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Implementation of Automatic Process of Edge Rotation Diagnostic System on J-TEXT Tokamak

Plasma Science and technology 2014年第8期16卷 789-793页

作者：张泽品程芝峰罗剑王之江张晓龙侯赛英成诚 State Key Laboratory of Advanced Electromagnetic Engineering and Technology College of Electrical and Electronic Engineering Huazhong University of Science and Technology

A spectral diagnostic control system （SDCS） is developed to implement automatic process of the edge rotation diagnostic system on the J-TEXT tokamak. The SDCS contains a control module, data operation module, data analysis module, and data upload module. The core of this system is a newly developed software ＂Spectra Assist＂, which completes the whole process by coupling all related subroutines and servers. The results of data correction and calculated rotation are presented. In the daily discharge of J-TEXT, SDCS is proved to have a stable performance and high efficiency in completing the process of data acquisition, operation and results output.

关键词： edge rotation diagnostic control system J-TEXT mixed programming

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Design of Digital Multi-Radian Phase Detector on J-TEXT

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Plasma Science and technology 2014年第10期16卷 974-977页

作者：李俊杨州军高丽刘明海庄革 School of Electrical and Electronic Engineering Huazhong University of Science and Technology State Key Laboratory of Advanced Electromagnetic Engineering and Technology

A real time system used to detect phase difference between two sinusoidal signals is proposed in this paper. The system is designed to process the phase signal of the far-infrared （FIR） hydrogen cyanide （HCN） interferometer on J-TEXT. It is based on zero-crossing detection and makes use of the digital circuit. Compared with a traditional zero-crossing phase detector, it doesn＇t need to sacrifice the time resolution to expand the phase range. The phase difference is divided into two parts, the integer part and the fraction part. In each detecting cycle, they are detected separately. It outputs digital signals that are more stable for transmission. A prototype was built on J-TEXT using discrete components. A practical method is proposed to deal with the counting error caused by the deviation of electronic components in manufacture. Reasonable results were obtained on the prototype. The phase resolution reaches 2π/64 in test, and can still be improved by raising the clock frequency.

关键词： phase detector multi-radian digital HCN interferometer

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Design of the Transmission Lines for 140 GHz ECRH System on HL-2A

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Plasma Science and technology 2014年第3期16卷 267-272页

作者：夏冬辉周俊饶军黄梅陆志鸿王贺陈罡宇王超卢波庄革 State Key Laboratory of Advanced Electromagnetic Engineering and TechnologyHuazhong University of Science and Technology Southwestern Institute of Physics

A new 140 GHz/2 MW/3 s electron cyclotron resonance heating （ECRH） system composed of two units is now being constructed on HL-2A. As a part of the system, two trans- mission lines marked No.7 ＆ 8 play the role of carrying microwave power from two gyrotrons to the tokamak port. Based on the oversized circular corrugated waveguide technology, an evacu~ ated transmission system with high power capability and high transmission efficiency is designed. Details are presented for the design of the corrugated waveguide, the layout of the proposed lines and the vacuum pumping system. Then mode conversion losses due to coupling, misalignment, bends and gaps are discussed to serve as a reference for analyzing the transmission efficiency and alignment. Finally, a dual-modes propagation case consisting of the HEll and LPn even modes is discussed.

关键词： HL-2A tokamak electron cyclotron resonance heating transmission line

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Design of Variable-Frequency Power Supply System Based on Multilevel Inverters for Dynamic Resonant Magnetic Perturbation Coils on J-TEXT Tokamak

Design of Variable-Frequency Power Supply System Based on Mu...

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IEEE Symposium on Fusion engineering

作者： M. Li J. Y. Nan B. Rao Y. H. Ding X. K. Ji Y. Pan State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Tecnology Wuhan China

The dynamic resonant magnetic perturbation (DRMP) coils have been designed to study the feedback control of tearing mode (TM) instability in J-TEXT tokamak with rotating resonant magnetic perturbation. The AC power supply system energizing coils should have the ability of controlled current frequency in the range of 1 kHz to 5 kHz and amplitude of 5 kA peak value at 5 kHz. In further study, TM will be feedback controlled. In this paper, the main circuit of the variable-frequency power supply system with thyristor rectifier and cascaded H-bridges multilevel inverter is proposed. In order to adapt for the digital feedback control, a fast algorithm to calculate conduction angles of cascaded inverter is emphasized. Experimental results of the main circuit prototype are presented in the end of this paper.

关键词： cascaded H-bridges multilevel inverter conduction angles calculation tearing mode instability control

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Inertial Control Methods of Variable-Speed Wind Turbine: Comparative Studies

Inertial Control Methods of Variable-Speed Wind Turbine: Com...

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IEEE Power and Energy Society General Meeting

作者： Li Sun Xiaoming Yuan Jiabing Hu Wei He State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Sci. and Tech.

ISBN: (纸本)9781467380416

This paper compares the principle and the dynamic process of different inertia releasing methods on variable-speed wind turbine. The basic principle of df/dt inertia control, tuning PLL control, and virtual synchronous control, is firstly analyzed. From the perspective of internal voltage, the internal voltage's motion of those inertia releasing methods is discussed. The comparison of the internal voltage's motion indicates that they play the same role through emulating the behavior of synchronous generator from different aspects. Time domain simulation shows the doubly fed induction generator with those different inertia control methods contribute the effective and similar inertial response.

关键词： Df/dt inertia control Inertial response Internal voltage Phase-locked loop Virtual synchronous control internal voltage Phase locked loops Control Methods Wind Energy Conversion Systems Variable speed double-fed induction generator Inertial forces Inertial Synchronous generators transient processes

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Design and implementation of voltage source converter excitation system to improve power system stability

Design and implementation of voltage source converter excita...

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Conference Record of the IEEE Industry Applications Society Annual Meeting (IAS)

作者： Zhu Chen Jiming Lu Chengxiong Mao Yuhao Zhou Dan Wang State Key Laboratory of Advanced Electromagnetic Engineering and Technology Wuhan Hubei P.R.China

This paper presents the design of the voltage source converter(VSC) excitation system and an integrated prototype using digital signal processor(DSP) as the core of the excitation controller is developed. Compared with the static excitation systems with thyristor, the VSC excitation system owns one more channel offering positive damping to power system by controlling reactive power of VSC on its ac side, and this approach is approved much faster than field voltage regulation. To design the prototype, the VSC excitation system has to meet the practical condition of the selected synchronous generator(SG) set such as generator capacity, terminal voltage, field voltage and field current, etc. The designed VSC excitation system consists of converters containing a front-end three-phase VSC and a back-end H-bridge chopper, a step-down transformer, and a coordinate excitation controller. Through a series of experiments, it is demonstrated that the VSC excitation system is able to improve both transient stability and steady-state stability limit of power systems. It is a prospective substitute to the conventional thyristor based static excitation system and an attractive solution to strengthen power system stability as well as increase the capability of long-distance transmission systems.

关键词： Power conversion Power system stability Choppers (circuits) Generators Voltage control Reactive power

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Characterization of the laser-triggered vacuum switches

Characterization of the laser-triggered vacuum switches

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International Conference on Pulsed Power

作者： W. Fan Z. He X. Mao State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan Hubei Province China

In this paper, a multi-electrode laser-triggered vacuum switch (LTVS) is developed to optimize the triggered vacuum switch (TVS) and meet the requirements of the pulsed power technology. The relationship between the laser trigger energy, operating voltage, polarity, average energy of the spot and the trigger characteristics which mainly contain the delay time, jitter time and minimum operating voltage is analyzed in detail. The interaction between a thermal mechanism and an ion collision mechanism is proposed to explain the switch conduction. It is concluded that the minimum delay time and the jitter time can reach 15 ns and ± 10 ns, respectively. The minimum operating voltage of 60 V is observed. Finally, the delay time is mainly decided by the average energy of the spot in the case of certain triggering energy and the polarity effect is one of the main factors affecting trigger stability.

关键词： Delays Electrodes Plasmas Jitter Laser beams Electric fields Discharges (electric)

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Design of anti-windup compensation for energy storage based damping controller to enhance power system stability

Design of anti-windup compensation for energy storage based ...

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IEEE General Meeting Power& Energy Society

作者： Jiakun Fang Wei Yao Zhe Chen Jinyu Wen Shijie Cheng State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Department of Energy Technology Aalborg University

ISBN: (纸本)9781467380416

The application of energy storage (ES) in power system is limited due to the high cost of the ES device, which exponentially increases with its capacity. This paper is to improve the saturation-dependent stability of the power system equipped with the energy storage based damping controller (ESDC), and hence, reduce the required size of the ES. The phenomenon that the capacity of ES is smaller than the required value produced by the ESDC, is modeled as actuator saturation using the saturation function. The proposed method is to design an anti-windup compensator (AWC), which in the event of saturation, produces a signal based on the output difference between the ESDC and saturated ES and then augment the signal to the ESDC to alleviate the adverse effect of saturation. The AWC is designed with the reduced- order model of power system and linear matrix inequality. Detailed design procedure is introduced. Case studies based on a modified 4-machine 2-area power system and 10-machine New England power system are carried out to demonstrate the effectiveness of the AWC design method.

关键词： Power system stability Energy storage Damping Design methodology electromagnetics Stability analysis Actuators

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The 5.8 T Cryogen-Free Gyrotron Superconducting Magnet System on HL-2A

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Plasma Science and technology 2014年第4期16卷 410-414页

作者：夏冬辉黄梅周俊白兴宇郑铁流饶军庄革 State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Southwestern Institute of Physics

A 5.8 T cryogen-free superconducting magnet （SCM） system with a warm bore hole of 160 mm in diameter, used for gyrotrons operating in the frequency range from 68 GHz to 140 GHz, is installed on the site of the HL-2A tokamak. The SCM consists of two separate solenoidal magnetic coils connected in series, a 4.2 K Gifford-McMahon （GM） refrigerator, a com- pressor, a coil power supply and two temperature monitors. The performance, test and preliminary experimental results of this SCM system are described in this paper. The magnetic field distribu- tion was measured along the axis, and a dummy tube was used for adjusting the magnet system. Finally, the magnet was used for the operation of a 68 GHz/500 kW gyrotron, which is part of an electron cyclotron resonance heating （ECRH） system. With an additional auxiliary coil and after adjusting tile magnet system, a maximum output power for the ECRH system of up to 400 kW was achieved.

关键词： ECRH gyrotron superconducting magnet cryogen free

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Research on capacitive current compensation of differential protection on segment parallel lines for different voltage levels

Research on capacitive current compensation of differential ...

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International Conference on Electric Utility Deregulation and Restructuring and Power Technologies (DRPT)

作者： Yan Yang Xianggen Yin Cui Tang Zhe Zhang Xiongwei Wang State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and Technology Wuhan Hubei Province China

ISBN: (纸本)9781467371070

Current differential protection is the main protection of transmission lines including multi-circuit lines, whose sensitivity and reliability is mainly affected by the distributed capacitive current, especially with the widespread application of segment parallel transmission lines, the relationship of the electrostatic coupling between the circuits is more complicated, which makes the distributed capacitive current compensation more difficult. However, in the paper both the interphase capacitive current and the capacitive current between lines are compensated for the segment parallel transmission lines on the lumped parameter Π equivalent circuit model, and by using PSACD and Matlab simulation software, it has further study of the relationship between the differential current and the length of segment parallel lines for different voltage levels, and some suggestions of capacitive current compensation schemes are proposed for segment parallel transmission lines under different voltage levels.

关键词： Power transmission lines Integrated circuit modeling Decision support systems Power industry Sensitivity Integrated circuit reliability

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