Lifetime Extension Research Articles

Failure modes analysis and reliability enhancement of wind turbines

AbstractThe transition of the global energy system to affordable, reliable and clean sources is an important target of several international climate change accords and conferences such as the United Nations Framework Convention on Climate Change (UNFCCC) and its Conferences of parties (COP), Kyoto protocol and the UN Sustainable Development Goals (SDGs). The wind power is at the heart of these energy systems transformation and climate change mitigation. Indeed, the global capacity of wind turbines has seen tremendous growth, especially, during the past two decades which has made wind energy the fastest growing renewable source in the world. Nevertheless, the problem of premature failures and low‐reliability level of wind turbines have been increasingly noticed. This paper presents a new systematic analytical approach for failure modes and reliability analysis of wind turbines. The approach is a combination of three aspects which are qualitative and quantitative analysis using the fault tree method, reliability assessment as well as lifetime estimation and enhancement. Firstly, the various failure modes are presented. Then, mathematical modeling and reliability evaluation have been developed and simulated. Afterward, the actions that can be considered to improve the reliability and, consequently, the lifetime of wind turbines have been presented and analyzed. The results of the developed approach revealed that major reliability improvements, failure rate reduction and lifetime extension can be achieved, leading to a better return on investment, reduced maintenance as well as a safer and more reliable clean energy production.

Perovskite Piezoelectric-Based Flexible Energy Harvesters for Self-Powered Implantable and Wearable IoT Devices

In the ongoing fourth industrial revolution, the internet of things (IoT) will play a crucial role in collecting and analyzing information related to human healthcare, public safety, environmental monitoring and home/industrial automation. Even though conventional batteries are widely used to operate IoT devices as a power source, these batteries have a drawback of limited capacity, which impedes broad commercialization of the IoT. In this regard, piezoelectric energy harvesting technology has attracted a great deal of attention because piezoelectric materials can convert electricity from mechanical and vibrational movements in the ambient environment. In particular, piezoelectric-based flexible energy harvesters can precisely harvest tiny mechanical movements of muscles and internal organs from the human body to produce electricity. These inherent properties of flexible piezoelectric harvesters make it possible to eliminate conventional batteries for lifetime extension of implantable and wearable IoTs. This paper describes the progress of piezoelectric perovskite material-based flexible energy harvesters for self-powered IoT devices for biomedical/wearable electronics over the last decade.

Consumer-oriented interventions to extend smartphones’ service lifetime

A promising strategy to reduce smartphones' environmental footprint is to increase their service lifetime, thereby reducing the demand for resource-intensive production of new devices. Most of the existing literature focuses on production-oriented measures, such as improving repairability, but what remains missing is a systematic overview of consumer-oriented interventions to extend smartphones' service lifetime. In this study, we applied the consumer intervention mapping approach by systematically identifying consumer decision situations along the smartphone life cycle and interventions that encourage consumers to make smartphone lifetime-extending decisions. We identify two main mechanisms to achieve lifetime extension: retention by increasing the time during which a user keeps a device, and recirculation by passing on a device to an additional user. Altogether, we identified 26 different types of interventions to induce consumers to make smartphone lifetime-extending decisions and structure these according to consumer-influence techniques, e.g., informing consumers about retention/recirculation options and environmental impacts caused throughout device life cycles, persuading consumers by creating emotional attachment, nudging consumers through product labels for secondhand devices, simplifying execution of lifetime-extending decision options through take-back programs, and incentivizing lifetime-extension through buy-back programs. These interventions' success in achieving lifetime extensions and reducing environmental impacts in practice depends on the degree to which they actually extend smartphones' service lifetime and reduce production of new devices (displacement rate), induction and re-spending effects associated with the interventions, and the interventions’ implementation feasibility, which conflicts of interest in the smartphone ecosystem often challenge. • Overview of consumer decision situations that impact smartphones' service lifetime. • Specification of consumer-oriented interventions for smartphone lifetime extension. • Discussion of environmental implications of lifetime-extending interventions.

Integrated Design for Lifetime Extension and ESR Monitoring of Hybrid DC Link in Solid-State Transformer From the Perspective of High-Frequency Ripple Current

Hybrid dc-link capacitors serve a critical role in cascaded two-stage systems, such as the solid-state transformer (SST) units being developed for medium-voltage utility grids. The capacitors need to absorb ripple current in a wide spectrum, which induces aging stresses. This article presents a technique to combine lifetime extension in design with condition monitoring (CM). It is found that the excessive high-frequency ripple current typically flows through electrolytic capacitors (E-caps). A dedicated transformer-based sensor is then designed, and its primary-side inductance acts as an external impedance to reduce the high-frequency current in the E-cap loop. On the other hand, the voltage induced by high-frequency current measured on the secondary side of the sensor can be used as an indicator of equivalent series resistance (ESR) degradation for CM. The integrated design features low complexity, pure passivity, and versatility, and the universal gauging principle for the sensor is elaborated. In the end, a 5-kW prototype of an SST unit is built to verify the performance of the proposed solution. The experimental results indicate a noticeable reduction in thermal and electrical stress, corresponding to a 40% extension of the E-cap lifetime, and the CM model can accurately track the change of the ESR.

Self‐healing natural rubber based on dynamic disulphide exchange towards fatigue lifetime extension

AbstractDynamic disulphide exchange mechanism was introduced to promote self‐healing characteristics to natural rubber compound and the corresponding healing mechanism and mechanical properties are presented. The formation of reversible dynamic disulphide bonds within rubber molecular chains was evidenced via FTIR and the total crosslink density of dynamic disulphide crosslinks was quantitatively measured by equilibrium swelling test. Scanning Electron Microscopy (SEM) results revealed that the healed area of the fractured surface adhered well with minor scar on the contact surface, suggesting that intermolecular diffusion occur at the fracture surface. It was also found that the tensile strength and tear strength of the broken samples able to recover 91% and 103%, respectively, under thermal healing at 150°C for 10 min. The fatigue lifespan of the materials increased 154.9% compared with the conventional rubber. The successful fabrication of self‐healing natural rubber through dynamically reversible disulphide exchange mechanism would be expected to open up new opportunities for development of sustainable rubber products.

Exploration of oxytetracycline degradation via Co/Fe composites: Advantages of bimetal for the contribution deviation of reactive oxygen species and the corresponding lifetime extension

Transition metals are usually applied for activating persulfate to degrade organic contaminants efficiently, and there are numerous researches utilizing bimetallic catalysts to harvest the higher performance. Mechanisms of reactive oxygen species (ROS) generation as well as the mutual transformation of bimetal have been reported a lot, yet the deviation of ROS contribution for contaminants degradation and the relevant role of metals seem to be explored deficiently. Herein, biochar decorated with bimetal of Co/Fe (Fe1/4Co1/2-PWBC600) was prepared for peroxymonosulfate (PMS) activation and oxytetracycline (OTC) degradation, and properties of catalysts were analyzed for elaborating the intrinsic difference of ROS generation. Results showed that the structure of ROS contribution was optimized in Fe1/4Co1/2-PWBC600/PMS system, and the co-dominance of SO4•‒ and 1O2 realized the better OTC degradation performance compared with the merely cobalt-based catalyst. Besides, durability tests showed that Fe1/4Co1/2-PWBC600 performed much better in oxidation resistance and reusability, which was owing to the co-dominance effect and the consumption buffering of oxygen vacancies. This work offered a new insight into the synthesis of bimetallic catalysts to strengthen the properties pertinently, realizing the higher performance of pollutants degradation and catalyst lifetime.

Design and Validation of Lifetime Extension Low Latency MAC Protocol (LELLMAC) for Wireless Sensor Networks Using a Hybrid Algorithm

As the battery-operated power source of wireless sensor networks, energy consumption is a major concern. The medium-access protocol design solves the energy usage of sensor nodes while transmitting and receiving data, thereby improving the sensor network’s lifetime. The suggested work employs a hybrid algorithm to improve the energy efficiency of sensor networks with nodes that are regularly placed. Every node in this protocol has three operating modes, which are sleep mode, receive mode, and send mode. Every node enters a periodic sleep state in order to conserve energy, and after waking up, it waits for communication. During the sleep mode, the nodes turn off their radios in order to reduce the amount of energy they consume while not in use. As an added feature, this article offers a channel access mechanism in which the sensors can send data based on the Logical Link Decision (LLD) algorithm and receive data based on the adaptive reception method. It is meant to select acceptable intermediary nodes in order to identify the path from the source to the destination and to minimize data transmission delays among the nodes in the network scenario. Aside from that, both simulation and analytical findings are used to examine the activity of the suggested MAC, and the created models are evaluated depending on their performance. With regard to energy consumption, latency, throughput, and power efficiency, the result demonstrates that the suggested MAC protocol outperforms the corresponding set of rules. The extensive simulation and analytical analysis showed that the energy consumption of the proposed LELLMAC protocol is reduced by 22% and 76.9% the end-to-end latency is 84.7% and 87.4% percent shorter, and the throughput is 60.3% and 70.5% higher than the existing techniques when the number of node is 10 and 100 respectively.

Rapid synchronous state-of-health diagnosis of membrane electrode assemblies in fuel cell stacks

Consistency evaluation and degradation diagnosis of membrane electrode assemblies (MEAs) in fuel cell stacks are critical issues for fuel cell lifetime extension and commercialization. This study aims to develop a high-efficiency, high-precision, and synchronous state-of-health (SOH) diagnosis methodology for MEAs at the stack level. The micro-current excitation (MCE) method based on multiple excitations is used to evaluate the MEA inconsistency of a 22-cell commercial stack, involving hydrogen crossover, short-circuit resistance, electrochemical surface area, and double-layer capacitance. High precision is demonstrated by the consistency in the membrane-related parameters and the difference in the electrode-related parameters between the cathode and anode tests. Herein, an efficient single excitation and natural discharging (SEND) analytical method based on the excitation-discharging-combined equivalent circuit model is originally proposed. The accuracy of SEND can be demonstrated by comparing its results with the standard results of the MCE, which fit the baseline y = x with high linearity and identical evaluation of inconsistency. Moreover, the stability of the SEND is proved by its independence from the excitation current, which is reflected by the presence of tiny standard deviations. In addition, the bifurcation feature in the integrated net charge curves of the excitation and natural discharging processes proves the irreversibility of partial oxidation reactions in the high-potential region of excitation. The SEND significantly increases the testing efficiency using only a single excitation. It has promising prospects for the rapid consistency-based MEA screening, degradation evaluation, and recombination of MEAs.

Environment: The Lifetime Extension of French Nuclear Power Plants

Environment: The Lifetime Extension of French Nuclear Power Plants

High-Precision Fault Detection for Electric Vehicle Battery System Based on Bayesian Optimization SVDD

Fault detection of the electric vehicle battery system is vital for safe driving, energy economy, and lifetime extension. This paper proposes a data-driven method to achieve early and accurate battery system fault detection to realize rapid early warning. The method first adopts the support vector data description model mapping the feature of unlabeled voltage and temperature into a minimum volume hypersphere in high-dimensional space. When the feature is located outside the hypersphere, it is judged to be faulty. Then, to overcome the problem of hyperparameters selection, Bayesian optimization and a small amount of label data are used to iteratively train the model. This step can greatly improve the fault detection ability of the model, which is conducive to mining early and minor faults. Finally, the proposed model is compared with three unsupervised fault detection models, principal component analysis, kernel principal component analysis, and support vector data description to validate the performance of fault detection and robustness, respectively. The experimental results show that: 1. the proposed model has high detection accuracy in all four fault datasets, especially in the highly concealed cumulative short-circuit fault, which is substantially ahead of the other three models; and 2. The proposed model has higher and more stable accuracy than the other three models even in the case of a large range of signal-to-noise ratio.

Construction of Z-scheme Ag/AgCl/Bi2WO6 photocatalysts with enhanced visible-light photocatalytic performance for gaseous toluene degradation

As a typical aromatic volatile organic compounds (VOCs), toluene is difficult to be decomposed by photocatalysts under visible-light driven. Herein, the Ag/AgCl/Bi2WO6 heterojunction photocatalysts were synthesized by multi-step process involving chemical deposition of AgCl on the surface of Bi2WO6 and subsequently photoreduction of Ag0 nanoparticles by UV light. The as-synthesized photocatalysts were characterized by XRD, SEM, TEM, XPS, UV–vis, PL and ESR to investigate the microstructures and electronic structures. The corresponding degradation efficiencies of gaseous toluene were evaluated and the optimal Ag/AgCl/Bi2WO6 exhibited almost 99.9% removal rate after 60 min illumination with visible light (>420 nm). The optical absorption properties and radical trapping experiments revealed the possible energy band structure of Ag/AgCl/Bi2WO6 heterojunction. Finally, the possible enhancement mechanism was also proposed that the cooperation of surface plasmon resonance (SPR) effect, efficient separation of electron-hole pairs, extension of the carrier lifetime as well as the high redox potentials of Z-scheme heterojunction were the primary reasons. Therefore, construction of Z-scheme heterojunction of Ag/AgCl/Bi2WO6 with higher redox ability is an effective way to degradation gaseous toluene under visible-light irradiation.

Battery lifetime extension through optimal design and control of traction and heating systems in hybrid drivetrains

In this paper, we investigate the optimal design and control of an integrated energy and thermal management system (IETMS) of a battery-assisted trolley bus that is subject to minimum battery lifetime requirements. Therefore, we jointly optimize both the control trajectories of the traction and the heating systems and the design of the thermal energy buffer. We further analyze the resulting Pareto fronts which characterize the trade-off between the battery lifetime and the energy consumption. This holistic approach fills a gap in the literature published, namely the formulation of an optimization problem that combines component sizing with a battery-health-aware IETMS. While the model derived allows the formulation of a convex optimal control problem for a given vehicle design, the combined design and control problem is non-convex. Therefore, we perform grid searches within a reasonable subset of the design space and show that the problem is smooth, has only one stationary point, and that the solver converges to the optimal solution even for the simultaneous, non-convex problem formulation. We further present a case study showing that, if an IETMS is used, a realistic bus service life without battery replacement can be achieved with a reduction of energy consumption of up to 7% on some driving missions, compared to a heuristic heating strategy. If the design of the thermal system is co-optimized, battery lifetime can be extended further by up to 15% without affecting the amount of energy consumed. In summary, our study reveals a potential to make electric transportation more efficient in terms of both energy and costs based on a holistic consideration of battery-health-aware IETMS with optimized component dimensioning.

Capacitor Lifetime-Based Power Routing of ISOP-DAB Converter Within Comprehensive Constraint

Power routing (PR) provides a good choice to improve the modular converter reliability by equalizing the lifetime among multi-cells. The existing PR strategies just equalize the lifetime of power semiconductor devices by routing lighter loads for aged cells. However, the neglect of capacitor may mislead the multi-cell lifetime convergence. Besides, the light load allocation of the aging cell does not always mean the lifetime extension considering topologies and operation principles. Hence, this article proposed a capacitor lifetime-based PR for input-series-output-parallel connected dual active bridge converter. The proposed strategy can achieve the same accuracy as existing PR strategies, greatly reducing computation time and the complexity of the hardware circuit. Moreover, the nonmonotonic relationship between the damage growth rate and load of each cell is revealed and a damage growth rate constraint is developed to ensure the PR feasibility. Simulation is performed to verify the validity of the proposed strategy and constraints. Finally, a scaled down prototype has been developed to verify the PR feasibility and obtain the nonmonotonic relationship, verifying the necessity of proposed constraints. In addition, the effect of PR on the thermal stress and cumulative damage of capacitors is verified by a temperature test.

May material bottlenecks hamper the global energy transition towards the 1.5 °C target?

Potentially scarce materials play an important role in many current and emerging technologies needed for a sustainable energy and mobility system. This paper examines the global demand for 25 potentially scarce materials that would result from an energy system that is compatible with the 1.5 °C target. It further analyses the risk for short- and mid-term material shortages. To determine the material requirements, an extensive prospective database was built up on the specific demand of these materials in key technologies. A second database describes the potential development of sub-technology market shares within a technology class. A material flow analysis model was used to determine the annual and cumulative material requirements as well as the recycling potential in the underlying scenario. The results show that production of all materials has to increase, in some cases significantly, in a short period of time to meet the demand for the energy and transportation system. In addition, the cumulative demand for some materials significantly exceeds current reserves and even resources. In particular, lithium (demand increase (DI) more than factor 10, cumulated demand (CD) exceeds reserves up to factor 2), cobalt (DI/CD: <7/<3), and nickel (CD/DI: <2.4/<1.4) for batteries, dysprosium (DI < 8) and neodymium (DI < 1.5) (for permanent magnets (wind turbines and electric motors), and iridium (DI < 2.9) as well as platinum (DI < 1.8) (fuel cells, electrolyzers) are affected. The construction of battery electric and fuel cell electric vehicles thus represents a major driver of the material demand. Depending on the material, shortages can be reduced or delayed by technology substitution, material recycling, technology lifetime extension, increased material efficiency, and a smaller future vehicle stock, but not entirely avoided. Hence, it can be expected that material bottlenecks will result in increasing material prices, at least in the short to medium term.

Prolonged in situ self-healing in structural composites via thermo-reversible entanglement

Natural processes continuously degrade a material’s performance throughout its life cycle. An emerging class of synthetic self-healing polymers and composites possess property-retaining functions with the promise of longer lifetimes. But sustained in-service repair of structural fiber-reinforced composites remains unfulfilled due to material heterogeneity and thermodynamic barriers in commonly cross-linked polymer-matrix constituents. Overcoming these inherent challenges for mechanical self-recovery is vital to extend in-service operation and attain widespread adoption of such bioinspired structural materials. Here we transcend existing obstacles and report a fiber-composite capable of minute-scale and prolonged in situ healing — 100 cycles: an order of magnitude higher than prior studies. By 3D printing a mendable thermoplastic onto woven glass/carbon fiber reinforcement and co-laminating with electrically resistive heater interlayers, we achieve in situ thermal remending of internal delamination via dynamic bond re-association. Full fracture recovery occurs below the glass-transition temperature of the thermoset epoxy-matrix composite, thus preserving stiffness during and after repair. A discovery of chemically driven improvement in thermal remending of glass- over carbon-fiber composites is also revealed. The marked lifetime extension offered by this self-healing strategy mitigates costly maintenance, facilitates repair of difficult-to-access structures (e.g., wind-turbine blades), and reduces part replacement, thereby benefiting economy and environment.

The circular economy and longer product lifetime: Framing the effects on working time and waste

An important goal of circular economy strategies is the extension of product lifetimes, under the assumption that this will deliver reductions in materials, energy use and waste. More broadly, longer lifetimes might counter the “broken windows fallacy” on which much of economic growth is based. The aim of this paper is to elaborate on this assumption rather than take it for granted. What are the systemic effects of policies aimed at saving materials? Who will benefit from them? To answer these research questions, we start connecting two issues that are often handled separately, despite being closely interlinked, namely (i) working time reduction and (ii) (over)production and waste generation. Trends in work indicators and material consumption in the EU15 countries confirm that higher material efficiency has not delivered the hoped-for benefits, thereby supporting the rest of our analysis. The conceptual framework that we propose shows that efforts towards material savings might allow reductions in working time per inhabitant while keeping labour compensation unchanged. However, such a possibility is hindered by competition over material efficiency gains.

Probabilistic temporal extrapolation of fatigue damage of offshore wind turbine substructures based on strain measurements

Abstract. Substructures of offshore wind turbines are becoming older and beginning to reach their design lifetimes. Hence, lifetime extensions for offshore wind turbines are becoming not only an interesting research topic but also a relevant option for industry. To make well-founded decisions on possible lifetime extensions, precise fatigue damage predictions are required. In contrast to the design phase, fatigue damage predictions can be based not only on aeroelastic simulations but also on strain measurements. Nonetheless, strain-measurement-based fatigue damage assessments for lifetime extensions have been rarely conducted so far. Simulation-based approaches are much more common, although current standards explicitly recommend the use of measurement-based approaches as well. For measurement-based approaches, the main challenge is that strain data are limited. This means that measurements are only available for a limited period and only at some specific hotspot locations. Hence, spatial and temporal extrapolations are required. Available procedures are not yet standardised and in most cases not validated. This work focusses on extrapolations in time. Several methods for the extrapolation of fatigue damage are assessed. The methods are intended to extrapolate fatigue damage calculated for a limited time period using strain measurement data to a longer time period or another time period, where no such data are available. This could be, for example, a future period, a period prior to the installation of strain gauges or a period after some sensors have failed. The methods are validated using several years of strain measurement data from the German offshore wind farm Alpha Ventus. The performance and user-friendliness of the various methods are compared. It is shown that fatigue damage can be predicted accurately and reliably for periods where no strain data are available. Best results are achieved if wind speed correlations are taken into account by applying a binning approach and if a least some winter months of strain data are available.

Optimisation of satellite geometries in Very Low Earth Orbits for drag minimisation and lifetime extension

The utilisation of the Very Low Earth Orbit (VLEO) region offers significant application specific, technological, operational, and cost benefits. However, attaining sustained and economically viable VLEO flight is challenging, primarily due to the significant, barely predictable and dynamically changing drag caused by the residual atmosphere, which leads to a rapid deterioration of any spacecraft’s orbit unless mitigated by a combination of active and passive techniques. This article addresses one passive method by optimising satellite shapes in order to achieve a minimisation of the atmospheric drag force and thus extension of operational lifetime. Contrary to previous investigations in the field, a constant internal volume is maintained to account for the placement of satellite instruments and payload inside the structure. Moreover, the satellite geometry is not varied heuristically but optimised, via a numerical 2D profile optimisation specifically developed for this purpose. From the resulting optimal satellite profiles, 3D satellite bodies are derived, which are then verified via the Direct Simulation Monte Carlo method within the open-source particle code PICLas. In addition, rather unconventional designs, i.e. ring geometries, which are based on the assumption of fully specular particle reflections, are proposed and assessed. The optimised satellite geometries offer pure passive lifetime extensions of up to 46% compared to a slender reference body, while the above-mentioned ring geometries achieve passive lifetime extensions of more than 3000%. Finally, the article presents design recommendations for VLEO satellites in dependence of different surface properties.

Versatile Hole Selective Molecules Containing a Series of Heteroatoms as Self‐Assembled Monolayers for Efficient p‐i‐n Perovskite and Organic Solar Cells

AbstractInverted type perovskite solar cells (PSCs) have recently emerged as a major focus in academic and industrial photovoltaic research. Their multiple advantages over conventional PSCs include easy processing, hysteresis‐free behavior, high stability, and compatibility for tandem applications. However, the maximum power conversion efficiency (PCE) of inverted PSCs still lags behind those of conventional PSCs because suitable charge‐selective materials for inverted PSCs are limited. In this study, excellent hole‐selective materials for inverted PSCs are introduced. A series of tricyclic aromatic rings containing O, S, or Se, respectively, as a core heteroatom, along with a phosphonic acid anchor, form a self‐assembled monolayer (SAM) that directly contacts the perovskite absorber. The influence of heteroatoms in the aromatic structure on the molecular energetics and operating characteristics of the corresponding inverted PSCs is investigated using complementary experimental techniques as well as density functional theory (DFT) calculations. It is found that all of the SAMs formed an energetically well‐aligned interface with the perovskite absorber. The interaction energy between the Se‐containing SAM and perovskite absorber is the strongest among the series and it reduces the interfacial defect density, in turn leading to an extended charge carrier lifetime. As a result, PSCs incorporating the Se‐containing SAM achieves a PCE of 22.73% and retains ≈96% of their initial efficiency after a maximum power point tracking test of 500 h without encapsulation under ambient conditions. All of the SAMs are then employed in organic solar cells (OSCs). Again, the Se‐containing SAM‐based OSCs demonstrates the highest PCE of 17.9% among the three molecular SAM‐based OSCs. This study demonstrates the great potential for precisely engineered SAMs for use in high‐performance solar cells.

An α-Fairness Approach to Balancing the Energy Consumption Among Sensors for UAV–IoT Systems

The rise of Internet of Things (IoT) systems has enabled us to access real-time information about our surrounding environments. However, IoT data collection in hostile and inaccessible areas without infrastructure supports is a challenging issue due to the inherent physical constraints associated with the tiny sensors. A viable solution to this problem is to use agile and controllable unmanned aerial vehicles (UAVs) to collect the ground data and relay it to the remote cloud for further processing. Under this UAV–IoT scenario, the limited battery supply carried by the sensor must be efficiently utilized so as to prolong the lifetime of the IoT system. Nevertheless, lifetime extension does not merely entail the reduction of the sum energy expenditure of sensors. In this article, we first show that minimizing the sum energy consumption cannot effectively extend the system lifetime due to the imbalance in energy expenditure among sensors, which, in fact, can render early energy depletion for some overburdened sensors. We also reveal a tradeoff between energy efficiency and energy fairness. To tackle this imbalance issue, we then propose an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula> -fairness approach to balance the energy consumption among IoT sensors. Specifically, in our study, the heterogeneities among the sensor nodes—different data loads, diverse residual energy levels, and distinct channel gains, have been taken into consideration. Based on this, an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula> -utility function is designed. In the maximization of the utility function, the bandwidth allocation, transmission power, and the UAV’s trajectory are jointly optimized. In addition, we also demonstrate how to properly set the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha $ </tex-math></inline-formula> value according to the specific application scenarios, thus to achieve different levels of energy fairness and promote the functional longevity of the system to the best effort.