Reverse Flow Research Articles

The phenomenon and suppression strategy of overvoltage caused by PV power reverse flow

In the current distribution network’s energy structure, photovoltaic (PV) occupies a high proportion. However, the access of a high proportion of PV will lead to the phenomenon of reverse power flow in the distribution network, and then the problem of line overvoltage. When the reverse power flow increases, the problem of line overvoltage also worsens, which endangers the normal operation of power system. To solve this problem, this paper starts with the voltage rise theory of distribution network lines. Firstly, through strict mathematical derivation, it compares the influence of main network line parameters and distribution network line parameters on the voltage rise, and summarizes a simple calculation equation for the voltage rise of the distribution network with high proportion PV. Then, according to the mechanism of voltage rise and the principle of inverter control, considering the economy and practicability of the overvoltage suppression strategy, a reverse power flow overvoltage suppression strategy of a system with high proportion PV is proposed. Finally, a PV system model simulating a small village is used to verify the effectiveness of the proposed overvoltage suppression strategy.

Analytical Investigation on Flow Reversal in a Fully Developed Steady Mixed Convection Flow With Boundary Condition of the Third Kind

ABSTRACTThis work presents exact solutions to analyze the effect of the Biot number on mixed convection flow in a vertical channel with asymmetric heating and flow reversal. The equations governing flow formation and temperature distributions are offered with convective boundary conditions. Closed‐form solutions for temperature, velocity, and skin friction are found and simulated graphically.

Natural convective heat transfer analysis of a vertical tapered inner annulus tube with dual inverted frusto-conical turbulator using CFD

Vertical tube heat exchangers play a pivotal role in various industrial processes, where efficient heat transfer is essential for optimal system performance. This research introduces a novel heat exchanger design, the Dual Inverted Frusto-Conical Turbulator Attached Tapered Inner Annulus Tube, aimed at enhancing natural convection in vertical annulus heat exchangers using nano-coolants. Traditional designs often suffer from non-uniform heat transfer due to varying boundary layer thicknesses along the height of the annulus. The proposed design mitigates this by incorporating a tapered inner annulus tube, which has a larger diameter at the bottom and gradually decreases towards the top. This taper reduces wall friction and boundary layer thickness, enhancing thermal diffusivity and improving the heat transfer rate. To further optimize heat transfer, Dual Inverted Frusto-Conical Turbulators are strategically placed around the tapered tube, generating controlled turbulence that minimizes drag and avoids unwanted flow reversals and recirculation. Simulation results show a Nusselt number of 321, a friction factor of 0.023, and a pressure drop of 154 Pa at a Reynolds number of 5000. The design also achieved a thermal conductivity of 0.3 kW/mK, thermal efficiency variation of 0.8658%, and a heat transfer coefficient of 26,000 W/m2K.

Feasibility, safety, and clinical outcomes of modified laparoscopic cervicoisthmic cerclage for refractory cervical insufficiency: A single-arm clinical trial-Part 1.

To assess the feasibility, safety, and outcomes of modified laparoscopic transabdominal cerclage in patients with refractory cervical insufficiency. This single-arm clinical trial examined women with refractory cervical insufficiency who underwent modified laparoscopic transabdominal cerclage at a specialized center in Japan between December 2017 and May 2022. Various parameters related to patient demographics, surgical techniques, outcomes, and complications were evaluated. The study enrolled 30 women with a median age of 36 years. The modified laparoscopic transabdominal cerclage was technically successful in all cases. The delivery rate and fetal survival rate at 28 days in the third trimester were both 93%. Surgical complication involving small bowel injury occurred in one case and was promptly repaired. No fetal complications or pregnancy losses occurred within 28 days of the procedure. Perinatal outcomes included a cesarean section rate of 93%, a neonatal intensive care unit admission rate of 30%, and an overall fetal survival rate of 93%. Additionally, no absence or reversal of end-diastolic flow in the uterine artery was identified at the time of cerclage in any of the cases. This study demonstrated the feasibility and safety of modified laparoscopic transabdominal cerclage for refractory cervical insufficiency. The procedure achieved a high delivery rate in the third trimester and a good overall fetal survival rate. The study findings highlight the importance of anatomical precision during thread placement in modified laparoscopic transabdominal cerclage. This technique is promising for treating refractory cervical insufficiency and potentially preventing second-trimester losses and extreme preterm births.

Impact of Gas Accumulation on the Stability of Parallel Upward Ventilation in High-Temperature Sloped Shafts of Deep Wells

To explore the causes and influencing factors of wind flow oscillations in high-temperature inclined aisles of deep wells under parallel upward ventilation, this study conducts a comprehensive investigation using theoretical analysis and numerical simulations. Based on the kinetic analysis of gas flow, a discriminant formula for wind flow reversal in the side branch is derived. Further analysis identifies initial wind speed and branch length as key factors influencing the reversal. Both gas pressure and thermal pressure contribute to wind flow reversal in the side branch, and the opposing directions of these pressures cause high-temperature gas to periodically flow between the two branches, resulting in wind flow oscillations. A higher initial wind speed can effectively reduce the oscillation amplitude due to increased initial kinetic energy and a larger pressure difference, but it does not extend the oscillation duration. Increasing the branch length can suppress wind flow oscillations by increasing airflow frictional resistance and damping.

Stability Analysis of Hybrid Nanofluid with Inclined MHD and Joule Effects: Flow Reversal and Flow Separation

Stability Analysis of Hybrid Nanofluid with Inclined MHD and Joule Effects: Flow Reversal and Flow Separation

Significance of heat transfer in a reversible esterification of Arrhenius activation energy with partial slip

The significance of heat transfer during a reversible esterification process in a magnetohydrodynamic boundary layer Casson fluid flow along a vertical stretching plate is examined. The multi-slip conditions are considered in a porous medium. The presence of chemical process requiring an activation energy is considered in the analysis. The study also investigates the hydromagnetic boundary layer Casson fluid flow alongwith partial slip conditions across a vertical stretching plate. The incorporation of multi-slip constraints in a porous medium, alongside magnetic fields and other parameters, highlights its relevance in diverse engineering fields such as thermal engineering, polymerization, and biodiesel industries. Understanding the characteristics of such fluids under complex conditions is vital for optimizing heat and mass transfer in industrial applications, making this investigation timely and valuable. The nonlinear differential set of equations are solved numerically involving Runge-Kutta based shooting approach of fourth order and the results are verified with the bvp4c tool and the findings are explored using graphical plots. The predominance of significant factors on flow configurations are analyzed and presented in graphs and tables. A comprehensive analysis is provided on the effects on velocity, concentration, and temperature of diverse parameters such as reaction rate constant, magnetic parameter, suction parameter, mass Grashof number, Prandtl number, Casson parameter, thermal radiation parameter and slip parameters. The tabular representation of the adverse effects of drag coefficient, rate of mass transfer and Nusselt number on flow configurations for various significant parameters is presented. It is inferred that for the case of reversible and irreversible flows, the shear stress rate escalates by 29% when the magnetic parameter elevates from 0.5 to 1.5 and about 35% when the Casson parameter elevates from 0.5 to 1.5. For the suction parameter, the coefficient of drag increased by 27% and 26% for irreversible and reversible flows respectively. When the reaction rate increases from 0.5 to 1.5, the rate of shear stress elevates by 0.5% and 0.02% for irreversible and reversible flows in order. The Nusselt number decreased about 7% and 8% when the magnetic parameter and Casson parameter rises from 0.5 to 1.5 respectively, for irreversible and reversible flows. It is noteworthy that the previous studies are in precise agreement with the present investigation.

Strategic Dual Approach for the Management of a Symptomatic Giant Partially Thrombosed Aneurysm at the Basilar Tip - Integrating Intrasaccular Flow Diversion and Endovascular Flow Reversal.

Managing giant partially thrombosed intracranial aneurysms presents significant challenges due to their unfavorable natural history and the lack of standardized treatment approaches. Conventional treatments, whether open surgical or endovascular, often struggle to manage these aneurysms effectively, resulting in high recurrence rates or significant morbidity. The patient was a 62-year-old male with a symptomatic giant partially thrombosed aneurysm at the tip of the basilar artery, presenting with left-sided hemiparesis and dysarthria. Diagnostic imaging revealed a giant aneurysm with a wide-necked, canalized portion. A two-stage endovascular treatment was conducted, involving a balloon occlusion test (BOT) and intraoperative monitoring (IOM) for maximum patient safety. The treatment utilized stent-assisted Woven EndoBridge (WEB) embolization and serial bilateral vertebral artery trapping. The procedure successfully isolated the aneurysm and postoperative imaging confirmed the absence of recanalization, preserving the intact posterior circulation. The patient showed stable recovery and no neurological deficits during the 12-month follow-up period. This technical note demonstrates the feasibility and efficacy of strategically integrating intrasaccular flow diversion using a WEB device and flow reversal through bilateral vertebral artery trapping for treating giant partially thrombosed aneurysms.

Abatement of volatile organic compounds (VOCs) and fluorine gases by a microwave plasma torch (MPT)

The use of microwave plasma torch (MPT) in the abatement of potent greenhouse and fluorinated (F-gases) gases is crucial due to their high global warming potential. The purpose of this study was the abatement of volatile organic compounds (VOCs) and carbon tetrafluoride (CF4) using specifically designed reverse vortex flow reactor (RVR) and pillar of fire reactor (POF). The RVR has properties that are crucial for their synergistic effects with the MPT, and the POF configurations showed high-efficiency combustion due to plasma radicals and a large contact area with the MPT. The study used Aspen Plus and COMSOL software to analyse the mass balance involved in the thermal decomposition of isopropyl alcohol (C₃H₈O) and CF4 and to design the RVR and POF reactors. Using MPT without hydrocarbon fuel, low-concentration C₃H₈O and CF4 were successfully destroyed in high-flow streams. The experiment on C₃H₈O showed that using a plasma power of 2 kW and 1 cubic meter per minute (CMM) of bulk gas, a destruction removal efficiency (DRE) of 95 % was achieved for a polluted C₃H₈O of 410 ppm. In a second experiment, a DRE of 94 % was achieved for a polluted C₃H₈O of 370 ppm. The first CF4 experiment achieved a DRE of 93.3 % with a 7 kW plasma power and 1 CMM bulk gas polluted at 285 ppm. In the second experiment, the presence of highly reactive hydroxyl radicals (OH*) in steam plasma improved the DRE to 99.8 % at 7 kW plasma power and 100 LPM bulk polluted at 180 ppm.

Chronic Constrictive Pericarditis in Northeast India: A 10-Year Single-Center Study of Demographic and Clinical Profiles.

Introduction Chronic constrictive pericarditis (CCP) is a progressive disease characterized by thickening and fibrosis of the pericardium, leading to restricted diastolic filling and impaired cardiac function. In Northeast India, limited healthcare infrastructure poses challenges in diagnosing and managing CCP, potentially worsening patient outcomes. Therefore, this study aims to assess the demographic and clinical profiles of patients with CCPin this regionover 10 years and compare our findings to the relevant but limited published literature in South Asia. Methods We retrospectively analyzed the medical records of 42 patients diagnosed with CCP referred to our department from 2011 to 2020. Demographic, clinical, and paraclinical data during hospitalization and follow-up were collected. All patients underwent clinical examination imaging studies, including high-resolution chest computed tomography and echocardiography. Symptomatic patients underwent open pericardiectomy, and postoperative histopathological examination was performed. Results Of the 42 patients, 34 (81%) were male and eight (19%) were female. A significant proportion of the patients were under the age of 20 years (n = 18, 42.9%), followed by the 21- to 40-year age group (n = 13, 31%). Eighteen patients (42.9%) were from Meghalaya, 12 (28.6%) were from Assam, and seven (16.7%) were from Nagaland. Twenty-two patients (52.4%) had a prior history of pulmonary or extrapulmonary tuberculosis (TB) and had received antitubercular therapy for at least six months. Dyspnea on exertion was the most common symptom among the patients: 12 (28.6%) of them were classified as New York Heart Association class IV, 20 (47.6%) as class III, and 10 (23.8%) as class II. Clinical examination revealed pedal edema in 36(85.7%), hepatomegaly in 22 (52.4%), ascites in 15 (35.7%), and pleural effusion in 13 (31%) patients. Echocardiography showed septal bounce in 26 (61.9%), pericardial calcification in 17 (40.5%), and hepatic vein flow reversal in 12 (28.6%) patients. All patients were on diuretics and digoxin before surgery. Postoperative biopsy confirmed TBas the etiology in 28 (66.7%) patients and nonspecific etiology in 14 (33.3%) of them. Conclusions CCP in Northeast India predominantly affects young males and is largely associated with TB. Despite efforts to control TB, it remains a major contributor to CCP in this region. Recognizing the clinical presentation and diagnostic profile is essential for improving management strategies and patient outcomes.

Study of unsteady shear flow near stall in a shrouded supercritical carbon dioxide centrifugal compressor

This study investigates the unsteady shear flow patterns and their relation with the aerodynamic instability of a shrouded supercritical carbon dioxide (SCO2) centrifugal compressor impeller using the dynamic mode decomposition method combined with detached eddy simulation. The results demonstrate that discrete shedding vortex array in the blade tip region is the dominant mode of the SCO2 shrouded centrifugal compressor impeller, with a frequency of 0.5 times the blade passing frequency. In contrast, the main flow structures in the identical impeller using ideal air consist of small-scale shedding vortices near the suction surface and the separated secondary flow. Further analysis of flow field details indicates that the shedding vortex structure inside the shrouded centrifugal impeller originates from the Kelvin–Helmholtz instability generated on the shear interface between the mainstream and the recirculation flow. The greater shear intensity within the SCO2 centrifugal impeller is the reason for the evident occurrence of vortex shedding phenomena in its flow field. Additionally, during the transition from near-stall to stall, vortex pairing phenomena happens at the throat of the centrifugal impeller due to evolutional behaviors of the vortexes. The occurrence of vortex pairing leads to faster blockage of the blade tip region and then the secondary flow spillage over to adjacent passage, ultimately resulting in reverse flow in the blade tip region and extensive blockage at the impeller inlet. The unsteady shear flow evolution clearly demonstrates the processes of stall in SCO2 shrouded impellers.

Forced flow reversal in ferrofluidic Couette flow via alternating magnetic field

Time-dependent boundary conditions are very common in natural and industrial flows and by far no exception. An example of this is the movement of a magnetic fluid forced due to temporal modulations. In this study, we used numerical methods to examine the dynamics of ferrofluidic wavy vortex flows (WVF2, with dominant azimuthal wavenumber m=2) in the counter-rotating Taylor–Couette system, which was subjected to time-periodic modulation/forcing in a spatially homogeneous magnetic field. In the absence of a magnetic field, all WVF2 states move in the opposite direction to the rotation of the inner cylinder, they are retrograde. However, when strength or frequency of the alternating magnetic field increases, the motion direction of the flow pattern changes. Thus, the alternating field provides a precise and controllable key parameter for triggering the system response and controlling the flow. Aside, we also observed intermittent behavior when one solution became unstable, leading to random transitions in both, the transition time and toward the different final solutions. Our findings suggest that, in ferrofluids, flow pattern reversal can be induced by varying a magnetic field in a controlled manner, which may have applications in the development of modern fluid devices in laboratory experiments. These findings provide a framework to study other types of magnetic flows driven by time-dependent forcing.

Thermal Transport in the Entry Region of a Microchannel in the Presence of Electro-osmotic Flow

Abstract The motion of a polar fluid in microducts induced by an external electric field, known as electro-osmotic flow, enables fluid circulation without the need for mechanical devices. This feature makes it particularly appealing for the thermal management of electronic components, as microchannels with almost any cross-sectional shape can be easily integrated on the chips. Therefore, it is essential to evaluate how the channel’s geometry influences heat transfer performance. This study investigates the thermal entry region and fully developed electro-osmotic flow in a microchannel with a rectangular cross-section and smoothed corners, with one adiabatic wall and uniform temperature elsewhere. The paper proposes correlations for the Poiseuille and Nusselt numbers, taking into account the aspect ratio and non-dimensional smoothing radius under fully developed thermal and hydrodynamic conditions, which can be valuable for practical design purposes. The study also emphasizes how Joule heating may lead to the reversal of heat flow and how the thermal entry length is linearly dependent on the logarithm of the non-dimensional Joule heating in thermally developing flow. Additionally, it demonstrates that smoothing the corners may increase the local Nusselt number over sharp corners, but it may also shorten the thermal entry length.

Large eddy simulation of droplet dispersion and deposition over street canyons

Predicting droplet transport in the atmosphere is a major issue for a large number of dispersion problems such as spray cooling systems in streets, urban lawn sprinklers [Milesi et al., “Interferometric laser imaging for respiratory droplets sizing,” Environ. Manage. 36, 426–438 (2005)], and dispersion of virus such as COVID or from a terrorist attack [Balachandar et al., “Host-to-host airborne transmission as a multiphase flow problem for science-based social guidelines,” Int. J. Multiphase Flow 132, 103439 (2020)]. Here, we investigate the propagation of droplets issued from a source near the ground between square obstacles with different spacings. The aerodynamic field is determined by large eddy simulation coupled with an immersed boundary method for the obstacles. Droplets are tracked by a Lagrangian approach. An evaporation model is used to account for varying humidity conditions. Droplet concentration, mass flux, and deposition rates are obtained for different evaporation conditions and obstacle spacings. The results show high deposition rates on the internal wall of the first obstacle due to droplet advection by the reverse flow of the primary vortex. In addition to this, droplets may escape the canyon and propagate downstream as far as eight times the obstacle distance (8H). The concentration of air-borne droplets downstream the canyon is higher for smaller street canyon openings. When evaporation is accounted for, the ground-level droplet concentration may be reduced by up to 30% in the case of small canyon openings.

An Automated Geometric Analysis and Characterization of an Oil-Lubricated Twin-Screw Compressor for Predictive Modeling

Abstract Compressor manufacturing companies are showing a growing interest in the development of validated compressor simulation models capable of predicting the behaviour of the machine if subjected to appropriate modifications. A validated predictive model of the entire compressor is useful for analysing the influence of the variation of some fundamental parameters, such as the variation of volumes or new inlet and outlet sections, on the behaviour of the machine. To create these models, geometric parameters such as the variation in volumes, the variation in inlet and outlet sections and the presence of leakage or blowhole phenomena must be provided as input. The precision of these geometric parameters is of fundamental importance for the correct operation of the model and subsequent design analyses. In this work, the authors analysed the complete geometry of an oil-lubricated twin-screw compressor. In particular, an automated calculation methodology was developed using CAD software capable of defining the characteristic curves of the volumes and areas of the compressor: starting from the geometries of the rotors and the stator case, the fluid volumes delimited at the bottom by the rotors and at the top by the case were defined through a Boolean subtraction operation. Subsequently, the volumes that complete the compression phase together were isolated and, through an automatic kinematic analysis with steps of 5° of rotation, starting from the zero reference (null volumes), the characteristic curves of the volumes and inlet and outlet areas were defined through the use of special virtual sensors. The passage sections of the leakage and blowhole leaks were defined in the same way. Particular attention was paid to the analysis of leakage and blowhole phenomena, the presence of which determines a reverse flow of part of the mass flow rate of air during the compression phase, resulting in a decrease in volumetric efficiency. Knowledge of this data is of fundamental importance for the subsequent creation of the 1D/0D model.

A simulation study on the influence of marginal pinching upon liquid film dynamics

In fluid dynamics, the generation and bursting of surface bubble liquid films in surfactant-laden environments involve complex phenomena, one of which is marginal pinching at the film's foot—a crucial yet inadequately understood aspect due to experimental limitations. Considering its profound impact on liquid film drainage and lifetime, we utilize high-resolution numerical simulations incorporating a weakly compressible scheme and adaptive mesh refinement to dissect the marginal pinching dynamics with unprecedented detail. Our approach elucidates the pinching dynamics and tracks the evolution of film thickness during the critical late-stage drainage process. By leveraging detailed geometric data from pinched regions, we significantly refine existing drainage models, enhancing their predictive accuracy regarding rupture thickness and film lifetime across various viscosities, surfactant concentrations, and bubble sizes. This refined model demonstrates robust alignment with our simulation results. Furthermore, we establish a quantifiable relationship between the prefactor governing reverse flow induced by the Marangoni effect and surfactant concentration. The methodologies and findings of this study provide foundational knowledge that paves the way for optimized industrial processes and an enhanced understanding of natural phenomena.

Noninvasive Tools to Predict Necrotizing Enterocolitis in Infants with Congenital Heart Diseases: A Narrative Review.

Necrotizing enterocolitis (NEC) is the most frightening gastrointestinal emergency in newborns. Despite being primarily a disease of premature infants, neonates with congenital heart disease (CHD) are at increased risk of development. Acute and chronic hemodynamic changes in this population may lead to mesenteric circulatory insufficiency. In this narrative review, we describe monitoring tools, alone or in multimodal use, that may help in the early recognition of patients with CHD at major risk of NEC development. We focused on vital parameters, echocardiography, Doppler flowmetry, abdominal near-infrared spectroscopy (aNIRS), and abdominal ultrasound (aUS). The number of studies on this topic is small and includes a wide range of patients' ages and types of CHD. Peripheral oxygen saturation (SpO2) and certain echocardiographic indices (antegrade and retrograde velocity time integral, cardiac output, etc.) do not seem to differentiate infants with further onset of NEC from those not developing it. Hypotensive events, persistent diastolic flow reversal in the descending aorta, and low mesenteric oxygen saturation (rsSO2) measured by aNIRS appear to occur more frequently in infants who later develop NEC. aUS may be helpful in the diagnosis of cardiac NEC, potentially showing air contrast tracked to the right atrium in the presence of pneumatosis. This narrative review describes the current knowledge on bedside tools for the early prediction of cardiac NEC. Future research needs to further explore the use of easy-to-learn, reproducible instruments to assist patient status and monitor patient trends.

Novel Fluidic Oscillator Evaluation Considering Dimensional Modifications

Although flow mixing and cooling can be greatly enhanced when considering the use of fluidic oscillators (FOs), they are more commonly employed in active flow control (AFC) applications where the injected pulsating flow interacts with the boundary layer, usually in order to delay its separation. In fact, prior to any FO implementation in a given application, it is essential to study the range of frequencies and amplitudes it can generate as a function of the incoming mass flow and its dimensions. This is what is being performed in the present manuscript for a rather novel FO configuration. A numerical study of a standard three-dimensional (3D) FO configuration, and also using a two-dimensional (2D) approach, is initially presented. After comparing the 3D and the 2D results and analyzing the main differences, we modified some of the internal dimensions of the FO in order to evaluate the variation in its dynamic performance. The present results clarify which internal dimensional modifications are more effective in generating larger output frequencies and velocity field variations. Care is taken to analyze the origin of self-sustained oscillations. This paper links, for the first time, the origin of the pressure force oscillations at the feedback channel’s outlet, with the interaction of the mixing chamber central jet and the reverse feedback channel flow at the mixing chamber’s converging walls. A novel equation relating the FO outlet mass flow frequency with the time-averaged FC reverse flow is presented and discussed. In fact, the present study needs to be seen as the continuation of a former one, recently published by authors, where the effects of several Reynolds numbers as well as some different internal dimensions were considered.

A closed-loop dual-channel supply chain network for leather products: An integrated simulation optimization clustering approach

The leather industry is pivotal to the economic development of certain countries; however, it also poses significant environmental challenges. Thus, this study aims to design a closed-loop leather supply chain network that incorporates waste recycling and product regeneration processes. In light of the growing prevalence of both in-store and online shopping, the concept of a dual-channel supply chain is examined. Furthermore, as advertising through traditional and social media continues to expand, this research uniquely investigates the impact of two advertising modalities—SMS and social networks—alongside the design and layout of retail environments, considering their effects on product sales within the supply chain context. Additionally, outlet stores are integrated into the model to facilitate the sale of products that may become outdated over time, thereby enhancing the model's real-world applicability. To achieve this, a multi-product, multi-period mathematical model is developed to minimize costs and maximize customer responsiveness in both forward and reverse supply chain flows. The K-means clustering method is employed to categorize customers based on recency, frequency, and monetary (RFM) features. Through simulation, demand parameters are derived for each customer cluster across various scenarios. Moreover, the Aghezzaf approach is utilized to address scenario-based uncertainties within the model, and the proposed multi-objective model is solved using the Augmented Epsilon constraint method. A real-world case study is conducted to apply the proposed model, and critical parameters are examined through sensitivity analysis to validate its effectiveness. The findings suggest that incorporating return flows into the supply chain can significantly enhance both producer profitability and customer responsiveness regarding leather products.

Analyzing the influence of electric vehicle charging scheduling on distribution transformer lifespan

The ongoing growth in global electricity demand and rapid proliferation of electric vehicles (EVs) are posing challenges to the operation of the low voltage power networks and their components. This study aims to analyze the impacts of peak-load demand on the distribution transformers, considering mild and extreme combinations of electric energy demand and localized charging of plug-in EVs under their different penetration levels, hypothesizing that shifting the demand for charging throughout the day can reduce the aging of distribution transformers. The proposed method employs a fuzzy-logic-based tool, which incorporates the influence of ambient temperature, higher harmonics, reactive power compensation, reverse power flows, and overload. Three different charging/discharging modes have been considered: demand charging, off-peak charging, and synergy of off-peak charging and vehicle-to-house technology. The results indicate that off-peak charging emerges as 2.1 times more effective than demand charging in terms of the transformer's loss of life, particularly for ultimate EV penetration of 100 %. It is demonstrated that the utilization of charging scheduling for EVs should be prioritized to defer costly system upgrades and reinforcements, particularly when EV penetration exceeds 50 %.