The induction of Electromagnetic Fields that are generated through the interaction of highvoltage transmission lines with neighboring buried metallic pipelines produce uncontrolled hazardous potential voltages, which can infringe safety limits. The paper presents the findings of the electromagnetic interference effects on water buried pipelines constructed within the vicinity of an Extra High-Voltage 380 kV transmission overhead line (OHL) in Riyadh-Salboukh route within the Saudi national grid power network. The presented case study showed that some segments of the buried pipelines under this line have not experienced voltages that exceeded the standard limits for the steady-state condition. However, in the event of L-G fault currents (short circuits), the pipelines experienced a voltage level that is above the local electric utility safety limits. Therefore, the work produced implemented the mitigation method of gradient control wires to reduce the potential voltages experienced by the pipelines to enforce the safety limit. The variation of wire resistance has been proven to be a feasible solution to reduce the excessive induced voltages. The comparison has shown that a 0.1 is sufficient to maintain the safe limit for at least this line. These findings may vary depending on the OHL design and site topology.

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Previous theoretical research efforts which were validated by experimental findings demonstrated the thermo-economic benefits of the hybrid concentrated photovoltaic-thermoelectric (CPV-TE) system over the stand-alone CPV. However, the operating conditions and TE material properties for maximum CPV-TE performance may differ from those required in a standalone thermoelectric module (TEM). For instance, a high-performing TEM requires TE materials with high Seebeck coefficients and electrical conductivities, and at the same time, low thermal conductivities ( k ). Although it is difficult to attain these ideal conditions without complex material engineering, the low k implies a high thermal resistance and temperature difference across the TEM which raises the PV backplate’s temperature in a hybrid CPV-TE operation. The increased PV temperature may reduce the overall system’s thermodynamic performance. To understand this phenomenon, a study is needed to guide researchers in choosing the best TE material for an optimal operation of a CPV-TE system. However, no prior research effort has been made to this effect. One method of finding the optimum TE material property is to parametrically vary one or more transport parameters until an optimum point is determined. However, this method is time-consuming and inefficient since a global optimum may not be found, especially when large incremental step sizes are used. This study provides a better way to solve this problem by using a multiobjective optimization genetic algorithm (MOGA) which is fast and reliable and ensures that the global optimum is obtained. After the optimization has been conducted, the best performing conditions for maximum CPV-TE energy, exergy, and environmental (3E) performance are selected using the technique for order performance by similarity to ideal solution (TOPSIS) decision algorithm. Finally, the optimization workflow is deployed for 7000 test cases generated from 10 features using the optimal machine learning (ML) algorithm. The result of the optimization chosen by the TOPSIS decision-making method generated an output power, exergy efficiency, and CO2 saving of 44.6 W, 18.3%, and 0.17 g/day, respectively. Furthermore, among other ML algorithms, the Gaussian process regression was the most accurate in learning the CPV-TE performance dataset, although it required more computational effort than some algorithms like the linear regression model.

Utilities aim to improve asset management strategies and enhance the utilization of their assets through low-risk reliable practices. Overhead lines and conductor designs have been evolving to increase systems' power capacity and mechanical integrity, which have also extended asset lifetimes. Nevertheless, it is still challenging to predict a conductor's fatigue stresses due to wind-induced vibrations that can help to estimate its useful life. A finite element model (FEM) has been established in COMSOL to study the free and forced wind-induced vibrations and the resultant fatigue on single multi-layer conductors considering their complex round and trapezoidal stranding patterns. The FEM analysis is based on multi-physics accounting for the conductor's thermal and mechanical aspects as well as material and geometry properties. Consequently, the fatigue is quantified for both inter-layer and inter-wire interactions. The simulations show that free conductor vibrations are dictated by the conductor materials and tension distribution between the core and aluminum strands. The bigger the difference between the material properties of the core and aluminum, the lesser the conductor vibrations, especially when the aluminum becomes slack. In fact, a conductor equipped with carbon core (ACCC), has the best vibration resistance among other conductors with steel core (ACSR) and homogeneous (AAACs). Forced vibration simulations identified non-linear fatigue stresses for round and trapezoidal designs, which is more pronounced in larger conductor sizes. Larger trapezoidal ACSRs exhibit better fatigue resistance compared to smaller and round stranded AAACs.

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