A Novel Automatic Load Shedding Scheme to Improve Survivability of Distribution Networks

With the deployments of smart grid technologies and communication networks in modern power systems, frequency relays, which are used for the purpose of power system protection, are to achieve more advanced and reliable performance. Load shedding strategies, which prevent power systems from suffering frequency instability based on the real time data frequency relays, are facing a challenge to adequately and accurately take shedding actions, as power system loads are varying all the time. On the generation side, increasingly non-dispatch able and inflexible renewable power generations being integrated to the system complicates generation predictions and results in frequent power imbalance. This paper proposes a load shedding scheme with different magnitudes and load shedding orders for distribution networks, with its effect on power system frequency stability verified in a benchmark IEEE 33-bus distribution system, which is simulated in Dig SILENT Power Factory package.