Contribution of HVDC Systems in Increasing the Electrical Network Inertia: A Case Study

This work studies the possibility of controlling HVDC (High Voltage Direct Current) systems to support the primary frequency regulation of the traditional rotating generators; in particular, the paper presents how to provide the synthetic inertia function by means of the energy stored into the HVDC connection itself. Simulations on a two-terminal grid have been performed, implementing a synthetic inertia model based on a classic frequency-derivative grid controller. Simulations show that HVDC can support the grid inertia as long as a good frequency derivative measurement is available and proper DC capacitors are given.