A physically-based computer model of aggregate electric waterheating loads

Electric water heaters have been the focus of several previous studies because of their pervasiveness in power systems and their consequent potential importance when considering conservation through more efficient design and operation of the heaters. Also, because such devices are associated with an energy storage capability, they are often considered within load management by direct device control programs. Finally, they tend to be responsible for persistent system load transients in a cold load pickup situation. Understanding of the above issues can be greatly enhanced with the availability of a computer model of aggregate electric water heating loads. A physically-based such model is presented and its dynamic properties are investigated via numerical simulation under various operating conditions and parameter configurations. The results are analyzed in the paper     

Controlling the average residential electric water heater power demand using fuzzy logic

This paper describes a fuzzy logic-based control strategy for shifting the average power demand of residential electric water heaters. The proposed control strategy can shift the average power demand of residential electric water heaters from periods of high demand for electricity to off-peak periods. A minimum temperature for hot water, defined as customer comfort level, is used as a control variable. Water temperature is not allowed to fall below the minimum temperature set by the customer. Simulation results show that the proposed strategy can shift the average power demand of residential water heaters to improve the load factor of residential load profile.     

A novel domestic electric water heater model for a multi-objective demand side management program

This paper presents a novel domestic hot water heater model to be used in a multi-objective demand side management program. The model incorporates both the thermal losses and the water usage to determine the temperature of the water in the tank. Water heater loads are extracted from household load data and then used to determine the household water usage patterns. The benefits of the model are: (1) the on/off state of the water heater and temperature of the water in the tank can be accurately predicted, and (2) it enables the development of water usage profiles so that users can be classified based on usage behaviour. As a result, the amount of ancillary services and peak shaving that can be achieved are accurately predictable and can be maximized without adversely affecting users.     

基于需求侧响应的家庭电热水器优化调度

电热水器是家庭中极为重要的负荷,对实时电价机制下家庭电热水器的优化调度问题进行分析是非常有意义的。首先,将电热水器热力学模型归纳为一阶显式方程,并以此为基础,利用线性整数规划对电热水器的优化调度问题进行求解。然后,对不同程度的舒适区间无选择性调整方案的经济性进行了讨论。最后,探讨了基于多维度信息的综合权重排序法在有选择性舒适区间调整方案中的应用,并对两者进行了比较。仿真结果表明,调整舒适区间上下限能够明显降低调度计划的用电费用。而且,基于多维度信息的综合权重排序法能够有效选择舒适区间调整节点,在很短的调整时长内获得较好的经济效益。     

A probabilistic model for residential consumer loads

A probabilistic model for residential loads is proposed in this paper. The model differs from other similar models in that it uses a beta probability distribution function (beta PDF) to describe the load uncertainty. It further models the load parameter uncertainty as a bivariate distribution of load current means and standard deviations. By separating the probabilistic load uncertainty and the load parameter uncertainty, the model becomes very useful for the analysis of distribution systems where primarily residential consumers are connected, e.g., electrification projects. The model was tested using a Monte Carlo-type simulation and the results are sufficiently accurate for practical design purposes.     

电热膜热水器安全性能设计的几点探讨

电热膜热水器是一种快热式电热水器，是电热膜技术在家用电器上新开发的一种应用产品。本文依据强制性国家标准对其主要安全技术指标进行分析，并提出解决的可行方法。     

组合加热方式在电热水器上的研究及应用

本文通过对储水式电热水器内胆不同位置加热对出热水量的影响进行分析,同时进行对比试验验证并结合理论支持,研究使用热水量的多少与加热内胆中不同位置低温水的关系,满足消费者对不同热水容积的需求.确保大用水量时热水够用,减少少量用水的加热等待时间,同时避免加热多余的热水,做到节能环保.     

Sequential Monte Carlo simulation for composite power systemreliability analysis with time varying loads

The paper illustrates the development and utilization of an annual chronological load curve for each load bus in a composite generation and transmission system and a sequential Monte Carlo simulation approach for composite system reliability assessment. Antithetic variates as a variance reduction technique has been applied to the simulation model to increase the efficiency of the simulation. An approximate method using a load duration curve of the system load and an enumeration process have been applied to the developed load model and the results are compared in this paper     

储水式电热水器防腐技术浅析

目前储水式电热水器在我国城市家庭中保有量大,维护保养、元器件的寿命、内胆和加热器耐腐蚀程度都会影响热水器的使用寿命,其中内胆腐蚀后可能引起漏水、漏电、爆裂等问题,危及用户的人身和财产安全.通过介绍和比对加热管防腐、镁棒阳极和电子阳极等防腐措施在储水式电热水器中的应用,认为电子阳极替换镁阳极是储水式热水器发展的重要方向.     

储水式电热水器热水器输出率的提高分析及应用

本文通过对影响电热水器热水输出率的因素进行分析,结合理论支持,并对改善方案进行对比实验验证,确定了影响电热水器热水输出率的主要因素,为电热水器提高热水输出率确定了技术改进方向,可同步缩短开发周期.最主要的是通过改善措施的推广应用,单台电热水器可以年节约5％的电能,按照中国保有量0.7亿台,一年节约用电1亿度,折合4万个家庭的年用电量.为中国经济的可持续性发展作出了极大的贡献.     

CPS互动架构下的聚合电热水器消纳风能策略

调控聚合温控负荷可高效地消纳可再生能源。针对聚合智能温控负荷群消纳可再生能源场景中的用户使用舒适度及能源消纳效率问题,在基于信息物理系统的可再生能源消纳互动架构下,提出典型温控负荷——电热水器的映射模型。在考虑用户行为信息感知的前提下,提出基于加热-剩余时间比(HRTR)的电热水器群分区方法,以及考虑分区差异性的可再生能源消纳控制策略。不同控制策略的仿真对比表明所提策略能更好地消纳可再生能源且能保证用户的高使用舒适度。     

基于蒙特卡洛法的用电信息采集系统可靠性评估模型

采集终端的可靠性是用电信息采集系统安全运行的关键。本文建立了用电信息采集系统可靠性评估模型，包括采集终端的停运模型、多维特征因子关联失效判定模型以及风险评估方法。分别采用序贯蒙特卡洛法与非序贯蒙特卡洛法对算例进行风险评估，通过对二者的评估结果进行对比分析，序贯蒙特卡洛法因其是采用时间抽样技术，可以在时间轴上对采集系统进行仿真，更适合用电采集系统的风险评估。同时，采用多维特征因子关联模型来判断用电信息采集系统是否失效，对用电信息采集系统的风险指标与多维特征因子关联模型中的阈值E之间的关系进行了研究，获得了二者之间的关系曲线，通过对实际算例分析可知，阈值E的最优取值是曲线中的拐点。     

A centralized demand response control strategy for domestic electric water heater group based on appliance cloud platform

Motivated by the potential ability of the domestic electric water heater (EWH) in demand response (DR), this paper proposes a centralized DR control strategy to dispatch the EWH loads considering a domestic EWH group based on the appliance cloud platform. The objective is to solve the problem of water heater load control when the appliance cloud platform participates in DR of load curtailment. To solve the problem, first, a DR system model of the appliance cloud platform is presented. Second, a model of single EWH thermal dynamics in static mode of operation is built based on energy flow analysis. Third, based on the system model and the model of EWH thermal dynamics, a DR control strategy in the timescale of minutes is proposed to implement DR control of an EWH load group in a centralized way by the appliance cloud platform. Finally, simulation results confirm the viability and efficiency of the proposed control strategy.     

Experiment of an electric water heater with autonomous frequency regulation

Integration of wind power generation into power systems has been limited because of the problem of frequency regulation during light‐load periods at night in some areas in Japan. As a solution, autonomous frequency regulation by electric water heaters (EWHs) has been proposed. A control board to control the power consumption of an EWH is fabricated. It measures both the power system frequency and thermal energy stored in a hot‐water tank, and then turns on/off a heating element according to a control algorithm. It is confirmed that the board can measure power system frequency every 1 s with a resolution of better than 0.01 Hz and that it can measure the vertical temperature distribution in the storage tank with an acceptable accuracy to calculate the future power consumption ratio, which is a parameter that decides the turn on/off of the heating element while considering end‐user comfort. Then, an EWH with autonomous frequency regulation is fabricated by embedding the board, and the EWH is operated to investigate the performance. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

电热水器缓冲材料选择与结构设计

电热水器因其特殊的圆柱形结构,使其运输过程中垫层易碎及存储过程中堆码倾斜.以圆柱形电热水器包装材料为研究对象,分析了产品目前的运输环境,总结出了现有EPS缓冲衬垫的不足.分别对EPS材料、EPO材料进行压缩试验及断裂弯曲试验,对比发现,EPO材料更加适用于圆柱型家用电器.设计出了以EPO材料为基材的缓冲下衬垫结构,对原有EPS下衬垫进行替代,并对缓冲衬垫材料及结构的可行性进行了分析.     

A Monte Carlo model for calculating spot market prices ofelectricity

The authors describe a model for calculating the spot price of electricity of a typical electric power system. The model combines economic dispatch calculations with loadflow and customer response functions in a Monte Carlo simulation model. The model contributes to the implementation of spot prices by providing a practical means of evaluating the spot price of a typical electric power system. It offers several different approaches for calculating generation curtailment premiums and transmission congestion charges. The model formulation is presented and its application is illustrated with case study results     

A physical model of an induction electric heater for cryogenic control devices

A physical model of an induction electric heater for cryogenic control devices has been proposed. The chosen method of research has been justified. The scheme of the model, the structure of the measuring equipment, and a research technique that determines the energy characteristics of the induction heater have been considered, and recommendations on its design have been made. It is shown that it is advisable to use a three-leg laminated core with the winding located in the middle core as a basic element. Such a structure of the induction heater allows one to carry out research varying the material and shapes of the heated object. A microprocessor measuring complex that allows one to control and record up to six electric signals with an error no higher than 2% has been proposed.     

内胆漏水检测系统在电热水器上的应用研究

随着我国居民生活改善的需求,电热水器因其出水恒温、使用舒适、安装方便,一直是消费者家庭热水解决方案的首选,但由于用材、工艺、使用水质等原因,使用一定时间后内胆漏水案例也时有发生.本论文主要论述的是通过在电热水器内部设置检测内胆漏水结构的方法,当内胆漏水时通过控制系统控制电磁阀切断供水水源,从而解决内胆漏水不易察觉,轻者导致热水器内胆表面生锈腐蚀、外壳生锈腐蚀,重者长时间累积的腐蚀致使热水器漏水损坏房屋,甚至造成火灾等问题,给用户减少财产损失.同时通过检测内胆上不同的漏水点,使生产者便于统计制造环节的缺陷来加以改进生产工艺,提升行业产品的质量水平,最终提高产品安全性,带来洗浴的舒适.通过使用本论文方案的电热水器实际使用情况,结合实际测试结果的对比分析,得出本方案对于改进现有电热水器在选材、适用水质、制造工艺方面对于内胆漏水影响的问题改善有重大而深远的意义.     

基于蒙特卡罗法的测量不确定度评定

当采用不确定度传递律进行测量不确定度评定（GUM方法）有困难或不方便时,蒙特卡罗法是实用的替代方法。在建立数学模型、设定输入量概率密度函数的基础上,通过对概率分布随机采样进行分布传递,确定输出量的概率密度函数,从而得到输出量的估计值、标准不确定度以及在指定包含概率下的包含区间,实现对测量不确定度的评定。通过小功率座校准因子测量不确定度评定示例,说明了采用蒙特卡罗法进行测量不确定度评定的实现方法,并与GUM方法进行了比较。     

计及用户舒适度的电热水器多目标优化控制策略

需求响应通过电价或激励信号引导电力用户改变用电行为,提高电力系统的经济性和可靠性,用户的舒适度是需求响应项目在实行过程中需要考虑的重要内容。电热水器用量大、储热性较好,是重要的需求响应资源。文中以自动混水恒温型电热水器为研究对象,提出一种兼顾经济需求和舒适度的灵活调控方案,建立水箱热力学模型与自动混水阀控制系统,引入用电舒适度指标,建立了兼顾电费和舒适度指标的多目标优化模型;通过遗传算法优化求解,得到电热水器(EWH)最佳功率分布时段,并与传统控制策略和以最小化用电费用为目的的单目标优化策略进行对比,最后算例验证了该方法的有效性。