决策支持系统在电力燃料运营中的应用

从决策支持系统的基本方法出发,介绍该系统在电力燃料运营中的应用,利用系统中的分析模型,重点对电力燃料运营管理中重要指标标煤单价问题进行分析和预测,可为决策提供一定依据,采用的方法正确可行并已得到验证。     

面向火电厂厂级监控信息系统应用和基于组件对象模型实现的决策支持系统

基于火电厂厂级监控信息系统(SIS)的目标分析，依照决策支持系统（DSS）的结构及其设计思想，在对DSS的总体结构和对火电厂SIS的问题体系进行深人研究的基础上，基于组件对象模型（COM）技术，对面向SIS应用的DSS的详细设计和实现，包括人机交互与问题处理系统、数据库系统、模型库系统等主干子系统的设计和实现提出有效的方案。     

计及不确定性的高比例清洁能源在微电网中的消纳

近几十年来可再生能源在电网的渗透率逐年提高,其不出力确定性使电网运行更加复杂.因此,为了提高再生能源(renewable energy,RE)接入的可靠性,需要电力系统具有高度灵活性.随着储能系统(ener-gy storage systems,ESS)接入和需求响应(demand response,DR)研究的深入,...     

Evaluation of adipose tissue distribution in obese fa/fa Zucker rats by in vivo MR imaging: effects of peroxisome proliferator-activated receptor agonists

High-resolution MRI of obese (fa/fa) Zucker rats was investigated to characterize and assess in vivo adipose tissue distribution. Thirty animals were gavaged with a placebo, a PPAR activator (pioglitazone), or a dual PPAR activator (LM 4156). At day 15, T₁-weighted images were acquired in vivo using a 2TMRI system with a high in-plane spatial resolution (254 m). Fat volumes of selected territories were measured by image segmentation, and the retroperitoneal fat was weighed post-mortem. Body-weight gain was significant with pioglitazone (101.8±5.9 g, p<0.01 vs. placebo). The good quality of MR images allowed the delimitation and quantification of different fat territories. In response to pioglitazone, the retroperitoneal fat was more important compared to placebo (+23%, p<0.01) while subcutaneous fat was not different. No significant effects were observed with LM 4156. In vivo measurements of fat volumes were strongly correlated with ex vivo tissue weights (r=0.91). High-resolution MRI provides an in vivo measurement of adipose tissue distribution in obese Zucker rats. Specific fat depots of regions that were particularly involved in drug response were determined in vivo. Fat remodeling was observed with pioglitazone but not with a dual PPAR activator (LM 4156).     

一种电能质量扰动监测与识别新方法

为了能够为各类电能扰动事件的本质研究和有效治理提供准确、可靠的依据,提出基于时频原子变换（timefrequency transform,TFT）和改进型自组织映射神经网络（improved self-organizing map,ISOM）的电能质量扰动在线监测与识别新方法。TFT具有自适应复带通滤波特性,其频窗中心与频窗半径解耦及频窗宽度不受中心频率的约束,可以灵活调整。通过设置恰当的频域窗口,TFT可有效抑制邻近频率分量的相互干扰,且有较好的动态响应速度。TFT能准确监测电力系统波形中电能质量事件,并为类型识别提供物理意义明确、指标具体的实时模式特征。依据TFT提取的特征向量,ISOM可准确识别单一或同时存在的多重电能质量事件,并对其严重程度进行直观表达,能动态反映电能质量事件各自的发展变化轨迹。仿真验证结果表明了所提出方法的有效性和优越性。     

新风量、新风品质及新风处理对室内空气品质的影响

分析了新风量、新风品质及新风处理对室内空气品质的影响,提出在热舒适基础上的可接受的室内空气品质必须考虑节能的需求,指出带热回收装置的新风预处理系统和独立新风系统是暖通空调系统的发展方向。     

结合二代小波与快速傅里叶变换的L电能质量数据压缩算法

针对大量电能质量数据的传输和储存问题,提出一种结合快速傅里叶变换(FFT)和二代小波(SGWT)的电能质量数据压缩算法,包括FFT、SGWT有损压缩和LZW(字符串表编码)无损压缩的流程图。分别对暂态和稳态扰动信号进行仿真比较,结果表明所提出的算法与FFT以及SGWT相比,可有效降低存储空间,可得到更高的压缩率且在压缩比、均方误差与运行时间等性能指标上取得较好平衡。     

模式分类方法在电能质量扰动信号分类中的应用综述

文中首先将电能质量扰动信号分类方法划分为模式分类法与非模式分类法,然后简要介绍了模式分类法,综述了人工神经网络、贝叶斯分类、专家系统、支持向量机几种典型的模式分类方法在电能质量扰动信号分类中的应用,对比分析了各种方法的利弊,并对现存的问题及以后的发展趋势进行了展望。     

监控组态软件数据库系统体系的研究及实现

基于通用实时数据库特点,重点研究了监控组态软件实时数据库的功能和特点,提出了一种监控组态软件中的实时数据库系统(RTDBS)的体系结构,并且探讨了该体系结构的组成.最后,给出了它的实现模型及性能指标数据.     

A demand response based solution for LMP management in power markets

In recent years, most of the countries around the world have gone through the power system restructuring process. Along with this restructuring in power market there are some issues like LMP problems that need to be solved base on demand response. In this article, demand-side management (DSM) programs have been effective to address LMPs in the market and system operators experience throughout their day-to-day activities. In particularly, these programs can help independent system operator (ISO) to reduce price volatility during peak demand hours. For achieving this purpose, a multi-objective optimal power flow is proposed to study the impact of a model for a demand response program on price spikes. Actually a new framework using demand response program was presented for price spikes reduction. As a case study for the formulation, the IEEE 9-bus, load curve of Mid-Atlantic region of the New York network is used to compare local prices in the system with and without emergency demand response program (EDRP). The study results demonstrate the effectiveness of these programs in an electricity market and showing them as appropriate tools in managing the LMPs of the power market more efficiently.     

基于数据仓库和OLAP的电力决策支持系统的设计

数据仓库(Data Warehouse)和联机分析处理(OLAP,On-Line Analytical Processing)是构建决策支持系统(DSS,Decision and Support System)的关键技术。文章首先以电力系统为研究背景,分析了目前电力系统中企业信息化建设的不足,提出了构建DSS的解决方案;然后简要介绍了数据仓库和OLAP的基本概念、特点及其体系结构;最后针对电力系统中的电力变压器运行负载情况,设计出一种电力决策支持系统,具体实现了系统的体系结构、数据仓库以及OLAP设计,为电力系统的决策分析提供有效手段。     

A probabilistic approach to stability and stabilization of networked control systems

In this paper, a probabilistic approach is proposed to study the modeling, stability, and stabilization problems for networked control systems (NCSs) with simultaneous random network communication delay and data dropout. Different from existing modeling approaches, the proposed NCSs model naturally captures the stochastic characteristics of the considered NCSs by taking into account the effects of the random network communication delay and data dropout. Based on the developed NCSs model, necessary and sufficient conditions of stability analysis, state, and output feedback stabilization problems are tackled. Moreover, necessary and sufficient stability and stabilization conditions are also presented for the case when the occurrence probabilities of delay and data dropout are partially known. Finally, three numerical examples are provided to demonstrate the effectiveness and the reduced conservatism of the proposed method. Copyright © 2014 John Wiley & Sons, Ltd.     

一种实用的幅值和功率测量新算法

为解决电力系统全局信息的快速准确测量问题,提出了一种实用的幅值和功率测量算法。结合电力系统实际情况,对离散傅里叶变换(DFT)算法中的强非线性部分进行了合理简化,从而可以方便地利用DFT计算结果对其自身进行补偿修正。该算法充分利用了DFT算法的快速、对谐波有抑制能力的优点。与传统DFT方法相比,文中方法测量精度有明显提高,且计算负担增加很少。算例验证了这一特点。     

SFTP在网级与省级电能质量监测系统中的应用

根据对传统电能质量监测系统的分析与研究,提出了基于网级电能质量监测中心系统与省级电能质量监测系统之间历史数据传输的方式和技术协议。利用安全的文件传输协议SFTP传输省级电能质量监测系统的历史数据到网级电能质量监测中心系统,从而解决了省级系统与网级系统间数据传输安全性和可靠性的问题。     

Output feedback stabilizability and passivity in nonstationary and nonlinear systems

Passivity properties and passivity conditions have been shown to be very important for the stability of various methodologies of control with uncertainty in linear‐time‐invariant (LTI) systems. Many publications have defined the conditions that allow LTI systems to become strictly passive (and their transfer function strictly positive real) via constant or dynamic output feedback. As beyond the usual uncertainty, real‐world systems are not necessarily invariant, this paper expands the applicability of previous results to nonstationary and nonlinear systems. The paper first reviews a few pole–zero dynamics definitions in nonstationary systems and relates them to stability and passivity of the systems. The paper then finds the sufficient conditions that allow nonstationary systems to become stable and strictly passive via static or dynamic output feedback. Applications in robotics and adaptive control are also presented. Copyright © 2009 John Wiley & Sons, Ltd.     

Global hybrid modeling and control of a buck converter: A novel concept

Several attempts have been made to design suitable controllers for DC–DC converters. However, these designs suffer from model inaccuracy or their inability to desirably function in both continuous and discontinuous current modes. This paper presents a novel switching scheme based on hybrid modeling to control a buck converter using mixed logical dynamical (MLD) methodologies. The proposed method is capable of globally controlling the converter in both continuous and discontinuous current modes of operation by considering all constraints in the physical plant such as maximum inductor current and capacitor voltage limits. Different loads and input voltage disturbances are simulated in MATLAB and results are presented to demonstrate the suitability of the controller. The transient and steady‐state performance of the closed‐loop control over a wide range of operating points shows satisfactory operation of the proposed controller. Copyright © 2008 John Wiley & Sons, Ltd.     

一种变采样周期的网络控制系统控制与调度协同设计新方法

针对存在时变时延与随机丢包的变采样周期网络控制系统,提出了一种鲁棒控制与采样周期调度协同设计方法。运用模糊控制中的最大隶属度解模糊方法,依据系统误差大小使得采样周期在几个固定值之间切换。根据采样周期计算出满足性能指标的状态反馈矩阵K,并按照当前的采样周期选择相对应的K来计算控制量。可以避免由同时考虑时变采样周期与时变时延所带来的强保守性。设计鲁棒控制器时采用Markov 链描述系统随机丢包,使得建模更贴近实际情况,运用标称点法确定由时延组成的系统不确定项的范数界,可以进一步减小保守性。最后,数值仿真结果验证了该协同设计方法的可行性与有效性。     

STATCOM-PSS控制对风电并网系统稳定性和电能质量的改善

如何保证风电并网系统的暂态稳定性和电能质量不降低是当前需解决的问题。基于解耦控制策略和同步发电机PSS控制策略,提出在风电并网中系统采用STATCOM-PSS控制的解决方案。研究表明STATCOM-PSS控制策略能有效恢复风电并网处的故障后电压,提高风电场的故障穿越能力,改善风电并网系统的暂态稳定性和风力发电机组的电能质量。     

A unified approach for the solution of power flows in electric power systems including wind farms

This paper proposes a solution approach of the power flow problem to assess the steady-state condition of power systems with wind farms in a single frame of reference, in which the state variables of the wind generators are combined with the nodal voltage magnitudes and angles of the entire network for a unified iterative solution through the Newton-Raphson method. Different wind energy conversion systems (WECS) are mathematically derived from the steady-state representation of the induction generator. Suitable strategies for initializing the state variables of the wind generators are also proposed in this paper. Lastly, three numerical examples are presented to numerically illustrate the applicability of the proposed approach.     

DSP主机接口在分布式电能质量监测仪中的应用

提出在分布式电能质量监测仪中采用数字信号处理器(DSP)的主机接口(HPI)实现双CPU间的通信.整个电能质量监测系统采用高级精简指令集计算机(ARM,型号S3C2410X)和DSP(型号TMS320C6713)双CPU结构的总体设计方案.文中给出了HPI的硬件连接图,介绍了在WinCE操作系统中编写HPI驱动程序的要点,给出了监刚仪使用的HPI驱动程序的接口函数HPI_Init的流程图,以及驱动程序对 S3C2410X相关寄存器的设置,最后介绍了影响HPI通信速度的因素和监测仪所采用的HPI通信规范.