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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 997-1002页

作者： Lei Chen Yong Min Liangshuai Hao Guangzheng Xing Yalou Li Shiyun Xu IEEE Department of Electrical Engineering Tsinghua University China Electric Power Research Institute

This letter studies large-disturbance stability of the power system with a synchronous generator(SG) and a converter-interfaced generation(CIG) connected to infinite bus. The power system is multi-timescale and first simplified. It is shown that the boundary of region of attraction(ROA) of the simplified model is composed of stable manifolds of unstable equilibrium point(UEP) or semi-singular point(SSP), named anchor points, and singular surface pieces. The type of anchor point determines the dominant instability pattern of the power system. When the anchor point is UEP or SSP, the dominant instability pattern is the instability of rotor angle of SG or the instability of phase-locked loop and outer control loop(OCL) of CIG, respectively. Transition of dominant instability pattern can be analyzed with the relative position relationship between UEP and SSP. The effect of OCL is discussed. When the OCL is activated, the ROA becomes smaller and the system is more prone to instability of CIG. It is necessary to consider the OCL when studying the large-disturbance stability of the power system.

关键词： Power system stability Mathematical models phase locked loops Stability criteria Transient analysis Power system dynamics Rotors

Seed laser frequency stabilization for Doppler wind lidar

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Chinese Optics Letters 2012年第9期10卷 52-54页

作者：卞正兰黄崇德陈迪俊彭交波高敏董作人刘继桥蔡海文瞿荣辉龚尚庆 Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences Graduate University of Chinese Academy of Sciences Shandong Huachentel Technology Development Co.

We demonstrate a tunable wavelength-locked seed laser source with high-frequency stability to realize the precise measurements of global atmospheric wind field. An Nd：YAG laser at 1 064 nm is used as the master laser （ML）. Its frequency is locked to a confocal Fabry-Perot interferometer by using the Pound-Drever- Hall method, which ensures the peak-to-peak value of its frequency drifts less than 180 kHz over 2 h. Another Nd：YAG laser at 1 064 nm, as the slave laser, is offset-locked to the above ML using optical phase locked loop, retaining virtually the same absolute frequency stability as the ML. The tunable ranges of the frequency differences between two lasers are up to 3 OHz, and the tuning step length was an arbitrary integral multiple of 200 kHz. The researched seed laser source is compact and robust, which can well satisfy the requirement of the Doppler wind lidar.

关键词： Frequency stability Laser mode locking Neodymium Optical radar phase locked loops

High-precision optical phase-locking based on wideband acousto-optical frequency shifting

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Chinese Optics Letters 2014年第2期12卷 38-41页

作者：王云祥邱琪史双瑾苏君廖云熊彩东 School of Optoelectronic Information University of Electronic Science and Technology of China

We present a high-precision optical phase-locking based on wideband acousto-optical frequency shifting.Increasing the modulating bandwidth stabilizes the loop at a high loop gain,thus improving phase correction capability.An optical phase-locked loop with a wide control bandwidth is constructed.The closed-loop residual phase error is only 0.26°or smaller than λ/1000.The loop exhibits excellent correction capability for high-frequency noises.The correctable frequency range reaches 35 kHz when the noise amplitude is ±λ/2,and becomes even wider for smaller noise amplitudes.

关键词： Amplitude modulation Locks (fasteners) Optical materials phase locked loops

Stable multi-frequency generator based on phase-locked optical frequency combs

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Chinese Optics Letters 2014年第2期12卷 14-17页

作者：张超孙东宁谢玮霖夏宗杨王锶惟石宏霄佟亦天董毅胡卫生 State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong University

A photonic generation of multi-frequency source based on the heterodyne of two phase-locked optical frequency combs（OFCs） is proposed and demonstrated.By applying an optical phase-locked loop,the phase noise induced by optical links is decreased by approximately 70,66,and 35 dB at 0.01,0.1,and 1.0 Hz offset frequencies,respectively.The proposed scheme provides 8 radio frequency signals,the frequencies of which span from 540 to 4040 MHz,with a 500-MHz interval.The number of generated signals can be readily scaled by using OFCs with broader bands,whereas the frequencies can be scaled by tuning the repetition rates of OFCs.

关键词： Natural frequencies phase locked loops

160-Gb/s polarization-multiplexing optical NRZ-DQPSK transmission using differential detection

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Chinese Optics Letters 2011年第10期9卷 30-33页

作者：闻和廖金鑫郑小平张汉一 State Key Laboratory on Integrated Optoelectronics/Tsinghua National Laboratory for Information Science and Technology Department of Electronic EngineeringTsinghua University

Using differential detection, we perform polarization-multiplexing 160-Gb/s optical non-return-to-zero （NRZ） differential quadrature phase shift keying （DQPSK） signal transmission over 100-kin standard single mode fiber at a bit error rate （BER） of less than 10^-9. The enabling technology includes clock recovery, fine dispersion compensation, and polarization tracking for de-multiplexing. Furthermore, a hybrid clock recovery scheme is proposed. The scheme is realized with ordinary devices using an optoelectrical modulator to down-convert the clock frequency and a phase-locked loop for filtering, which can provide an indication signal that simultaneously monitors residual dispersion and tracking polarization.

关键词： Bit error rate Electric clocks Error detection Multiplexing Optical communication phase locked loops Polarization Quadrature phase shift keying Signal detection Single mode fibers

134-W phase locking of two-dimensional four-fiber lasers with improved self-imaging resonator

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Chinese Optics Letters 2010年第7期8卷 680-682页

作者：王炜柯兵张海波薛宇豪李震刘侠周军楼祺洪 Shanghai Key Laboratory of All Solid-State Laser and Applied Techniques Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences Graduate University of Chinese Academy of Sciences

We experimentally demonstrate the phase locking of a two-dimensional （2D） array of four fiber lasers using an improved self-imaging resonator with a spatial filter. The high visibility interference round stripes of the coherent beam profile are observed. The coherent output power of the fiber array exceeds 134 W. Tile entire system operates quite stably, and no thermal effects observe in the spatial filter, indicating that the coherent output power can be increased using this method.

关键词： phase locked loops Resonators Two dimensional

Design and implementation of a clock recovery circuit for fast Ethernet applications

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Journal of Systems Engineering and Electronics 2004年第4期15卷 507-510页

作者： ZhuQuanqing ZouXuecheng ShenXubang InstituteforPatternRecognitionandArtificialIntelligence StateKeyLaboratoryforImageProcessingandIntelligentControlHuazhongUniversityofScienceandTechnologyWuhan430074P.R.China DepartmentofElectronicScienceandTechnology HuazhongUniversityofScienceandTechnologyWuhan430074P.R.China

A circuit architechure to realize clock recovery for fast Ethernet applications is presented, whick includies system architecture, modified MueUer Muller algorithm for 100BASE-TX, phase detector for 100BASE-TX and multiple output charge pump PLL. The clock recovery circuit is verified by TSMC 0.35um 1P5M CMOS process. The results show that this clock recovery circuit exactly extracts the timing information. It has advantages over others for simple and easy implementation.

关键词： Clocks phase locked loops Detectors Charge pumps Adaptive equalizers CMOS integrated circuits Timing

Optimized design of laser range finding system using the self-mixing effect in a single-mode VCSEL

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Chinese Optics Letters 2006年第2期4卷 87-90页

作者：王焕钦赵天鹏徐军何德勇吕亮桂华侨黄伟明海谢建平 Department of Physics

An optimized design of laser range finding system using the self-mixing effect in a single-mode verticalcavity surface-emitting laser （VCSEL） is proposed. In order to improve the ranging accuracy and expand dynamic measurement range, we apply difference frequency analog phase-locked loop （PLL） instead of fast Fourier transform （FFT） to process signal, and choose the optimum triangular wave frequency .fm= 500 Hz and small modulation current △Ip p = 0.28 mA to modulate single-mode VCSEL. The experiment results show that, without controlling the laser＇s temperature, the ranging accuracy is better than 2 mm and the measurement dynamic range is as large as 50-500 mm when the sampling time is 0.1 s and the room temperature is 0--55℃.

关键词： Design Dynamics Laser applications Light emission Modulation Optimization phase locked loops Signal processing Surface phenomena Temperature

On the Periodic Solutions of a Class Two Order Differential System

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建筑科学与工程学报 1996年第3期 135-137页

作者： Li Lin(Beijing Institute of Petro-Chemical Technology 102600)Ying Yirong(Northwestern Institute of Architectural Engineering 710061 )

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关键词： phase locked loops periodic solution stability

A High-speed Low-power Pulse-swallow Divider with Robustness Consideration

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A High-speed Low-power Pulse-swallow Divider with Robustness...