Aiming at the comparatively laggard level of power plant electrical system automation, this paper analyzes the feasibility,necessity and some key points of the application of integrated automation technology to power ...Aiming at the comparatively laggard level of power plant electrical system automation, this paper analyzes the feasibility,necessity and some key points of the application of integrated automation technology to power plant electrical system. New idea using fieldbus control system technology is presented. This paper also gives the outline and detailed schemes.展开更多
The reliability and maintainability of electrical system of drum shearer at Parvade. 1 Coal Mine in central Iran was analyzed. The maintenance and failure data were collected during 19 months of shearer operation. Acc...The reliability and maintainability of electrical system of drum shearer at Parvade. 1 Coal Mine in central Iran was analyzed. The maintenance and failure data were collected during 19 months of shearer operation. According to trend and serial correlation tests, the data were independent and identically distributed （iid） and therefore the statistical techniques were used for modeling. The data analysis show that the time between failures （TBF） and time to repair （TTR） data obey the lognormal and Weibull 3 parameters distribution respectively. Reliability-based preventive maintenance time intervals for electrical system of the drum shearer were calculated with regard to reliability plot. The reliability-based maintenance intervals for 90%, 80%, 70% and 50% reliability level are respectively 9.91, 17.96, 27.56 and 56.1 h. Also the calculations show that time to repair （TTR） of this system varies in range 0.17-4 h with 1.002 h as mean time to repair （MTTR）. There is a 80% chance that the electrical system of shearer of Parvade. 1 mine repair will be accomplished within 1.45 h.展开更多
The core of computer numerical control(CNC) machine tool is the electrical system which controls and coordinates every part of CNC machine tool to complete processing tasks, so it is of great significance to strengthe...The core of computer numerical control(CNC) machine tool is the electrical system which controls and coordinates every part of CNC machine tool to complete processing tasks, so it is of great significance to strengthen the reliability of the electrical system. However, the electrical system is very complex due to many uncertain factors and dynamic stochastic characteristics when failure occurs. Therefore, the traditional fault tree analysis(FTA) method is not applicable. Bayesian network(BN) not only has a unique advantage to analyze nodes with multiply states in reliability analysis for complex systems, but also can solve the state explosion problem properly caused by Markov model when dealing with dynamic fault tree(DFT). In addition, the forward causal reasoning of BN can get the conditional probability distribution of the system under considering the uncertainty;the backward diagnosis reasoning of BN can recognize the weak links in system, so it is valuable for improving the system reliability.展开更多
Electrical system of military vehicle is a typical parameterized nonlinear system where complicated bifurcations may exist and threaten its safe and stable operation. An algebraic criterion for Hopf bifurcation is pre...Electrical system of military vehicle is a typical parameterized nonlinear system where complicated bifurcations may exist and threaten its safe and stable operation. An algebraic criterion for Hopf bifurcation is presented briefly and applied to find Hopf bifurcation point of the electrical system with automatic voltage regulator(AVR) dynamics in military vehicle. Hopf bifurcation controllers are designed for this electrical system by using wash-out filter,linear feedback,nonlinear feedback and their combination. The linear feedback control makes the system bring Hopf bifurcation at preferable parameter,the nonlinear feedback control modifies the type of the bifurcation,and the wash-out filter enhances the system damping,thus,the Hopf bifurcation is eliminated and the electrical system stability is ensured. Simulation results show the controller's validity.展开更多
Based on the integrated design and airworthiness verification of civil aircraft system,this paper completes the simulation modeling and fault modeling of aircraft electrical system. The aircraft electrical system is c...Based on the integrated design and airworthiness verification of civil aircraft system,this paper completes the simulation modeling and fault modeling of aircraft electrical system. The aircraft electrical system is constructed in the form of dual generators and dual-channel power supply. The main power supply adopts the three-stage power generation system,the auxiliary power supply system uses the permanent magnet synchronous power generation system and a battery. The transmission and distribution system is responsible for the electrical power conversion and the logic control in the system fault-pattern. The simulation results show that the system is reasonable and effective,which provides a reference for the optimal design and control of the actual aircraft electrical system.展开更多
In recent years, the level of science and technology has been changing with each passing day, especially the development and research in the field of artificial intelligence has become a hot topic of social concern. H...In recent years, the level of science and technology has been changing with each passing day, especially the development and research in the field of artificial intelligence has become a hot topic of social concern. However, due to the limitation of related technologies, artificial intelligence has not been widely promoted and applied in many industries. In this paper, the application of artificial intelligence technology is deeply analyzed from the perspective of electrical automation control, hoping to provide development ideas for the current electrical automation control in our country.展开更多
With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would ...With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would greatly threaten the safety and proper working of the whole system. This paper focuses on a power quality improvement project to solve these problems. A hybrid compensating scheme, including an active compensator and a passive compensator, is carried out. Because of the specificity of oilfield drilling electrical system, compensators are redesigned against features of this application background. And then the current detection point arrangement of this hybrid system is also taken into consideration to build the whole system much more effective and reliable. Now the improvement project is already implemented in application field, and the power quality of the system is greatly improved.展开更多
With the development of social economy and the acceleration of people's work and life rhythm, the rapid development of China's aviation industry has been strongly promoted. Air travel has become a convenient w...With the development of social economy and the acceleration of people's work and life rhythm, the rapid development of China's aviation industry has been strongly promoted. Air travel has become a convenient way for ordinary citizens to travel. In this case, people pay more attention to the safety of flight. As an important part of an airplane, the aviation electrical system carries many key missions in the flight and plays a very important role in the safe flight of the airplane. The management of the aviation electrical system is an important part of the aviation safety management. Aviation safety is related to the safety of people's lives and property, as well as the development of the aviation industry. Based on this, starting from the basic concept of aviation safe flight, this paper gives an overview of aviation power system, analyzes the factors affecting the safety of aviation power system, and expounds the importance of aviation electrical system to safe flight, hoping to provide effective reference for relevant personnel, so as to better promote the development of China's aviation industry.展开更多
Green energy conservation is the mainstream trend in the current development of the construction industry.The application of energy-saving technology in building electrical system design can effectively reduce energy ...Green energy conservation is the mainstream trend in the current development of the construction industry.The application of energy-saving technology in building electrical system design can effectively reduce energy consumption,avoid unnecessary energy consumption,and truly achieve energy conservation and environmental protection.Based on this,the article elaborates on the principles of energy-saving design in building electrical systems,and actively explores the application of energy-saving technologies from different perspectives such as optimizing power supply and distribution system design,adopting high-efficiency energy-saving lighting equipment,applying renewable energy,promoting smart home technology,and improving the efficiency of building electrical equipment.展开更多
The electrical system of WK-35 electric shovel 6SE70 is seriously aging, and the electrical failure of the fryer frequently occurs, resulting in repeated maintenance of the equipment, high labor intensity and high pro...The electrical system of WK-35 electric shovel 6SE70 is seriously aging, and the electrical failure of the fryer frequently occurs, resulting in repeated maintenance of the equipment, high labor intensity and high production cost. Chinas automation industry has experienced rapid development for many years, and the inverter has made great progress in product performance and appearance. The self-developed electric shovel electric control system can provide a complete set of solutions for 10m3 ~ 55m3 electric shovel AC telex system and related products, and completed the localization and digital transformation of electric shovels.展开更多
With the proposal of intelligent manufacturing concept, electrical automation is more and more widely used in mechanical manufacturing and special equipment. The electrical control system is mainly composed of three m...With the proposal of intelligent manufacturing concept, electrical automation is more and more widely used in mechanical manufacturing and special equipment. The electrical control system is mainly composed of three modules: input, logic and execution. It can not only display the current, temperature and other data during the operation of electrical equipment, but also realize intelligent control and maintain the safe operation of the whole equipment.We should analyze different types of electrical equipment, formulate maintenance plans according to their circuits, electronic component functions and computer control systems, regularly overhaul the equipment and control systems, and eliminate potential safety hazards in time;Use intelligent detection equipment to quickly detect the electrical control system, check the performance of current and electronic components, and replace damaged electronic components and components in time;Standardize the conventional detection method, check the wires, motors, electrical windings and transformers of electrical equipment, quickly locate the fault location and improve the maintenance efficiency;Actively learn the information detection technology, monitor the temperature, current and voltage of the electrical control system, and timely arrange maintenance personnel for troubleshooting in case of abnormal data, so as to ensure the safe and smooth operation of the electrical control system.展开更多
BACKGROUND In pediatric and adolescent athletes,there is a lack of understanding about the impact of factors such as race on the structural or cardiovascular adaptations in response to exercise which may unnecessarily...BACKGROUND In pediatric and adolescent athletes,there is a lack of understanding about the impact of factors such as race on the structural or cardiovascular adaptations in response to exercise which may unnecessarily disqualify athletes from the competitive sport.We hypothesized that race has an impact on cardiac adaptions in non-adult athletes.AIM To explore the racial disparity in electrocardiographic(ECG)and echocardiographic(ECHO)parameters in healthy adolescent athletes.METHODS A comprehensive electronic systematic literature search using MEDLINE database was performed from inception to September 20,2024.Inclusion criteria included randomized or observational cohort studies that recruited adolescent competitive athletes in any sport discipline and compared between the Black and White races with an age range of 12-18 years.RESULTS Of 723 records that were identified by the literature search,seven studies(n=5036)were included.The mean age was 13.0-18.0 years old with male predominance.Black athletes had significantly longer PR interval[mean difference(MD)=17.49 millisecond,95% CI:11.70-23.29]and shorter QRS complex duration(MD=-7.35 millisecond,95% CI:-9.17 to-5.53)and corrected QT interval(MD=-4.95 millisecond,95% CI:-7.69 to-2.22)than the White athletes.Black athletes were approximately four times more likely to have first-degree atrioventricular(AV)block,inverted T wave,ST-segment elevation,and left atrium(LA)enlargement than their White counterparts.In terms of ECHO parameters,Black athletes had significantly greater septal wall thickness(MD=0.85 mm,95% CI:0.62-1.07),posterior wall thickness(MD=1.07 mm,95% CI:0.36-1.78),relative wall thickness(MD=0.03,95%CI:0.001-0.06),maximal wall thickness(MD=1.05 mm,95%CI:0.28-1.83),and LA diameter(MD=1.64 mm,95%CI:0.16-3.12).CONCLUSION Race has an impact on the ECG and ECHO parameters that reflect cardiac adaptations in adolescent athletes.Black athletes tend to have an increased prevalence of distinct ECG changes such as first-degree AV block and T-wave inversions compared with their White counterparts.Despite having thicker septal and posterior walls,the overall prevalence of left ventricular hypertrophy did not differ between the races.展开更多
Although previous studies have demonstrated that transcranial focused ultrasound stimulation protects the ischemic brain,clear criteria for the stimulation time window and intensity are lacking.Electrical impedance to...Although previous studies have demonstrated that transcranial focused ultrasound stimulation protects the ischemic brain,clear criteria for the stimulation time window and intensity are lacking.Electrical impedance tomography enables real-time monitoring of changes in cerebral blood perfusion within the ischemic brain,but investigating the feasibility of using this method to assess post-stroke rehabilitation in vivo remains critical.In this study,ischemic stroke was induced in rats through middle cerebral artery occlusion surgery.Transcranial focused ultrasound stimulation was used to treat the rat model of ischemia,and electrical impedance tomography was used to measure impedance during both the acute stage of ischemia and the rehabilitation stage following the stimulation.Electrical impedance tomography results indicated that cerebral impedance increased after the onset of ischemia and decreased following transcranial focused ultrasound stimulation.Furthermore,the stimulation promoted motor function recovery,reduced cerebral infarction volume in the rat model of ischemic stroke,and induced the expression of brain-derived neurotrophic factor in the ischemic brain.Our results also revealed a significant correlation between the impedance of the ischemic brain post-intervention and improvements in behavioral scores and infarct volume.This study shows that daily administration of transcranial focused ultrasound stimulation for 20 minutes to the ischemic hemisphere 24 hours after cerebral ischemia enhanced motor recovery in a rat model of ischemia.Additionally,our findings indicate that electrical impedance tomography can serve as a valuable tool for quantitatively evaluating rehabilitation after ischemic stroke in vivo.These findings suggest the feasibility of using impedance data collected via electrical impedance tomography to clinically assess the effects of rehabilitatory interventions for patients with ischemic stroke.展开更多
The major aim of stroke therapy is to stimulate brain repair and improve behavioral recovery after cerebral ischemia.One option is to stimulate endogenous neurogenesis in the subventricular zone and direct the newly f...The major aim of stroke therapy is to stimulate brain repair and improve behavioral recovery after cerebral ischemia.One option is to stimulate endogenous neurogenesis in the subventricular zone and direct the newly formed neurons to the damaged area.However,only a small percentage of these neurons survive,and many do not reach the damaged area,possibly because the corpus callosum impedes the migration of subventricular zone-derived stem cells into the lesioned cortex.A second major obstacle to stem cell therapy is the strong inflammatory reaction induced by cerebral ischemia,whereby the associated phagocytic activity of brain macrophages removes both therapeutic cells and/or cell-based drug carriers.To address these issues,neurogenesis was electrically stimulated in the subventricular zone,followed by isolation of proliferating cells,including newly formed neurons,which were subsequently mixed with a nutritional hydrogel.This mixture was then transferred to the stroke cavity of day 14 post-stroke mice.We found that the performance of the treated animals improved in behavioral tests,including novel object,open field,hole board,grooming,and“time-to-feel”adhesive tape tests.Furthermore,immunostaining revealed that the stem cell marker nestin,the neuroepithelial marker Mash1,and the immature neuronal marker doublecortin-positive cells survived in the transplanted area for 2 weeks,possibly due to reduced phagocytic activity and supportive angiogenesis.These results clearly indicate that the transplantation of committed subventricular zone stem cells combined with a protective nutritional gel directly into the infarct cavity after the peak of stroke-induced neuroinflammation represents a feasible approach to improve neurorestoration after cerebral ischemia.展开更多
Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generat...Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generated aerosol particles using a water spray system integrated with an innovative system for pre-injecting electrically charged mist in our facility.To simulate aerosol generation in reactor decommissioning,a high-power laser was used to irradiate various materials(including stainless steel,carbon steel,and concrete),generating aerosol particles that were agglomerated with injected water mist and subsequently scavenged by water spray.Experimental results demonstrate enhanced aerosol removal via aerosol-mist agglomeration,with charged mist significantly improving particle capture by increasing wettability and size.The average improvements for the stainless steel,carbon steel,and concrete were 40%,44%,and 21%,respectively.The results of experiments using charged mist with different polarities(both positive and negative)and different surface coatings reveal that the dominant polarity of aerosols varies with the irradiated materials,influenced by their crystal structure and electron emission properties.Notably,surface coatings such as ZrO_(2)and CeO_(2)were found to possibly alter aerosol charging characteristics,thereby affecting aerosol removal efficiency with charged mist configurations.The innovative aerosol-mist agglomeration approach shows promise in mitigating radiation exposure,ensuring environmental safety,and reducing contaminated water during reactor dismantling.This study contributes critical knowledge for the development of advanced aerosol management strategies for nuclear reactor decommissioning.The understanding obtained in this work is also expected to be useful for various environmental and chemical engineering applications such as gas decontamination,air purification,and pollution control.展开更多
Sustainable water,energy and food(WEF)supplies are the bedrock upon which human society depends.Solar-driven interfacial evaporation,combined with electricity generation and cultivation,is a promising approach to miti...Sustainable water,energy and food(WEF)supplies are the bedrock upon which human society depends.Solar-driven interfacial evaporation,combined with electricity generation and cultivation,is a promising approach to mitigate the freshwater,energy and food crises.However,the performance of solar-driven systems decreases significantly during operation due to uncontrollable weather.This study proposes an integrated water/electricity cogeneration-cultivation system with superior thermal management.The energy storage evaporator,consisting of energy storage microcapsules/hydrogel composites,is optimally designed for sustainable desalination,achieving an evaporation rate of around 1.91 kg m^(-2)h^(-1).In the dark,heat released from the phase-change layer supported an evaporation rate of around 0.54kg m^(-2)h^(-1).Reverse electrodialysis harnessed the salinity-gradient energy enhanced during desalination,enabling the long-running WEC system to achieve a power output of~0.3 W m^(-2),which was almost three times higher than that of conventional seawater/surface water mixing.Additionally,an integrated crop irrigation platform utilized system drainage for real-time,on-demand wheat cultivation without secondary contaminants,facilitating seamless WEF integration.This work presents a novel approach to all-day solar water production,electricity generation and crop irrigation,offering a solution and blueprint for the sustainable development of WEF.展开更多
As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft ele...As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft electrical power distribution system based on the distributed computer system is proposed. The principles, features and structure of the aircraft electrical power distribution system and the distributed computer system named electrical load management system (ELMS) are studied. The ELMS composed of four electrical load management centers (ELMCs) and two power source processors (PSPs) operates in the 1553B buses. Principles of the ELMCs and the PSPs are introduced. With the application of the distributed computer system, the aircraft electrical power distribution system is simple, adaptable and flexible.展开更多
Electrical system planning of the large-scale offshore wind farm is usually based on N-1 security for equipment lectotype. However, in this method, owing to the aggregation effect in large-scale offshore wind farms, o...Electrical system planning of the large-scale offshore wind farm is usually based on N-1 security for equipment lectotype. However, in this method, owing to the aggregation effect in large-scale offshore wind farms, offshore electrical equipment operates under low load for long periods, thus wasting resources. In this paper, we propose a method for electrical system planning of the large-scale offshore wind farm based on the N+ design. A planning model based on the power-limited operation of wind turbines under the N+ design is constructed, and a solution is derived with the optimization of the upper power limits of wind turbines. A comprehensive evaluation and game analysis of the economy, risk of wind abandonment, and environmental sustainability of the planned offshore electrical systems have been conducted. Moreover, the planning of an infield collector system, substation, and transmission system of an offshore electrical system based on the N+ design is integrated. For a domestic offshore wind farm, evaluation results show that the proposed planning method can improve the efficiency of wind energy utilization while greatly reducing the investment cost of the electrical system.展开更多
The current research of vehicle electrical power supply system mainly focuses on electric vehicles（EV） and hybrid electric vehicles（HEV）.The vehicle electrical power supply system used in traditional fuel vehicles...The current research of vehicle electrical power supply system mainly focuses on electric vehicles（EV） and hybrid electric vehicles（HEV）.The vehicle electrical power supply system used in traditional fuel vehicles is rather simple and imperfect;electrical/electronic devices（EEDs） applied in vehicles are usually directly connected with the vehicle＇s battery.With increasing numbers of EEDs being applied in traditional fuel vehicles,vehicle electrical power supply systems should be optimized and improved so that they can work more safely and more effectively.In this paper,a new vehicle electrical power supply system for traditional fuel vehicles,which accounts for all electrical/electronic devices and complex work conditions,is proposed based on a smart electrical/electronic device（SEED） system.Working as an independent intelligent electrical power supply network,the proposed system is isolated from the electrical control module and communication network,and access to the vehicle system is made through a bus interface.This results in a clean controller power supply with no electromagnetic interference.A new practical battery state of charge（So C） estimation method is also proposed to achieve more accurate So C estimation for lead-acid batteries in traditional fuel vehicles so that the intelligent power system can monitor the status of the battery for an over-current state in each power channel.Optimized protection methods are also used to ensure power supply safety.Experiments and tests on a traditional fuel vehicle are performed,and the results reveal that the battery So C is calculated quickly and sufficiently accurately for battery over-discharge protection.Over-current protection is achieved,and the entire vehicle＇s power utilization is optimized.For traditional fuel vehicles,the proposed vehicle electrical power supply system is comprehensive and has a unified system architecture,enhancing system reliability and security.展开更多
To evaluate the thermal performance of a low-temperature electrical radiant floor heating system,an experimental facility equipped with a constant temperature chamber and different specimen floors is designed and buil...To evaluate the thermal performance of a low-temperature electrical radiant floor heating system,an experimental facility equipped with a constant temperature chamber and different specimen floors is designed and built.The heating cable is installed in the floor slab with a unit-rated power of 30 W/m.Twenty-four different schemes are worked out and tested,which include three kinds of composite floor structures and eight kinds of cable distances.The cable distances are 30,40,50,60,80,100,130,150 mm.The main affective factors of the thermal performance and their influencing regularity are discussed.The experimental results show that the system has good stability and reliability,and the ratio of the radiation heat-transfer rate to the gross heat-transfer rate is greater than 50%.When the floor structure and the cable distance are fixed,the gross heat-transfer rate of the upper floor surface has a maximum value at an optimal cable distance.Under the experimental conditions in this paper,the optimal cable distance is 50 mm.展开更多
文摘Aiming at the comparatively laggard level of power plant electrical system automation, this paper analyzes the feasibility,necessity and some key points of the application of integrated automation technology to power plant electrical system. New idea using fieldbus control system technology is presented. This paper also gives the outline and detailed schemes.
文摘The reliability and maintainability of electrical system of drum shearer at Parvade. 1 Coal Mine in central Iran was analyzed. The maintenance and failure data were collected during 19 months of shearer operation. According to trend and serial correlation tests, the data were independent and identically distributed （iid） and therefore the statistical techniques were used for modeling. The data analysis show that the time between failures （TBF） and time to repair （TTR） data obey the lognormal and Weibull 3 parameters distribution respectively. Reliability-based preventive maintenance time intervals for electrical system of the drum shearer were calculated with regard to reliability plot. The reliability-based maintenance intervals for 90%, 80%, 70% and 50% reliability level are respectively 9.91, 17.96, 27.56 and 56.1 h. Also the calculations show that time to repair （TTR） of this system varies in range 0.17-4 h with 1.002 h as mean time to repair （MTTR）. There is a 80% chance that the electrical system of shearer of Parvade. 1 mine repair will be accomplished within 1.45 h.
基金the National Science and Technology Major Project of China(No.2014ZX04014-011)
文摘The core of computer numerical control(CNC) machine tool is the electrical system which controls and coordinates every part of CNC machine tool to complete processing tasks, so it is of great significance to strengthen the reliability of the electrical system. However, the electrical system is very complex due to many uncertain factors and dynamic stochastic characteristics when failure occurs. Therefore, the traditional fault tree analysis(FTA) method is not applicable. Bayesian network(BN) not only has a unique advantage to analyze nodes with multiply states in reliability analysis for complex systems, but also can solve the state explosion problem properly caused by Markov model when dealing with dynamic fault tree(DFT). In addition, the forward causal reasoning of BN can get the conditional probability distribution of the system under considering the uncertainty;the backward diagnosis reasoning of BN can recognize the weak links in system, so it is valuable for improving the system reliability.
基金Sponsored by Foundation for Science Research Development of Nanjing University of Science and Technology
文摘Electrical system of military vehicle is a typical parameterized nonlinear system where complicated bifurcations may exist and threaten its safe and stable operation. An algebraic criterion for Hopf bifurcation is presented briefly and applied to find Hopf bifurcation point of the electrical system with automatic voltage regulator(AVR) dynamics in military vehicle. Hopf bifurcation controllers are designed for this electrical system by using wash-out filter,linear feedback,nonlinear feedback and their combination. The linear feedback control makes the system bring Hopf bifurcation at preferable parameter,the nonlinear feedback control modifies the type of the bifurcation,and the wash-out filter enhances the system damping,thus,the Hopf bifurcation is eliminated and the electrical system stability is ensured. Simulation results show the controller's validity.
基金supported by the Key Research and Development Program of Shaanxi Province(2018GY-185)
文摘Based on the integrated design and airworthiness verification of civil aircraft system,this paper completes the simulation modeling and fault modeling of aircraft electrical system. The aircraft electrical system is constructed in the form of dual generators and dual-channel power supply. The main power supply adopts the three-stage power generation system,the auxiliary power supply system uses the permanent magnet synchronous power generation system and a battery. The transmission and distribution system is responsible for the electrical power conversion and the logic control in the system fault-pattern. The simulation results show that the system is reasonable and effective,which provides a reference for the optimal design and control of the actual aircraft electrical system.
文摘In recent years, the level of science and technology has been changing with each passing day, especially the development and research in the field of artificial intelligence has become a hot topic of social concern. However, due to the limitation of related technologies, artificial intelligence has not been widely promoted and applied in many industries. In this paper, the application of artificial intelligence technology is deeply analyzed from the perspective of electrical automation control, hoping to provide development ideas for the current electrical automation control in our country.
文摘With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would greatly threaten the safety and proper working of the whole system. This paper focuses on a power quality improvement project to solve these problems. A hybrid compensating scheme, including an active compensator and a passive compensator, is carried out. Because of the specificity of oilfield drilling electrical system, compensators are redesigned against features of this application background. And then the current detection point arrangement of this hybrid system is also taken into consideration to build the whole system much more effective and reliable. Now the improvement project is already implemented in application field, and the power quality of the system is greatly improved.
文摘With the development of social economy and the acceleration of people's work and life rhythm, the rapid development of China's aviation industry has been strongly promoted. Air travel has become a convenient way for ordinary citizens to travel. In this case, people pay more attention to the safety of flight. As an important part of an airplane, the aviation electrical system carries many key missions in the flight and plays a very important role in the safe flight of the airplane. The management of the aviation electrical system is an important part of the aviation safety management. Aviation safety is related to the safety of people's lives and property, as well as the development of the aviation industry. Based on this, starting from the basic concept of aviation safe flight, this paper gives an overview of aviation power system, analyzes the factors affecting the safety of aviation power system, and expounds the importance of aviation electrical system to safe flight, hoping to provide effective reference for relevant personnel, so as to better promote the development of China's aviation industry.
文摘Green energy conservation is the mainstream trend in the current development of the construction industry.The application of energy-saving technology in building electrical system design can effectively reduce energy consumption,avoid unnecessary energy consumption,and truly achieve energy conservation and environmental protection.Based on this,the article elaborates on the principles of energy-saving design in building electrical systems,and actively explores the application of energy-saving technologies from different perspectives such as optimizing power supply and distribution system design,adopting high-efficiency energy-saving lighting equipment,applying renewable energy,promoting smart home technology,and improving the efficiency of building electrical equipment.
文摘The electrical system of WK-35 electric shovel 6SE70 is seriously aging, and the electrical failure of the fryer frequently occurs, resulting in repeated maintenance of the equipment, high labor intensity and high production cost. Chinas automation industry has experienced rapid development for many years, and the inverter has made great progress in product performance and appearance. The self-developed electric shovel electric control system can provide a complete set of solutions for 10m3 ~ 55m3 electric shovel AC telex system and related products, and completed the localization and digital transformation of electric shovels.
文摘With the proposal of intelligent manufacturing concept, electrical automation is more and more widely used in mechanical manufacturing and special equipment. The electrical control system is mainly composed of three modules: input, logic and execution. It can not only display the current, temperature and other data during the operation of electrical equipment, but also realize intelligent control and maintain the safe operation of the whole equipment.We should analyze different types of electrical equipment, formulate maintenance plans according to their circuits, electronic component functions and computer control systems, regularly overhaul the equipment and control systems, and eliminate potential safety hazards in time;Use intelligent detection equipment to quickly detect the electrical control system, check the performance of current and electronic components, and replace damaged electronic components and components in time;Standardize the conventional detection method, check the wires, motors, electrical windings and transformers of electrical equipment, quickly locate the fault location and improve the maintenance efficiency;Actively learn the information detection technology, monitor the temperature, current and voltage of the electrical control system, and timely arrange maintenance personnel for troubleshooting in case of abnormal data, so as to ensure the safe and smooth operation of the electrical control system.
文摘BACKGROUND In pediatric and adolescent athletes,there is a lack of understanding about the impact of factors such as race on the structural or cardiovascular adaptations in response to exercise which may unnecessarily disqualify athletes from the competitive sport.We hypothesized that race has an impact on cardiac adaptions in non-adult athletes.AIM To explore the racial disparity in electrocardiographic(ECG)and echocardiographic(ECHO)parameters in healthy adolescent athletes.METHODS A comprehensive electronic systematic literature search using MEDLINE database was performed from inception to September 20,2024.Inclusion criteria included randomized or observational cohort studies that recruited adolescent competitive athletes in any sport discipline and compared between the Black and White races with an age range of 12-18 years.RESULTS Of 723 records that were identified by the literature search,seven studies(n=5036)were included.The mean age was 13.0-18.0 years old with male predominance.Black athletes had significantly longer PR interval[mean difference(MD)=17.49 millisecond,95% CI:11.70-23.29]and shorter QRS complex duration(MD=-7.35 millisecond,95% CI:-9.17 to-5.53)and corrected QT interval(MD=-4.95 millisecond,95% CI:-7.69 to-2.22)than the White athletes.Black athletes were approximately four times more likely to have first-degree atrioventricular(AV)block,inverted T wave,ST-segment elevation,and left atrium(LA)enlargement than their White counterparts.In terms of ECHO parameters,Black athletes had significantly greater septal wall thickness(MD=0.85 mm,95% CI:0.62-1.07),posterior wall thickness(MD=1.07 mm,95% CI:0.36-1.78),relative wall thickness(MD=0.03,95%CI:0.001-0.06),maximal wall thickness(MD=1.05 mm,95%CI:0.28-1.83),and LA diameter(MD=1.64 mm,95%CI:0.16-3.12).CONCLUSION Race has an impact on the ECG and ECHO parameters that reflect cardiac adaptations in adolescent athletes.Black athletes tend to have an increased prevalence of distinct ECG changes such as first-degree AV block and T-wave inversions compared with their White counterparts.Despite having thicker septal and posterior walls,the overall prevalence of left ventricular hypertrophy did not differ between the races.
基金supported by the Fundamental Research Funds for the Central Universities,Nos.G2021KY05107,G2021KY05101the National Natural Science Foundation of China,Nos.32071316,32211530049+1 种基金the Natural Science Foundation of Shaanxi Province,No.2022-JM482the Education and Teaching Reform Funds for the Central Universities,No.23GZ230102(all to LL and HH).
文摘Although previous studies have demonstrated that transcranial focused ultrasound stimulation protects the ischemic brain,clear criteria for the stimulation time window and intensity are lacking.Electrical impedance tomography enables real-time monitoring of changes in cerebral blood perfusion within the ischemic brain,but investigating the feasibility of using this method to assess post-stroke rehabilitation in vivo remains critical.In this study,ischemic stroke was induced in rats through middle cerebral artery occlusion surgery.Transcranial focused ultrasound stimulation was used to treat the rat model of ischemia,and electrical impedance tomography was used to measure impedance during both the acute stage of ischemia and the rehabilitation stage following the stimulation.Electrical impedance tomography results indicated that cerebral impedance increased after the onset of ischemia and decreased following transcranial focused ultrasound stimulation.Furthermore,the stimulation promoted motor function recovery,reduced cerebral infarction volume in the rat model of ischemic stroke,and induced the expression of brain-derived neurotrophic factor in the ischemic brain.Our results also revealed a significant correlation between the impedance of the ischemic brain post-intervention and improvements in behavioral scores and infarct volume.This study shows that daily administration of transcranial focused ultrasound stimulation for 20 minutes to the ischemic hemisphere 24 hours after cerebral ischemia enhanced motor recovery in a rat model of ischemia.Additionally,our findings indicate that electrical impedance tomography can serve as a valuable tool for quantitatively evaluating rehabilitation after ischemic stroke in vivo.These findings suggest the feasibility of using impedance data collected via electrical impedance tomography to clinically assess the effects of rehabilitatory interventions for patients with ischemic stroke.
基金supported by European Union Funding Programme,PNRR,No. 760058(to DMH)the UEFISCDI Project,No. PN-III-P4-IDPCE-2020-059(to APW)
文摘The major aim of stroke therapy is to stimulate brain repair and improve behavioral recovery after cerebral ischemia.One option is to stimulate endogenous neurogenesis in the subventricular zone and direct the newly formed neurons to the damaged area.However,only a small percentage of these neurons survive,and many do not reach the damaged area,possibly because the corpus callosum impedes the migration of subventricular zone-derived stem cells into the lesioned cortex.A second major obstacle to stem cell therapy is the strong inflammatory reaction induced by cerebral ischemia,whereby the associated phagocytic activity of brain macrophages removes both therapeutic cells and/or cell-based drug carriers.To address these issues,neurogenesis was electrically stimulated in the subventricular zone,followed by isolation of proliferating cells,including newly formed neurons,which were subsequently mixed with a nutritional hydrogel.This mixture was then transferred to the stroke cavity of day 14 post-stroke mice.We found that the performance of the treated animals improved in behavioral tests,including novel object,open field,hole board,grooming,and“time-to-feel”adhesive tape tests.Furthermore,immunostaining revealed that the stem cell marker nestin,the neuroepithelial marker Mash1,and the immature neuronal marker doublecortin-positive cells survived in the transplanted area for 2 weeks,possibly due to reduced phagocytic activity and supportive angiogenesis.These results clearly indicate that the transplantation of committed subventricular zone stem cells combined with a protective nutritional gel directly into the infarct cavity after the peak of stroke-induced neuroinflammation represents a feasible approach to improve neurorestoration after cerebral ischemia.
基金financial support from the Nuclear Energy Science&Technology and Human Resource Development Project of the Japan Atomic Energy Agency/Collaborative Laboratories for Advanced Decommissioning Science(No.R04I034)The author Ruicong Xu appreciates the scholarship(financial support)from the China Scholarship Council(CSC,No.202106380073).
文摘Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generated aerosol particles using a water spray system integrated with an innovative system for pre-injecting electrically charged mist in our facility.To simulate aerosol generation in reactor decommissioning,a high-power laser was used to irradiate various materials(including stainless steel,carbon steel,and concrete),generating aerosol particles that were agglomerated with injected water mist and subsequently scavenged by water spray.Experimental results demonstrate enhanced aerosol removal via aerosol-mist agglomeration,with charged mist significantly improving particle capture by increasing wettability and size.The average improvements for the stainless steel,carbon steel,and concrete were 40%,44%,and 21%,respectively.The results of experiments using charged mist with different polarities(both positive and negative)and different surface coatings reveal that the dominant polarity of aerosols varies with the irradiated materials,influenced by their crystal structure and electron emission properties.Notably,surface coatings such as ZrO_(2)and CeO_(2)were found to possibly alter aerosol charging characteristics,thereby affecting aerosol removal efficiency with charged mist configurations.The innovative aerosol-mist agglomeration approach shows promise in mitigating radiation exposure,ensuring environmental safety,and reducing contaminated water during reactor dismantling.This study contributes critical knowledge for the development of advanced aerosol management strategies for nuclear reactor decommissioning.The understanding obtained in this work is also expected to be useful for various environmental and chemical engineering applications such as gas decontamination,air purification,and pollution control.
基金supported by the National Natural Science Foundation of China(No.52070057)China Postdoctoral Science Foundation(No.2023M730855)Heilongjiang Postdoctoral Fund(No.LBH-Z22183)for financial support。
文摘Sustainable water,energy and food(WEF)supplies are the bedrock upon which human society depends.Solar-driven interfacial evaporation,combined with electricity generation and cultivation,is a promising approach to mitigate the freshwater,energy and food crises.However,the performance of solar-driven systems decreases significantly during operation due to uncontrollable weather.This study proposes an integrated water/electricity cogeneration-cultivation system with superior thermal management.The energy storage evaporator,consisting of energy storage microcapsules/hydrogel composites,is optimally designed for sustainable desalination,achieving an evaporation rate of around 1.91 kg m^(-2)h^(-1).In the dark,heat released from the phase-change layer supported an evaporation rate of around 0.54kg m^(-2)h^(-1).Reverse electrodialysis harnessed the salinity-gradient energy enhanced during desalination,enabling the long-running WEC system to achieve a power output of~0.3 W m^(-2),which was almost three times higher than that of conventional seawater/surface water mixing.Additionally,an integrated crop irrigation platform utilized system drainage for real-time,on-demand wheat cultivation without secondary contaminants,facilitating seamless WEF integration.This work presents a novel approach to all-day solar water production,electricity generation and crop irrigation,offering a solution and blueprint for the sustainable development of WEF.
文摘As a matured technique used in many fields,the distributed computer system is still a new management method for the aeronautical electrical power distribution system in our country. In this paper, a novel aircraft electrical power distribution system based on the distributed computer system is proposed. The principles, features and structure of the aircraft electrical power distribution system and the distributed computer system named electrical load management system (ELMS) are studied. The ELMS composed of four electrical load management centers (ELMCs) and two power source processors (PSPs) operates in the 1553B buses. Principles of the ELMCs and the PSPs are introduced. With the application of the distributed computer system, the aircraft electrical power distribution system is simple, adaptable and flexible.
基金supported by the National Natural Science Foundation of China (No.51907115)the Major Natural Science Project of Shanghai Municipal Education Commission (No.2021-01-07-00-07-E00122)+1 种基金the Shanghai Science and Technology Innovation Action Plan Project (No.22dz1206100)the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning (No.TP2020066)。
文摘Electrical system planning of the large-scale offshore wind farm is usually based on N-1 security for equipment lectotype. However, in this method, owing to the aggregation effect in large-scale offshore wind farms, offshore electrical equipment operates under low load for long periods, thus wasting resources. In this paper, we propose a method for electrical system planning of the large-scale offshore wind farm based on the N+ design. A planning model based on the power-limited operation of wind turbines under the N+ design is constructed, and a solution is derived with the optimization of the upper power limits of wind turbines. A comprehensive evaluation and game analysis of the economy, risk of wind abandonment, and environmental sustainability of the planned offshore electrical systems have been conducted. Moreover, the planning of an infield collector system, substation, and transmission system of an offshore electrical system based on the N+ design is integrated. For a domestic offshore wind farm, evaluation results show that the proposed planning method can improve the efficiency of wind energy utilization while greatly reducing the investment cost of the electrical system.
基金Supported by Collaborative Innovation Center of Intelligent New Energy Vehicle of U.S.and China-Clean Energy Research Center,Fund of China Scholarship Council(Grant No.201406215015)
文摘The current research of vehicle electrical power supply system mainly focuses on electric vehicles（EV） and hybrid electric vehicles（HEV）.The vehicle electrical power supply system used in traditional fuel vehicles is rather simple and imperfect;electrical/electronic devices（EEDs） applied in vehicles are usually directly connected with the vehicle＇s battery.With increasing numbers of EEDs being applied in traditional fuel vehicles,vehicle electrical power supply systems should be optimized and improved so that they can work more safely and more effectively.In this paper,a new vehicle electrical power supply system for traditional fuel vehicles,which accounts for all electrical/electronic devices and complex work conditions,is proposed based on a smart electrical/electronic device（SEED） system.Working as an independent intelligent electrical power supply network,the proposed system is isolated from the electrical control module and communication network,and access to the vehicle system is made through a bus interface.This results in a clean controller power supply with no electromagnetic interference.A new practical battery state of charge（So C） estimation method is also proposed to achieve more accurate So C estimation for lead-acid batteries in traditional fuel vehicles so that the intelligent power system can monitor the status of the battery for an over-current state in each power channel.Optimized protection methods are also used to ensure power supply safety.Experiments and tests on a traditional fuel vehicle are performed,and the results reveal that the battery So C is calculated quickly and sufficiently accurately for battery over-discharge protection.Over-current protection is achieved,and the entire vehicle＇s power utilization is optimized.For traditional fuel vehicles,the proposed vehicle electrical power supply system is comprehensive and has a unified system architecture,enhancing system reliability and security.
文摘To evaluate the thermal performance of a low-temperature electrical radiant floor heating system,an experimental facility equipped with a constant temperature chamber and different specimen floors is designed and built.The heating cable is installed in the floor slab with a unit-rated power of 30 W/m.Twenty-four different schemes are worked out and tested,which include three kinds of composite floor structures and eight kinds of cable distances.The cable distances are 30,40,50,60,80,100,130,150 mm.The main affective factors of the thermal performance and their influencing regularity are discussed.The experimental results show that the system has good stability and reliability,and the ratio of the radiation heat-transfer rate to the gross heat-transfer rate is greater than 50%.When the floor structure and the cable distance are fixed,the gross heat-transfer rate of the upper floor surface has a maximum value at an optimal cable distance.Under the experimental conditions in this paper,the optimal cable distance is 50 mm.
