In recent years, in the process of low-carbon economy construction in China, the original power generation mode has been changed, and photovoltaic power generation technology has been adopted, which has promoted the r...In recent years, in the process of low-carbon economy construction in China, the original power generation mode has been changed, and photovoltaic power generation technology has been adopted, which has promoted the rapid development of related industries. When constructing a new generation mode, there are high requirements for the application of various equipments. Among them, the generator set belongs to special equipment, which needs to be managed in order to realize the scientific utilization of energy and the protection of surrounding environment. At present, China has gradually expanded the construction scale of related industries, and at the same time introduced more advanced technology, and carried out all-round control on the power generation mode. This paper analyzes and discusses the operation control technology of distributed photovoltaic power generation.展开更多
The traditional relay protection debugging technology of generator-transformer group ignores the suppression of voltage distortion of generator-transformer group, which leads to the phase lag problem of generator-tran...The traditional relay protection debugging technology of generator-transformer group ignores the suppression of voltage distortion of generator-transformer group, which leads to the phase lag problem of generator-transformer group in the process of relay protection, and cannot realize the relay protection of generator-transformer group of power plant grid-connected unitsin stable and safe debugging. The protection effect of power relay is reduced with the application of automation and intelligent technology, so we should study new technology. This paper takes the remote operation and maintenance technology of power relay protection as the research object, and analyzes the specific application and development status of this technology in modern society. It is hoped that it can be helpful to the future development of power relay protection and is beneficial to my country's power relay protection with stable development.展开更多
Intelligent substation has the characteristics of high quality, standardization and scale, which can provide strong support for the construction of smart grid. However, there will be many problems in the operation of ...Intelligent substation has the characteristics of high quality, standardization and scale, which can provide strong support for the construction of smart grid. However, there will be many problems in the operation of smart substation. Relay protection device is an extremely important part in the working process of intelligent substation, which can effectively guarantee the normal operation of the whole intelligent substation. This paper analyzes the relay protection devices in the operation of smart substations in China, and puts forward reasonable suggestions on safety and operation and maintenance, which can provide theoretical basis for relevant practitioners, improve the stability and safety of smart substations, and promote the rapid development of smart grid in China.展开更多
Sino magnetics technology is a high-tech enterprise specializing in R&D and production of rare earth permanent magnet materials.It is reported that the enterprise has accelerated the construction of annual3000 ton...Sino magnetics technology is a high-tech enterprise specializing in R&D and production of rare earth permanent magnet materials.It is reported that the enterprise has accelerated the construction of annual3000 tons of high performance sintered NdFeB production base,and the construction of the base has been completed and put into use.展开更多
Development of the medium and low voltage DC distribution system is of great significance to a regional transmission of electric energy,increasing a penetration rate of new energy,and enhancing a safety of the operati...Development of the medium and low voltage DC distribution system is of great significance to a regional transmission of electric energy,increasing a penetration rate of new energy,and enhancing a safety of the operation of the AC/DC interconnected grid.This paper first summarizes the medium and low voltage DC distribution system schemes and plans put forward by many countries,and then elaborate status of under-construction medium and low voltage DC distribution system project cases in China.Based on these project cases,this paper analyzes key issues involved in the medium and low voltage DC distribution system topologies,equipment,operation control technologies and DC fault protections,in order to provide theoretical and technical reference for future medium and low voltage DC distribution system-related projects.Finally,this paper combines a current China research status to summarize and give a prediction about the future research direction of medium and low voltage DC distribution system,which can provide reference for the research of medium and low voltage DC distribution system.展开更多
Following the dramatic increase of iron and steel output ,iron ore is increasingly in short supply ,and the quality of blast furnace （BF） raw materials is increasingly inferior. All these factors have a strong impac...Following the dramatic increase of iron and steel output ,iron ore is increasingly in short supply ,and the quality of blast furnace （BF） raw materials is increasingly inferior. All these factors have a strong impact on the BF operation. According to the analysis of the raw material properties at Baosteel and the combination of the BF smelting mechanism and its operational practice, this study probes into the operational countermeasures for dealing with the change of raw materials and puts forward optimized BF control technology to ensure the operation of BFs is stable and smooth.展开更多
The importance of a nation’s infrastructure is a vital core for economic growth, development, and innovation. Health, wealth, access to education, public safety, and helping prepare for global crises like pandemics a...The importance of a nation’s infrastructure is a vital core for economic growth, development, and innovation. Health, wealth, access to education, public safety, and helping prepare for global crises like pandemics are all dependent on functioning and reliable infrastructures. In decades, the substantial threats affecting infrastructures globally whether in the form of extreme weather, Covid-19 pandemic, or the threats of state and non-state actors’ hackers, demanded urgency in building resilience infrastructures both during crises and in more stable conditions. At the same time, the adoption of emerging and innovative technologies boosts the development of the infrastructures using information, communication, and technology (ICT) platform. This shift accelerated its evolution toward digitization where interdependent and interconnected cyberspace demands collaborative and holistic strategies in protecting critical and high risks infrastructure assets from a growing number of disruptive cyberattacks. These ever-evolving cyber threats are creating increasingly dangerous and targeted cyberattacks to damage or disrupt the critical infrastructures delivering vital services to government, energy, healthcare, transportation, telecommunication, and other critical sectors. The infrastructure’s high risks assets present serious challenges and are crucial to safety, efficiency, and reliability. Any nation must recognize and determine how to cope with any type of threats to their critical infrastructure as well as the strategies to remain resilient. This article first describes the challenges and the need for critical infrastructure protection including the related global risks challenges. It then reviews the United Nations, the European Union, and the United States’ strategies, priorities, and urgencies of critical infrastructure protection. Subsequently, it surveys the critical infrastructure protection resilience strategies including ISO, IEC, ISA, NIST, CAF and CMM frameworks.展开更多
We presented Mathematical apparatus of the choice of optimum parameters of technical, technological systems and materials on the basis of vector optimization. We have considered the formulation and solution of three t...We presented Mathematical apparatus of the choice of optimum parameters of technical, technological systems and materials on the basis of vector optimization. We have considered the formulation and solution of three types of tasks presented below. First, the problem of selecting the optimal parameters of technical systems depending on the functional characteristics of the system. Secondly, the problem of selecting the optimal parameters of the process depending on the technological characteristics of the process. Third, the problem of choosing the optimal structure of the material depending on the functional characteristics of this material. The statement of all problems is made in the form of vector problems of mathematical (nonlinear) programming. The theory and the principle of optimality of the solution of vector tasks it is explained in work of https://rdcu.be/bhZ8i. The implementation of the methodology is shown on a numerical example of the choice of optimum parameters of the technical, technological systems and materials. On the basis of mathematical methods of solution of vector problems we developed the software in the MATLAB system. The numerical example includes: input data (requirement specification) for modeling;transformation of mathematical models with uncertainty to the model under certainty;acceptance of an optimal solution with equivalent criteria (the solution of numerical model);acceptance of an optimal solution with the given priority of criterion.展开更多
A fourth-order Gm-C Chebyshev low-pass filter is presented as channel selection filter for reconfigurable multi-mode wireless receivers. Low-noise technologies are proposed in optimizing the noise characteristics of b...A fourth-order Gm-C Chebyshev low-pass filter is presented as channel selection filter for reconfigurable multi-mode wireless receivers. Low-noise technologies are proposed in optimizing the noise characteristics of both the Gm cells and the filter topology. A frequency tuning strategy is used by tuning both the transconductance of the Gm cells and the capacitance of the capacitor banks. To achieve accurate cut-off frequencies, an on-chip calibration circuit is presented to compensate for the frequency inaccuracy introduced by process variation. The filter is fabricated in a 0.13 m CMOS process. It exhibits a wide programmable bandwidth from 322.5 k Hz to20 MHz. Measured results show that the filter has low input referred noise of 5.9 n V/（Hz）^（1/2） and high out-of-band IIP3 of 16.2 d Bm. It consumes 4.2 and 9.5 m W from a 1 V power supply at its lowest and highest cut-off frequencies respectively.展开更多
文摘In recent years, in the process of low-carbon economy construction in China, the original power generation mode has been changed, and photovoltaic power generation technology has been adopted, which has promoted the rapid development of related industries. When constructing a new generation mode, there are high requirements for the application of various equipments. Among them, the generator set belongs to special equipment, which needs to be managed in order to realize the scientific utilization of energy and the protection of surrounding environment. At present, China has gradually expanded the construction scale of related industries, and at the same time introduced more advanced technology, and carried out all-round control on the power generation mode. This paper analyzes and discusses the operation control technology of distributed photovoltaic power generation.
文摘The traditional relay protection debugging technology of generator-transformer group ignores the suppression of voltage distortion of generator-transformer group, which leads to the phase lag problem of generator-transformer group in the process of relay protection, and cannot realize the relay protection of generator-transformer group of power plant grid-connected unitsin stable and safe debugging. The protection effect of power relay is reduced with the application of automation and intelligent technology, so we should study new technology. This paper takes the remote operation and maintenance technology of power relay protection as the research object, and analyzes the specific application and development status of this technology in modern society. It is hoped that it can be helpful to the future development of power relay protection and is beneficial to my country's power relay protection with stable development.
文摘Intelligent substation has the characteristics of high quality, standardization and scale, which can provide strong support for the construction of smart grid. However, there will be many problems in the operation of smart substation. Relay protection device is an extremely important part in the working process of intelligent substation, which can effectively guarantee the normal operation of the whole intelligent substation. This paper analyzes the relay protection devices in the operation of smart substations in China, and puts forward reasonable suggestions on safety and operation and maintenance, which can provide theoretical basis for relevant practitioners, improve the stability and safety of smart substations, and promote the rapid development of smart grid in China.
文摘Sino magnetics technology is a high-tech enterprise specializing in R&D and production of rare earth permanent magnet materials.It is reported that the enterprise has accelerated the construction of annual3000 tons of high performance sintered NdFeB production base,and the construction of the base has been completed and put into use.
基金supported by the National Key Rese arch and Development Program of China(2018YFB0904100)Science and Technology Project of State Grid(SGHB0000KXJS1800685)
文摘Development of the medium and low voltage DC distribution system is of great significance to a regional transmission of electric energy,increasing a penetration rate of new energy,and enhancing a safety of the operation of the AC/DC interconnected grid.This paper first summarizes the medium and low voltage DC distribution system schemes and plans put forward by many countries,and then elaborate status of under-construction medium and low voltage DC distribution system project cases in China.Based on these project cases,this paper analyzes key issues involved in the medium and low voltage DC distribution system topologies,equipment,operation control technologies and DC fault protections,in order to provide theoretical and technical reference for future medium and low voltage DC distribution system-related projects.Finally,this paper combines a current China research status to summarize and give a prediction about the future research direction of medium and low voltage DC distribution system,which can provide reference for the research of medium and low voltage DC distribution system.
文摘Following the dramatic increase of iron and steel output ,iron ore is increasingly in short supply ,and the quality of blast furnace （BF） raw materials is increasingly inferior. All these factors have a strong impact on the BF operation. According to the analysis of the raw material properties at Baosteel and the combination of the BF smelting mechanism and its operational practice, this study probes into the operational countermeasures for dealing with the change of raw materials and puts forward optimized BF control technology to ensure the operation of BFs is stable and smooth.
文摘The importance of a nation’s infrastructure is a vital core for economic growth, development, and innovation. Health, wealth, access to education, public safety, and helping prepare for global crises like pandemics are all dependent on functioning and reliable infrastructures. In decades, the substantial threats affecting infrastructures globally whether in the form of extreme weather, Covid-19 pandemic, or the threats of state and non-state actors’ hackers, demanded urgency in building resilience infrastructures both during crises and in more stable conditions. At the same time, the adoption of emerging and innovative technologies boosts the development of the infrastructures using information, communication, and technology (ICT) platform. This shift accelerated its evolution toward digitization where interdependent and interconnected cyberspace demands collaborative and holistic strategies in protecting critical and high risks infrastructure assets from a growing number of disruptive cyberattacks. These ever-evolving cyber threats are creating increasingly dangerous and targeted cyberattacks to damage or disrupt the critical infrastructures delivering vital services to government, energy, healthcare, transportation, telecommunication, and other critical sectors. The infrastructure’s high risks assets present serious challenges and are crucial to safety, efficiency, and reliability. Any nation must recognize and determine how to cope with any type of threats to their critical infrastructure as well as the strategies to remain resilient. This article first describes the challenges and the need for critical infrastructure protection including the related global risks challenges. It then reviews the United Nations, the European Union, and the United States’ strategies, priorities, and urgencies of critical infrastructure protection. Subsequently, it surveys the critical infrastructure protection resilience strategies including ISO, IEC, ISA, NIST, CAF and CMM frameworks.
文摘We presented Mathematical apparatus of the choice of optimum parameters of technical, technological systems and materials on the basis of vector optimization. We have considered the formulation and solution of three types of tasks presented below. First, the problem of selecting the optimal parameters of technical systems depending on the functional characteristics of the system. Secondly, the problem of selecting the optimal parameters of the process depending on the technological characteristics of the process. Third, the problem of choosing the optimal structure of the material depending on the functional characteristics of this material. The statement of all problems is made in the form of vector problems of mathematical (nonlinear) programming. The theory and the principle of optimality of the solution of vector tasks it is explained in work of https://rdcu.be/bhZ8i. The implementation of the methodology is shown on a numerical example of the choice of optimum parameters of the technical, technological systems and materials. On the basis of mathematical methods of solution of vector problems we developed the software in the MATLAB system. The numerical example includes: input data (requirement specification) for modeling;transformation of mathematical models with uncertainty to the model under certainty;acceptance of an optimal solution with equivalent criteria (the solution of numerical model);acceptance of an optimal solution with the given priority of criterion.
基金Project supported by the National Natural Science Foundation of China(No.61574045)
文摘A fourth-order Gm-C Chebyshev low-pass filter is presented as channel selection filter for reconfigurable multi-mode wireless receivers. Low-noise technologies are proposed in optimizing the noise characteristics of both the Gm cells and the filter topology. A frequency tuning strategy is used by tuning both the transconductance of the Gm cells and the capacitance of the capacitor banks. To achieve accurate cut-off frequencies, an on-chip calibration circuit is presented to compensate for the frequency inaccuracy introduced by process variation. The filter is fabricated in a 0.13 m CMOS process. It exhibits a wide programmable bandwidth from 322.5 k Hz to20 MHz. Measured results show that the filter has low input referred noise of 5.9 n V/（Hz）^（1/2） and high out-of-band IIP3 of 16.2 d Bm. It consumes 4.2 and 9.5 m W from a 1 V power supply at its lowest and highest cut-off frequencies respectively.
