电力需求侧数据标识的研究与设计

目前,我国电力行业针对需求侧管理数据分类标识编码尚没有一套科学统一的标准.在深入研究现有需求侧数据标识编码方法的基础上,结合用电数据的特点和属性,提出了一套基于树型结构的数据分类体系和统一的标识编码方法.与现有的数据标识方法相比,该方法不仅满足了数据分类编码的基本原则,而且有效地节省了数据传输和存储的资源.该标准的应用为保证信息的一致性、实现电力系统间数据信息的交换和共享提供了基础.     

基于Panel Data模型的中国城市居民生活用电预测研究

通过对中国典型城市居民1992～2006年生活用电及其影响因素数据的聚类分析,得出中国城市居民生活用电在不同收入水平下的用电特征,首先通过分析各个阶段居民拥有电器种类及各种电器的增长率,对不同阶段的电器赋予权重,得到一个综合电器指数作为预测的输入端.其次,基于面板数据模型对不同类型用电居民的生活用电做预测,并得出预测误差,不仅考虑了数据的时间效应还考虑了截面效应,也避免了由于数据序列不足而造成的用电特点不明显.通过对中国典型城市的实证分析,论证了该方法的有效性.     

电力需求侧数据标识的研究与设计

目前,我国电力行业针对需求侧管理数据分类标识编码尚没有一套科学统一的标准。在深入研究现有需求侧数据标识编码方法的基础上,结合用电数据的特点和属性,提出了一套基于树型结构的数据分类体系和统一的标识编码方法。与现有的数据标识方法相比,该方法不仅满足了数据分类编码的基本原则,而且有效地节省了数据传输和存储的资源。该标准的应用为保证信息的一致性、实现电力系统间数据信息的交换和共享提供了基础。     

Dynamic data system modelling of electrical power demand

Time-series models are fitted to electrical load demand and ambient temperature using the dynamic data system methodology to identify the dynamic features of demand and temperature and to evaluate the impact of temperature dynamics on load demand. The models are used to forecast demand and the results agree closely with the actual data.     

Dynamic origin-destination demand estimation using automatic vehicle identification data

This paper proposes a dynamic origin-destination (OD) estimation method to extract valuable point-to-point split-fraction information from automatic vehicle identification (AVI) counts without estimating market-penetration rates and identification rates of AVI tags. A nonlinear ordinary least-squares estimation model is presented to combine AVI counts, link counts, and historical demand information into a multiobjective optimization framework. A joint estimation formulation and a one-sided linear-penalty formulation are further developed to take into account possible identification and representativeness errors, and the resulting optimization problems are solved by using an iterative bilevel estimation procedure. Based on a synthetic data set, this study shows the effectiveness of the proposed estimation models under different market-penetration rates and identification rates.     

基于大数据挖掘的终端用户供电需求划分方法

针对不同供电区域多类型终端用户对供电可靠性的差异化需求以及目前配网侧依据单一供电可靠率指标衡量用户供电可靠性的局限性,提出一种基于大数据挖掘的终端用户的供电需求划分方法。首先,进行终端用户差异化供电需求量化,构建终端用户供电需求信息模型;然后,采用综合K-means与基于密度聚类（density-based spatial clustering of applications with noise,DBSCAN）的大数据挖掘进行终端用户的聚类,实现用户的分类;最后采用改进的灰色关联度实现区域内终端用户可靠性等级划分。通过对含多类型终端用户的供电区域仿真分析,结合对比方案分析,进一步验证所提出的基于大数据挖掘的终端用户的供电可靠性需求划分方法的有效性。     

需量结算用户抄表结算异常情况分析

最大需量的计算是否准确,对于采用最大需量计算基本电费的企业用户来说至关重要。影响最大需量准确性的因素包括最大需量设置周期、抄表例日的调整、最大需量记录装置是否准确等。通过对最大需量计算中产生问题的具体分析、探讨,明确了影响最大需量计算准确性的几种因素,并从管理和技术方面提出相关建议,以期对准确计算最大需量用户的电费提供借鉴。     

基于负荷分解技术的小区电能替代需求分析

电能替代不仅提高了居民家庭用能设备的电气化水平,同时减少了环境污染,符合社会可持续发展对能源消费的要求.提出一种基于负荷分解技术的比例模型,用于估计电能替代后小区总用电增量.首先分析用户用能场景,提出可用于电能替代的电器.基于公开数据集建立这类电器的负荷分解模型,并在此基础上为小区少量用户安装电流采集器获取低频电能数据...     

基于多面体不确定集的需求响应不确定性研究

随着需求响应技术的不断发展,用户侧柔性资源体现出越来越强的可调度潜力。然而由于用户习惯、模型精度、使用环境,大部分分散式可调度负荷呈现一定的不确定性,给负荷精准调度带来一定困难。多面体不确定集相比于传统盒式不确定集,在描述样本不确定性空间时引入负荷相关系数,能够压缩样本空间不确定测度,提高优化策略的精准性和经济性。通过拉丁超立方抽样模拟分析不同相关性条件下盒式不确定集与多面体不确定集的策略表现,可知基于多面体不确定集建立的负荷群调度优化策略模型能够降低调度成本,甄别优质响应资源,体现负相关负荷的互补性。     

满足工艺角覆盖率的模拟运算放大器设计

电源电压、工艺偏差和温度变化(PVT)对电阻、电容、晶体管、MOS管等的参数和特性都会产生一定的影响,从而影响电路的性能.从满足工艺角覆盖率的角度出发,进行模拟运算放大器的设计,首先采用对称型运算跨导放大器的形式,提高了匹配,提供了更好的失调和CMRR特性;同时采用共集共射输入,提高了输入电阻.其中共射管采用射极负反馈结构增大了线性输入范围,提高转换速率.仿真结果表明,所设计的运算放大器可满足工艺角覆盖率的要求.     

电力需求与GDP关系的面板数据模型分析

基于面板数据模型对冀北5市电力需求与GDP之间的关系进行了分析,解决了一般模型对二维数据尤法处理的问题。通过模型形式设定检验判断不同地Ⅸ用电规模、用电结构是否存在差异,为崩电分析提供了一种新的手段。分析了模型中各方程的截距和斜率,实现了各地区特点的定量化比较。在面板数据模型中应用虚拟变量法,证明了经济周期对用电需求有显著影响。     

美国需求响应综述

需求响应是智能电网框架里的一个重要组成部分,处于配用电侧。需求响应被认为是输电系统和电能批发市场可靠、经济运行的一个重要因素。住美国电力市场下的主能量市场和辅助服务市场,实施的需求响应计划可分为基于市场和基于可靠性2种。往不同的电力市场机制下,需求响应产品可包括能量、辅助备用服务以及容量。首先对智能电网下的需求响应新特点进行分析,进而概述美国智能电网下的需求响应计划及其参与的产品市场,再分析新形势给电网带来的影响,最后对中国实施需求响应提小一些建议。     

兼容广义需求侧资源的配电网经济运行研究

在考虑了广义需求侧资源参与竞争性电力市场的情况下,构建了兼顾电能市场和备用市场的基于广义需求侧资源的配电网经济运行模型,以期实现发电侧和用电侧资源的联合优化调度.算例分析结果表明,该模型在技术上可行、经济上有效;且主网资源价格、备用需求和备用使用概率等为配电网经济运行的主要影响因素.     

关于推进需求响应调度的若干建议

概述可再生能源电力消纳困难是我国电力系统绿色运行面临的突出问题,分析了需求响应调度是改善电力系统绿色运行的战略选择和现实有效途径,并就推进需求响应调度提出了一系列具体建议。     

电力需求侧管理(PDSM)综述

介绍了电力需求侧管理(PDSM)的基本概念和国外的实施情况,阐述了我国实施电力需求侧管理(PDSM)的紧迫性和可行性,分析了在我国实施电力需求侧管理(PDSM)的支持环境和技术支持措施,提出了有待进一步研究的问题.     

电力需求侧管理(PDSM)综述

介绍了电力需求侧管理(PDSM)的基本概念和国外的实施情况,阐述了我国实施电力需求侧管理(PDSM)的紧迫性和可行性,分析了在我国实施电力需求侧管理(PDSM)的支持环境和技术支持措施,提出了有待进一步研究的问题。     

Reactive power demand of transformers with DC bias

It has been observed that the presence of DC bias currents/fluxes in power transformers generates harmonic currents and voltages with an associated increase in reactive power (kVAr) demand resulting in a voltage drop. Such DC biases can occur: in transformers near high-voltage DC (HVDC) terminals; due to imperfect or half-controlled rectification resulting in DC, even and odd harmonics; because of geomagnetically induced currents; as a consequence of nuclear explosions changing the Earth's magnetic field; and due to rectifiers working in a normal (e.g., half-wave) mode. The actual network conditions causing such kVAr demand and its suppression, canceling, or mitigation are not very well understood, particularly for transformers with three legs. This article explains for the first time this kVAr demand and its suppression based on experimental data. Tests were performed for three-phase power transformers with three legs, with or without the influence of a magnetic tank     

Supplementing demand management programs with distributed generation options

Ever increasing electrical energy demand is forcing power serving entities around the world to use various demand management programs to help in stressful times of the electric power grid. Demand management programs aim to control electrical energy demand among customers and create load relief for electric utilities. Recently demand management contracts have been designed in which incentives are offered to customers who willingly sign up for load interruption. In recent years much technological advancement has been made in distributed generation, and the cost of using this option can bring about extra flexibility into existing demand management schemes. This paper explores the use of distributed generation technology within the existing demand management ideas. More specifically, it compares economic aspects of using demand management contracts with the use of distributed generation. A key observation of this paper is that there may be cases where it is more beneficial to use distributed generation rather than demand management contracts.     

Medical flow measurement with drop counters. Methods for improvingaccuracy

Several methods for improving the accuracy of drop counters are presented. A table gives a summary of the characteristics of the sensors described and the results achieved as compared with a reference balance. A disadvantage of all sensors considered is the effect of their inclination, which can cause errors in measurement in clinical applications. Another common disadvantage of all methods is that they are sensitive to mechanical shock and oscillation. Further developments may include utilization of statistical methods and filtering algorithms to improve accuracy. Especially interesting for the measurement of drop volume are sensors that measure travel time using multiple light-barriers or other configurations. Another point of interest may be the measurement of the volume of the growing drop. Optical principles seem to be a very promising means for this type of measurement. For the measurement of drop mass, it is very advantageous to combine gravitational and momentum measuring methods to provide two independent values. A major advantage of this technique is its independence of the liquid type, if used as a balance. The mass flow sensor detects very low flow rates and can be used with different media without recalibration. In future studies, silicone with a stiffness independent of temperature changes will be investigated. Another aim for further development is application to flow rates below 1 mL/h