Browsing by Author "208"
  • Item
    The challenges of estimating the impact of distributed energy resources flexibility on the TSO/DSO boundary node operating points
    ( 2018) Luís Seca ; Vladimiro Miranda ; Manuel Matos ; João Vieira Silva ; Jean Sumaili ; Ricardo Jorge Bessa ; 4417 ; 208 ; 214 ; 4882 ; 6299 ; 5164
    The increasing penetration of renewable energy sources characterized by a high degree of variability and uncertainty is a complex challenge for network operators that are obligated to ensure their connection while keeping the quality and security of supply. In order to deal with this variable behavior and forecast uncertainty, the distribution networks are equipped with flexible distributed energy resources capable of adjusting their operating point to avoid technical issues (voltage problems, congestion, etc.). Within this paradigm, the flexibility that, in fact, can be provided by such resources, needs to be estimated/forecasted up to the transmission network node (primary substation) and requires new tools for TSO/DSO coordination. This paper addresses this topic by developing a methodology capable of finding the flexibility area while taking into account the technical grid constraints. The proposed approach is based on the formulation of a single optimization problem which is run several times, according with the expected precision for the flexibility area estimation. To each optimization problem run, a different objective function belonging to a family of straight lines is assigned. This allows exploring the active and reactive power flow limits at the TSO/DSO boundary nodes - which define the flexibility area. The effectiveness of the proposed model has been evaluated on two test networks and the results suggest a step forward in the TSO/DSO coordination field. Nevertheless, further investigations to study the effect of assets with discrete control nature (e.g., on load tap changers - OLTC, capacitor banks) on the occurrence of disjoint flexibility areas should be carried. © 2017 Elsevier Ltd.
  • Item
    Estimating Breaker Status with Electrical State Images and Convolutional Neural Networks
    ( 2019) Vladimiro Miranda ; Teixeira,L ; Jorge Correia Pereira ; 208 ; 1809
  • Item
    Estimating the Active and Reactive Power Flexibility Area at the TSO-DSO Interface
    ( 2018) João Vieira Silva ; Sebastian Viana,M ; Goncer,B ; Caujolle,M ; Vladimiro Miranda ; Manuel Matos ; Seca,L ; Ricardo Jorge Bessa ; Sumaili,J ; 6299 ; 4882 ; 208 ; 214
  • Item
    Impact of different central path neighborhoods on gross error identification in State Estimation with generalized correntropy interior point method
    ( 2019) Moayyed,H ; Shabnam Pesteh ; Vladimiro Miranda ; Jorge Correia Pereira ; 1809 ; 7130 ; 208
  • Item
    A new interior point solver with generalized correntropy for multiple gross error suppression in state estimation
    ( 2019) Shabnam Pesteh ; Moayyed,H ; Vladimiro Miranda ; Jorge Correia Pereira ; Victor Silva Freitas ; Simoes Costa,AS ; London Jr,JBA ; 1809 ; 208 ; 7130 ; 7194
    This paper provides an answer to the problem of State Estimation (SE) with multiple simultaneous gross errors, based on Generalized Error Correntropy instead of Least Squares and on an interior point method algorithm instead of the conventional Gauss–Newton algorithm. The paper describes the mathematical model behind the new SE cost function and the construction of a suitable solver and presents illustrative numerical cases. The performance of SE with the data set contaminated with up to five simultaneous gross errors is assessed with confusion matrices, identifying false and missed detections. The superiority of the new method over the classical Largest Normalized Residual Test is confirmed at a 99% confidence level in a battery of tests. Its ability to address cases where gross errors fall on critical measurements, critical sets or leverage points is also confirmed at the same level of confidence. © 2019 Elsevier B.V.