A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL...A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.展开更多
In recent years,China has made significant progress in the construction of highways,resulting in an improved highway network that has provided robust support for economic and social development.However,the rapid expan...In recent years,China has made significant progress in the construction of highways,resulting in an improved highway network that has provided robust support for economic and social development.However,the rapid expansion of highway construction,power supply,and distribution has led to several challenges in mechanical and electrical engineering technology.Ensuring the safe,stable,and cost-effective operation of the power supply and distribution system to meet the diverse requirements of highway operations has become a pressing issue.This article takes an example of a highway electromechanical engineering power supply and distribution construction project to provide insight into the construction process of highway electromechanical engineering power supply and distribution technology.展开更多
In China, electricity consumption keeps growing at a high speed and installed capacity will be dou- bled in the next fifteen years. As the world second CO2 producer and also a member of Kyoto Protocol, how to balance ...In China, electricity consumption keeps growing at a high speed and installed capacity will be dou- bled in the next fifteen years. As the world second CO2 producer and also a member of Kyoto Protocol, how to balance energy needs and environmental protection responsibility in the future is a serious problem for China. As such, there are a number of technology choices for today's electric power generation. After discussing the current advanced power generation technologies based on Chinese energy structure and current conditions of power industry, this paper gives a reference to the technology options for China in the future.展开更多
In China, electricity consumption keeps growing at a high speed and installed capacity will be doubled in the next fifteen years. As the world second CO2 producer and also a member of Kyoto Protocol, how to balance en...In China, electricity consumption keeps growing at a high speed and installed capacity will be doubled in the next fifteen years. As the world second CO2 producer and also a member of Kyoto Protocol, how to balance energy needs and environmental protection responsibility in the future is a serious problem for China. As such, there are a number of technology choices for today's electric power generation. After discussing the current advanced power generation technologies based on Chinese energy structure and current conditions of power industry, this paper gives a reference to the technology options for China in the future. Here published is the second part of the paper.展开更多
Within the seven years’ period from 1987 to 1994. the total installed capacity of China’s electric power industry doubled from 100 GW to 200 GW. This high rate of growth has imposed new and more stringent requiremen...Within the seven years’ period from 1987 to 1994. the total installed capacity of China’s electric power industry doubled from 100 GW to 200 GW. This high rate of growth has imposed new and more stringent requirements on all the branches in the展开更多
In order to quickly and accurately locate the fault location of the distribution network and increase the stability of the distribution network,a fault recovery method based on multi-objective optimization algorithm i...In order to quickly and accurately locate the fault location of the distribution network and increase the stability of the distribution network,a fault recovery method based on multi-objective optimization algorithm is proposed.The optimization of the power distribution network fault system based on multiagent technology realizes fast recovery of multi-objective fault,solve the problem of network learning and parameter adjustment in the later stage of particle swarm optimization algorithm falling into the local extreme value dilemma,and realize the multi-dimensional nonlinear optimization of the main grid and the auxiliary grid.The system proposed in this study takes power distribution network as the goal,applies fuzzy probability algorithm,simplifies the calculation process,avoids local extreme value,and finally realizes the energy balance between each power grid.Simulation results show that the Multi-Agent Technology enjoys priority in restoring important load,shortening the recovery time of power grid balance,and reducing the overall line loss rate of power grid.Therefore,the power grid fault self-healing system can improve the safety and stability of the important power grid,and reduce the economic loss rate of the whole power grid.展开更多
A new family of converters,high-performance AC/DC power factor correction(PFC) switching converters with one-cycle control technology and active floating-charge technology,was derived and experimentally verified.The t...A new family of converters,high-performance AC/DC power factor correction(PFC) switching converters with one-cycle control technology and active floating-charge technology,was derived and experimentally verified.The topology of a single-phase CCM and DCM Boost-PFC switching converter was also analyzed.Its operating prniciples and control methods were expounded.Based on these,a new type of AC/DC switching converter circuits for PFC combined with one-cycle control technology was presented herein.The proposed AC/DC switching converter significantly helps improve the converter efficiency and its power factor value.展开更多
Triggered spark-gap switch is a popular discharge switch for pulse power systems.Previous studies have focused on planarizing this switch using thin film techniques in order to meet the requirements of compact size in...Triggered spark-gap switch is a popular discharge switch for pulse power systems.Previous studies have focused on planarizing this switch using thin film techniques in order to meet the requirements of compact size in the systems.Such switches are one-shot due to electrodes being too thin to sufficiently resist spark-erosion.Additionally,these switches did not employ any structures in securing internal gas composition,resulting in inconsistent performance under harsh atmospheres.In this work,a novel planar triggered spark-gap switch(PTS)with a hermetically sealed cavity was batched-prepared with printed circuit board(PCB)technology,to achieve reusability with low cost.The proposed PTS was inspected by micro-computed tomography to ensure PCB techniques meet the requirements of machining precision.The results from electrical experiments demonstrated that PCB PTS were consistent and reusable with lifespan over 20 times.The calculated switch voltage and circuit current were consistent with those derived from real-world measurements.Finally,PCB PTS was used to introduce hexanitrostilbene(HNS)pellets in a pulse power system to verify its performance.展开更多
The parameters of power system slowly change with time due to environmental effects or may change rapidly due to faults. It is preferable that the control technique in this system possesses robustness for various faul...The parameters of power system slowly change with time due to environmental effects or may change rapidly due to faults. It is preferable that the control technique in this system possesses robustness for various fault conditions and disturbances. The used flexible alternating current transmission system （FACTS） in this paper is an advanced super-conducting magnetic energy storage （ASMES）. Many control techniques that use ASMES to improve power system stability have been proposed. While fuzzy controller has proven its value in some applications, the researches applying fuzzy controller with ASMES have been actively reported. However, it is sometimes very difficult to specify the rule base for some plants, when the parameters change. To solve this problem, a fuzzy model reference learning controller （FMRLC） is proposed in this paper, which investigates multi-input multi-output FMRLC for time-variant nonlinear system. This control method provides the motivation for adaptive fuzzy control, where the focus is on the automatic online synthesis and tuning of fuzzy controller parameters （i.e., using online data to continually learn the fuzzy controller that will ensure that the performance objectives are met）. Simulation results show that the proposed robust controller is able to work with nonlinear and nonstationary power system （i.e., single machine-infinite bus （SMIB） system）, under various fault conditions and disturbances.展开更多
It is a known fact that the epileptic power situation in Nigeria has become a recurring decimal. In the light of this stark reality of a country like Nigeria which is constantly plunged into pitch darkness all year ro...It is a known fact that the epileptic power situation in Nigeria has become a recurring decimal. In the light of this stark reality of a country like Nigeria which is constantly plunged into pitch darkness all year round, it has become expedient for a sustainable and urgent remedy to be sought if our country will ever think of rubbing shoulders with the economies of the world. It is this pathetic scenario, we find ourselves in that it has given rise to this paper which tends to review possible ways and means of redressing the ugly trend. This paper examines the prospects and possible applications of Smart Grid Technology (SGT) to the Nigeria Power System. Nigeria Power System consists of 28 buses, 32 Transmission lines and 10 generating stations, with a view to reduce the high active and reactive transmission losses. The study shows that smart grid system will make the present network more efficient and reliable by connecting different sources of distributed generators into the existing grid. Basic requirements necessary for the application of SGT using the Nigeria Power System as a case study were discussed.展开更多
This paper introduces the development of technology and its measures for city power network in China, looks forward to the prospect of development in forthcoming decade and the technical principles to be adopted.
In order to effectively imitate the dynamic operation characteristics of the HVDC （high voltage direct current） power transmission system at a real ±500kV HVDC transmission project, the electromechanical-electr...In order to effectively imitate the dynamic operation characteristics of the HVDC （high voltage direct current） power transmission system at a real ±500kV HVDC transmission project, the electromechanical-electromagnetic transient hybrid simulation was carried out based on advanced digital power system simulator （ADPSS）. In the simulation analysis, the built hybrid model＇s dynamic response outputs under three different fault conditions are considered, and by comparing with the selected fault recording waveforms, the validities of the simulation waveforms are estimated qualitatively. It can be ascertained that the hybrid simulation model has the ability to describe the HVDC system＇s dynamic change trends well under some special fault conditions.展开更多
Based on the collection of relevant literature and cases,the research and application status of on-line monitoring technology for electromagnetic environment of power transmission and transformation projects at home a...Based on the collection of relevant literature and cases,the research and application status of on-line monitoring technology for electromagnetic environment of power transmission and transformation projects at home and abroad were introduced.Moreover,the problems existing in the on-line monitoring of electromagnetic environment were expounded,and the development prospect was forecasted.展开更多
The development and construction of Ultra Super Critical(USC) fossil fired power plants and advanced nuclear power plants are the most important and effective issue to improve national electricity structure in China a...The development and construction of Ultra Super Critical(USC) fossil fired power plants and advanced nuclear power plants are the most important and effective issue to improve national electricity structure in China and to fulfill the national emission aim which had been proposed and promised.Further, steel technology is one of the most imperative fundamentals to ensure the development and construction of USC fossil fired power plants and advanced nuclear power plants.This paper briefly introduced the state-of-the -art and achievement of steel technology used for USC fossil fired power plants and advanced nuclear power plants in China so far.Meanwhile,the authors also analyzed and discussed the potential research and development plans of the important steel technology in China in the near future.展开更多
Broadband over Power Line (BPL) is an alternative means of providing high-speed Internet access, Voice over Internet Protocol (VoIP), and other broadband services to homes and businesses by using the existing medium v...Broadband over Power Line (BPL) is an alternative means of providing high-speed Internet access, Voice over Internet Protocol (VoIP), and other broadband services to homes and businesses by using the existing medium voltage (MV) and low voltage (LV) power lines. This paper provides a comprehensive understanding about BPL with its implementation prospects. In this context, the existing power grid infrastructures are discussed elaborately. BPL system functionality with its components and its benefits over other access technologies is also pointed out. Implementation scenarios for various deployment options are illustrated here. The different implementation challenges for BPL system, such as the characteristics of power lines, attenuation problem, noise, potential interference with the other radio frequencies are also presented with their remedies. Comparative analysis between several broadband access technologies shows the feasibility of BPL deployments all over the world.展开更多
With the continuous development and progress of science and technology in China, automation technology has occupied an important position in many fields while its application in power system is increasingly widespread...With the continuous development and progress of science and technology in China, automation technology has occupied an important position in many fields while its application in power system is increasingly widespread. Therefore, the application of electrical automation technology in power system is of great significance for power supply stability and work efficiency. In this paper, the author analyzes the application of electric automation technology in power system and makes contributions to the sustainable and stable development of power enterprises.展开更多
China is a large developing country with rapid growth rate. To the year 2050, its electric power will be increased by six to eight times, reaching 1.5—1.8 TW total installed capacity. The development can not only rel...China is a large developing country with rapid growth rate. To the year 2050, its electric power will be increased by six to eight times, reaching 1.5—1.8 TW total installed capacity. The development can not only rely on the existing technology, it is crucial to accelerate the new technology development. This article discusses the perspective of various new technologies from the available energy resources and the required increase of electric power.展开更多
Network information communication technology in power systems is the key to ensuring the safe and efficient operation of power grids.The network information communication technology itself has advantages in automation...Network information communication technology in power systems is the key to ensuring the safe and efficient operation of power grids.The network information communication technology itself has advantages in automation operation and information transmission,thus is widely applied to the power system.In the case of ensuring that the power system is compatible with the network information communication technology,the control of the power system can be strengthened,and the operational efficiency of the power system can be improved.This paper mainly analyzes the specific application of network information communication technology in power system.展开更多
Hydroelectric power equipment consists of a hydro-turbine and a hydrogenerator whose weldments have the features of complicated construction and large bulk as well as some parts operating under water. With the increas...Hydroelectric power equipment consists of a hydro-turbine and a hydrogenerator whose weldments have the features of complicated construction and large bulk as well as some parts operating under water. With the increase of unit rating of the hydroelectric power equipment, the application field of high strength steel and dissimilar steel has been enlarged. What to be introduced in this paper is the development of the welding technology of large hydroelectric generating equipment in China since the 1970s, and the development orientation of its welding construction and procedure in the future.展开更多
基金supported by the National Natural Science Foundation of China under Grant 62034002 and 62374026.
文摘A frequency servo system-on-chip(FS-SoC)featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium(Cs)atomic clocks.The proposed power stabilization loop(PSL)technique,incorporating an off-chip power detector(PD),ensures that the output power of the FS-SoC remains stable,mitigating the impact of power fluctuations on the atomic clock's stability.Additionally,a one-pulse-per-second(1PPS)is employed to syn-chronize the clock with GPS.Fabricated using 65 nm CMOS technology,the measured phase noise of the FS-SoC stands at-69.5 dBc/Hz@100 Hz offset and-83.9 dBc/Hz@1 kHz offset,accompanied by a power dissipation of 19.7 mW.The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7×10^(-11) with 1-s averaging time.
文摘In recent years,China has made significant progress in the construction of highways,resulting in an improved highway network that has provided robust support for economic and social development.However,the rapid expansion of highway construction,power supply,and distribution has led to several challenges in mechanical and electrical engineering technology.Ensuring the safe,stable,and cost-effective operation of the power supply and distribution system to meet the diverse requirements of highway operations has become a pressing issue.This article takes an example of a highway electromechanical engineering power supply and distribution construction project to provide insight into the construction process of highway electromechanical engineering power supply and distribution technology.
文摘In China, electricity consumption keeps growing at a high speed and installed capacity will be dou- bled in the next fifteen years. As the world second CO2 producer and also a member of Kyoto Protocol, how to balance energy needs and environmental protection responsibility in the future is a serious problem for China. As such, there are a number of technology choices for today's electric power generation. After discussing the current advanced power generation technologies based on Chinese energy structure and current conditions of power industry, this paper gives a reference to the technology options for China in the future.
文摘In China, electricity consumption keeps growing at a high speed and installed capacity will be doubled in the next fifteen years. As the world second CO2 producer and also a member of Kyoto Protocol, how to balance energy needs and environmental protection responsibility in the future is a serious problem for China. As such, there are a number of technology choices for today's electric power generation. After discussing the current advanced power generation technologies based on Chinese energy structure and current conditions of power industry, this paper gives a reference to the technology options for China in the future. Here published is the second part of the paper.
文摘Within the seven years’ period from 1987 to 1994. the total installed capacity of China’s electric power industry doubled from 100 GW to 200 GW. This high rate of growth has imposed new and more stringent requirements on all the branches in the
基金This work is supported by the project of Hebei power technology of state grid from 2018 to 2019:Research and application of real-time situation assessment and visualization(SZKJXM20170445).
文摘In order to quickly and accurately locate the fault location of the distribution network and increase the stability of the distribution network,a fault recovery method based on multi-objective optimization algorithm is proposed.The optimization of the power distribution network fault system based on multiagent technology realizes fast recovery of multi-objective fault,solve the problem of network learning and parameter adjustment in the later stage of particle swarm optimization algorithm falling into the local extreme value dilemma,and realize the multi-dimensional nonlinear optimization of the main grid and the auxiliary grid.The system proposed in this study takes power distribution network as the goal,applies fuzzy probability algorithm,simplifies the calculation process,avoids local extreme value,and finally realizes the energy balance between each power grid.Simulation results show that the Multi-Agent Technology enjoys priority in restoring important load,shortening the recovery time of power grid balance,and reducing the overall line loss rate of power grid.Therefore,the power grid fault self-healing system can improve the safety and stability of the important power grid,and reduce the economic loss rate of the whole power grid.
文摘A new family of converters,high-performance AC/DC power factor correction(PFC) switching converters with one-cycle control technology and active floating-charge technology,was derived and experimentally verified.The topology of a single-phase CCM and DCM Boost-PFC switching converter was also analyzed.Its operating prniciples and control methods were expounded.Based on these,a new type of AC/DC switching converter circuits for PFC combined with one-cycle control technology was presented herein.The proposed AC/DC switching converter significantly helps improve the converter efficiency and its power factor value.
基金We gratefully acknowledge support from the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20151486).
文摘Triggered spark-gap switch is a popular discharge switch for pulse power systems.Previous studies have focused on planarizing this switch using thin film techniques in order to meet the requirements of compact size in the systems.Such switches are one-shot due to electrodes being too thin to sufficiently resist spark-erosion.Additionally,these switches did not employ any structures in securing internal gas composition,resulting in inconsistent performance under harsh atmospheres.In this work,a novel planar triggered spark-gap switch(PTS)with a hermetically sealed cavity was batched-prepared with printed circuit board(PCB)technology,to achieve reusability with low cost.The proposed PTS was inspected by micro-computed tomography to ensure PCB techniques meet the requirements of machining precision.The results from electrical experiments demonstrated that PCB PTS were consistent and reusable with lifespan over 20 times.The calculated switch voltage and circuit current were consistent with those derived from real-world measurements.Finally,PCB PTS was used to introduce hexanitrostilbene(HNS)pellets in a pulse power system to verify its performance.
文摘The parameters of power system slowly change with time due to environmental effects or may change rapidly due to faults. It is preferable that the control technique in this system possesses robustness for various fault conditions and disturbances. The used flexible alternating current transmission system （FACTS） in this paper is an advanced super-conducting magnetic energy storage （ASMES）. Many control techniques that use ASMES to improve power system stability have been proposed. While fuzzy controller has proven its value in some applications, the researches applying fuzzy controller with ASMES have been actively reported. However, it is sometimes very difficult to specify the rule base for some plants, when the parameters change. To solve this problem, a fuzzy model reference learning controller （FMRLC） is proposed in this paper, which investigates multi-input multi-output FMRLC for time-variant nonlinear system. This control method provides the motivation for adaptive fuzzy control, where the focus is on the automatic online synthesis and tuning of fuzzy controller parameters （i.e., using online data to continually learn the fuzzy controller that will ensure that the performance objectives are met）. Simulation results show that the proposed robust controller is able to work with nonlinear and nonstationary power system （i.e., single machine-infinite bus （SMIB） system）, under various fault conditions and disturbances.
文摘It is a known fact that the epileptic power situation in Nigeria has become a recurring decimal. In the light of this stark reality of a country like Nigeria which is constantly plunged into pitch darkness all year round, it has become expedient for a sustainable and urgent remedy to be sought if our country will ever think of rubbing shoulders with the economies of the world. It is this pathetic scenario, we find ourselves in that it has given rise to this paper which tends to review possible ways and means of redressing the ugly trend. This paper examines the prospects and possible applications of Smart Grid Technology (SGT) to the Nigeria Power System. Nigeria Power System consists of 28 buses, 32 Transmission lines and 10 generating stations, with a view to reduce the high active and reactive transmission losses. The study shows that smart grid system will make the present network more efficient and reliable by connecting different sources of distributed generators into the existing grid. Basic requirements necessary for the application of SGT using the Nigeria Power System as a case study were discussed.
文摘This paper introduces the development of technology and its measures for city power network in China, looks forward to the prospect of development in forthcoming decade and the technical principles to be adopted.
基金supported by the General Program of Chinese Postdoctoral Science Foundation under Grant No.2012M511595
文摘In order to effectively imitate the dynamic operation characteristics of the HVDC （high voltage direct current） power transmission system at a real ±500kV HVDC transmission project, the electromechanical-electromagnetic transient hybrid simulation was carried out based on advanced digital power system simulator （ADPSS）. In the simulation analysis, the built hybrid model＇s dynamic response outputs under three different fault conditions are considered, and by comparing with the selected fault recording waveforms, the validities of the simulation waveforms are estimated qualitatively. It can be ascertained that the hybrid simulation model has the ability to describe the HVDC system＇s dynamic change trends well under some special fault conditions.
基金Supported by the Open Project of Jiangsu Key Laboratory of Environmental Engineering(ZX2017005)
文摘Based on the collection of relevant literature and cases,the research and application status of on-line monitoring technology for electromagnetic environment of power transmission and transformation projects at home and abroad were introduced.Moreover,the problems existing in the on-line monitoring of electromagnetic environment were expounded,and the development prospect was forecasted.
文摘The development and construction of Ultra Super Critical(USC) fossil fired power plants and advanced nuclear power plants are the most important and effective issue to improve national electricity structure in China and to fulfill the national emission aim which had been proposed and promised.Further, steel technology is one of the most imperative fundamentals to ensure the development and construction of USC fossil fired power plants and advanced nuclear power plants.This paper briefly introduced the state-of-the -art and achievement of steel technology used for USC fossil fired power plants and advanced nuclear power plants in China so far.Meanwhile,the authors also analyzed and discussed the potential research and development plans of the important steel technology in China in the near future.
文摘Broadband over Power Line (BPL) is an alternative means of providing high-speed Internet access, Voice over Internet Protocol (VoIP), and other broadband services to homes and businesses by using the existing medium voltage (MV) and low voltage (LV) power lines. This paper provides a comprehensive understanding about BPL with its implementation prospects. In this context, the existing power grid infrastructures are discussed elaborately. BPL system functionality with its components and its benefits over other access technologies is also pointed out. Implementation scenarios for various deployment options are illustrated here. The different implementation challenges for BPL system, such as the characteristics of power lines, attenuation problem, noise, potential interference with the other radio frequencies are also presented with their remedies. Comparative analysis between several broadband access technologies shows the feasibility of BPL deployments all over the world.
文摘With the continuous development and progress of science and technology in China, automation technology has occupied an important position in many fields while its application in power system is increasingly widespread. Therefore, the application of electrical automation technology in power system is of great significance for power supply stability and work efficiency. In this paper, the author analyzes the application of electric automation technology in power system and makes contributions to the sustainable and stable development of power enterprises.
文摘China is a large developing country with rapid growth rate. To the year 2050, its electric power will be increased by six to eight times, reaching 1.5—1.8 TW total installed capacity. The development can not only rely on the existing technology, it is crucial to accelerate the new technology development. This article discusses the perspective of various new technologies from the available energy resources and the required increase of electric power.
文摘Network information communication technology in power systems is the key to ensuring the safe and efficient operation of power grids.The network information communication technology itself has advantages in automation operation and information transmission,thus is widely applied to the power system.In the case of ensuring that the power system is compatible with the network information communication technology,the control of the power system can be strengthened,and the operational efficiency of the power system can be improved.This paper mainly analyzes the specific application of network information communication technology in power system.
文摘Hydroelectric power equipment consists of a hydro-turbine and a hydrogenerator whose weldments have the features of complicated construction and large bulk as well as some parts operating under water. With the increase of unit rating of the hydroelectric power equipment, the application field of high strength steel and dissimilar steel has been enlarged. What to be introduced in this paper is the development of the welding technology of large hydroelectric generating equipment in China since the 1970s, and the development orientation of its welding construction and procedure in the future.
