Examinando por Autor "Khosravi, Nima"
Mostrando 1 - 3 de 3
- Resultados por página
- Opciones de ordenación
Ítem A data-driven methodology to design user-friendly tariffs in energy communities(Elsevier, 2024-03) Tlenshiyeva, Akmaral; Tostado-Véliz, Marcos; Hasanien, Hany M.; Khosravi, Nima; Jurado-Melguizo, FranciscoIn recent years, energy communities have emerged as a feasible solution to empower domestic end-users to engage in local power trading with their neighbours, in an attempt to improve the efficiency and economy of residential consumers. From a mercantilist point of view, launching local markets with eventual local electricity prices might be beneficial for community users as they are inhibited from external volatile prices and possible market imperfections. However, local pricing strategies should take into account users’ preferences and avoid undesirable effects of response fatigue (i.e. excessive number of response signals within a short-time period). This way, local electricity tariffs should be stable and send coherent response signals easily interpretable by users. In this sense, the necessity of developing proper designing tools for local electricity tariffs is clear. This paper focuses on this issue. In particular, the main novelties of this paper are twofold: on the one hand, the developed tool designs community tariffs over a year basis instead of daily spot prices, as made in existing approaches. Thereby, the resulting tariff keeps stable yearly similar to conventional tariffs offered by retailers worldwide. Secondly, the designed tariff takes into account the negative effects of response fatigue, so that the considered pricing mechanism limits the number of pricing signals sent to consumers, taking this feature as an external parameter. This way, the designer is able to tune up the total number of pricing signals that users received within a time period, thus ensuring that they are not discouraged to partake in the community. The proposed design approach is raised as a data-driven framework, taking advantage of real databases collecting demand, renewable generation and retailer prices. Such profiles serve as inputs for a designed bi-level Stackelberg-based problem, in which the reaction of prosumers is implicitly assumed. A case study is conducted on a benchmark energy community. Different tariff mechanisms are analysed such as flat, time-of-use and happy hours tariffs. The results obtained serve to validate the new proposal as well as analyse the effect of local market mechanisms in energy communities.Ítem A novel control approach to improve the stability of hybrid AC/DC microgrids(Elsevier, 2023-08-15) Khosravi, Nima; Baghbanzadeh, Rasoul; Oubelaid, Adel; Tostado-Véliz, Marcos; Bajaj, Mohit; Hekss, Zineb; Echalih, Salwa; Belkhier, Youcef; Abou Houran, Mohamad; Aboras, Kareem M.Overall, voltage and frequency(V/F) stability are essential in microgrids (MGs) to ensure reliable and high-quality power supply for critical loads and to support the integration of renewable energy sources (RESs) while maintaining the stability of the power system. Therefore, V/F stability is particularly important for causes such as load balancing, quality of power supply, renewable energy integration, and grid stability. This study aims to introduce an interactive control system for hybrid MGs (HMGs) based on distributed energy resources (DERs). Here, the defined control strategy objective is to ensure the four system parameters’ stability, including voltage/frequency (V/F) and active/reactive (P/Q) power for the units. In this study, the research innovation consists of two layers. The first layer aims to adjust the unit V/F, using an internal voltage and current controller loop combined in the power droop controller (PDC). The second layer is concerned with the steady-state error minimization, created in the first layer due to the droop controller performance. Therefore, the secondary distributed V/F control strategies are designed based on finite-time consensus theory (FTCT) owing to its resistance and stability against various load perturbations and system disturbances, which makes flexible convergence time possible according to different user preferences and operating conditions. The simulation results prove the efficiency of the proposed method strategy. Furthermore, the values of improving the amplitude of oscillations and fluctuations for V/F components vary from 0.02pu-0.2pu and 0.178pu-0.216pu, respectively.Ítem Low-voltage ride-through capability in a DFIG using FO-PID and RCO techniques under symmetrical and asymmetrical faults(Nature, 2023-10-16) Sabzevari, Kiomars; Khosravi, Nima; Abdelghany, Muhammad Bakr; Belkhier, Youcef; Tostado-Véliz, Marcos; Kotb, Hossam; Govender, ScottThe power grid faults study is crucial for maintaining grid reliability and stability. Understanding these faults enables rapid detection, prevention, and mitigation, ensuring uninterrupted electricity supply, safeguarding equipment, and preventing potential cascading failures, ultimately supporting the efficient functioning of modern society. This paper delves into the intricate challenge of ensuring the robust operation of wind turbines (WTs) in the face of fault conditions, a matter of substantial concern for power system experts. To navigate this challenge effectively, the implementation of symmetrical fault ride-through (SFRT) and asymmetrical fault ride-through (AFRT) control techniques becomes imperative, as these techniques play a pivotal role in upholding the stability and dependability of the power system during adverse scenarios. This study addresses this formidable challenge by introducing an innovative SFRT–AFRT control methodology based on rotor components optimization called RCO tailored for the rotor side converter (RSC) within a doubly-fed induction generator (DFIG) utilized in wind turbine systems. The proposed control strategy encompasses a two-fold approach: firstly, the attenuation of both positive and negative components is achieved through the strategic application of boundary constraints and the establishment of reference values. Subsequently, the optimization of the control characteristic ‘ ’ is accomplished through the utilization of a particle swarm optimization (PSO) algorithm integrated within an optimization loop. This intricate interplay of mechanisms aims to optimize the performance of the RSC under fault conditions. To measure the efficacy of the proposed control technique, a comparative analysis is conducted. Fractional-order (FO) proportional–integral–derivative (PID) controllers are employed as an additional method to complement the novel approach. By systematically juxtaposing the performance of the proposed SFRT–AFRT control technique with the FO-PID controllers, a comprehensive evaluation of the proposed approach's effectiveness is attained. This comparative assessment lends valuable insights into the potential advantages and limitations of the novel control technique, thereby contributing to the advancement of fault mitigation strategies in WT systems. Finally, the paper highlights the economic viability of the proposed control method, suggesting its suitability for addressing broader power network issues, such as power quality, in future wind farm research.