With the increasing urgency of the carbon emission reduction task,the generation expansion planning process needs to add carbon emission risk constraints,in addition to considering the level of power adequacy.However,...With the increasing urgency of the carbon emission reduction task,the generation expansion planning process needs to add carbon emission risk constraints,in addition to considering the level of power adequacy.However,methods for quantifying and assessing carbon emissions and operational risks are lacking.It results in excessive carbon emissions and frequent load-shedding on some days,although meeting annual carbon emission reduction targets.First,in response to the above problems,carbon emission and power balance risk assessment indicators and assessment methods,were proposed to quantify electricity abundance and carbon emission risk level of power planning scenarios,considering power supply regulation and renewable energy fluctuation characteristics.Secondly,building on traditional two-tier models for low-carbon power planning,including investment decisions and operational simulations,considering carbon emissions and power balance risks in lower-tier operational simulations,a two-tier rolling model for thermal power retrofit and generation expansion planning was established.The model includes an investment tier and operation assessment tier and makes year-by-year decisions on the number of thermal power units to be retrofitted and the type and capacity of units to be commissioned.Finally,the rationality and validity of the model were verified through an example analysis,a small-scale power supply system in a certain region is taken as an example.The model can significantly reduce the number of days of carbon emissions risk and ensure that the power balance risk is within the safe limit.展开更多
Fully non-inductive plasma start-up was successfully achieved by using a well- controlled microwave source on the spherical tokamak, QUEST. Non-inductive plasmas were maintained for approximately 3-5 min, during which...Fully non-inductive plasma start-up was successfully achieved by using a well- controlled microwave source on the spherical tokamak, QUEST. Non-inductive plasmas were maintained for approximately 3-5 min, during which time power balance estimates could be achieved by monitoring wall and cooling-water temperatures. Approximately 70%-90% of the injected power could be accounted for by calorimetric measurements and approximately half of the injected power was found to be deposited on the vessel wall, which is slightly dependent on the magnetic configuration. The power distribution to water-cooled limiters, which are expected to be exposed to local heat loads, depends significantly on the magnetic configuration, however some of the deposited power is due to energetic electrons, which have large poloidal orbits and are likely to be deposited on the plasma facing components.展开更多
In this paper a simple code has been developed to analyze power balance and qualitatively evaluate current profiles for discharges with lower hybrid current drive (LHCD) and ion Bernstein wave (IBW) heating in the...In this paper a simple code has been developed to analyze power balance and qualitatively evaluate current profiles for discharges with lower hybrid current drive (LHCD) and ion Bernstein wave (IBW) heating in the HT-7 tokamak. Electron and ion thermal diffusivity, profiles of the bootstrap current density and total plasma current density can be estimated by this code using the experimental data. This code offers an easy and reasonable means to understand plasma transport in HT-7.展开更多
The development of regional integrated electric-thermal energy systems(RIETES) is considered a promising direction for modern energy supply systems. These systems provide a significant potential to enhance the compreh...The development of regional integrated electric-thermal energy systems(RIETES) is considered a promising direction for modern energy supply systems. These systems provide a significant potential to enhance the comprehensive utilization and efficient management of energy resources. Therein, the real-time power balance between supply and demand has emerged as one pressing concern for system stability operation. However, current methods focus more on minute-level and hour-level power optimal scheduling methods applied in RIETES. To achieve real-time power balance, this paper proposes one virtual asynchronous machine(VAM) control using heat with large inertia and electricity with fast response speed. First, the coupling timescale model is developed that considers the dynamic response time scales of both electric and thermal energy systems. Second, a real-time power balance strategy based on VAM control can be adopted to the load power variation and enhance the dynamic frequency response. Then, an adaptive inertia control method based on temperature variation is proposed, and the unified expression is further established. In addition, the small-signal stability of the proposed control strategy is validated. Finally, the effectiveness of this control strategy is confirmed through MATLAB/Simulink and HIL(Hardware-in-the-Loop) experiments.展开更多
A power balance static random-access memory(SRAM) for resistance to differential power analysis(DPA) is proposed. In the proposed design, the switch power consumption and short-circuit power consumption are balanc...A power balance static random-access memory(SRAM) for resistance to differential power analysis(DPA) is proposed. In the proposed design, the switch power consumption and short-circuit power consumption are balanced by discharging and pre-charging the key nodes of the output circuit and adding an additional shortcircuit current path. Thus, the power consumption is constant in every read cycle. As a result, the DPA-resistant ability of the SRAM is improved. In 65 nm CMOS technology, the power balance SRAM is fully custom designed with a layout area of 5863.6 μm^2.The post-simulation results show that the normalized energy deviation(NED) and normalized standard deviation(NSD) are 0.099% and 0.04%, respectively. Compared to existing power balance circuits, the power balance ability of the proposed SRAM has improved 53%.展开更多
The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics.Because wind energy varies across all timescales of utility activity,...The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics.Because wind energy varies across all timescales of utility activity,renewable energy generation should be supplemented and enhanced,from real-time,minute-to-minute variations to annual alterations influencing long-termstrategy.Wind energy generation does not only fluctuate but is also challenging to accurately forecast the timeframes of significance to electricity decision makers;day-ahead and long-term making plans of framework sufficiency such as meeting the network peak load annually.A utility that integrates wind and solar energy into its electricity mix would understand how to adapt to uncertainty and variability in operations while sustaining grid stability.Due to hydropower’s adaptability,a system using hydropower as one of its generating resources could be precisely adapted to absorb the variability of wind and solar energy.The objective of this research study is to create a hybrid system comprising hydro-wind and solar(Hybrid-HWS)integration for power balancing in an isolated electrical network in Klipkop village,Pretoria region,South Africa.The desirability of designing and building goaf storage tank in regard to capability,the fullness of line throughoutwater pumping,dispensing,storage tank spillage,and pressure difference throughout liquid flow within the storage tanks were preliminary assessed using geotechnical and weather forecasting data from a distinctive area of Klipkop town in Pretoria,South Africa.Different facility hours premised on daylight accessibility are scheduled to balance maximum load at early and late hours.However,in the scenario of electrical power,time shift requiring storage for extended periods of time,such as in terms of hours,Hybrid-HWS has been found to have a crucial role.The results of simulations showed a coordinated process design for Hybrid-HWS Energy Storage(ES)to determine everyday strategic planning in reducing the variability of the system resulting from wind-solar-pumped hydro ES output inadequacies and satisfy daily load demands.It could be recommended that by considering the adaptability characteristics,extremely rapidly,ramping,peaking support and maximum stabilizing aid of the system could be archived with pump-hydro into the energy mix which can provide specific guidelines for energy policymakers.展开更多
Mr. Luo Haocai taught at Peking University Law School for a long time. Even though he held such important positions as vice president of Peking University (PKU),chairman of the Central Committee of China Zhi Gong Part...Mr. Luo Haocai taught at Peking University Law School for a long time. Even though he held such important positions as vice president of Peking University (PKU),chairman of the Central Committee of China Zhi Gong Party, vice president of the Supreme People’s Court, and vice chairman of the Ninth and Tenth National Committee of the CPPCC, he preferred being called "Teacher Luo." My frequent interactions with Teacher Luo started in 2007 and continued to 2016 when he was the president of the CSHRS.展开更多
The research reported in this paper focuses on non-technical power loss reduction for power distribution systems. Such reduction of costs of energy not served (ENS.COST), is intelligently evaluated and optimized using...The research reported in this paper focuses on non-technical power loss reduction for power distribution systems. Such reduction of costs of energy not served (ENS.COST), is intelligently evaluated and optimized using a firefly algorithm, from where savings of 43.3% on energy not served are achieved.展开更多
The SG-Ⅲlaser facility(SG-Ⅲ)is the largest laser driver for inertial confinement fusion(ICF)researches in China,which has 48 beamlines and can deliver 180 kJ ultraviolet laser energy in 3 ns.In order to meet the req...The SG-Ⅲlaser facility(SG-Ⅲ)is the largest laser driver for inertial confinement fusion(ICF)researches in China,which has 48 beamlines and can deliver 180 kJ ultraviolet laser energy in 3 ns.In order to meet the requirements of precise physics experiments,some new functionalities need to be added to SG-Ⅲand some intrinsic laser performances need upgrade.So at the end of SG-Ⅲ's engineering construction,the 2-year laser performance upgrade project started.This paper will introduce the newly added functionalities and the latest laser performance of SG-Ⅲ.With these function extensions and performance upgrade,SG-Ⅲis now fully prepared for precise ICF experiments and solidly paves the way towards fusion ignition.展开更多
An X-ray radiation source with approximately constant radiation temperature is realized by irradiating golden hohlraum with a shaped laser pulse. A simple theoretical model based on power balance is used to design the...An X-ray radiation source with approximately constant radiation temperature is realized by irradiating golden hohlraum with a shaped laser pulse. A simple theoretical model based on power balance is used to design the shape of the drive laser pulse. Experiments are carried out on the Shenguang III prototype laser facility, and the experimentM results are presented for radiation sources with the flat-top lasting about 2.5 ns at two different peak temperatures of about 150 eV and 170 eV, respectively, including the the drive laser pulses and the time integrated possible improvements are discussed. time histories of the temperatures, the shapes of radiation spectra. The validity of the model and展开更多
An experiment was performed on the Shenguang III prototype laser facility to continue the study on hohlraum radiation source with approximately constant radiation temperature using a continuously shaped laser pulse.A ...An experiment was performed on the Shenguang III prototype laser facility to continue the study on hohlraum radiation source with approximately constant radiation temperature using a continuously shaped laser pulse.A radiation source with a flattop temperature of about130 e V that lasted about 5 ns was obtained.The previous analytical iteration method based on power balance and self-similar solution of ablation was modified taking into account the plasma movements and it was used to design the laser pulse shape for experiment.A comparison between experimental results and simulation is presented and better agreement was achieved using the modified method.Further improvements are discussed.展开更多
The book Theory of International Politics without a doubt is a pillar in the field of international relations.Kenneth Waltz is considered as the founder of Neorealist theory or what is known“Structural Realism”.His ...The book Theory of International Politics without a doubt is a pillar in the field of international relations.Kenneth Waltz is considered as the founder of Neorealist theory or what is known“Structural Realism”.His book was published at a time when Neo-liberalism was dominant.Indeed,he opened a huge debate in IR and challenged the consensus that prevailed at the time.The concepts of anarchy and power are at the center of Waltz’s theory of international politics where he tried to explain how the structure of the international system is,and how this system affects the behavior of states,which they are considered as the main players in the international system.Thus,the current study’s aim is to analyze and identify the main arguments and concepts of the book and the critics directed to it.To do so,in the first section,the intellectual background of the author and introduction to the book has been mentioned.Second,the arrangement of the chapters of the book is illustrated.Following are the main arguments and concepts of the book.Then critics directed to the book are presented,and finally,the conclusion is discussed.展开更多
The security dilemma is a common problem faced with the states in the ongoing anarchic international system.It does matter in the Middle East like the other ones and also has its impact on the arms races in the region...The security dilemma is a common problem faced with the states in the ongoing anarchic international system.It does matter in the Middle East like the other ones and also has its impact on the arms races in the region too.Meanwhile there are some characters named as the order and change predicaments such as the colonial background,weak infrastructure of state construction,and the identity politics embedded in the region that do convert the current complex security dilemma into a complicated one.Not only does it have effect on the regional order,the arm race and disarmament,and also offense/defense paradox,but also does it get on the violent bandwagon in the region.Synergies of the both dilemmas did lead the region into the domestic environment change alongside of regional disorder too.Non-neutral involving the trans-regional powers into the(in)security situation in the region not only did not mitigate the situation but also volatile it too.In conclusion the paper does strive to introduce three phrased manners for transition of the complicated security dilemma.展开更多
The concept of constant voltage operation is proposed in this paper and it is demonstrated that the ultimate goal of power grid development is constant voltage operation.The topic is expanded into three aspects:the be...The concept of constant voltage operation is proposed in this paper and it is demonstrated that the ultimate goal of power grid development is constant voltage operation.The topic is expanded into three aspects:the benefits of constant voltage operation,the technology and equipment to realize constant voltage operation,and the reactive power compensation capacity needed for constant voltage operation.The benefits of constant voltage operation have four aspects:1)Constant voltage operation is the ultimate presentation of the strong smart grid;2)Constant voltage operation can resist grid disturbances in the most powerful manner and greatly improve the power system stability;3)Constant voltage operation can effectively eliminate the voltage fluctuation problem involved with the integration of large scale renewable energy;4)Constant voltage operation can minimize the grid power loss.The means to realize constant voltage operation is primarily the modular multilevel converter based STATCOM(MMC-STATCOM),which has encountered great acceptance during recent years.Simualtion verifications are run in a modified IEEE 300-bus system and the Pearl River Delta grid in PSS/E.The results indicate that constant voltage operation can greatly improve the stability of power systems and the capacity of installed MMC-STATCOMs is within an acceptable range.展开更多
In order to overcome the problems of power flow control and fault current limiting in multi-terminal high voltage direct current(MTDC)grids,this paper proposes a modular multi-terminal DC power flow controller(MM-DCPF...In order to overcome the problems of power flow control and fault current limiting in multi-terminal high voltage direct current(MTDC)grids,this paper proposes a modular multi-terminal DC power flow controller(MM-DCPFC)with fault current limiting function.The topology structure,operation principle,and equivalent circuit of MM-DCPFC are introduced,and such a structure has the advantages of modularity and scalability.The power balance mechanism is studied and a hierarchical power balance control strategy is proposed.The results show that MM-DCPFC can achieve internal power exchange,which avoids the use of external power supply.The fault characteristics of MM-DCPFC are analyzed,fault current limiting and self-protection methods are proposed,and the factors affecting the current limiting capability are studied.The simulation models are established in PLECS,and the simulation results verify the effectiveness of MM-DCPFC in power flow control,fault current limiting,and scalability.In addition,a prototype is developed to validate the function and control method of MM-DCPFC.展开更多
Highly wind power integrated power system requires continuous active power regulation to tackle the power imbalances resulting from the wind power forecast errors. The active power balance is maintained in real-time w...Highly wind power integrated power system requires continuous active power regulation to tackle the power imbalances resulting from the wind power forecast errors. The active power balance is maintained in real-time with the automatic generation control and also from the control room, where regulating power bids are activated manually. In this article, an algorithm is developed to simulate the activation of regulating power bids, as performed in the control room, during power imbalance between generation and load demand. In addition, the active power balance is also controlled through automatic generation control, where coordinated control strategy between combined heat and power plants and wind power plant enhances the secure power system operation. The developed algorithm emulating the control room response,to deal with real-time power imbalance, is applied and investigated on the future Danish power system model. The power system model takes the hour-ahead regulating power plan from power balancing model and the generation and power exchange capacities for the year 2020 into account.The real-time impact of power balancing in a highly wind power integrated power system is assessed and discussed by means of simulations for different possible scenarios.展开更多
The North Atlantic Treaty Organization(NATO)and the Shanghai Cooperation Organization(SCO)both have geopolitical interests in Central Asia and the Gulf.The former is a military alliance,whose members have built substa...The North Atlantic Treaty Organization(NATO)and the Shanghai Cooperation Organization(SCO)both have geopolitical interests in Central Asia and the Gulf.The former is a military alliance,whose members have built substantial presence in the Greater Middle East,including the US military presence in Afghanistan,Djibouti,Iraq,Kuwait,Qatar,Saudi Arabia,the UAE,Bahrain and Oman;the British military presence in Afghanistan and Bahrain;the French military presence in Afghanistan,Djibouti and the UAE.In comparison,SCO is a political bloc,whose members are at a low level of military integration.Like Russia’s military presence in Kyrgyzstan and Tajikistan,China has logistics base in Djibouti;India has military presence in Tajikistan.The three SCO members enjoy better geographical proximality,while the three NATO members are stronger in military deployments and power projection capabilities.The SCO major powers have consolidated their respective land power in Central Asia,while NATO members have obtained both land power in Afghanistan and marine power in the Gulf.While the SCO’s and NATO’s respective military positions have been strengthened,Central Asia and the Gulf are faced with serious economic,political and social problems and interstate conflict.In the light of this,the military presence of outside NATO and SCO powers may rest on a weak foundation and may face various hurdles in the future.展开更多
In this paper,a Backstepping Global Integral Terminal Sliding Mode Controller(BGITSMC)with the view to enhancing the dynamic stability of a hybrid AC/DC microgrid has been presented.The proposed approach controls the ...In this paper,a Backstepping Global Integral Terminal Sliding Mode Controller(BGITSMC)with the view to enhancing the dynamic stability of a hybrid AC/DC microgrid has been presented.The proposed approach controls the switch-ing signals of the inverter,interlinking the DC-bus with the AC-bus in an AC/DC microgrid for a seamless interface and regulation of the output power of renewable energy sources(Solar Photovoltaic unit,PMSG-based wind farm),and Battery Energy Storage System.The proposed control approach guarantees the dynamic stability of a hybrid AC/DC microgrid by regulating the associated states of the microgrid system to their intended values.The dynamic stabil-ity of the microgrid system with the proposed control law has been proved using the Control Lyapunov Function.A simulation analysis was performed on a test hybrid AC/DC microgrid system to demonstrate the performance of the proposed control strategy in terms of maintaining power balance while the system’s operating point changed.Furthermore,the superiority of the proposed approach has been demonstrated by comparing its performance with the existing Sliding Mode Control(SMC)approach for a hybrid AC/DC microgrid.展开更多
The international order of territory-based sovereign nation-states(Westphalia)has been in transition towards a so-called‘post-Westphalian order’,but pre-Westphalian structures still prevail.This has been most releva...The international order of territory-based sovereign nation-states(Westphalia)has been in transition towards a so-called‘post-Westphalian order’,but pre-Westphalian structures still prevail.This has been most relevant in the Middle East and North Africa,especially in the Persian Gulf.This coincides with the increasingly delicate(im)balance of power and the changing role of the state in the Persian Gulf,expressed in such narratives as the decline of the state,the United States‘withdrawal’from the region as well as the Iranian-Saudi‘Cold War.’The paper aims at analysing war and peace in this context of the transition of the international order and the regional(im)balance of power,and highlights that war or peace in the Persian Gulf will be the outcome of the competitive multi-polarity of traditional and modern,pre-Westphalian,Westphalian and post-Westphalian actors and factors,where the modalities and methodology of all will play a role.展开更多
基金supported by Science and Technology Project of State Grid Anhui Electric Power Co.,Ltd. (No.B6120922000A).
文摘With the increasing urgency of the carbon emission reduction task,the generation expansion planning process needs to add carbon emission risk constraints,in addition to considering the level of power adequacy.However,methods for quantifying and assessing carbon emissions and operational risks are lacking.It results in excessive carbon emissions and frequent load-shedding on some days,although meeting annual carbon emission reduction targets.First,in response to the above problems,carbon emission and power balance risk assessment indicators and assessment methods,were proposed to quantify electricity abundance and carbon emission risk level of power planning scenarios,considering power supply regulation and renewable energy fluctuation characteristics.Secondly,building on traditional two-tier models for low-carbon power planning,including investment decisions and operational simulations,considering carbon emissions and power balance risks in lower-tier operational simulations,a two-tier rolling model for thermal power retrofit and generation expansion planning was established.The model includes an investment tier and operation assessment tier and makes year-by-year decisions on the number of thermal power units to be retrofitted and the type and capacity of units to be commissioned.Finally,the rationality and validity of the model were verified through an example analysis,a small-scale power supply system in a certain region is taken as an example.The model can significantly reduce the number of days of carbon emissions risk and ensure that the power balance risk is within the safe limit.
基金supported by Grant-in-Aid for JSPS Fellows(KAKENHI Grant Number 16H02441,24656559)performed with the support and under the auspices of the NIFS Collaboration Research Program(NIFS05KUTRO14,NIFS11KUTR061,NIFS13KUTR085,NIFS14KUTR103)+1 种基金supported in part by the Collaborative Research Program of the Research Institute for Applied Mechanics,Kyushu Universitypartly supported by the JSPS-NRF-NSFC A3 Foresight Program in the Field of Plasma Physics(No.11261140328)
文摘Fully non-inductive plasma start-up was successfully achieved by using a well- controlled microwave source on the spherical tokamak, QUEST. Non-inductive plasmas were maintained for approximately 3-5 min, during which time power balance estimates could be achieved by monitoring wall and cooling-water temperatures. Approximately 70%-90% of the injected power could be accounted for by calorimetric measurements and approximately half of the injected power was found to be deposited on the vessel wall, which is slightly dependent on the magnetic configuration. The power distribution to water-cooled limiters, which are expected to be exposed to local heat loads, depends significantly on the magnetic configuration, however some of the deposited power is due to energetic electrons, which have large poloidal orbits and are likely to be deposited on the plasma facing components.
基金National Natural Science Foundation of China(No.10505008)
文摘In this paper a simple code has been developed to analyze power balance and qualitatively evaluate current profiles for discharges with lower hybrid current drive (LHCD) and ion Bernstein wave (IBW) heating in the HT-7 tokamak. Electron and ion thermal diffusivity, profiles of the bootstrap current density and total plasma current density can be estimated by this code using the experimental data. This code offers an easy and reasonable means to understand plasma transport in HT-7.
基金supported by the National Key R&D Program of China (Grant No. 2022YFB3304001)the Major Program of the National Natural Science Foundation of China (Grant No. 52293413)。
文摘The development of regional integrated electric-thermal energy systems(RIETES) is considered a promising direction for modern energy supply systems. These systems provide a significant potential to enhance the comprehensive utilization and efficient management of energy resources. Therein, the real-time power balance between supply and demand has emerged as one pressing concern for system stability operation. However, current methods focus more on minute-level and hour-level power optimal scheduling methods applied in RIETES. To achieve real-time power balance, this paper proposes one virtual asynchronous machine(VAM) control using heat with large inertia and electricity with fast response speed. First, the coupling timescale model is developed that considers the dynamic response time scales of both electric and thermal energy systems. Second, a real-time power balance strategy based on VAM control can be adopted to the load power variation and enhance the dynamic frequency response. Then, an adaptive inertia control method based on temperature variation is proposed, and the unified expression is further established. In addition, the small-signal stability of the proposed control strategy is validated. Finally, the effectiveness of this control strategy is confirmed through MATLAB/Simulink and HIL(Hardware-in-the-Loop) experiments.
基金Project supported by the Zhejiang Provincial Natural Science Foundation of China(No.LQ14F040001)the National Natural Science Foundation of China(Nos.61274132,61234002)the K.C.Wong Magna Fund in Ningbo University,China
文摘A power balance static random-access memory(SRAM) for resistance to differential power analysis(DPA) is proposed. In the proposed design, the switch power consumption and short-circuit power consumption are balanced by discharging and pre-charging the key nodes of the output circuit and adding an additional shortcircuit current path. Thus, the power consumption is constant in every read cycle. As a result, the DPA-resistant ability of the SRAM is improved. In 65 nm CMOS technology, the power balance SRAM is fully custom designed with a layout area of 5863.6 μm^2.The post-simulation results show that the normalized energy deviation(NED) and normalized standard deviation(NSD) are 0.099% and 0.04%, respectively. Compared to existing power balance circuits, the power balance ability of the proposed SRAM has improved 53%.
基金This study was supported by the DUT Scholarship Scheme Masters:2022(RFA Smart Grid)Funding.
文摘The integration of solar and wind energy into the electrical grid has received global research attention due to their unpredictable characteristics.Because wind energy varies across all timescales of utility activity,renewable energy generation should be supplemented and enhanced,from real-time,minute-to-minute variations to annual alterations influencing long-termstrategy.Wind energy generation does not only fluctuate but is also challenging to accurately forecast the timeframes of significance to electricity decision makers;day-ahead and long-term making plans of framework sufficiency such as meeting the network peak load annually.A utility that integrates wind and solar energy into its electricity mix would understand how to adapt to uncertainty and variability in operations while sustaining grid stability.Due to hydropower’s adaptability,a system using hydropower as one of its generating resources could be precisely adapted to absorb the variability of wind and solar energy.The objective of this research study is to create a hybrid system comprising hydro-wind and solar(Hybrid-HWS)integration for power balancing in an isolated electrical network in Klipkop village,Pretoria region,South Africa.The desirability of designing and building goaf storage tank in regard to capability,the fullness of line throughoutwater pumping,dispensing,storage tank spillage,and pressure difference throughout liquid flow within the storage tanks were preliminary assessed using geotechnical and weather forecasting data from a distinctive area of Klipkop town in Pretoria,South Africa.Different facility hours premised on daylight accessibility are scheduled to balance maximum load at early and late hours.However,in the scenario of electrical power,time shift requiring storage for extended periods of time,such as in terms of hours,Hybrid-HWS has been found to have a crucial role.The results of simulations showed a coordinated process design for Hybrid-HWS Energy Storage(ES)to determine everyday strategic planning in reducing the variability of the system resulting from wind-solar-pumped hydro ES output inadequacies and satisfy daily load demands.It could be recommended that by considering the adaptability characteristics,extremely rapidly,ramping,peaking support and maximum stabilizing aid of the system could be archived with pump-hydro into the energy mix which can provide specific guidelines for energy policymakers.
文摘Mr. Luo Haocai taught at Peking University Law School for a long time. Even though he held such important positions as vice president of Peking University (PKU),chairman of the Central Committee of China Zhi Gong Party, vice president of the Supreme People’s Court, and vice chairman of the Ninth and Tenth National Committee of the CPPCC, he preferred being called "Teacher Luo." My frequent interactions with Teacher Luo started in 2007 and continued to 2016 when he was the president of the CSHRS.
文摘The research reported in this paper focuses on non-technical power loss reduction for power distribution systems. Such reduction of costs of energy not served (ENS.COST), is intelligently evaluated and optimized using a firefly algorithm, from where savings of 43.3% on energy not served are achieved.
基金This work is supported by the SG-Ⅲ performance upgrade project.
文摘The SG-Ⅲlaser facility(SG-Ⅲ)is the largest laser driver for inertial confinement fusion(ICF)researches in China,which has 48 beamlines and can deliver 180 kJ ultraviolet laser energy in 3 ns.In order to meet the requirements of precise physics experiments,some new functionalities need to be added to SG-Ⅲand some intrinsic laser performances need upgrade.So at the end of SG-Ⅲ's engineering construction,the 2-year laser performance upgrade project started.This paper will introduce the newly added functionalities and the latest laser performance of SG-Ⅲ.With these function extensions and performance upgrade,SG-Ⅲis now fully prepared for precise ICF experiments and solidly paves the way towards fusion ignition.
文摘An X-ray radiation source with approximately constant radiation temperature is realized by irradiating golden hohlraum with a shaped laser pulse. A simple theoretical model based on power balance is used to design the shape of the drive laser pulse. Experiments are carried out on the Shenguang III prototype laser facility, and the experimentM results are presented for radiation sources with the flat-top lasting about 2.5 ns at two different peak temperatures of about 150 eV and 170 eV, respectively, including the the drive laser pulses and the time integrated possible improvements are discussed. time histories of the temperatures, the shapes of radiation spectra. The validity of the model and
文摘An experiment was performed on the Shenguang III prototype laser facility to continue the study on hohlraum radiation source with approximately constant radiation temperature using a continuously shaped laser pulse.A radiation source with a flattop temperature of about130 e V that lasted about 5 ns was obtained.The previous analytical iteration method based on power balance and self-similar solution of ablation was modified taking into account the plasma movements and it was used to design the laser pulse shape for experiment.A comparison between experimental results and simulation is presented and better agreement was achieved using the modified method.Further improvements are discussed.
文摘The book Theory of International Politics without a doubt is a pillar in the field of international relations.Kenneth Waltz is considered as the founder of Neorealist theory or what is known“Structural Realism”.His book was published at a time when Neo-liberalism was dominant.Indeed,he opened a huge debate in IR and challenged the consensus that prevailed at the time.The concepts of anarchy and power are at the center of Waltz’s theory of international politics where he tried to explain how the structure of the international system is,and how this system affects the behavior of states,which they are considered as the main players in the international system.Thus,the current study’s aim is to analyze and identify the main arguments and concepts of the book and the critics directed to it.To do so,in the first section,the intellectual background of the author and introduction to the book has been mentioned.Second,the arrangement of the chapters of the book is illustrated.Following are the main arguments and concepts of the book.Then critics directed to the book are presented,and finally,the conclusion is discussed.
文摘The security dilemma is a common problem faced with the states in the ongoing anarchic international system.It does matter in the Middle East like the other ones and also has its impact on the arms races in the region too.Meanwhile there are some characters named as the order and change predicaments such as the colonial background,weak infrastructure of state construction,and the identity politics embedded in the region that do convert the current complex security dilemma into a complicated one.Not only does it have effect on the regional order,the arm race and disarmament,and also offense/defense paradox,but also does it get on the violent bandwagon in the region.Synergies of the both dilemmas did lead the region into the domestic environment change alongside of regional disorder too.Non-neutral involving the trans-regional powers into the(in)security situation in the region not only did not mitigate the situation but also volatile it too.In conclusion the paper does strive to introduce three phrased manners for transition of the complicated security dilemma.
文摘The concept of constant voltage operation is proposed in this paper and it is demonstrated that the ultimate goal of power grid development is constant voltage operation.The topic is expanded into three aspects:the benefits of constant voltage operation,the technology and equipment to realize constant voltage operation,and the reactive power compensation capacity needed for constant voltage operation.The benefits of constant voltage operation have four aspects:1)Constant voltage operation is the ultimate presentation of the strong smart grid;2)Constant voltage operation can resist grid disturbances in the most powerful manner and greatly improve the power system stability;3)Constant voltage operation can effectively eliminate the voltage fluctuation problem involved with the integration of large scale renewable energy;4)Constant voltage operation can minimize the grid power loss.The means to realize constant voltage operation is primarily the modular multilevel converter based STATCOM(MMC-STATCOM),which has encountered great acceptance during recent years.Simualtion verifications are run in a modified IEEE 300-bus system and the Pearl River Delta grid in PSS/E.The results indicate that constant voltage operation can greatly improve the stability of power systems and the capacity of installed MMC-STATCOMs is within an acceptable range.
基金supported in part by National Key R&D Program of China(No.2018YFB0904600)National Natural Science Foundation of China(No.51807053)。
文摘In order to overcome the problems of power flow control and fault current limiting in multi-terminal high voltage direct current(MTDC)grids,this paper proposes a modular multi-terminal DC power flow controller(MM-DCPFC)with fault current limiting function.The topology structure,operation principle,and equivalent circuit of MM-DCPFC are introduced,and such a structure has the advantages of modularity and scalability.The power balance mechanism is studied and a hierarchical power balance control strategy is proposed.The results show that MM-DCPFC can achieve internal power exchange,which avoids the use of external power supply.The fault characteristics of MM-DCPFC are analyzed,fault current limiting and self-protection methods are proposed,and the factors affecting the current limiting capability are studied.The simulation models are established in PLECS,and the simulation results verify the effectiveness of MM-DCPFC in power flow control,fault current limiting,and scalability.In addition,a prototype is developed to validate the function and control method of MM-DCPFC.
基金a part of Ph.D.project funded by Sino-Danish centre for education and research(SDC)
文摘Highly wind power integrated power system requires continuous active power regulation to tackle the power imbalances resulting from the wind power forecast errors. The active power balance is maintained in real-time with the automatic generation control and also from the control room, where regulating power bids are activated manually. In this article, an algorithm is developed to simulate the activation of regulating power bids, as performed in the control room, during power imbalance between generation and load demand. In addition, the active power balance is also controlled through automatic generation control, where coordinated control strategy between combined heat and power plants and wind power plant enhances the secure power system operation. The developed algorithm emulating the control room response,to deal with real-time power imbalance, is applied and investigated on the future Danish power system model. The power system model takes the hour-ahead regulating power plan from power balancing model and the generation and power exchange capacities for the year 2020 into account.The real-time impact of power balancing in a highly wind power integrated power system is assessed and discussed by means of simulations for different possible scenarios.
基金The authors are indebted to China’s Ministry of Education program“Theoretical and Empirical Studies of China’s Participation in the Middle East Security Affairs”(16JJDGJW011)to the“Shu Guang”Project of Shanghai Municipal Education Commission and Shanghai Education Development Foundation(15SG29).
文摘The North Atlantic Treaty Organization(NATO)and the Shanghai Cooperation Organization(SCO)both have geopolitical interests in Central Asia and the Gulf.The former is a military alliance,whose members have built substantial presence in the Greater Middle East,including the US military presence in Afghanistan,Djibouti,Iraq,Kuwait,Qatar,Saudi Arabia,the UAE,Bahrain and Oman;the British military presence in Afghanistan and Bahrain;the French military presence in Afghanistan,Djibouti and the UAE.In comparison,SCO is a political bloc,whose members are at a low level of military integration.Like Russia’s military presence in Kyrgyzstan and Tajikistan,China has logistics base in Djibouti;India has military presence in Tajikistan.The three SCO members enjoy better geographical proximality,while the three NATO members are stronger in military deployments and power projection capabilities.The SCO major powers have consolidated their respective land power in Central Asia,while NATO members have obtained both land power in Afghanistan and marine power in the Gulf.While the SCO’s and NATO’s respective military positions have been strengthened,Central Asia and the Gulf are faced with serious economic,political and social problems and interstate conflict.In the light of this,the military presence of outside NATO and SCO powers may rest on a weak foundation and may face various hurdles in the future.
文摘In this paper,a Backstepping Global Integral Terminal Sliding Mode Controller(BGITSMC)with the view to enhancing the dynamic stability of a hybrid AC/DC microgrid has been presented.The proposed approach controls the switch-ing signals of the inverter,interlinking the DC-bus with the AC-bus in an AC/DC microgrid for a seamless interface and regulation of the output power of renewable energy sources(Solar Photovoltaic unit,PMSG-based wind farm),and Battery Energy Storage System.The proposed control approach guarantees the dynamic stability of a hybrid AC/DC microgrid by regulating the associated states of the microgrid system to their intended values.The dynamic stabil-ity of the microgrid system with the proposed control law has been proved using the Control Lyapunov Function.A simulation analysis was performed on a test hybrid AC/DC microgrid system to demonstrate the performance of the proposed control strategy in terms of maintaining power balance while the system’s operating point changed.Furthermore,the superiority of the proposed approach has been demonstrated by comparing its performance with the existing Sliding Mode Control(SMC)approach for a hybrid AC/DC microgrid.
文摘The international order of territory-based sovereign nation-states(Westphalia)has been in transition towards a so-called‘post-Westphalian order’,but pre-Westphalian structures still prevail.This has been most relevant in the Middle East and North Africa,especially in the Persian Gulf.This coincides with the increasingly delicate(im)balance of power and the changing role of the state in the Persian Gulf,expressed in such narratives as the decline of the state,the United States‘withdrawal’from the region as well as the Iranian-Saudi‘Cold War.’The paper aims at analysing war and peace in this context of the transition of the international order and the regional(im)balance of power,and highlights that war or peace in the Persian Gulf will be the outcome of the competitive multi-polarity of traditional and modern,pre-Westphalian,Westphalian and post-Westphalian actors and factors,where the modalities and methodology of all will play a role.