Cost optimized dynamic design of offshore windfarm transformers with reliability and contingency considerations

Offshore Windfarm Design Optimization Using Dynamic Rating for Transmission Components

“…As per the latest auction results, discount rate i = 6.75% and γ = 44.9 [e/MWh] are used similar to the strike price of the 1.2 GW Doggerbank Creyke Beck A [1]. For all the design cases, the cost and mass of oil-filled components can be empirically derived using (40) [15], such that Z is replaced by the relevant parameter (c or m). Similarly for XLPE insulated subsea cables with Cu conductor, the cost can be calculated using (41), where coefficients g 1 , g 2 and g 3 are dependent on nominal voltage of the cable [4].…”

“…On the other hand, only a handful of research has been done on the OWF transmission system, with most publications focused only on the optimal design of HVAC submarine cables without the application of DTR [3], [9]- [11]. The potential of cost reduction by optimization of remaining components [15] and by employing DTR on the entire system altogether to resolve any unintentional system bottlenecks is completely unexplored [16], [17]. This paper uniquely targets the optimized design of the entire OWF transmission system by using coordinated DTR of the major HV components.…”

“…Empirically derived Thermo-Electric Equivalent (TEE) models fit this profile to a large extent. For oil-filled components, the first-order differential models from [18], [19] can be made fit for linear estimation [16], [20] for intermittent dynamic offshore wind generation [15]. Contrarily, singlecore equivalent TEE models for three-core HVAC subsea cables in [21]- [23] are complicated to design [24], but can be transformed to account for effective losses in long cables [25], [26] and backfill soil's thermal parameter variation [27].…”

Assessment of dynamic transformer rating, considering current and temperature limitations

“…Nowadays, the thermal rating assessment is a relevant problem for engineers and researchers dealing with power system operation and planning. Thermal ratings have a strong impact on the optimal solution of a power system scheduling [1], a wind power integration [2][3][4], a hosting capacity of substations [5], [6], an asset management [7] among many others [8]. Moreover, due climate change problem the system operators should manage a power system with a large share of Distributed Energy Resources (DER) [9].…”

Estimating Wind Farm Transformers Rating through Lifetime Characterization Based on Stochastic Modeling of Wind Power

“…In the technical literature, rating of power transformers that connect wind power plants to the grid is investigated in [5], where a dynamic approach for exploiting the variability of power production is proposed. In [6] a cost optimization methodology is proposed which uses statistical scenarios based on distribution functions and Markov Chain models and accounts for maintenance and design requirements for transformer contingency in off-shore wind farms. The calculation of transformer limits according to the shape of the loading profile in presence of renewable generation is analyzed in [7], where an energy-limit concept for oil-immersed technology is proposed.…”