Improving Power System Frequency Response with a Novel Load Shedding Method
60th ESReDA Seminar: Advances in Modelling to Improve Network Resilience 2022
Andrejs Utāns, Antans Sauļus Sauhats, Laila Zemīte, Dmitrijs Guzs

The life of the modern society relies completely on electricity supply that is why electrical grid have always been considered a life-critical infrastructure. The likelihood of various extreme events, classical, weather-related and modern, man-made threats, has been increased dramatically in recent decades. Along with that, power systems are undergoing radical, renewable energy source (RES)-related transformations which affects both, the structure of the generation sources and the dynamical behavior of the system after it was exposed by an extreme event. System dynamics during transients is often neglected in resilience-related studies. But, an adequate performance when system is transiting from a steady-state to a degraded, but stable one, is vitally important because it directly affect the remaining operational capacity of the system and its’ ability to recover faster. During transients the power grid is under control of various protection and automation systems which, to a large degree, determine the post-event state of the network and its ability remain partially functional. Therefore, enhancing the performance of the automation systems may become a cost-effective solution for improving the entire resilience of the power network. This paper addresses the problem of preventing significant decline of the system frequency resulting from a large imbalance of power. Frequency instability prevention has always been a top priority task and become even more so due to displacement of the traditional generation sources in favor of non-inertial RES. Novel Load Shedding (LS) Method based on monitoring of synchronous condensers’ power injection will be presented in the paper. Unlike traditional, frequency measurement-based Under Frequency LS (UFLS), new method will shed the load without waiting while frequency drops below the trigger of traditional UFLS. Comparing with traditional UFLS, new approach allows to achieve much better frequency profile for the same power imbalance/load shed. Power system dynamics modeling software will be used to demonstrate the performance of the proposed method. The method is most efficient for a networks with high penetration of non-inertial RES and with synchronous condensers providing major part of the system inertia.


Keywords
power system resilience frequency response load shedding synchronous condenser.

Utāns, A., Sauhats, A., Zemīte, L., Guzs, D. Improving Power System Frequency Response with a Novel Load Shedding Method. In: 60th ESReDA Seminar: Advances in Modelling to Improve Network Resilience, France, Grenoble, 4-5 May, 2022. Grenoble: Francija, 2022, pp.1-6.

Publication language
English (en)
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