Toward a wide-area load shedding scheme: Adaptive determination of frequency threshold and shed load values

摘要

This manuscript revealed an adaptive wide‐area load shedding scheme based on synchrophasors provided by PMUs. Itrnwas discussed that the conventional UFLS schemes and the existing adaptive approaches are based on constant loadrnshedding steps and frequency thresholds. Thus, inaccurate decisions were yielded in regard of small and large disturbances. In contradiction, the proposed approach was shown to adaptively tune the frequency threshold of thernUFLS process and successfully differentiating the small and large disturbances. Furthermore, adaptive determinationrnof the amount of shed load at each bus has led to improvements in load shedding scheme. Such a feature wasrnshown to preserve the sensitive and essential portion of loads at each bus to stay in electrification process. As anticipated,rnan efficient performance was noticed in load shedding process through the simulation studies. Specifically speaking, itrnwas deduced that the conventional and the previous adaptive approaches do not contribute to desired voltage andrnfrequency performances. However, the proposed approach curbed the fluctuations so swiftly and reliably. Moreover,rnthe wide‐area nature of the synchrophasors data offered a global insight into the load shedding task. With respect tornsimulation results, this feature resulted to a wide‐area selection of shedding candidates whereas the previous methodsrnresulted in local shedding patterns. These technical achievements approve the validity and outperformance of thernproposed approach to be taken in use in AOCs and dispatching center of transmission networks. Adoption of recentrnnotions such as short‐term frequency approximation and a predictive load shedding approach could add to the worthrnof the proposed approach which requires further investigations.