Actively Mode-Locked Fiber Optical Parametric Oscillator

We demonstrate active mode locking of a fiber optical parametric oscillator (FOPO). By inserting an amplitude modulator (AM) into a continuous-wave pumped FOPO loop, intracavity loss is varied periodically. When the modulation frequency of AM coincides with the harmonics of longitudinal modes spacing of the loop cavity, stable 10-GHz pulse train can be obtained. By adjusting the intracavity filter, the wavelength of the pulse train can be tuned over 21 nm.     

An Optical Parametric Amplified Fiber Switch for Optical Signal Processing and Regeneration

An optical parametric amplified (OPA) fiber switch is described in this paper. This device switches input signals without shifting the wavelength by changing the polarization state of the signal using optical parametric amplification. The OPA fiber switch features ultra-broadband, highly efficient switching with a high contrast ratio. We experimentally test the prototype of the OPA fiber switch, which uses a highly nonlinear fiber. Optical demultiplexing of 160 Gb/s differential phase-shift keying (DPSK) signals is demonstrated in the whole C-band and shows that it provides almost penalty-free optical detection. The application of amplitude noise suppression with the OPA fiber switch by using parametric gain saturation is then proposed and demonstrated for a 160 Gb/s DPSK signal. When it is set to an amplitude-limiting condition, the OPA fiber switch successfully increases the optical signal-to-noise ratio by 4 dB and effectively suppresses the phase deterioration in 160 Gb/s DPSK transmission by increasing the system margin by more than 5 dB.     

A Comprehensive Study on Crosstalk Suppression Techniques in Fiber Optical Parametric Amplifier by Modulation Format

With the presence of multiple-WDM input signals, ON-OFF keying (OOK)-modulated signals suffer from crosstalk in fiber optical parametric amplifier (OPA) due to cross-gain modulation (XGM) and four-wave mixing (FWM) effects. We demonstrated substantial crosstalk suppression in one-pump OPA by using return-zero differential phase-shift keying (RZ-DPSK) modulation format, which with its pattern-independent amplitude and subunity duty cycle would be effective in reducing the XGM and FWM effects significantly. By using the RZ-DPSK format, the power penalty was improved by at least 0.8 dB over RZ-OOK, non-RZ (NRZ)-DPSK, and NRZ-OOK formats with four 10 Gb/s channels, separated by 200 GHz spacing. With eight 10 Gb/s channels separated by 100 GHz spacing, a Q-factor penalty of the RZ-DPSK signal was reduced by 2.4 dB compared to RZ-OOK counterparts.     

Parallel-Flux Parametric Voltage Regulator and Comparison with Orthogonal-Flux Parametric Voltage Regulator

An analysis of the parallel-flux parametric voltage regulator shows that it offers all the desirable characteristics of the orthogonal-flux parametric voltage regulator and that it offers several additional advantages. The most striking additional advantage is a much higher energy transfer capability, which implies higher efficiency in material utilization.     

Orthogonal-Flux Parametric Voltage Regulator

A mathematical analysis of the orthogonal-flux voltage regulator explains three important properties of the regulator-the output waveform is independent of disturbances in the input waveform, the output voltage shuts off automatically under low line voltage, and the output voltage shuts off automatically under an overload. The output voltage will not tun on again unless the overload is removed and special action is taken to initiate the output. These properties result from parametric action in a ferroresonant circuit.     

考虑网络传输延迟的二级电压控制

随着电力数据信息网络的发展,为了提高控制系统的灵活性和可靠性,二级电压实时控制系统的控制信息和数据可以逐步发展到在基于TCP/IP的标准数据网络上传输.基于网络传输的闭环控制系统设计必须考虑信息传榆延迟的影响.根据二级电压控制的基本原理,建立了考虑网络传输延迟的二级电压控制模型,设计了基于多步预测和延迟补偿的二级电压控制器,以保证控制系统在网络环境下具有良好的控制性能和稳定性.以新英格兰39节点系统为例进行数字仿真,验证了这种基于网络通信的新型二级电压控制器的性能和效果.     

一类多滞量周期扰动非线性系统的周期解

采用更精确的先验估计，利用拓扑度讨论了一类具有多滞量的周期扰动非线性系统的T-周期解，得到了系统存在T-周期解的充分条件．证明了具有滞后的单种群对数模型在一定条件下存在的正周期解．     

Parametric CMOS upconverters and downconverters

This paper discusses parametric CMOS mixers as potential radio‐frequency front‐end contributors to advanced mm‐wave and sub‐mm‐wave wireless communicators. It outlines fundamental concepts underlying parametric circuit operation highlighting its benefits with regards to power consumption, speed, and noise performance. The implementation of parametric CMOS architectures is detailed. Critical device properties and figures of merit are shown. Measurement results of prototype designs are given. Copyright © 2013 John Wiley & Sons, Ltd.     

Parametric representation of brune functions

It is shown that a parametric representation for Brune functions can be given which, although being more complicated than for Foster functions, is simple enough to be of practical interest. This holds in particular if use is made of substantial simplifications obtainable by eliminating certain subclasses of Brune functions which are of no practical interest. Applications to broadband matching and switched networks are pointed out.     

考虑通信延迟的分散网络化预测负荷频率控制

针对现代电力市场情况下负荷频率控制系统存在不可忽略的通信延迟的问题,提出一种基于网络化预测控制的分散负荷频率控制策略。这种控制策略在改进的广义预测控制的基础上,增加了网络延迟补偿器以补偿固定和随机通信网络通信延迟,此外,还采用带遗忘因子的递归最小二乘法在线辨识预测模型来消除系统运行状态改变和模型不精确的影响。以3区域负荷频率控制系统为例,考虑了发电机组发电速率约束的影响,仿真结果表明,所提出的基于网络化预测控制的分散负荷频率控制不仅能够有效补偿固定和随机通信延迟,且其控制效果优于常规的比例积分型负荷频率控制器。     

计及反馈信号多时滞特性的广域阻尼控制

广域测量系统是由多种通信媒质组成的复杂网络系统。由于不同通信媒质和装置的通信延迟时间各异且具有随机性,闭环电力系统在数学上是一个典型的非线性、多时滞且变时滞的动力系统。文中首先将非线性多时滞的系统模型线性化为线性多时滞的模型,然后分析了线性多时滞系统的稳定时滞域的拓扑性质,最后根据其拓扑性质设计了对时滞的异步变化不敏感的广域阻尼控制器。时域仿真结果表明:对于2区4机系统,当区内通信和区间通信分别具有不同时滞及其随机性的情况下,所设计的控制器仍能有效阻尼区间联络线上的低频振荡。     

Parametric identification in potential transformer modelling

It is shown that a wideband lumped parameter equivalent circuit of a potential transformer can be determined through parametric system identification by the least squares method. Because of limitations in the measuring equipment, up to four different sets of input/output signals are necessary. Compared with other tests for finding the equivalent circuit, this method is less time consuming. Results obtained on a 50 Hz (20/√3) kV/(110/√ 3) V potential transformer are presented     

一种新型参数化绘图软件包

本文介绍了一种新型参数化绘图技术,这种参数化绘图技术的不同之处在于参数化绘图的编程工作不是采取通常的手工编程,而是通过直观的交互式绘图自动完成参数化编程工作.该图形编程软件包是在Auto CAD 10.0版环境下开发出的,并已经成功地运行.     

Parametric synthesis of passive filter-compensating devices

A method of optimal design for passive power filters based on performance optimization in the space of input impedance parameters is considered. The poles and the normalization coefficient of the filter operating impedance are variable parameters. A filter designed with the help of the proposed method satisfies requirements of reactive power compensation, harmonic filtering, and minimizing the amplification of minor harmonics. A design example illustrating the proposed approach is given.     

Parametric performance of a transient streaming electrificationmodel

Recent experimental and field studies of streaming electrification have shown that transient phenomena can be of paramount importance in the distribution and accumulation of charge. Unlike most previous steady-state analyses, the development of a transient model has permitted some of the complex interactions to be isolated and understood. The results of exercising this model here have clarified the dependency on operational, geometric, and chemical parameters, and provide significant insight into the physical and chemical behavior which underlies the electrification process     

Parametric Synthesis of a Track Condition Classifiier

An approach to the synthesis of track condition taught classifiers of the main railways is considered. In contrast to the conventional synthesis of rail chains with two classes of states, it is proposed to divide the track state into three classes, distinguishing a control mode class, which allows reliable identification of a rail break. An algorithm for classifier parameters optimization is developed, the research results are presented. The proposed technique can significantly increase the depth of recognition and classification of the track state space.