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Traction power systems for electrified railways:evolution,state of the art,and future trends 被引量:1
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作者 Haitao Hu Yunjiang Liu +4 位作者 Yong Li Zhengyou He Shibin Gao Xiaojuan Zhu Haidong Tao 《Railway Engineering Science》 EI 2024年第1期1-19,共19页
Traction power systems(TPSs)play a vital role in the operation of electrified railways.The transformation of conventional railway TPSs to novel structures is not only a trend to promote the development of electrified ... Traction power systems(TPSs)play a vital role in the operation of electrified railways.The transformation of conventional railway TPSs to novel structures is not only a trend to promote the development of electrified railways toward high-efficiency and resilience but also an inevitable requirement to achieve carbon neutrality target.On the basis of sorting out the power supply structures of conventional AC and DC modes,this paper first reviews the characteristics of the existing TPSs,such as weak power supply flexibility and low-energy efficiency.Furthermore,the power supply structures of various TPSs for future electrified railways are described in detail,which satisfy longer distance,low-carbon,high-efficiency,high-reliability and high-quality power supply requirements.Meanwhile,the application prospects of different traction modes are discussed from both technical and economic aspects.Eventually,this paper introduces the research progress of mixed-system electrified railways and traction power supply technologies without catenary system,speculates on the future development trends and challenges of TPSs and predicts that TPSs will be based on the continuous power supply mode,employing power electronic equipment and intelligent information technology to construct a railway comprehensive energy system with renewable energy. 展开更多
关键词 Railway traction power system Future electrified railway flexible continuous power supply Renewable energy Integrated energy system
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Structured Microgrids (SμGs) and Flexible Electronic Large Power Transformers (FeLPTs) 被引量:4
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作者 Don Tan 《CES Transactions on Electrical Machines and Systems》 CSCD 2020年第4期255-263,共9页
Structured microgrids(SμGs)and Flexible electronic large power transformers(FeLPTs)are emerging as two essential technologies for renewable energy integration,flexible power transmission,and active control.SμGs prov... Structured microgrids(SμGs)and Flexible electronic large power transformers(FeLPTs)are emerging as two essential technologies for renewable energy integration,flexible power transmission,and active control.SμGs provide the integration of renewable energy and storage to balance the energy demand and supply as needed for a given system design.FeLPT’s flexibility for processing,control,and re-configurability offers the capability for flexible transmission for effective flow control and enable SμGs connectivity while still keeping multiscale system level control.Early adaptors for combined heat and power have demonstrated significant economic benefits while reducing environmental foot prints.They bring tremendous benefits to utility companies also.With storage and active control capabilities,a 300-percent increase in bulk transmission and distribution lines are possible without having to increase capacity.SμGs and FeLPTs will also enable the utility industry to be better prepared for the emerging large increase in base load demand from electric transportation and data centers.This is a win-win-win situation for the consumer,the utilities(grid operators),and the environment.SμGs and FeLPTs provide value in power substation,energy surety,reliability,resiliency,and security.It is also shown that the initial cost associated with SμG and FeLPTs deployment can be easily offset with reduced operating cost,which in turn reduces the total life-cycle cost by 33%to 67%. 展开更多
关键词 Terms-Structured microgrids flexible electronic large power transformers energy systems renewable integration grid modernization active control life-cycle cost
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Flexible Power Regulation and Limitation of Voltage Source Inverters under Unbalanced Grid Faults 被引量:2
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作者 Peng Cheng Kongyuan Li +2 位作者 Chao Wu Jing Ma Limin Jia 《CES Transactions on Electrical Machines and Systems》 CSCD 2022年第2期153-161,共9页
This paper develops a flexible power regulation and limitation strategy of voltage source inverters(VSIs)under unbalanced grid faults.When the classical power theory is used under unbalanced grid faults,the power osci... This paper develops a flexible power regulation and limitation strategy of voltage source inverters(VSIs)under unbalanced grid faults.When the classical power theory is used under unbalanced grid faults,the power oscillations and current distortions are inevitable.In the proposed strategy,the extended power theory is introduced to compute the power feedbacks together with the classical power theory.Based on the combination of the classical and extended power theory,the proposed strategy can achieve the sinusoidal current provision and the flexible regulation between three common targets,i.e.,constant active power,balanced current,and constant reactive power.Meanwhile,the proposed strategy is associated with a power limiter,which is capable to keep the currents under the pre-defined threshold and to compute the maximum apparent power for better utilization of the inverter capacity.With this power limiter,the rated inverter capacity is fully used for both the active and reactive power provisions under unbalanced grid faults.Using the proposed power regulation and limitation,the VSI can avoid overcurrent tripping and flexibly regulate its power under unbalanced grid faults.All the conclusions are verified by the real-time hardware-in-loop tests. 展开更多
关键词 flexible power regulation power limiter Voltage source inverter Unbalanced faults
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PASSIVE-ACTIVE CONTROL OF A FLEXIBLE ISOLATION SYSTEM
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作者 Song KongjieZhang BingSun LinglingSun YuguoSchool of Mechanical Engineering, Shandong University, Jinan 250061, China 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2003年第4期408-410,416,共4页
Passive-active control of a flexible isolation system is investigated from the viewpoint of power flow. Dynamic transfer equations of the system are deduced based on a matrix method which uses mobility or impedance re... Passive-active control of a flexible isolation system is investigated from the viewpoint of power flow. Dynamic transfer equations of the system are deduced based on a matrix method which uses mobility or impedance representations of three substructures: the source of vibration, the receiver and the mounting system which connects the source to the receiver. The cancellation of axial input forces to the receiver is considered as the active control strategy and its effects are discussed. The results of the study show that the strategy adopted herein can effectively reduce the power transmitted to the receiver. 展开更多
关键词 flexible isolation system power flow Active control
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FPGA-based Digital Implementation of Flexible Power Control for Three-phase to Single-phase MMC-based Advanced Co-phase Traction Power Supply System
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作者 Jiangpeng Yang Hongjian Lin +8 位作者 Haotian Zhu Zeliang Shu Lan Ma Changsong Cai Pengcheng Zhang Li He Ruoyu Li Shasha Song Josep M.Guerrero 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2023年第6期2015-2027,共13页
A three-phase to single-phase modular multilevel converter based advanced co-phase traction power supply(MMC-ACTPS) system is an effective structure to address the concerns of phase splitting and poor power quality of... A three-phase to single-phase modular multilevel converter based advanced co-phase traction power supply(MMC-ACTPS) system is an effective structure to address the concerns of phase splitting and poor power quality of the conventional electrified railway. Due to the large number of MMCACTPS system modules, I/O resources and computing speed have high requirements on processors. Moreover, the module capacitor balance is challenging because the sorting time is too long when the traditional sorting algorithm for voltage balance is used. To solve the above issues, a digital implementation scheme of flexible power control strategy for three-phase to single-phase MMC-ACTPS system based on field programmable gate array(FPGA), which has sufficient I/O resources, has been proposed. Due to the parallel execution characteristics of the FPGA, the execution time of the controller and the modulator can be greatly reduced compared with a digital signal processor(DSP) + FPGA or DSpace. In addition, an improved sorting algorithm is proposed to reduce the sorting time and the implementation steps are analyzed. Finally, simulation and experimental results are presented to demonstrate the effectiveness and correctness of the proposed control strategy. 展开更多
关键词 Advanced co-phase power traction supply(ACTPS)system modular multilevel converter(MMC) digital implementation flexible power transmission circulating current mitigation
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OPTIMUM CONTROL OF VIBRATION AND STRUCTURE-BORNE NOISE FOR MACHINERY ON FLEXIBLE FOUNDATION 被引量:4
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作者 Xiong Yeping Song Kongjie Wang Chun ( Shandong University of Technology) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 1996年第1期13-20,共3页
Faced with the key problems of machinerv- induced vibration and structure-borne noise when dynamic machines are mounted on flexible foundations such as upper floors of facto- ry buildings, the vibration and... Faced with the key problems of machinerv- induced vibration and structure-borne noise when dynamic machines are mounted on flexible foundations such as upper floors of facto- ry buildings, the vibration and noise transmission mechanism and optimal control for the flexible system are systematically studied by the novel approach of power flow. A more general system of machinery-isolators一flexible foundation is modelled. Based on substructure transfer matrix tech- nique the power flow input and transmitted are formulated in closed forms, and the effects that the flexibility of foundation and the asymmetricity of system have upon the power flow transmis- sion spectra are revealed, Also the inverse problems of isolation design are discussed by using an optimum method. Optimum design for a typical example about a force fan mounted on a con- crete building floor is successfully performed to show that the model is practical, the theory and the optimisation developed are reasonable and effective. Thereby, theoretical bases for accurate prediction of isolation effectiveness and an optimum method for practical design of a general flexi- ble isolation system are provided. 展开更多
关键词 power flow Structure-borne nosie flexible subsystems Optimum control
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Power Source Flexibility Margin Quantification Method for Multi-energy Power Systems Based on Blind Number Theory 被引量:2
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作者 Bai Xiao Jialiang Wang +4 位作者 Zhiwen Xiao Gangui Yan Ling Dong Maochun Wang Hongzhi Yang 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2023年第6期2321-2331,共11页
The grid connection of a high proportion of re-newable energy generation increases the uncertainty in power systems.Therefore,the flexibility margin of different energy sources needs to be quantified to cope with the ... The grid connection of a high proportion of re-newable energy generation increases the uncertainty in power systems.Therefore,the flexibility margin of different energy sources needs to be quantified to cope with the uncertainty change and maintain the dynamic balance of power system flexibility.In this paper,first,the flexibility characteristics of source,net,load and power and load community(PLC)are analyzed.The dynamic equilibrium relationship among them is briefly introduced.Secondly,taking into full consideration the complex output characteristics of different energy sources and combining their respective flexibility characteristics,a quantitative model of the power source flexibility margin for thermal power,hydro-power,gas power and concentrating solar power is established.A quantitative model for a power source flexibility margin in PV and wind power based on blind number theory is estab-lished.Furthermore,the calculation method of theoretical power generation capacity,which can reflect different characteristics of output power of various energy sources,is presented.The actual output power of each power source in each period is predicted.Finally,a case study shows that the model and method can consider the operating characteristics of different types of power sources,and quickly and accurately quantify the adjustable range of flexibility margins of each power source at different periods of time,which can provide an important basis for evaluating the capacity of renewable energy consumption and the optimal operation of multi-energy power systems(MEPSs). 展开更多
关键词 Load forecasting multi-energy power system power generation capacity power source flexibility margin
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The Averaged-value Model of a Flexible Power Electronics Based Substation in Hybrid AC/DC Distribution Systems 被引量:4
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作者 Hong Liu Zhanfeng Deng +5 位作者 Xialin Li Li Guo Di Huang Shouqiang Fu Xiangyu Chen Chengshan Wang 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2022年第2期452-464,共13页
The concept of a flexible power electronics substation(FPES)was first applied in the Zhangbei DC distribution network demonstration project.As a multi-port power electronics transformer(PET)with different AC and DC vo... The concept of a flexible power electronics substation(FPES)was first applied in the Zhangbei DC distribution network demonstration project.As a multi-port power electronics transformer(PET)with different AC and DC voltage levels,the FPES has adopted a novel topology integrating modular multilevel converter(MMC)and four-winding medium frequency transformer(FWMFT)based multiport DC-DC converter,which can significantly reduce capacitance in each sub-module(SM)of a MMC and also save space and cost.In this paper,in order to accelerate speed of electromagnetic transient(EMT)simulations of FPES based hybrid AC/DC distribution systems,an averaged-value model(AVM)is proposed for efficient and accurate representation of FPES.Assume that all SM capacitor voltages are perfectly balanced in the MMC,then the MMC behavior can be modeled using controlled voltage sources based on modulation voltages from control systems.In terms of the averaged current transfer characteristics among the windings of the FWMFT,we consider that all multiport DC-DC converters are controlled with the same dynamics,a lumped averaged model using controlled current and voltage sources has been developed for these four-port DC-DC converters connected to the upper or lower arms of the MMC.The presented FPES AVM model has been tested and validated by comparison with a detailed IGBT-based EMT model.Results show that the AVM is significantly more efficient while maintaining its accuracy in an EMT simulation. 展开更多
关键词 Averaged-value model(AVM) flexible power electronics substation(FPES) four-winding medium frequency transformer(FWMFT) hybrid AC/DC distribution systems modular multilevel converter(MMC) multiport DC-DC converter
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Stochastic Flexibility Evaluation for Virtual Power Plants by Aggregating Distributed Energy Resources
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作者 Siyuan Wang Wenchuan Wu +2 位作者 Qizhan Chen Junjie Yu Peng Wang 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2024年第3期988-999,共12页
To manage a large amount of flexible distributed energy resources(DERs)in the distribution networks,the virtual power plant(VPP)is introduced into the industry.The VPP can optimally dispatch these resources in a clust... To manage a large amount of flexible distributed energy resources(DERs)in the distribution networks,the virtual power plant(VPP)is introduced into the industry.The VPP can optimally dispatch these resources in a cluster manner and provide flexibility for the power system operation as a whole.Most existing studies formulate the equivalent power flexibility of the aggregating DERs as deterministic optimization models without considering their uncertainties.In this paper,we introduce the stochastic power flexibility range(PFR)and timecoupling flexibility(TCF)to describe the power flexibility of VPP.In this model,both operational constraints and the randomness of the DERs’output are incorporated,and a combined model and data-driven solution is proposed to obtain the stochastic PFR,TCF,and cost function of VPP.The aggregating model can be easily incorporated into the optimization model for the power system operator or market bidding,considering uncertainties.Finally,a numerical test is performed.The results show that the proposed model not only has higher computational efficiency than the scenario-based methods but also achieves more economic benefits. 展开更多
关键词 Chance constrained optimization combined model and data-driven stochastic power flexibility virtual power plant
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Power flow transmission in a coupled flexible system with active executive elements
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作者 HUO Rui SHI Yin (Institute of Naval Ship Equipment Noise & Vibration, Naval University, of Engineering Wuhan 430033) SONG Kongjie (College of Mechanic Engineering, Shandong University of Technology Jinan 250061) 《Chinese Journal of Acoustics》 2002年第1期51-58,共8页
Based on its prototype of machine-isolator-foundation systems, a theoretical model for dynamic coupled linear system is established, in which both the passive and active control factors are considered. Power flow is u... Based on its prototype of machine-isolator-foundation systems, a theoretical model for dynamic coupled linear system is established, in which both the passive and active control factors are considered. Power flow is used as the cost function to evaluate the isolation effectiveness. And the transmission of vibratory power flow from a vibrating rigid body into a simply supported thin panel through passive isolators and actuators is investigated numerically. The active control strategy is summarized in the conclusion. 展开更多
关键词 flow flexible power flow transmission in a coupled flexible system with active executive elements
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District heating system operation in power systems with high share of wind power 被引量:6
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作者 Ilias DIMOULKAS Mikael AMELIN Fabian LEVIHN 《Journal of Modern Power Systems and Clean Energy》 SCIE EI 2017年第6期850-862,共13页
The integration of continuously varying and not easily predictable wind power generation is affecting the stability of the power system and leads to increasing demand for balancing services.In this study,a short-term ... The integration of continuously varying and not easily predictable wind power generation is affecting the stability of the power system and leads to increasing demand for balancing services.In this study,a short-term operation model of a district heating system is proposed to optimally schedule the production of both heat and power in a system with high wind power penetration.The application of the model in a case study system shows the increased flexibility offered by the coordination of power generation,consumption and heat storage units which are available in district heating systems. 展开更多
关键词 District heating systems Combined heat and power(CHP) flexible power system operation Heat storage
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Multi-energy Storage System Model Based on Electricity Heat and Hydrogen Coordinated Optimization for Power Grid Flexibility 被引量:44
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作者 Yun Teng Zedi Wang +3 位作者 Yan Li Qian Ma Qian Hui Shubin Li 《CSEE Journal of Power and Energy Systems》 SCIE CSCD 2019年第2期266-274,共9页
Based on decreasing the flexibility of the power grid through the integration of large-scale renewable energy,a multi-energy storage system architectural model and its coor-dination operational strategy with the same ... Based on decreasing the flexibility of the power grid through the integration of large-scale renewable energy,a multi-energy storage system architectural model and its coor-dination operational strategy with the same flexibility as in the pumped storage power station and battery energy storage system(BESS)are studied.According to the new energy fluctuation characteristics and the different peak valley parameters in the power grid,this paper proposes a electricity heat hydrogen multi-energy storage system(EHH-MESS)and its coordination and optimization operational model to reduce the curtailment of wind power and photovoltaic(PV)to the power grid and improve the flexibility of the power grid.Finally,this paper studied the simulation model of an energy storage optimization control strategy after the multi-energy storage system is connected to the distribution networks,and analyzed three operational modes of the multi-energy storage system.The simulation results show that the EHH-MESS proposed in this paper has a better power grid regulation flexibility and economy,and can be used to replace the battery energy storage system based on MATLAB. 展开更多
关键词 Electricity heat and hydrogen conversion flexibility of power grid multi-energy storage new energy curtailment
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Recent advances in flexible batteries:From materials to applications 被引量:5
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作者 Fuwei Xiang Fang Cheng +4 位作者 Yongjiang Sun Xiaoping Yang Wen Lu Rose Amal Liming Dai 《Nano Research》 SCIE EI CSCD 2023年第4期4821-4854,共34页
Along with the rapid development of flexible and wearable electronic devices,there have been a strong demand for flexible power sources,which has in turn triggered considerable efforts on the research and development ... Along with the rapid development of flexible and wearable electronic devices,there have been a strong demand for flexible power sources,which has in turn triggered considerable efforts on the research and development of flexible batteries.An ideal flexible battery would have not only just high electrochemical performance but also excellent mechanical deformabilities.Therefore,battery constituent components,chemistry systems,device configurations,and practical applications are all pivotal aspects that should be thoroughly considered.Herein,we systematically and comprehensively review the fundamentals and recent progresses of flexible batteries in terms of these important aspects.Specifically,we first discuss the requirements for constituent components,including the current collector,electrolyte,and separator,in flexible batteries.We then elucidate battery chemistry systems that have been studied for various flexible batteries,including lithium-ion batteries,non-lithium-ion batteries,and high-energy metal batteries.This is followed by discussions on the device configurations for flexible batteries,including onedimensional fiber-shaped,two-dimensional film-shaped,and three-dimensional structural batteries.Finally,we summarize recent efforts in exploring practical applications for flexible batteries.Current challenges and future opportunities for the research and development of flexible batteries are also discussed. 展开更多
关键词 flexible batteries flexible power sources wearable electronics electrochemistries battery applications
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Guest editorial:special section on energy storage systems and operational flexibility in power systems
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作者 Shengwei MEI Liangzhong YAO 《Journal of Modern Power Systems and Clean Energy》 SCIE EI 2016年第4期517-518,共2页
The energy storage system(ESS) is becoming an important component in power systems to mitigate the adverse impact of intermittent renewable energy resources and improve power grid reliability and efficiency.However,st... The energy storage system(ESS) is becoming an important component in power systems to mitigate the adverse impact of intermittent renewable energy resources and improve power grid reliability and efficiency.However,storage devices driven by different technologies can have specific grid impacts.This special section is dedicated to reflecting the 展开更多
关键词 Guest editorial:special section on energy storage systems and operational flexibility in power systems
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Distributed Source-Load-Storage Cooperative Low-Carbon Scheduling Strategy Considering Vehicle-to-Grid Aggregators
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作者 Xiao Xu Ziwen Qiu +1 位作者 Teng Zhang Hui Gao 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2024年第2期440-453,共14页
The vehicle-to-grid(V2G)technology enables the bidirectional power flow between electric vehicle(EV)batteries and the power grid,making EV-based mobile energy storage an appealing supplement to stationary energy stora... The vehicle-to-grid(V2G)technology enables the bidirectional power flow between electric vehicle(EV)batteries and the power grid,making EV-based mobile energy storage an appealing supplement to stationary energy storage systems.However,the stochastic and volatile charging behaviors pose a challenge for EV fleets to engage directly in multi-agent cooperation.To unlock the scheduling potential of EVs,this paper proposes a source-load-storage cooperative low-carbon scheduling strategy considering V2G aggregators.The uncertainty of EV charging patterns is managed through a rolling-horizon control framework,where the scheduling and control horizons are adaptively adjusted according to the availability periods of EVs.Moreover,a Minkowski-sum based aggregation method is employed to evaluate the scheduling potential of aggregated EV fleets within a given scheduling horizon.This method effectively reduces the variable dimension while preserving the charging and discharging constraints of individual EVs.Subsequently,a Nash bargaining based cooperative scheduling model involving a distribution system operator(DSO),an EV aggregator(EVA),and a load aggregator(LA)is established to maximize the social welfare and improve the low-carbon performance of the system.This model is solved by the alternating direction method of multipliers(ADMM)algorithm in a distributed manner,with privacy of participants fully preserved.The proposed strategy is proven to achieve the objective of low-carbon economic operation. 展开更多
关键词 Electric vehicle(EV) low-carbon scheduling mobile storage system Nash bargaining power flexibility alternating direction method of multipliers(ADMM).
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Review of protection and fault handling for a flexible DC grid 被引量:29
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作者 Jinghan He Keao Chen +3 位作者 Meng Li Yiping Luo Chenguang Liang Yin Xu 《Protection and Control of Modern Power Systems》 2020年第1期138-152,共15页
With the development of power electronics technology,the flexible DC grid will play a significant role in promoting the transformation and reformation of the power grid.It is immune to commutation failure and has high... With the development of power electronics technology,the flexible DC grid will play a significant role in promoting the transformation and reformation of the power grid.It is immune to commutation failure and has high flexibility in power control and renewable energy grid integration.However,the protection and fault handling technology for a flexible DC grid is a big challenge because of the limited overcurrent capability of the converters.This paper summarizes the development of the flexible DC grid,and analyzes the fault characteristics in detail.Next,the applicability,advantages and disadvantages of the existing protection principle,fault isolation and recovery schemes are reviewed.Finally,the key problems and development trend of the future flexible DC grid are pointed out and forecasted respectively. 展开更多
关键词 flexible DC power grid Fault analysis PROTECTION Fault isolation Reclose
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Cross-seam Hybrid MTDC System for Integration and Delivery of Large-scale Renewable Energy
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作者 Kaiqi Sun Huangqing Xiao +1 位作者 Jiuping Pan Yilu Liu 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2021年第6期1352-1362,共11页
To better utilize the diversity of renewable energies in the U. S., this paper proposes a cross-seam hybrid multi-terminal high-voltage direct current(MTDC) system for the integration of different types of renewable e... To better utilize the diversity of renewable energies in the U. S., this paper proposes a cross-seam hybrid multi-terminal high-voltage direct current(MTDC) system for the integration of different types of renewable energies in the U. S.Based on a developed station-hybrid converter design, the proposed hybrid MTDC system further investigates the connection methods of renewable energies and develops novel flexible power flow control strategies for realizing uninterrupted integration of renewable energies. In addition, the frequency response control of the hybrid MTDC system is proposed by utilizing the coordination between the converters in the hybrid MTDC system.The feasibility of the hybrid MTDC system and the performance of its corresponding control strategies are conducted in the PSCAD/EMTDC simulation. The simulation results indicate that the proposed hybrid MTDC system could realize the uninterrupted integration of renewable energies and flexible power transmission to both coasts of U.S. 展开更多
关键词 Multi-terminal high-voltage direct current(MTDC)system cross-seam interconnection integration of large-scale renewable energies flexible power flow control frequency response control
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Non-isolated stacked bidirectional soft-switching DC-DC converter with PWM plus phase-shift control scheme 被引量:2
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作者 Ye MEI Qun JIANG +3 位作者 Heya YANG Wuhua LI Xiangning HE Shun LI 《Journal of Modern Power Systems and Clean Energy》 SCIE EI 2017年第4期631-641,共11页
In this paper, a non-isolated stacked bidirectional DC-DC converter with zero-voltage-switching(ZVS) is introduced for the high step-up/step-down conversion systems. The extremely narrow turn-on and/or turn-off duty c... In this paper, a non-isolated stacked bidirectional DC-DC converter with zero-voltage-switching(ZVS) is introduced for the high step-up/step-down conversion systems. The extremely narrow turn-on and/or turn-off duty cycle existing in the conventional bidirectional buck-boost converters can be extended due to the stacked module configuration for large voltage conversion ratio applications. Furthermore, the switch voltage stress is halved because of the series connection of half bridge modules. The PWM plus phase-shift control strategy is employed, where the duty cycle is adopted to regulate the voltages between the input and output sides and the phaseshift angle is applied to achieve the power flow regulation.This decoupled control scheme can not only realize seamless bidirectional transition operation, but also achieve adaptive voltage balance for the power switches. In addition, ZVS soft-switching operation for all active switches is realized to minimize the switching losses. Finally, a prototype of 1 kW operating at 100 kHz is built and tested to demonstrate the effectiveness of the proposed converter and the control strategy. 展开更多
关键词 Bidirectional DC-DC converter PWM plus phase-shift control(PPS) Zero voltage switching(ZVS) Large voltage conversion ratio flexible power flow regulation
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Analysis and Control of MVDC Demonstration Project in the UK:ANGLE-DC
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作者 Gayan ABEYNAYAKE James YU +1 位作者 Andrew MOON Jun LIANG 《供用电》 2020年第10期44-50,共7页
The emerging medium voltage direct current(MVDC)distribution networks are becoming more attractive due to their flexible power flow control and lower losses compared to traditional AC networks.This will significantly ... The emerging medium voltage direct current(MVDC)distribution networks are becoming more attractive due to their flexible power flow control and lower losses compared to traditional AC networks.This will significantly increase the wide uptake of renewable energy sources.The optimum utilization of the existing assets is an important aspect in grid upgrading and planning.One feasible option is to convert existing MVAC lines into MVDC operation.One of the practical demonstrations is the“ANGLE-DC”project which is also the first MVDC link in the UK.This paper highlights the innovative approach,challenges and key benefits delivered by the ANGLE-DC project. 展开更多
关键词 medium voltage direct current(MVDC) MVDC converters operational challenges distribution network flexible power flow control
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Auxiliary Service Dynamic Compensation Mechanism Design for Incentivizing Market Participants to Provide Flexibility in China
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作者 Yibo Wang Yifan Wang +3 位作者 Chuang Liu Yuan Fang Guowei Cai Weichun Ge 《Protection and Control of Modern Power Systems》 SCIE EI 2024年第5期112-128,共17页
Because of the rapid growth of new energy and the accompanying considerable uncertainty in the power market,the demand for flexibility in a power sys-tem has risen sharply.In the meantime,the market structure of auxil... Because of the rapid growth of new energy and the accompanying considerable uncertainty in the power market,the demand for flexibility in a power sys-tem has risen sharply.In the meantime,the market structure of auxiliary services has changed,resulting in market participants(MPs)benefiting less than expected from providing flexible services.To encourage MPs to provide flexibility,this study proposes a dynamic design framework for an auxiliary service compensation mech-anism.To evaluate the proposed framework,a case study is conducted,examining a peak-shaving service in Liao-ning province in northeast China.First,the operational status and limitations of the typical product,the peak-shaving service,in China’s flexibility auxiliary ser-vices market are analyzed.Then,taking into consideration the time value of the flexible products provided by the MPs,a dynamic mechanism for hierarchical compensation of flexibility auxiliary service costs is proposed,and a mathematical model aimed at optimizing the MPs’comprehensive income is constructed.The results show that,compared with the existing traditional mechanism,the proposed method can effectively guarantee fair remu-neration for the flexibility provider,while easing the tense supply-demand relationship in the flexibility market. 展开更多
关键词 power system flexibility auxiliary services market peak shaving auxiliary service differentiated operation scenario dynamic hierarchical compensation mechanism
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