International Transactions on Electrical Energy Systems最新文献

Accurate estimation of neutral current (I_n) in industrial three-phase power systems is critical for harmonic suppression, equipment protection, and operational safety. This study proposes an ensemble regression framework optimized by a multiobjective genetic algorithm (GA) using 12,328 real-field measurements based on 29 electrical characteristics (P, Q, S; I_rms; U_rms; PF, dPF; I_THD, etc.). The GA simultaneously determines the selection and weights of the base learners (SVR, ANN, GPR, RF, GBR, XGB, DT, and GPR-RQ), improving eight performance metrics together: RMSE, MAE, SMAPE, MdAPE, R², EVS, maximum error, and PBIAS. Comparative analyses show that GA achieves high accuracy in 10-fold cross-validation compared to PSO, SA, random search, and average voting strategies (e.g., R² = 0.9972, RMSE = 1.83, and SMAPE = 10.31%); unseen test data maintained competitive overall performance (e.g., R² = 0.9820; SMAPE = 56.17%). In noise robustness, R² = 0.9933 was achieved in target-injected disturbance scenarios. Optimization reached Pareto convergence in approximately 50 generations. In the explainability analysis, SHAP and LIME outputs showed significant differences (p < 0.05) in 28 out of 29 variables; despite low inter-method correlation (Pearson ≈ −0.022), they provided complementary insights. The results demonstrate that the GA-XAI–supported ensemble provides high accuracy, interpretability, and applicability for I_n prediction. To the best of our knowledge, this study presents the first I_n prediction framework that statistically compares SHAP and LIME when used together with a GA-optimized ensemble and reports the process in a reproducible MATLAB script. We translate these distinctions into a practical protocol: SHAP for global monitoring and policy and LIME for case-level triage, thus enabling practitioners to confidently leverage complementary XAI signals during operations.

Reliable electricity access is crucial for sustainable development, yet Bangladesh’s coastal regions face challenges due to an unreliable grid. The off-grid hybrid system based on renewable energy is recommended in the existing research for Bhasan Char, optimized through the application of HOMER Pro software with the components being solar PV (48.3 kW), wind turbine (40 kW), diesel generator (50 kW), battery storage (91 strings), and a system converter (34.7 kW). Five different system configurations were analyzed, and Case 1 was the most cost-effective with a net present cost (NPC) of 25.87 million Bangladeshi taka (BDT), cost of energy (COE) of 16.29 BDT/kWh, and operating cost of 958,523 BDT/year. The system also offers a high renewable fraction (93.9%), low emissions (7651 kg CO₂/year), and payback period of 2.74 years. In addition, sensitivity analysis and heatmap correlation using Python were also utilized to compare system performance under various situations. Results show a low-cost and clean model that uses low fossil fuel but is highly economically feasible. The study submits an expandable model for off-grid coastal areas’ sustainable electrification that is consistent with Bangladesh’s energy security and conservation policies.

The integration of solar power systems into cruising ships is gaining popularity in the marine sector due to the restrictions imposed by the Marine Pollution Protocol and the rapid growth of photovoltaic (PV) technology. However, this integration brings various challenges in the operation of the ship energy system, including resource uncertainty, power imbalance, and reduced service reliability. Therefore, this study proposes a novel three-stage operation strategy for ship multienergy systems to compensate for the uncertainty of PV generation. In Stage 1, a day-ahead scheduling process is performed to determine the setpoints of major system components. The goal is to minimize operating costs while meeting electrical, heating, and cooling demands. In Stage 2, a deep neural network-based PV prediction model is developed. Particle swarm optimization is used to achieve fast convergence and high accuracy. A detailed statistical analysis is then applied for early detection of data drift, which may cause a significant drop in prediction accuracy. The uncertainty of PV output is then estimated based on the new trends observed in the incoming dataset. In Stage 3, a demand response (DR)-based scheme is introduced to compensate for the uncertainty of PV power, identified in Stage 2. The DR programs allow sharing the load demand among different intervals by adjusting controllable loads. As a result, the amount of power mismatches caused by the uncertainty factor has decreased. Finally, simulation results also demonstrate that the amount of load shedding requirement in the ship energy system is significantly reduced using the proposed method.

This research offers a hands-on examination of using Jordan’s naturally abundant, high-purity Wadi Rum silica sand (SiO₂ > 99%) as an affordable material for thermal energy storage (TES) in concentrated solar power (CSP) systems aimed at home-scale applications. During the 3 days of continuous testing, the setup achieved a peak heat transfer rate of 18.7 kW, heating water by 27°C, reaching a top outlet temperature of 54.9°C. The silica sand proved to be an effective thermal reservoir, attaining internal temperatures between 67°C and 69°C. On average, the system produced 11.2 kWh of thermal energy per day, with an overall efficiency of 50.2%, while cutting daily CO₂ emissions by about 2.07 kg. The economic assessment showed a payback time of just 1.49 years, which reduced to 1.04 years with a 30% subsidy. Altogether, the findings confirm that Wadi Rum silica sand offers a practical, sustainable, and financially attractive pathway for thermal storage, directly advancing Jordan’s drive toward a cleaner and more self-reliant energy future.

Under the carbon neutrality framework, the traditional coal chemical industry requires the upgrade and transformation of industrial parks to reduce carbon emissions while maintaining economic benefits. This study establishes a green electricity–hydrogen coupled coal chemical system and proposes a robust optimization model incorporating uncertainties in wind and solar power. First, a model for green electricity-driven coal chemical production is developed based on thermodynamic principles, considering material and energy flows. Second, utilizing vine copula theory and Markov transition matrices, a confidence interval-based uncertainty set is constructed to characterize the stochastic nature of renewable energy. Finally, a robust optimization model integrating system dynamics and uncertainty sets is formulated, implemented on the MATLAB–YALMIP platform, and solved using the CPLEX solver. Results show that the proposed uncertainty set enhances wind–solar variability capture (correlation 0.0253 higher than the polyhedral uncertainty set). The system achieves about 1.2-Mt CO₂ yr⁻¹ reduction and annual revenue between 0.48 and 3.45 billion CNY (average 1.42 billion CNY), proving both robustness and economic advantage. In terms of economic assessment, the model not only overcomes the limitations of wind–solar data acquisition but also enables reasonable evaluation under diverse scenarios. This work provides novel insights into the green transformation and economic assessment of the coal chemical industry and contributes to economic budgeting and benefit evaluation for other types of industrial parks.

In recent years, managing power in the electrical systems that utilize intelligent infrastructures has become a modern solution for operators. This technology enables more effective control and improves the overall performance of electrical networks. Accordingly, this paper focused on economic and technical power management in an intelligent electrical distribution network (IEDN) with demand response programs (DRPs) at day-ahead. The proposed approach is implemented in IEDN by the bilayer optimization approach considering the contribution of the electrical distribution company (EDC) and consumers. In the first layer, implementation of the DRPs such as local power generation (LPG) by battery storage systems (BSSs), power load curtailment (PLC) program, and power load shifting (PLS) program is scheduled for minimizing bills of consumers. On the other side, in the second layer optimization, income of EDC is maximized and power losses of IEDN are minimized considering scheduled load demand in the first layer optimization. The optimization in both the layers is modeled as multiobjective functions, and optimization of consumers’ bills is done subject to power prices in EDC. The effect of the suggested approach is examined on technical metrics such as voltage profile and peak-to-average ratio (PAR) index. The improved grasshopper optimization algorithm (IGOA) and Shannon entropy decision-making method are used for solving bilayer optimization approach and multiobjective functions. In the end, the results reveal the optimal values of the objective functions of each layer, based on a comparative examination of different case studies, thereby considering consumer engagement.

As the proportion of renewable energy sources continues to rise, the stability and reliability of the power system face enormous challenges. Virtual synchronous generators (VSGs) enhance grid stability by simulating conventional synchronous generator characteristics and providing virtual inertia and damping to the system. However, VSGs with fixed inertia and damping parameters are difficult to adapt to the complex and changing grid environment. To this end, this manuscript proposes an adaptive control strategy based on variable universe fuzzy control to realize the adaptive adjustment of VSG inertia and damping parameters. First, the mathematical model of VSG is established to analyze the influence of inertia and damping on the power–frequency characteristics of the system, and the variable universe fuzzy controller is designed based on the principle of parameter optimization to realize the real-time optimal regulation of parameters. Second, model predictive current control (MPCC) is introduced to replace the traditional voltage and current PI regulation, and a novel three-vector model predictive current control strategy (NTV-MPCC) is proposed, which makes the synthesized voltage vector changeable in both amplitude and direction and effectively reduces harmonic distortion and current ripple. Finally, the effectiveness of the proposed control strategy is verified by simulation, which shows that the proposed method is able to improve the dynamic response capability, steady-state performance, and current quality of the VSG system.

This study proposes an improved version of the wild horse optimizer (WHO) for the optimal allocation and sizing of distributed generators (DGs) and capacitor banks (CBs) to promote the system’s susceptibility. The proposed method, namely, improved WHO (IWHO), aims to improve the performance of the system not only in terms of power loss, voltage deviation index (VDI), and voltage stability index (VSI) as in most previous studies, but also in terms of generation cost and total emissions. Five operational cases are carried out on four different systems, the IEEE 33-bus, 69-bus, 118-bus standard radial distribution systems and the real 78-bus Egyptian distribution system, to demonstrate the best performance of the proposed technique. In addition, two multiobjective functions are implemented to compare with the original WHO and other existing optimization techniques. Based on the statistical analysis, the simulation results prove that the proposed IWHO provides the best results for flexible operations, especially for large-scale complex systems. After the optimal integration of DGs and CBs, the power loss was reduced up to 94.18%, 98.53%, 92.05%, and 93.87%; the cost was reduced by 43.23%, 43.77%, 14.68%, and 99.99%; and the emissions were reduced by 99.96%, 99.99%, 76.01%, and 61.20% for 33-bus, 69-bus, 118-bus radial systems and the real 78-bus system, respectively. It is observed that the IWHO algorithm also gives recognized enhancements in conflicting objective functions such as technical, economic, and environmental objectives.

A mathematical model of a double-star permanent magnet synchronous motor is proposed, coupled with an estimator for speed, position, and currents based on an extended Kalman filter. This filter is optimized using a novel methodology. The primary objective is to determine the optimal values for the three noise covariance matrices to ensure the convergence of the parameter estimation. To enhance the estimator’s performance, several innovative optimization strategies are introduced. These combine different techniques, notably particle swarm optimization with the Nelder–Mead simplex algorithm, as well as a genetic algorithm coupled with this same hybrid method. Other approaches are also deployed, such as a fuzzy self-tuning method for success-history–based parameter adaptation for differential evolution, along with a fuzzy version of the linear population size reduction success-history–based adaptive differential evolution algorithm. Furthermore, an accelerated procedure for initializing the covariance matrices is implemented. Specifically, the error estimation covariance matrix and the measurement noise covariance matrix are fixed, while the process noise covariance matrix is the subject of the optimization. The validity of the proposed approach is demonstrated through comprehensive numerical simulations. These simulations include the machine model, its power supply, and the parameter estimator, all implemented within the MATLAB/Simulink environment.

One well-known fault that arises from water intrusion and power cable insulation failure is the incipient fault (IF) in underground power cables (UPCs). Therefore, it is necessary to provide appropriate models for modeling this fault and also to generate data close to the actual value for validating IF detection methods. This study presents a model for IFs in UPCs, which provides the necessary data for the assessment. A few articles have been devoted to modeling the IF in UPCs, despite the numerous articles that have been introduced on arc modeling in other applications. This work deals with driving effective modeling of IFs in power cables from the two modified Avdonin models using the records of experiments obtained from a laboratory setup. The transient characteristics of IFs are demonstrated in the proposed models using the idea of transient coefficients. Also, the least squares method is used to update the models’ coefficients for every power frequency cycle. Finally, two error indices are introduced to establish each model’s optimal coefficients. Probability distribution functions (PDFs) were utilized to simulate the stochastic conduct of the model coefficients, which change with each cycle. As a result, for each combination of the model’s coefficients, some PDFs are examined, and the PDF that most closely matches the actual data is chosen. Also, the proposed models of this study are compared with the modified polynomial and modified Schwarz models.