New Functions of VSC Based HVDC Transmission Systems that Can Effectively Support the Future South-East European Grid with Low Inertia and Large Amount of Res Generation

The energy mix in South-East Europe is nowadays mainly composed by hydro and fossil fuels generation almost equally distributed in the share of electricity generation. Wind and solar PV generation play a very marginal role playing cumulatively less than 7% of the total generation, while fossil fuels exceed 52% of the total generation. A Multi-Terminal HVDC grid between the different countries in South-East Europe may provide various operational and socio-economic gains. In this paper are presented some grid specific challenges and explored some new functions of HVDC transmission systems based on VSC technology that can effectively support the grid with large amount of RES. The paper aims to explore how the VSC converters can improve the system’s voltage stability and provide the necessary frequency control when the inertia in the grid is very low and how the HVDC transmission system can accomplish transferring the primary and secondary reserves solving the rising problems related to dispatchability and inertia response in RES based power grids.