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Modélisation des ilots non-intentionnels et caractérisation des méthodes passives de détection d’ilotage

Abstract : Unintentional islands might appear when a subpart of the grid is disconnected from the power system and keeps working because of local generation. These events are unwanted: their behavior is not controlled and leads to potential risks for people and for electric equipment. Unintentional islanding is a complex phenomenon and badly understood. Nowadays it is considered to be rare, but a priori its occurrence probability is currently steadily increasing. This rising is the consequence of several phenomena: firstly, the development of distributed generation of small and average size directly connected to the distribution grid; secondly, the enlargement of frequency thresholds used by isolating protections; and thirdly, the implementation of power regulations of active and reactive power in the generation unit. Within this context, the Smart Grid chair of Enedis financed this PhD thesis in order to better characterize these islanding phenomena and to improve their detection.To achieve these targets, a first priority of the PhD was to improve the comprehension of unintentional islanding through symbolic calculation. This approach makes it possible to solve a simple model and to explain the evolution of the frequency during an island. These results are completed with several laboratory experiments and by numeric simulations. Models are designed based on a thorough bibliography, in particular for load modeling.A second priority of the PhD was to estimate the efficiency of anti-islanding protections through the computation of non-detection zone (NDZ). The impact of several loads on the NDZ is analyzed to improve the understanding of unintentional islanding, which is a complex phenomenon. The efficiency of new anti-islanding protections using thresholds on the rate of change of frequency (ROCOF) is also thoroughly evaluated. It is shown that the computation method used by the protection plays a key role. At last, the calculation methods of the NDZ is improved regarding previous methods. Among other things, it allows to radically change the estimations of the impact of new power regulations P(f) and Q(U).
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Submitted on : Wednesday, October 31, 2018 - 10:53:06 AM
Last modification on : Tuesday, October 6, 2020 - 4:24:20 PM


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  • HAL Id : tel-01909471, version 1



Olivier Arguence. Modélisation des ilots non-intentionnels et caractérisation des méthodes passives de détection d’ilotage. Energie électrique. Université Grenoble Alpes, 2018. Français. ⟨NNT : 2018GREAT045⟩. ⟨tel-01909471⟩



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