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Circuit Model with Current Interruption for Hybrid High Voltage DC Circuit Breakers to Achieve Precise Current Experiments

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CSEE Journal of Power and Energy Systems 2022年第4期8卷 1250-1260页

作者： Zhonghao Dongye Lei Qi Bing Ji xiaoguang wei Xiang Cui State Key Laboratory of Altermate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China School of Engineering University of LeicesterLE17RH LeicesterU.K State Key Laboratory of Advanced Power Transmission Technology Global Energy Interconection Research Institute Co.Ld.Beijing 102209China

The current interruption test based on an LC resonance circuit for hybrid DC circuit breakers(HVDC CBs)is widely employed to characterize the current interruption capability of *** order to ensure a high-fidelity replica of the fault current in a high voltage application,this paper first proposes an equivalent model of the test circuit,where not only parasitic resistances but also the threshold voltages and on-state resistances of various semiconductor devices are ***,the analytical formula of the test current is derived by including the working principle of the HVDC ***,the parameter extraction method,which combines finite element analysis and measurements by an impedance analyzer,is given in this *** extracted result implies that,in current interruption transients,equivalent resistances of 500 kV CB are as large as 535 mS,which have a significant influence on current ***,the 34 kV/25 kA current interruption test for the 500 kV CB is *** measured results are proved to be consistent with the analytical results obtained from the proposed model,and the relative error is less than 2%.

关键词： Current interruption test high voltage DC circuit breaker

Comparisons and Improvements of Key Operating Characteristics of Current Source Converter Applied in HVDC System

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CSEE Journal of Power and Energy Systems 2023年第5期9卷 1601-1612页

作者： Wenwen Zhang Longlong Chen xiaoguang wei Guangfu Tang Lei Qi Chong Gao Zhiyuan He the North China Electric Power University Beijing 102206China the State Key Laboratory of Advanced Power Transmission Technology Beijing Institute Of Smart EnergyBeijing 102206China the State Grid Smart Grid Research Institute Co.Ltd Beijing 102209China

Because of its controlled power factor and no commutation failure,current source converter(CSC)made up of reverse-blocking IGCTs(RB-IGCTs)offers broad application prospects in the field of HVDC *** voltage and power operating range as the most important operating characteristics should be paid attention to but they are always ***,the relationship between valve voltage and modulation index is *** particular,valve voltage of converter under the three typical modulation methods is compared,analyzed,and ***,with the help of the independent control strategy and coordinated control strategy of both ends,power operating ranges of the three modulation methods are comprehensively analyzed and ***,in order to solve power coupling at a low active power,the improved coordination control strategy at both ends in this paper is proposed and the relationships among active power,reactive power,DC current and phase angle difference are given in ***,a 500 kV/3 kA simulation system was built in PSCAD/EMTDC to obtain comparison results of the key operating characteristics of CSC under different modulation methods and the converter can realize unity power operation under random active power after adopting the improved coordinated control strategy,and DC current does not decrease to zero,verifying effectiveness of the coordinated control strategy.

关键词： Current source converter improved coordinated control strategy reverse-blocking IGCT valve voltage

Modeling of High-frequency Electromagnetic Oscillation for DC Fault in MMC-HVDC Systems

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CSEE Journal of Power and Energy Systems 2023年第3期9卷 1151-1160页

作者： Hong Shen Zhonghao Dongye Lei Qi Muxue Wang Xiangyu Zhang Peng Qiu xiaoguang wei State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China Electric Power Research Institute State Grid Zhejiang Electric Power CompanyHangzhou 310014China State Key Laboratory of Advanced Power Transmission Technology Global Energy Interconnection Research Institute Co.Ltd.Beijing 102209China

DC short-circuit faults pose a hazard to the operation of a modular multilevel converter(MMC)-based high voltage direct current(HVDC)system,necessitating reliable fault clearing solutions with rapid ***,because the parasitic capacitances of the main equipment oscillate with the lumped inductances of the HVDC system,strong electromagnetic oscillations with multiple frequencies occur during clearance *** oscillations will disturb the HVDC system’s protection and control ***,this paper focuses on the modeling of these ***,an equivalent circuit for the MMC-based HVDC system is proposed,taking into account the parasitic capacitances of the system’s major components,such as DC reactors,connecting cables,and DC circuit breakers(DCCBs).Second,four distinct oscillation stages are postulated based on action coordination of MMCs and DCCBs,and the associated analytical equations for the oscillation frequencies are ***,a 200 kV MMC-based DC converter station is subjected to an 6ms/6kA pole-to-pole(PTP)short-circuit *** oscillations have a frequency range of several kHz to several hundreds of *** measured waveforms correspond well with simulated results,including the parasitic ***,the relative errors between the simulated and measured frequencies are less than 5%.

关键词： DC short-circuit fault electromagnetic oscillation MMC-HVDC parasitic parameter wide-band model

Numerical Simulation of Damage and Fracture on Typical Interfaces of Plasma Sprayed Thermal Barrier Coatings

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稀有金属材料与工程 2011年第S3期40卷 166-170页

作者： Qi Hongyu, Yang xiaoguang, Xie Jian, wei Hongliang Beihang University, Beijing 100191, China Beihang Univ Sch Jet Prop Beijing 100191 Peoples R China

Modern thermal barrier coatings (TBC) are required to not only limit heat transfer through the coating but to also protect engine components from thermal cyclic load and oxidation. Failure mechanism of TBC is important for the safety status of components. To obtain a better understanding of the failure mechanism under thermal cyclic load, a new type of interface elements with three nodes which is based on the idea of interface damage mechanics was proposed. Compared with traditional interface elements, these elements have the quality of indicating the normal direction of interface with arbitrary shape. The modified model was implemented into ABAQUS by user subroutine UEL. The damage and fracture of cosine shape interface were numerical simulated considering the rough interface of the plasma sprayed thermal barrier coating. The calculating results show that, under thermal cycle loadings, the displacement between nodes of the interface elements is not continuous which represents the opening process of the interface crack, the damage increases with the number of thermal cycle loadings and the max damage is caused during the first cycle, the top of the interface is the critical position and the normal separation dominants; under tension loadings, the wavy interface has better capability of load bearing than the linear interface for PS-TBC. Simulation of damage and fracture for different materials with arbitrary interface using the modified interface elements is available, and the results are reasonable.

关键词： interface elements thermal barrier coatings interfaces damage fracture

Analysis and suppression of voltage oscillation at DC circuit breaker terminal in DC fault transient process

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High Voltage 2022年第6期7卷 1194-1203页

作者： Hong Shen Xianrui Huang Lei Qi Xiangyu Zhang Xiaojun Ni Peng Qiu xiaoguang wei Xiang Cui State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijingChina Electric Power Research Institute State Grid Zhejiang Electric Power CompanyHangzhouChina State Key Laboratory of Advanced Power Transmission Technology State Grid Smart Grid Research Institute Co.Ltd.BeijingChina

High-frequency voltage oscillation occurs at the initial stage of DC short-circuit fault in the modular multilevel converter(MMC)-based high-voltage direct-current systems,which directly threatens the reliable operation of the secondary equipment in DC circuit breakers(DCCBs).Therefore,this paper focusses on the voltage oscillation characteristic at DCCB terminals,considered the stray parameters of connecting lines,the parasitic parameters of main equipment and the impedance of grounding grid,established equivalent circuit models of MMC-HVDC converter station at the initial stage of pole-topole and pole-to-ground fault,and obtained the analytical formula for the voltage oscillation ***,the comparison with the DC short-circuit test data of�200 kV MMC-HVDC converter station verified the validity of the models and revealed the mechanism of voltage ***,the influence of the parameters of the converter station on the oscillation characteristics was *** was proposed to install the DCCB at the MMC valve's terminal near the DC side,and the oscillation frequency is about 10–60 kHz,which is more than 5 times lower than that at the DC reactor's terminal near the DC pole bus,and the disturbance of oscillation to DCCB was alleviated.

关键词： oscillation. oscillation transient

Analysis for magnetic field disturbance of hybrid DC circuit breaker during breaking

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High Voltage 2022年第3期7卷 523-535页

作者： Sihang Wu Hong Shen Lei Qi Bei Zhang Xiang Cui Xiangyu Zhang xiaoguang wei Longlong Chen State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijingChina Global Energy Interconnection Research Institute Co. Ltd.BeijingChina

The high current of hybrid DC circuit breaker(HCB)in the process of breaking generates strong transient magnetic field(MF),which may interfere with the normal operation of driver control units(DCUs).Therefore,the analysis for transient MF disturbance is of great *** to the large space scale of HCB,with the large number of power electronic devices,the numerical calculation method has the disadvantages of large consumption of resources and slow calculation speed in solving the transient MF inside the *** this study,the current generation mechanism of a 500 kV HCB is analysed,and the equivalent current path is obtained by considering the skin *** with the temporal and spatial distribution of transient current,the multi-process transient equivalent model of transient MF calculation is established,and the model has the advantages of high precision and high ***,the breaking experiment of HCB is carried out,and the transient MF near the DCU is *** experiment results verify the validity of the ***,the disturbance of transient MF at the DCU of the transfer branch during breaking 25 kA current is analysed.

关键词： breaking transient disturbance

Influence of epitaxial layer structure and cell structure on electrical performance of 6.5 kV SiC MOSFET

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Journal of Semiconductors 2022年第8期43卷 71-77页

作者： Lixin Tian Zechen Du Rui Liu Xiping Niu Wenting Zhang Yunlai An Zhanwei Shen Fei Yang xiaoguang wei State Key Laboratory of Advanced Power Transmission Technology Global Energy Interconnection Research Institute Co.Ltd.Beijing 102209China Key Laboratory of Semiconductor Material Sciences Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

Silicon carbide(SiC)material features a wide bandgap and high critical breakdown field *** also plays an important role in the high efficiency and miniaturization of power electronic *** is an ideal choice for new power electronic devices,especially in smart grids and high-speed *** the medium and high voltage fields,SiC devices with a blocking voltage of more than 6.5 kV will have a wide range of *** this paper,we study the influence of epitaxial material properties on the static characteristics of 6.5 kV SiC MOSFET.6.5 kV SiC MOSFETs with different channel lengths and JFET region widths are manufactured on three wafers and *** FN tunneling of gate oxide,HTGB and HTRB tests are performed and provide data support for the industrialization process for medium/high voltage SiC MOSFETs.

关键词： silicon carbide epitaxial layer channel length JFET region width FN tunneling HTGB

Modeling and Control of an Isolated Module Multilevel DC/DC Converter for DC Grid

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CSEE Journal of Power and Energy Systems 2017年第2期3卷 150-159页

作者： Xinying Wang Guangfu Tang Zhiyuan He xiaoguang wei Hui Pang Xiangning Xiao State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102200China Global Energy Interconnection Research Institute and the members of state key laboratory of advanced transmission technology Beijing 102209China

This paper presents an isolated DC/AC/DC converter using a middle frequency transformer coupling two modular multilevel converters(MMC),suitable for interconnecting DC transmission lines of different voltage levels in high voltage direct current(HVDC)*** basic operational principle of the isolated module multilevel DC/DC converter(IMMDCC)is *** dynamic model of IMMDCC is studied in detail and the transient relationship between DC side and AC side of IMMDCC is revealed,which is physically straightforward for understanding the power transfer in *** control strategy in D-Q coordinate system is put forward,and the fault characteristic and corresponding protection method is ***,computer simulation using Matlab/Simulink is performed to verify the dynamic model and the proposed control *** simulation results show good performances and the quick response ability of the proposed control strategy.

关键词： Control strategy DC fault dynamic modeling HVDC system isolated module multilevel DC/DC converter

A review of the etched terminal structure of a 4H-SiC PiN diode

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Journal of Semiconductors 2023年第11期44卷 69-78页

作者： Hang Zhou Jingrong Yan Jialin Li Huan Ge Tao Zhu Bingke Zhang Shucheng Chang Junmin Sun Xue Bai xiaoguang wei Fei Yang State Key Laboratory of Advanced Power Transmission Technology Beijing Institute of Smart EnergyBeijing 102209China

The comparison of domestic and foreign studies has been utilized to extensively employ junction termination extension(JTE)structures for power ***,achieving a gradual doping concentration change in the lateral direction is difficult for SiC devices since the diffusion constants of the implanted aluminum ions in SiC are much less than *** previously reported studies adopted many new structures to solve this ***,the JTE structure is strongly sensitive to the ion implantation ***,GA-JTE,double-zone etched JTE structures,and SM-JTE with modulation spacing were reported to overcome the above shortcomings of the JTE structure and effectively increase the breakdown *** provided a theoretical basis for fabricating terminal structures of 4H-SiC PiN *** paper summarized the effects of different terminal structures on the electrical properties of SiC devices at home and ***,the continuous development and breakthrough of terminal technology have significantly improved the breakdown voltage and terminal efficiency of 4H-SiC PiN power diodes.

关键词： PiN diode terminal structure mesa-JTE reverse breakdown voltage etching process