Frequency Stability Enhancement for a System with Integrated Renewable Energy Sources and HVDC Link

Frequency stability has not been a major concern among other types of stability which are angular stability and voltage stability. However nowadays with high penetration of renewable energy sources and increased number of power system interconnection between areas by HVDC Links, the requirement of frequency stability needs to be addressed in more details compared to a system with conventional generators as the main power source only. Load growth, pollution associated with conventional generator, and limitation of fossil fuel resources are the major reasons of aiming to have high penetration of renewable energy sources and interconnecting the areas. This paper illustrates the impact of adding high penetration of renewable energy sources and having HVDC link between two separate power systems on short term frequency stability. Inertia response period is considered as 10 seconds. Modified IEEE 9 bus was considered as the case study for this paper. Electrical Transient and Analysis Program (ETAP 19) was used for simulation. The contribution of this paper is to consider both renewable energy sources and HVDC in one simulation and propose a solution to enhance short term frequency stability.