异步电机用混合式模糊搜索效率优化控制研究

运行在额定工况的异步电机效率较高，但在轻载运行时效率会显著下降，因此进行异步电机的效率优化研究，对于节约能源、控制环境污染具有重要意义。基于损耗模型控制(LMC)的研究成果以及在线搜索控制(SC)的研究成果，提出了一种新型混合在线式直流最小功率模糊搜索效率优化控制算法(FLSC)，算法对模糊集合所作的不对称隶属度函数设计，解决了系统在效率最优点处的振荡问题。仿真以及电机台架实验表明，FLSC算法兼有LMC算法和SC算法的双重优点，能够显著提高系统的控制性能。     

660MW W型火焰锅炉燃烧系统低氮改造

鉴于国内W型火焰锅炉低氮改造成功案例较少,邯峰电厂根据"多级引射、耦合回流、分级燃烧"W型火焰锅炉低氮燃烧理论,对美国福斯特惠勒能源公司(FW公司)设计生产的660 MW W型火焰锅炉燃烧系统进行了低氮改造,在锅炉效率变化不大的情况下NOx排放量大为降低。     

高速多级圆筒型直线感应电机基础理论研究

针对目前直线感应电机推力小,速度低的问题,提出一种高速多级圆筒型直线感应电机,其具有动子质量轻,推力大,加工难度小等优点,特别适于高速发射领域.基于电磁场理论,推导考虑级间耦合的直线感应电机数学模型,用该模型分析电机的动态性能,得到了定子电流、动子速度和加速度等参数变化规律,并进行样机实验,其仿真结果与测量结果进行对比...     

一种实用的不良数据处理方法

电力系统中不良数据的存在会降低状态估计的收敛性能,甚至造成状态估计失败。如何可靠检测和修正不良数据成为状态估计应用的难题。针对这个问题,文章从状态估计实用化角度出发,首先提出越限系数H的概念来表征量测量的越限程度,然后利用电力系统量测量之间的约束关系和H值,提出一种基于网络节点分级的不良数据处理方法。该方法首先通过计算输入输出差额检测系统总的功率是否平衡,修正部分可疑量测量;接着对系统节点进行分级,根据节点分级结果运用基尔霍夫电流定律逐级逐点检测并修正可疑数据,最后通过状态估计得到最终结果。工程算例表明该算法简单、实用、速度快,能够过滤、智能修复和补充实时数据,有效地辨识和修正不良数据,提高了状态估计的收敛性能。     

微燃机冷热电三联供系统建模及热力学分析

某200 k W微燃机冷热电三联供系统按季节负荷特点分为热电联供和冷电联供2种模式,基于Ebsilon软件对该系统构建模型并进行仿真模拟及性能分析,分别计算出不同工况下冷热电三联供系统的一次能源利用率和效率。结果表明:冷电联供时,环境温度从24℃变化到38℃,系统一次能源利用率为65.2%~68%;热电联供时,环境温度从-10℃变化到24℃,系统一次能源利用率为66.4%~74.2%。系统冷电联供(取环境温度为32℃)运行时,效率为31.1%,损失之和为451.92 kW,当微燃机负荷率在30%~100%变化,系统一次能源利用率为60.3%~66.9%;系统热电联供(取环境温度为0℃)运行时,效率为38.5%,损失之和为408.4 kW,当微燃机负荷率在30%~100%变化,系统一次能源利用率为54.4%~68.5%。通过搭建的微燃机三联供系统模型对实际运行数据进行分析,结果认为:实际运行工况主要存在冷负荷较小的问题,通过蓄冷罐蓄存多余冷量,系统的一次能源利用率可提高13.8%。     

填充球蓄热室热效率影响因素数值分析

利用自行设计的填充球蓄热室蓄热放热过程模拟系统,从蓄热室几何参数,相变球性能参数和外界操作参数三个方面分析了各因素对热效率的影响,得出一定的规律,对工程设计具有一定的指导作用.     

变电站能效评估指标体系及建模方法

变电站在输送电能的过程中会产生大量能耗,变电站能效评估是进行电力系统能效提升的基础。首先,分析了变电站的能效及其影响因素;然后,从电气设备性能、系统运行状态、建筑结构性能和运行环境因素4个角度构建变电站能效评估指标体系,并给出指标计算模型;采用层次分析法(AHP)求取各能效指标权重,并利用灰色关联分析法对变电站进行能效综合评估;对实际变电站数据进行仿真分析,结果表明基于灰色AHP的变电站能效评估指标及模型能够有效反映变电站的能效水平。     

基于定子磁链规划的异步电机最优效率控制

针对异步电机效率优化问题,提出了在直接转矩控制下采用定子磁链规划的最优效率控制方法。基于电机的损耗模型,通过效率优化算法在线检测计算各个定子磁链值对应的功率损耗并进行在线搜索,寻求消耗功率最小的定子磁链值。仿真结果表明该方法能够减小异步电机轻负载时的输入功率,明显提高电机在轻负载情况下的稳态运行效率,同时保持较好的转矩动态性能,并且收敛速度较快。     

Deployment of cybersecurity for managing traffic efficiency and safety in smart cities

Boosting the concept of smart cities for implementing an intelligent management of traffic congestion while reducing cybersecurity concerns will not only be more efficient for reducing traffic congestion but also more resilient to cyber incidents. In this paper we proposed a framework that can act as a generalized firewall and work interactively with several critical infrastructures in a smart city to protect the respective operations from a variety of cyber threats. The objective is to develop several steps for a comprehensive traffic management framework in smart cities that facilitates the cooperation among drivers and between drivers and the traffic management authority. The transformative nature of the proposed study supports its applications to a variety of networked critical infrastructures, including electricity, gas, water, rails, and telecommunications, as they intend to respond effectively to a wide range of weather- or human-related disruptions. The contributions of this paper include: Improving the traffic management performance in urban transportation systems, assessing and mitigating the cybersecurity risk in urban traffic management, and facilitating efficient and cyber-secure traffic management in metropolitan areas; Developing and testing an interactive simulation platform for evaluating the traffic management performance under various traffic conditions; Validating and demonstrating the applications in a practical urban transportation system; Disseminating the proposed study results to a wide range of concerned audiences via user-group meetings, detailed education forums, and a close collaboration with the local traffic management authority.     

The Pay As You Save program in rural Arkansas: An opportunity for rural distribution cooperative profits

This case study highlights the success of the Ouachita Electric Cooperative’s Pay As You Save program in Camden, Ark., in bringing both electricity bill savings to customers and benefits to implementing utilities, especially in rural areas. It is not specifically a low-income energy assistance program, but does benefit customers with high energy burdens. Through its on-bill tariff design, PAYS overcomes many barriers, such as the split incentive challenge and the need for upfront outlays.