Browsing by Author "Santos, D."
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Optimal management of power networks using a dynamic line rating approachPublication . Duque, Joaquim; Santos, D.; Couto, António; Estanqueiro, AnaABSTRACT: Due to the stochastic nature of wind, the wind power integration into the power system poses serious challenges to the transmission system operators (TSO). The impact of large amounts of wind energy generation onto the power system may congest some of the transmission lines that transport it to the (sometimes) distant consumption centres. Since the occurrence of wind not only contributes to the loading of the connecting electric line, but also increases the line capacity, via convective cooling of the cables, a dynamic line rating (DLR) analysis computes a more realistic set of values for the line capacity, thus it can be a cost-effective solution to alleviate some overhead line congestion problems. This work presents an operational tool for the DLR analysis of power networks, allowing the optimal integration of renewable energy sources, especially where potentially congested lines may exist. The tool was applied to a real case study using forecast meteorological data, and the results achieved were compared with those obtained by using the Portuguese TSO method for assessing the transmission capacity of the lines. For high wind speed conditions, results show a noticeable increase on the cable’s convective cooling assessed by the DLR analysis. This assessment leads to a noticeable rise on the cables’ capacities that overcame the congestion associated with the high injection levels of wind power generation in the power grid.
- Towards a high-resolution offshore wind Atlas : the Portuguese casePublication . Couto, António; Silva, João M. Henriques da; Costa, Paula Silva; Santos, D.; Simões, Teresa; Estanqueiro, AnaABSTRACT: An accurate offshore wind resource assessment is a key tool for planning marine wind renewable exploitation. To achieve this goal, without resort to an extensive and costly network of anemometric stations or buoys, it becomes necessary to use the so-called atmospheric mesoscale models. This work presents a high spatial resolution (1x1 km) offshore wind resource Atlas for Portugal and the model calibration steps. During the calibration steps, the most adequate: i) atmospheric parameterizations - physics options, ii) initial and boundary conditions (IBC) meteorological datasets, and iii) data assimilation scheme were achieved through sensitivity tests using the common statistical metrics and hourly simulated/observational data. Results show that the most significant improvements are associated with the IBC dataset and the data assimilation scheme used. Thus, the results show that the assimilation procedures coupled with the new ERA-5 reanalysis dataset reduce significantly the errors of the wind speed and direction, especially the normalized mean square error. This reduction, depending on the different calibration setup, can be above 50%. The new Atlas confirms the previous indicators, Portugal presents a high wind power potential, especially for deep offshore regions.