Fires and human casualties caused by single phase-to-ground faults in distribution networks are frequent.However,existing ground fault suppression methods are affected by ground fault resistance.Thus,an adaptive suppr...Fires and human casualties caused by single phase-to-ground faults in distribution networks are frequent.However,existing ground fault suppression methods are affected by ground fault resistance.Thus,an adaptive suppression method that seamlessly combines principles of current and voltage suppression is proposed,which has good adaptability to different ground fault resistance.Meanwhile,a multi-criteria ground fault suppression exit strategy matched to adaptive suppression method is proposed to avoid damage of device caused by power backflow,which provides the possibility for reliable and fast exit of the fault suppression device.Experimental results demonstrate effectiveness and advantages of the adaptive suppression method and its exit strategy.展开更多
With the integration of large-scale renewable energy sources(RESs),the line commutated converter(LCC)based high-voltage direct-current(HVDC)inverter side suffers from degraded grid strength and escalating commutation ...With the integration of large-scale renewable energy sources(RESs),the line commutated converter(LCC)based high-voltage direct-current(HVDC)inverter side suffers from degraded grid strength and escalating commutation failure(CF)risks.In comparison with the widely used grid-following(GFL)RESs,grid-forming(GFM)RESs exhibit the favorable characteristics of voltage sources.Therefore,the hybrid operation of GFL-/GFM-RESs holds great potential in voltage support and may help CF suppression.This paper first analyzes the impacts of RESs on the first and subsequent CFs,respectively.It reveals that GFM-RESs alleviate the deterioration of grid voltage induced by GFL-RESs,thereby suppressing the first CF.However,current fault ride-through controls of RESs cannot fulfill the reactive power dynamic demand during the CF recovery process and rarely help mitigate subsequent CFs.Moreover,the limited overcurrent capability of GFM-RES hinders its ability to ride through CF.Based on the mechanism analysis,a CF suppression strategy based on the hybrid GFL/GFM operation is proposed.The proposed strategy optimized the controls of RESs to fulfill reactive power dynamics and offer voltage support during the CF process.Case studies are undertaken on the studied system and the CIGRE benchmark,respectively.The simulation results confirm the effectiveness of the proposed strategy for suppressing CF.展开更多
Aqueous sodium-ion batteries(ASIBs)and aqueous potassium-ion batteries(APIBs)present significant potential for large-scale energy storage due to their cost-effectiveness,safety,and environmental compatibility.Nonethel...Aqueous sodium-ion batteries(ASIBs)and aqueous potassium-ion batteries(APIBs)present significant potential for large-scale energy storage due to their cost-effectiveness,safety,and environmental compatibility.Nonetheless,the intricate energy storage mechanisms in aqueous electrolytes place stringent require-ments on the host materials.Prussian blue analogs(PBAs),with their open three-dimensional framework and facile synthesis,stand out as leading candidates for aqueous energy storage.However,PBAs possess a swift capacity fade and limited cycle longevity,for their structural integrity is compromised by the pronounced dis-solution of transition metal(TM)ions in the aqueous milieu.This manuscript provides an exhaustive review of the recent advancements concerning PBAs in ASIBs and APIBs.The dissolution mechanisms of TM ions in PBAs,informed by their structural attributes and redox processes,are thoroughly examined.Moreover,this study delves into innovative design tactics to alleviate the dissolution issue of TM ions.In conclusion,the paper consolidates various strategies for suppressing the dissolution of TM ions in PBAs and posits avenues for prospective exploration of high-safety aqueous sodium-/potassium-ion batteries.展开更多
Based on the development of the performance of magnetorheological damper,the tremor suppression strategy that uses angle displacement sensor and force sensor to sense the information of the tremor and uses the fuzzy n...Based on the development of the performance of magnetorheological damper,the tremor suppression strategy that uses angle displacement sensor and force sensor to sense the information of the tremor and uses the fuzzy neural network as the control algorithm is presented. The information of the maximum tremor torque can be achieved exactly by means fusing the data of displacement sensor and the data of force sensor. Due to the slow change of the maximum tremor torque,the fuzzy neural network with single input variable and single output variable is adopted as the control algorithm,and the mathematic model of fuzzy neural network is worked out. The elbow tremor suppression model is established to provide tremor information for fuzzy neural network training and tremor suppression strategy simulation,then the off-line fuzzy neural network training is finished with the selected training data set,and the tremor suppression strategy is simulated. Simulation results show that the tremor suppression strategy has presented is effectually for the tremor suppression.展开更多
Supercapacitors are one of the most promising energy storage devices in the fields of vehicle transportation,flexible electronic devices,aerospace,etc.However,the existed self-discharge that is the spontaneous voltage...Supercapacitors are one of the most promising energy storage devices in the fields of vehicle transportation,flexible electronic devices,aerospace,etc.However,the existed self-discharge that is the spontaneous voltage decay after supercapacitors are fully charged,brings about the wide gap between experimental studies and practical utilization of supercapacitors.Although eliminating the selfdischarge completely is not reachable,suppressing the self-discharge rate to the lowest point is possible and feasible.So far,the significant endeavors have been devoted to achieve this goal.Herein,we summary and discuss the possible mechanisms for the self-discharge and the underlying influence factors.Moreover,the strategies to suppress the self-discharge are systemically summed up by three independent but unified aspects:modifying the electrode,modulating the electrolyte and tuning the separator.Finally,the major challenges to suppress the self-discharge of supercapacitors are concluded and the promising strategies are also pointed out and discussed.This review is presented with the view of serving as a guideline to suppress the self-discharge of supercapacitors and to across-the-board facilitate their widespread application.展开更多
Aiming at the suppression of enemy air defense(SEAD)task under the complex and complicated combat sce-nario,the spatiotemporal cooperative path planning methods are studied in this paper.The major research contents in...Aiming at the suppression of enemy air defense(SEAD)task under the complex and complicated combat sce-nario,the spatiotemporal cooperative path planning methods are studied in this paper.The major research contents include opti-mal path points generation,path smoothing and cooperative rendezvous.In the path points generation part,the path points availability testing algorithm and the path segments availability testing algorithm are designed,on this foundation,the swarm intelligence-based path point generation algorithm is utilized to generate the optimal path.In the path smoothing part,taking ter-minal attack angle constraint and maneuverability constraint into consideration,the Dubins curve is introduced to smooth the path segments.In cooperative rendezvous part,we take esti-mated time of arrival requirement constraint and flight speed range constraint into consideration,the speed control strategy and flight path control strategy are introduced,further,the decoupling scheme of the circling maneuver and detouring maneuver is designed,in this case,the maneuver ways,maneu-ver point,maneuver times,maneuver path and flight speed are determined.Finally,the simulation experiments are conducted and the acquired results reveal that the time-space cooperation of multiple unmanned aeriel vehicles(UAVs)is effectively real-ized,in this way,the combat situation suppression against the enemy can be realized in SEAD scenarios.展开更多
This paper presents a novel approach that simultaneously enables photovoltaic(PV)inversion and flexible arc suppression during single-phase grounding faults.Inverters compensate for ground currents through an arc-elim...This paper presents a novel approach that simultaneously enables photovoltaic(PV)inversion and flexible arc suppression during single-phase grounding faults.Inverters compensate for ground currents through an arc-elimination function,while outputting a PV direct current(DC)power supply.This method effectively reduces the residual grounding current.To reduce the dependence of the arc-suppression performance on accurate compensation current-injection models,an adaptive fuzzy neural network imitating a sliding mode controller was designed.An online adaptive adjustment law for network parameters was developed,based on the Lyapunov stability theorem,to improve the robustness of the inverter to fault and connection locations.Furthermore,a new arc-suppression control exit strategy is proposed to allow a zerosequence voltage amplitude to quickly and smoothly track a target value by controlling the nonlinear decrease in current and reducing the regulation time.Simulation results showed that the proposed method can effectively achieve fast arc suppression and reduce the fault impact current in single-phase grounding faults.Compared to other methods,the proposed method can generate a lower residual grounding current and maintain good arc-suppression performance under different transition resistances and fault locations.展开更多
The ever-growing demands for renewable energy sources motivate the development of energy storage systems.Among them,supercapacitors are received increasing attention due to their high power density,long cycle life,fas...The ever-growing demands for renewable energy sources motivate the development of energy storage systems.Among them,supercapacitors are received increasing attention due to their high power density,long cycle life,fast recharge rate,and almost no maintenance.Nevertheless,their application is hindered by severe self-discharge behaviors,especially in wearable and energy storage devices.In recent years,tremendous excellent works have been reported to conquer this shortcoming through various creative strategies.Herein,we gives a timely spotlight on breakthroughs in the self-discharge mechanism investigations of supercapacitors and the corresponding suppression strategies.The self-discharge mechanisms of various supercapacitors were introduced first,followed by a summary of the strategies from materials(i.e.,electrode,electrolyte,and separator)to system and protocol optimization,furthermore,the connection between them,existing issues,and possible directions for future research are discussed.展开更多
In the animal kingdom there are countless strategies via which males optimize their reproductivesuccess when faced with male-male competition. These male strategies typically fall into two maincategories： pre- and po...In the animal kingdom there are countless strategies via which males optimize their reproductivesuccess when faced with male-male competition. These male strategies typically fall into two maincategories： pre- and post-copulatory competition. Within these 2 categories, a set of behaviors,referred to as reproductive suppression, is known to cause inhibition of reproductive physiologyand/or reproductive behavior in an otherwise fertile individual. What becomes evident when con-sidering examples of reproductive suppression is that these strategies conventionally encompassreproductive interference strategies that occur between members of a hierarchical social group.However, mechanisms aimed at impairing a competitor＇s reproductive output are also present innon-social animals. Yet, current thinking emphasizes the importance of sociality as the primarydriving force of reproductive suppression. Therefore, the question arises as to whether there is anactual difference between reproductive suppression strategies in social animals and equivalentpre-copulatory competition strategies in non-social animals. In this perspective paper we explore abroad taxonomic range of species whose individuals do not repeatedly interact with the same indi-viduals in networks and yet, depress the fitness of rivals. Examples like alteration of male repro-ductive physiology, female mimicry, rival spermatophore destruction, and cementing the rival＇sgenital region in non-social animals, highlight that male pre-copulatory reproductive suppressionand male pre-copulatory competition overlap. Finally, we highlight that a distinction between malereproductive interference in animals with and without a social hierarchy might obscure importantsimilarities and does not help to elucidate why different proximate mechanisms evolved. We there-fore emphasize that male reproductive suppression need not be restricted to social animals.展开更多
Aqueous zinc-ion batteries(AZIBs)suffer from poor electrolyte/anode interfacial stability and severe performance degradation under low-temperature conditions.To address these issues,this study proposes natural okra po...Aqueous zinc-ion batteries(AZIBs)suffer from poor electrolyte/anode interfacial stability and severe performance degradation under low-temperature conditions.To address these issues,this study proposes natural okra polysaccharides(OPs)as an electrolyte additive for interfacial engineering,OPs,rich in polar functional groups,preferentially adsorb onto the Zn/electrolyte interface via strong dipole interactions,forming a robust protective layer.This layer promotes uniform Zn deposition,suppresses side reactions and corrosion,and enhances the hydrogen-bond network of the electrolyte,thereby reducing interfacial water activity and lowering the freezing point.As a result,the low-temperature stability and electrochemical reversibility of AZIBs are significantly improved.Zn‖Zn symmetric cells incorporating OPs exhibit exceptional cycling stability,maintaining reversible zinc plating/stripping for over 5000 h at 2 mA cm^(-2) and 1 mAh cm^(-2) and sustaining stable operation at-10℃for 1600 h under 1 mA cm^(-2)and 0.5 mAh cm^(-2),as well as for 300 h under 10 mA cm^(-2) and 10 mAh cm^(-2).Furthermore,full cells employing V_(2)O_(5) cathodes retain 83%of their capacity after 1000 cycles,confirming the practical applicability of OPs as a functio nal electrolyte additive.This work demonstrates the significant potential of OPs to overcome key limitations of AZIBs,particularly for low-temperature operation,offering a sustainable and cost-effective strategy for next-generation energy storage.展开更多
基金supported by the National Natural Science Foundation of China(51677030).
文摘Fires and human casualties caused by single phase-to-ground faults in distribution networks are frequent.However,existing ground fault suppression methods are affected by ground fault resistance.Thus,an adaptive suppression method that seamlessly combines principles of current and voltage suppression is proposed,which has good adaptability to different ground fault resistance.Meanwhile,a multi-criteria ground fault suppression exit strategy matched to adaptive suppression method is proposed to avoid damage of device caused by power backflow,which provides the possibility for reliable and fast exit of the fault suppression device.Experimental results demonstrate effectiveness and advantages of the adaptive suppression method and its exit strategy.
基金supported by the National Natural Science Foundation of China under Grant 52225704 and Grant U23B20120.
文摘With the integration of large-scale renewable energy sources(RESs),the line commutated converter(LCC)based high-voltage direct-current(HVDC)inverter side suffers from degraded grid strength and escalating commutation failure(CF)risks.In comparison with the widely used grid-following(GFL)RESs,grid-forming(GFM)RESs exhibit the favorable characteristics of voltage sources.Therefore,the hybrid operation of GFL-/GFM-RESs holds great potential in voltage support and may help CF suppression.This paper first analyzes the impacts of RESs on the first and subsequent CFs,respectively.It reveals that GFM-RESs alleviate the deterioration of grid voltage induced by GFL-RESs,thereby suppressing the first CF.However,current fault ride-through controls of RESs cannot fulfill the reactive power dynamic demand during the CF recovery process and rarely help mitigate subsequent CFs.Moreover,the limited overcurrent capability of GFM-RES hinders its ability to ride through CF.Based on the mechanism analysis,a CF suppression strategy based on the hybrid GFL/GFM operation is proposed.The proposed strategy optimized the controls of RESs to fulfill reactive power dynamics and offer voltage support during the CF process.Case studies are undertaken on the studied system and the CIGRE benchmark,respectively.The simulation results confirm the effectiveness of the proposed strategy for suppressing CF.
基金This work was supported by the National Natural Science Foundation of China(52373306,52172233,and 51832004)the Natural Science Foundation of Hubei Province(2023AFA053)the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(2021CXLH0007).
文摘Aqueous sodium-ion batteries(ASIBs)and aqueous potassium-ion batteries(APIBs)present significant potential for large-scale energy storage due to their cost-effectiveness,safety,and environmental compatibility.Nonetheless,the intricate energy storage mechanisms in aqueous electrolytes place stringent require-ments on the host materials.Prussian blue analogs(PBAs),with their open three-dimensional framework and facile synthesis,stand out as leading candidates for aqueous energy storage.However,PBAs possess a swift capacity fade and limited cycle longevity,for their structural integrity is compromised by the pronounced dis-solution of transition metal(TM)ions in the aqueous milieu.This manuscript provides an exhaustive review of the recent advancements concerning PBAs in ASIBs and APIBs.The dissolution mechanisms of TM ions in PBAs,informed by their structural attributes and redox processes,are thoroughly examined.Moreover,this study delves into innovative design tactics to alleviate the dissolution issue of TM ions.In conclusion,the paper consolidates various strategies for suppressing the dissolution of TM ions in PBAs and posits avenues for prospective exploration of high-safety aqueous sodium-/potassium-ion batteries.
基金Sponsored by the National Natural Science Foundation (Grant No.60975067)
文摘Based on the development of the performance of magnetorheological damper,the tremor suppression strategy that uses angle displacement sensor and force sensor to sense the information of the tremor and uses the fuzzy neural network as the control algorithm is presented. The information of the maximum tremor torque can be achieved exactly by means fusing the data of displacement sensor and the data of force sensor. Due to the slow change of the maximum tremor torque,the fuzzy neural network with single input variable and single output variable is adopted as the control algorithm,and the mathematic model of fuzzy neural network is worked out. The elbow tremor suppression model is established to provide tremor information for fuzzy neural network training and tremor suppression strategy simulation,then the off-line fuzzy neural network training is finished with the selected training data set,and the tremor suppression strategy is simulated. Simulation results show that the tremor suppression strategy has presented is effectually for the tremor suppression.
基金partly supported by the National Natural Science Foundation of China(NSFC,No.51872035)the Talent Program of Rejuvenation of the Liaoning(No.XLYC1807002)+1 种基金the Fundamental Research Funds for the Central Universities(DUT19LAB20)the National Key Research Development Program of China(2016YFB0101201)。
文摘Supercapacitors are one of the most promising energy storage devices in the fields of vehicle transportation,flexible electronic devices,aerospace,etc.However,the existed self-discharge that is the spontaneous voltage decay after supercapacitors are fully charged,brings about the wide gap between experimental studies and practical utilization of supercapacitors.Although eliminating the selfdischarge completely is not reachable,suppressing the self-discharge rate to the lowest point is possible and feasible.So far,the significant endeavors have been devoted to achieve this goal.Herein,we summary and discuss the possible mechanisms for the self-discharge and the underlying influence factors.Moreover,the strategies to suppress the self-discharge are systemically summed up by three independent but unified aspects:modifying the electrode,modulating the electrolyte and tuning the separator.Finally,the major challenges to suppress the self-discharge of supercapacitors are concluded and the promising strategies are also pointed out and discussed.This review is presented with the view of serving as a guideline to suppress the self-discharge of supercapacitors and to across-the-board facilitate their widespread application.
文摘Aiming at the suppression of enemy air defense(SEAD)task under the complex and complicated combat sce-nario,the spatiotemporal cooperative path planning methods are studied in this paper.The major research contents include opti-mal path points generation,path smoothing and cooperative rendezvous.In the path points generation part,the path points availability testing algorithm and the path segments availability testing algorithm are designed,on this foundation,the swarm intelligence-based path point generation algorithm is utilized to generate the optimal path.In the path smoothing part,taking ter-minal attack angle constraint and maneuverability constraint into consideration,the Dubins curve is introduced to smooth the path segments.In cooperative rendezvous part,we take esti-mated time of arrival requirement constraint and flight speed range constraint into consideration,the speed control strategy and flight path control strategy are introduced,further,the decoupling scheme of the circling maneuver and detouring maneuver is designed,in this case,the maneuver ways,maneu-ver point,maneuver times,maneuver path and flight speed are determined.Finally,the simulation experiments are conducted and the acquired results reveal that the time-space cooperation of multiple unmanned aeriel vehicles(UAVs)is effectively real-ized,in this way,the combat situation suppression against the enemy can be realized in SEAD scenarios.
基金the Natural Science Foundation of Fujian,China(No.2021J01633).
文摘This paper presents a novel approach that simultaneously enables photovoltaic(PV)inversion and flexible arc suppression during single-phase grounding faults.Inverters compensate for ground currents through an arc-elimination function,while outputting a PV direct current(DC)power supply.This method effectively reduces the residual grounding current.To reduce the dependence of the arc-suppression performance on accurate compensation current-injection models,an adaptive fuzzy neural network imitating a sliding mode controller was designed.An online adaptive adjustment law for network parameters was developed,based on the Lyapunov stability theorem,to improve the robustness of the inverter to fault and connection locations.Furthermore,a new arc-suppression control exit strategy is proposed to allow a zerosequence voltage amplitude to quickly and smoothly track a target value by controlling the nonlinear decrease in current and reducing the regulation time.Simulation results showed that the proposed method can effectively achieve fast arc suppression and reduce the fault impact current in single-phase grounding faults.Compared to other methods,the proposed method can generate a lower residual grounding current and maintain good arc-suppression performance under different transition resistances and fault locations.
基金We thank the funding support from Anhui Provincial Natural Science Foundation(2008085ME155)National Innovative Talents Program(GG2090007001)+2 种基金Chinese Academy of Sciences(CAS)Program(KJ2090130001)USTC Startup Program(KY2090000044)USTC Tang Scholar(KY2090000065).
文摘The ever-growing demands for renewable energy sources motivate the development of energy storage systems.Among them,supercapacitors are received increasing attention due to their high power density,long cycle life,fast recharge rate,and almost no maintenance.Nevertheless,their application is hindered by severe self-discharge behaviors,especially in wearable and energy storage devices.In recent years,tremendous excellent works have been reported to conquer this shortcoming through various creative strategies.Herein,we gives a timely spotlight on breakthroughs in the self-discharge mechanism investigations of supercapacitors and the corresponding suppression strategies.The self-discharge mechanisms of various supercapacitors were introduced first,followed by a summary of the strategies from materials(i.e.,electrode,electrolyte,and separator)to system and protocol optimization,furthermore,the connection between them,existing issues,and possible directions for future research are discussed.
文摘In the animal kingdom there are countless strategies via which males optimize their reproductivesuccess when faced with male-male competition. These male strategies typically fall into two maincategories： pre- and post-copulatory competition. Within these 2 categories, a set of behaviors,referred to as reproductive suppression, is known to cause inhibition of reproductive physiologyand/or reproductive behavior in an otherwise fertile individual. What becomes evident when con-sidering examples of reproductive suppression is that these strategies conventionally encompassreproductive interference strategies that occur between members of a hierarchical social group.However, mechanisms aimed at impairing a competitor＇s reproductive output are also present innon-social animals. Yet, current thinking emphasizes the importance of sociality as the primarydriving force of reproductive suppression. Therefore, the question arises as to whether there is anactual difference between reproductive suppression strategies in social animals and equivalentpre-copulatory competition strategies in non-social animals. In this perspective paper we explore abroad taxonomic range of species whose individuals do not repeatedly interact with the same indi-viduals in networks and yet, depress the fitness of rivals. Examples like alteration of male repro-ductive physiology, female mimicry, rival spermatophore destruction, and cementing the rival＇sgenital region in non-social animals, highlight that male pre-copulatory reproductive suppressionand male pre-copulatory competition overlap. Finally, we highlight that a distinction between malereproductive interference in animals with and without a social hierarchy might obscure importantsimilarities and does not help to elucidate why different proximate mechanisms evolved. We there-fore emphasize that male reproductive suppression need not be restricted to social animals.
基金supported by the National Natural Science Foundation of China(22265007)the Guangxi Science and Technology Plan Project(GuikeAD25069100)+1 种基金the Guangdong Major Project of Basic Research(No.2023B0303000002)the High Level of Special Funds(No.G03034K00)。
文摘Aqueous zinc-ion batteries(AZIBs)suffer from poor electrolyte/anode interfacial stability and severe performance degradation under low-temperature conditions.To address these issues,this study proposes natural okra polysaccharides(OPs)as an electrolyte additive for interfacial engineering,OPs,rich in polar functional groups,preferentially adsorb onto the Zn/electrolyte interface via strong dipole interactions,forming a robust protective layer.This layer promotes uniform Zn deposition,suppresses side reactions and corrosion,and enhances the hydrogen-bond network of the electrolyte,thereby reducing interfacial water activity and lowering the freezing point.As a result,the low-temperature stability and electrochemical reversibility of AZIBs are significantly improved.Zn‖Zn symmetric cells incorporating OPs exhibit exceptional cycling stability,maintaining reversible zinc plating/stripping for over 5000 h at 2 mA cm^(-2) and 1 mAh cm^(-2) and sustaining stable operation at-10℃for 1600 h under 1 mA cm^(-2)and 0.5 mAh cm^(-2),as well as for 300 h under 10 mA cm^(-2) and 10 mAh cm^(-2).Furthermore,full cells employing V_(2)O_(5) cathodes retain 83%of their capacity after 1000 cycles,confirming the practical applicability of OPs as a functio nal electrolyte additive.This work demonstrates the significant potential of OPs to overcome key limitations of AZIBs,particularly for low-temperature operation,offering a sustainable and cost-effective strategy for next-generation energy storage.
