American Transmission Company (United States)

ABSTRACT Over the past two decades, new technologies and behavioral shifts – such as electric vehicles, solar photovoltaics, and increased work-from-home practices – have reshaped residential electricity consumption and cost. However, their combined or synergistic impact on a household’s electricity cost remains unexplored. Leveraging data from the 2020 Residential Energy Consumption Survey, this study uses a structural equation model to unravel the extent to which the bundled adoption of EV-PV and stay-at-home decisions impact the total electricity cost of households. Results indicate that adopting both EVs and PV reduces electricity costs by 31% despite a 16% rise in consumption. When combined with stay-at-home practices, households still experience a 13% cost reduction, even with a 25% increase in electricity consumption. These findings suggest that financial savings are not merely a byproduct of adopting new technologies or behavioral changes but could serve as a key consideration for household contemplating engagement with multiple modern energy solutions simultaneously.

The safe and stable operation of power systems is essential for supporting societal productivity and living standards. With the continual expansion of power grid infrastructure, the operation and maintenance of overhead transmission lines have become increasingly critical. Ground wire breakage has emerged as a significant factor affecting transmission line reliability. This study investigates strand breakage incidents on the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm \mathbf{5 0 0 ~ k V}$</tex> Jinzhong DC transmission line, in operation for many years, by integrating lightning activity records along the route with test results from ground wire and optical cable samples removed from fault sections. Analysis indicates that the primary cause of strand breakage is lightning-induced damage, which - under conditions of insufficient discharge capacity and absence of effective protective measures-leads to progressive failure of the ground wire. Based on the statistical and diagnostic findings, this paper proposes targeted preventive measures and operational recommendations to mitigate the risk of similar failures in the future.

Addressing the accuracy requirements for detecting zero-value defects in porcelain insulators, this paper develops a zero-value detection device based on the high-voltage impulse method, and systematically studies the response characteristics and influencing factors of normal and zero-value insulators under the action of impulse voltage. Through comparative analysis of the response voltage waveforms of the two types of insulators, it is found that under the impact of high-voltage impulse, the response voltage of normal porcelain insulators rapidly rises to a level close to the peak impulse voltage and then slowly discharges; whereas zero-value insulators with internal defects first exhibit multiple repeated breakdowns, then briefly maintain at a level far below the peak impulse voltage, and ultimately discharge rapidly through resistance-capacitance discharge. The response waveforms of the two types of insulators differ significantly, providing a key criterion for reliably identifying zero-value insulators. The initial discharge voltage of normal porcelain insulators of different tonnages under high-voltage impulse is basically consistent, with no significant correlation with the tonnage of the insulators. However, the tonnage of the insulators has a significant impact on the voltage decay rate, with larger tonnages resulting in slower voltage decay. However, if the surface of normal insulators is heavily polluted or the shed portion is immersed in water or salt solution, there is a risk of being misidentified as zero-value insulators. In the future, it is necessary to consider adding auxiliary criteria to eliminate the risk of zero-value misidentification caused by reduced surface resistance of insulators. This study provides theoretical and technical support for the efficient and reliable detection of zero-value defects in porcelain insulators.

The increasing penetration of inverter-based resources in Great Britain's power system has resulted in a decline in system strength, which has given rise to sub-synchronous oscillations. Traditional methods of assessing system strength are inadequate

We report on the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{S}+C+L$</tex> transmission over 40.4 km of low loss ST-HCF using Bismuth Doped Fiber Amplifier for S band and EDFAs for C and L bands. Based on coherent PCS256-QAM, PCS-64 QA M, and PCS-16QAM signalling, we demonstrate achievable information rate beyond 137 Tbls. ©2025 The Author(s)

The quality of foundation pile is greatly influenced by human factors, and quality assessment is delayed. This paper introduces a new evaluation system based on Internet of Things (IoT) monitoring data of the foundation pile construction process. First, an IoT monitoring system of foundation pile construction process quality is established to monitor the key parameters for quality control in the foundation pile construction process, such as pile length, position, verticality, water–cement ratio, grouting volume, drilling/lifting speed, etc. Next, the absolute gray relational degree analysis method and the analytic hierarchy process (AHP) entropy-weighted combination weighting method are used to divide the monitoring data into different levels and determine the weight coefficients for quality indicators during foundation pile construction. Last, the IoT monitoring and evaluation system of the foundation piles construction process quality is applied to engineering. The results indicate that the monitoring system is convenient and efficient, and the quality evaluation method is reliable. The construction process quality of cement-mixing piles is rated as excellent. The construction process quality of bored piles Z0103 and Z0232 is excellent, and pile Z0012 is qualified.

The high computational complexity of MIMO equalizers constrains both mode count and transmission reach in SDM systems. We review different strategies to alleviate the MIMO equalizer complexity, such as frequency domain equalization, partial MIMO equalization, and mode permutation.

Due to the unique structure and transmission ratio of the Ravigneaux planetary gearset, this paper investigates the nonlinear vibration characteristics of the Ravigneaux planetary gearset transmission systems. First, a dynamic model of the Ravigneaux planetary gearset transmission systems is established, considering nonlinear factors such as time-varying meshing stiffness, comprehensive equivalent errors, tooth clearance, and time-varying friction. Next, the dynamic equations are formulated and solved. The nonlinear behavior of the system is characterized through phase diagrams, Poincaré diagrams, time-domain plots, and frequency-domain plots. The bifurcation diagram and three-dimensional spectrum diagram illustrate how different external load excitation frequencies affect the system’s nonlinear behavior. The results indicate that as the external load excitation changes, the system’s motion state transits from chaotic to bifurcation and ultimately to periodic motion. Finally, the multiscale method is employed to examine the effects of various parameters on the main resonance characteristics of the system, determining the stability conditions for the primary resonance. The principal resonance analysis reveals that increasing damping, stiffness, and fluctuations in the external load can enhance the system’s stability.