VSC-HVDC System Based Ancillary Services for AC Grids

Abstract

In viewing an increased ratio of renewable resources like solar and wind farms, point-to-point Voltage Source Converter based High Voltage DC (VSC-HVDC) system commissioning are on the rise worldwide. They are becoming techno-economical solutions for integrating bulk renewable resources into significant load centers. In this scenario, it is requisite by most of the grid codes that VSC-HVDC grids need to provide ancillary services to the AC grids. Ancillary services such as active power and frequency support are crucial for the stability and reliability of the power system. Henceforth, this paper proposes a control strategy to achieve these ancillary services through the VSC-HVDC system. The proposed control method introduces the active power and frequency loops into conventional control and extracts the support from a point-to-point VSC-HVDC system. To validate the proposed control strategy, two case studies and a test system which is a point-to-point VSC-HVDC integrated into Kundur’s two-area power system, have been considered. An RT-LAB simulation platform has been used to develop and model the test system. Further, the performance of the proposed method is demonstrated in real-time by using one of the OPAL-RT simulators, OP5707.