Evaluation of the introduction of a micro‐cogeneration system into residential houses based on monitored daily‐basis energy demand data

In order to reduce CO₂ emission from residential sectors in Japan, PEFC with high efficiency and low environmental impact is expected as one of the promising micro‐cogeneration (µCGS) systems. However, the energy demands in houses largely differ from each other and the profiles are also changed every day. Thus, when µCGS is actually introduced, it is necessary to examine the equipment capacity and operation of µCGS in each house. In this paper, the optimization model is developed in order to evaluate the µCGS based on daily‐basis demand data. Using actually monitored energy demand data in four households, the differences between using daily‐basis data and using the monthly‐average data are evaluated from viewpoints of economic and environmental performance of µCGS systems. Moreover, by adding the penalty factor to disposal heat of µCGS, it is seen that system configuration and system operation of µCGS can attain CO₂ reduction and energy conservation as well as cost reduction. ©2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(4): 20–30, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20653     

Optimal operation of residential fuel cell system with rapidly fluctuating energy demand

Household cogeneration systems using proton exchange membrane fuel cells (PEMFC systems) have attracted attention due to their high energy efficiency. To bring out a PEMFC system's performance, it is crucial to use effectively both the electric power and hot water produced from a PEMFC system. Therefore, the optimal scheduling problem of a PEMFC system is very important. However, there are difficulties due to uncertainty of household energy demand. A difficulty to which little attention has been paid so far lies in the difference between the scheduled electric power output and the actual electric power output of a PEMFC system caused by rapid fluctuations in electric power demand. In this paper, we propose a new method of dealing with this problem. In our method, we treat the energy demand as a random variable and calculate its probability density at each time step. Then a constraint that takes account of the energy demand fluctuations is defined through the probability density and is incorporated into the original optimal scheduling problem of the PEMFC system. Using our method, we can deal with rapid energy demand fluctuations in settings of the scheduling problem with long time intervals. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 175(1): 8–17, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21064     

基于区块链的面向居民用户需求响应交易机制

居民用户是潜力可观的需求响应资源,其参与电力市场可带来显著的安全、经济效益,也将大幅提升分布式能源的消纳能力。针对目前存在的居民用户参与市场渠道不畅、机制缺乏的问题,构建了以能源服务公司代理居民用户参与实时电力市场为基础,面向居民用户开展需求响应的交易机制。能源服务公司以最大化需求响应效益为目标,组织居民用户就可提供响应量、期望补偿电价进行投标与竞价,其中补偿电价设计构成对居民用户的激励机制,同时保证金设计形成投标响应量兑现的保障机制,产生制衡负荷调控效果与保证用电自主权的作用。基于区块链技术,借助以太坊Rinkeby网络实现所提交易机制的支持系统。仿真结果证实了所提交易机制的可行性,同时表明区块链技术为解决居民用户需求响应问题提供了很好的实现途径。     

考虑综合需求响应的楼宇综合能源系统能量管理优化

针对楼宇综合能源系统（RIES）能量管理时未充分考虑影响室温因素及其对负荷建模的影响和刚性捆绑RIES、用户从而未全面考虑用户舒适度和用能支出的问题,文中提出了冷、热负荷参与阶梯型补贴和电负荷参与电价型综合需求响应的RIES能量管理优化模型及其求解方法。首先,综合考虑影响室温因素,得到离散化的楼宇热平衡方程,建立楼宇的柔性而非固定的冷、热、电负荷数学模型。其次,建立冷、热负荷参与的阶梯型补贴和电负荷参与的电价型综合需求响应机制。然后,考虑RIES向用户售能的收益、从外部购能的成本和支付用户的补贴费用,构建了以最大化RIES运行利润为目标、计及设备和系统运行约束的能量管理优化数学模型,并采用CPLEX对线性化后的模型进行求解。最后,通过算例仿真表明：计及综合需求响应的楼宇综合能源系统能量管理优化能统筹协调供需两侧资源,提升系统与用户的经济效益。     

基于平衡原理的热电联产系统能量梯级利用

结合热力学第一、第二定律,阐述了小型工业汽轮机引入热电联产系统的基本特性,并以某热电厂为例,给出了小型工业汽轮机驱动给水泵及供热系统循环泵的能量梯级利用的分析方法.结果表明,合理利用工业汽轮机驱动给水泵及循环水泵使循环的尽可能地得到利用,有利于热电厂的能量转换和提高电厂的经济性.     

计及电气热综合需求响应的区域综合能源系统优化调度

区域综合能源系统(Regional Integrated Energy System,RIES)是解决社会能源利用效率低以及可再生清洁能源难以消纳问题的有效途径之一.首先建立了包含风电、多种储能以及电转气(Power-to-Gas,P2G)设备的RIES模型.针对电、气、热负荷柔性特征和可调度价值,结合三种负荷在RIE...     

一种基于价格弹性矩阵的居民峰谷分时电价激励策略

需求响应(DR)是利用价格信号和激励机制来保证电力系统安全可靠和经济运行的重要措施.传统价格激励在所有时间段的激励作用是一致的,可能导致对某个特定时间段的预测精度不够.研究了需求价格弹性矩阵(PriceElasticity Matrix of Demand,PEMD),提出了一种基于弹性效应权重的改进价格弹性矩阵模型....     

计及含氢储能与电价型需求响应的能量枢纽日前经济调度

为了解耦冷热电联供(combined cool,heat and power system,CCHP)机组“以热定电”的运行约束,提高风电消纳能力,降低社会碳排放,提出了计及含氢储能与电价型需求响应的能量枢纽日前经济调度模型。源侧利用冷、热、电、氢4种储能装置,打破CCHP机组热电耦合约束;荷侧引入电价型需求响应改变用户用电行为,通过优化各机组出力与电负荷曲线,增加风机出力。该模型以系统日运行成本最低为目标,引入弃风惩罚成本增加风电消纳,综合功率平衡等约束,调用Gurobi求解器进行优化求解。对不同场景下能量枢纽的优化结果进行分析,并计算燃油汽车的碳排放量以量化氢燃料电池汽车节约的社会碳排放。结果表明:在电价型需求响应策略下,考虑CCHP与含氢储能的能量枢纽系统在增加风电消纳能力的同时降低了系统的日运行总成本,减少了社会碳排放。     

基于能量利用效率和耗能比的节能效果评估体系

本文提出了有效能量和无效能量的概念,并根据产生的原因或性质,对无效能量进行了较为详细的分类讨论.给出了能源利用效率(能效)和耗能比的定义,并介绍了其相互关系.在此基础上,建立了以能效和耗能比为主要指标的新型节能评估体系,并阐述了其重要意义:便于不同场合或者不同措施之间进行节能效果比较,利于有针对性地采取节能措施.     

基于智能电能表的居民需求响应协同策略

随着新能源大量接入,传统由发电跟踪负荷变化的运行模式面临挑战。需求响应是重要的调度资源,信息技术的发展提高了居民负荷的响应能力。在此背景下,负荷服务实体（LSE）通过电价机制协调用户的响应实现供需互动。首先,对家用电器设备的分类和建模得到响应电价的优化模型,建立了基于智能电表的家庭能源管理系统（HEMS）。其次,根据负荷服务实体的供电成本函数得到电价制定模型。以电价和响应功率作为互动信息协调不同用户的响应,进行迭代计算直到收敛,实现整体优化。考虑到用户优化会导致总成本振荡无法收敛,在优化目标函数中添加连续两次迭代间负荷变化的惩罚项。最后,通过算例仿真,分析了上述协同优化策略对LSE和用户的影响,验证了所提策略在平滑功率曲线和降低用户成本的效果。     

基于联邦学习的综合能源系统集成需求响应机制

随着能源集成技术的发展,需求响应已经逐渐进化到集成需求响应(IDR),同时用户对于隐私保护的关注也日益增长。针对拥有冷热电设备和负荷的配电网侧综合能源系统,建立了多能源耦合交互模型,以反映不同能源消费行为之间的相互影响,并以运行成本最低为目标,以设备出力特性和多能源负荷特性为约束,设计了IDR优化模型。为了保护用户隐私,提出了联邦学习(FL)架构,重写IDR模型并将其置于该FL架构中进行迭代计算。仿真结果表明所提计算方法与不考虑耦合的传统需求响应方案相比,具有较好的成本优势;与其他分布式需求响应算法相比,计算效率也有所提升。     

基于需求侧响应和储能电量预估的微网运行调度策略

微网在孤岛运行期间,若微电源和储能装置容量不足,则无法保证网内所有负荷的正常供电。为提高微网供电可靠性,同时尽可能利用可再生能源发电,提出了一种基于需求侧响应和储能电量预估的微网运行调度策略。该策略针对孤岛运行期间的微网,根据微源发电功率和负荷用电功率的超短期预测结果,对储能功率和剩余电量进行预估,结合预估结果和需求侧信息对各类负荷实施不同的调度策略。通过对可平移负荷的平移优化和对可中断负荷的适时逐级投切,达到微网内重要负荷可持续供电和其他负荷停电时间最短的目标。仿真算例验证了所提策略的正确性和有效性。     

基于家庭能耗计量装置的需求侧节能实验研究

选取西安市29户家庭作为数据采集对象,基于电力线载波技术搭建了远程自动抄表系统,其中5户安装了家庭智能计量与显示装置,通过实验验证实时能耗信息反馈是否能够引导人们减少家庭电力和天然气的消费。实验结果表明：通过能耗信息的实时反馈,家庭平均节电量为5.57%,平均节气量为5.86%。     

基于改进协同演化算法的综合能源系统经济性与可靠性优化规划

随着多能流耦合程度的加深以及能源利用需求的多样化,综合能源系统(IES)对规划方案的经济性与可靠性提出了更高的要求.然而,经济性与可靠性之间存在相互制约的复杂关系,导致二者难以实现协调优化.为此,提出了一种基于改进协同演化算法的IES经济性与可靠性优化规划方法.在多场景经济性评估模型和基于马尔科夫链蒙特卡洛法的供能可靠...     

Economic evaluation of demand‐side energy storage systems by using a multi‐agent‐based electricity market

With the wholesale electric power market opened in April 2005, deregulation of the electric power industry in Japan has faced a new competitive environment. In the new environment, Independent Power Producer (IPP), Power Producer and Supplier (PPS), Load Service Entity (LSE), and electric utility can trade electric energy through both bilateral contracts and single‐price auction at the electricity market. In general, the market clearing price (MCP) is largely changed by the amount of total load demand in the market. The influence may cause a price spike, and consequently the volatility of MCP will make LSEs and their customers face a risk of higher revenue and cost. DSM is attractive as a means of load leveling, and has an effect on decreasing MCP at peak load period. Introducing Energy Storage systems (ES) is one DSM in order to change demand profile at the customer side. In the case that customers decrease their own demand due to increased MCP, a bidding strategy of generating companies may be changed. As a result, MCP is changed through such complex mechanism. In this paper the authors evaluate MCP by multi‐agent. It is considered that customer‐side ES has an effect on MCP fluctuation. Through numerical examples, this paper evaluates the influence on MCP by controlling customer‐side ES corresponding to variation of MCP. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(3): 36–45, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20658     

Energy‐saving Technologies for Automobiles

Since entering the 21st century, we have been facing a globally urgent need for all nations, without exception, to deal with environmental concerns such as global warming and energy issues arising from the depletion of fossil fuels. As a countermeasure, next‐generation vehicles for a recycling‐based society that are energy‐efficient, compact, light, low‐cost and reliable need to spread in the society. In this study, we will explain the basic philosophy of how to approach next‐generation energy‐saving technologies for automobiles, the current status and technological issues of internal combustion engines (ICE), hybrid electric vehicles (HEVs), electric vehicles (EVs), and fuel cell vehicles (FCVs) with the latest examples. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

A method for operation of a residential fuel cell system with super capacitor storage and its application to an energy network

We propose electric double‐layer capacitor storage, which has quick response in the output or input of electricity but has a smaller capacity than normal secondary batteries, by application to a residential fuel cell cogeneration system to reduce spike‐shaped electric power consumption. The method is expected to enhance the system utilization rate and to moderate the burdens on a power grid connected to fuel cells or other distributed generators. A low‐pass filter method was introduced for balancing the power supply and demand, and leveling the power input from the grid. According to simulations performed using practically measured load patterns, the appropriate storage capacity is about 500 Wh for a household, and the fuel cell utilization rate or the grid burden improvement is increased by around 40% in comparison with the case of a system without storage capacity. It has been shown that, in an energy network method of five or more households, the storage capacity can be reduced to approximately 40% with extreme burden improvement of less than 90% of the stand‐alone condition. We have also verified the practical operation and the performance of the method by using an experimental system. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(3): 16–27, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20913     

基于供需能量平衡的用户侧综合能源系统电/热储能设备综合优化配置

针对智慧城市背景下用户侧综合能源系统中电/热储能综合优化配置问题研究不足的现状,从供需能量平衡角度出发,考虑电能替代和冷/热/电耦合,建立了综合能源系统中储能设备的综合优化配置模型?采用K-means聚类算法对用户侧的用能需求进行分析并归纳出典型场景。储能配置考虑典型日系统运行优化调度。以综合能源系统年运行费用最低为目标建立电/热储能综合配置优化模型。约束条件考虑了供需平衡?冷/热/电耦合、电能替代、设备安装运行等多种影响因素。优化变量为电/热储能设备的容量以及系统典型场景内设备调度值?算例分析表明所提方法合理可行,在保障系统运行安全性和可靠性的基础上具有明显的经济性。考虑电能替代不仅有利于环境保护,而且可以降低储能配置成本?     

An unequal clustering algorithm based on energy balance for wireless sensor networks

Sensor nodes in sensor networks often gather data and deliver them to the sink. However, the energy and radio range constraints force them to cooperate in transmitting the data to the destination with multihop communication. To achieve this, nodes have to be clustered and some of them are elected as the cluster head nodes to transmit the aggregated data. Unfortunately, the clustering brings extra traffic load to the cluster head nodes, particularly those closer to the sink. These nodes die faster than before as their energy is drained at a high rate. Therefore, some clustering and cluster head election algorithms were suggested to use the unequal clustering size to extend the lifetime of cluster head nodes. However, it is difficult to obtain the accurate cluster size in the process of unequal clustering. Moreover, some cluster head nodes with the overfull cluster members may die early. We propose an enhanced unequal clustering size algorithm to optimize the unequal cluster size in the different layers and balance the dissipation energy of all cluster head nodes. Simulation results show that our algorithm dissipates approximately the same energy of cluster head nodes in the different layers per round and obviously increases the number of rounds of data gathering and transmission. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

DC‐linked hybrid generation system with an energy storage device including photovoltaic generation and gas engine cogeneration for residential houses

For the past few years, hybrid generation systems including solar panel and gas cogeneration have been used for residential houses. Solar panels can generate electronic power at daytime but not at night. But the power consumption of residential houses usually peaks in the evening. The gas engine cogeneration system can generate electronic power without such a restriction, and it also can generate heat power to warm up a house or to produce hot water. In this paper we propose a solar panel and gas engine cogeneration hybrid system with an energy storage device, combined by a DC bus. If a blackout occurs, the system still can supply electronic power for special house loads. We propose a control scheme for the system related to the charging level of the energy storage device and the voltage of the utility grid, which can be applied to both grid‐connected and standalone operation. Finally, we report experiments designed to demonstrate system operation and calculations for loss estimation. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(4): 29–46, 2013; Published online in Wiley Online Library ( wileyonlinelibrary.com ).DOI 10.1002/eej.22321