as agreed under the Paris climate agreement, it is expected that large amounts of variable renewable energy supply will be connected to the Dutch Transmission Network. Future social, economic and technological developments will determine both the amount of electrification as the central or decentral nature of the future supply of electricity. By investigating different reports with scenarios for 2030 and 2050, key uncertainties for the Extra High Voltage (EHV) network can be identified. As of now, no open source model of the Dutch EHV network is available for research. In this thesis a synthetic model of the Dutch EHV network is created from only publicly available data in DIgSILENT PowerFactory. The created synthetic model can be used as a tool to investigate future steady-state power flows considering the sensitivities of the topology, component parameters and different operational scenarios. Besides this, a method is created for generation of future scenarios in Python. Using this model and method, simulations were done to gain key insights into the Steady-State security of the future Dutch EHV Transmission Network. For the case study, it is investigated what the effect of future additions of variable renewable energy sources (VRES) and selected locations of 10 GW installed capacity of electrolysers would be on the Dutch EHV transmission network for 2030.