110kV依克湖智能变电站保护组网方式分析

通过分析DL／T860规约标准下的“三层两网”组网方式,对110kV依克湖智能变电站保护配置组网方案进行研究。对于信息传输量大、可靠性要求高的主变保护和母线保护,采用光纤直接采样直接跳闸的组网方式,保护运行可靠,动作快速;对于备自投装置、低周低压减载等采用光纤网络采样网络跳闸的组网方式,能较好的实现保护信息量的配置,保护运行稳定可靠。采用双绞线以太网的MMS网络组网方式,按DL／T860规约建模,能形成智能化变电站监控系统。     

配电系统串联型电能质量补偿器的研究

本文介绍了配电系统串联型电能质量补偿器的构成及其工作原理。为了克服以往一些检测方法的缺陷和快速、准确地检测出电网电压的降落、升高、不对称以及谐波等各种,提出了一种以广义瞬时无功理论为基础的改进的检测方法。仿真及实验结果表明,以该检测方法为基础的串联型电能质量补偿器可以有效地补偿电网中的各种干扰,提高负载侧的电能质量。它将是解决配网电能质量问题的一种十分有发展前途的技术。     

复杂约束下梯级水电站短期厂网协调多目标MILP模型

随着电力系统负荷的增长及峰谷差的加大,电力消费结构不断优化.电网侧期望水电利用灵活启停特性充分参与电网调峰,以减小系统的峰谷差.电厂侧则在调度过程中追求梯级电量最大,以实现效益最大化.为协调厂网两侧对梯级出力过程的矛盾需求,同时满足厂网两侧复杂的约束条件,以梯级水电站的机组为调度单元,选取梯级发电量最大和电网剩余负荷峰谷差最小为目标函数.充分考虑电网侧联络线约束及电站侧尾水顶托、限制出力曲线、不规则振动区等与水头相关的复杂约束并线性化处理,构建了复杂约束条件下厂网协调多目标短期混合整数线性规划模型,对多目标函数进行归一化处理并采用权重法转化为单目标函数,利用Gurobi商业求解器进行模型求解.中国红水河梯级水电站的实际应用表明所提模型可获得兼顾厂网两侧目标期望的梯级发电计划.     

用聚合矿物复合材料制造铣床夹具

经过分析和反复试验,确定了聚合矿物复合（ Ｐ Ｍ Ｃ）材料制造铣床夹具脱模剂,设计了所用浇铸模具、夹具中的预埋件在大量反复试验的基础上,确定了实用的 Ｐ Ｍ Ｃ制造机床夹具的完整工艺过程     

对全过程工程造价管理与控制的探讨

随着社会经济的发展,现代施工进程成为十分复杂的生产活动。如何在保证工程质量的前提下,降低建设工程成本．加强建设工程造价管理,直接关系到投资效益和社会效益。本文主要从决策阶段工程造价的控制、设计阶段工程造价的控制、招标阶段工程造价的控制、施工阶段工程造价的控制、竣工结算阶段工程造价的控制展开论述。     

多层过盈联接的设计方法

为提高多层过盈联接件的使用性能和工作可靠性,基于传统设计方法提出了一种新的设计方法.以锁紧盘为研究对象,按照由里往外的次序采用厚壁圆筒理论与Lame方程对主轴与轴套接触面进行计算,采用轴套校核方法对轴套与内环接触面进行计算以及采用内环受力分析对内、外环接触面进行计算.与传统设计方法相比,提出的方法全面考虑各设计参数的影响,计算所得结果与实际模拟的结果规律相符,误差小且精度较高.最后通过实验验证了锁紧盘能够传递实际运转过程中承受的载荷,满足设计给定的工况要求.     

Electric Vehicle Charging Simulation Framework Considering Traffic, User, and Power Grid

The traffic and user have significant impacts on the electric vehicle (EV) charging load but are not considered in the existing research. We propose a novel integrated simulation framework considering the traffic, the user, and power grid as well as the EV traveling, parking and charging based on cellular automaton (CA). The traffic is modeled by the traffic module of the proposed framework based on CA, while the power grid and user are modeled in the EV charging module. The traffic flow, user’s charging preference, user’s charging satisfaction, and the total supply capability (TSC) in the surveyed region are considered in the proposed framework. Two cases are carried out to show the interactions between the user and power grid. It is shown that the proposed framework can accurately simulate the interactions among traffic situation, user’s behavior and TSC, which are significantly lacking in the existing research. The proposed framework is scalable in considering additional interrelated elements.     

Crystallographically oriented W-type barium hexaferrite BaZn2Fe16−xScxO27 with high squareness ratio

A series of oriented W-type barium hexaferrites of composition BaZn₂Fe_16?xSc_xO₂₇ (where x?=?0, 0.1, 0.2, 0.3, 0.4) has been synthesized by conventional ceramic methods and characterized by XRD, SEM, EDS, FTIR, and VSM. In this work, the effect of trivalent Sc substitution for trivalent Fe on the structure and magnetic properties of Zn₂W has been studied. The XRD results showed that all the specimens consisted of single phase of W-type ferrites. EDS analysis confirmed that the content of Ba, Zn, Sc, and Fe were closed to the elemental composition of BaZn₂Fe_16?xSc_xO₂₇. The SEM revealed the hexagonal platelet-like structure of the BaZn₂Fe_16?xSc_xO₂₇ and the average grain sizes of all samples remain in the range of single domain dimension (0.5 µm?~?1 µm). The SEM also demonstrated that the samples maintained high crystallographic c-axis texture when Sc³⁺ content was less than 0.4. The SEM results were consistent with magnetic hysteresis loops. As the function of Sc substitution, the squareness ratio (M_r/M_s) ranged from 0.78 to 0.82, which was critical for self-biased application. Moreover, the magnetocrystalline anisotropy field (H_a) decreased. The saturation magnetization (M_s) increased from 53.61 to 54.04 emu/g as x increased from 0 to 0.1, and then it decreased to 46.50 when x > 0.1. The samples showed other excellent magnetic properties, such as appropriate anisotropy field (~?9 kOe),and high coercive fields (~?1300 Oe). Therefore, the prepared Zn₂W ferrites are suitable candidate for the microwave devices operated at low frequency.

     

Annealing temperature-dependent morphology and structure of ZnO nanoflowers for high-sensitivity ultraviolet photodetectors

Journal of Materials Science: Materials in Electronics - Here, using a facile hydrothermal method, the single-crystalline ZnO nanoflowers were firstly synthesized and then annealed at different...     

考虑㶲损失的三联供系统容量配置与运行模式研究

节能减排一直是世界各国持续关注的热点问题,综合能源三联供系统因其具有更高的一次能源利用率而被广泛应用。针对综合能源三联供系统的容量配置和运行模式规划问题,提出考虑(火用)损失的综合性能指标作为优化的目标函数,从高效、低碳、经济三个方面进行综合优化。以燃气轮机的容量和运行模式为设计变量,建立综合能源三联供系统容量配置与运行模式研究模型。将此方法应用到某宾馆建筑的联供系统进行分析,研究结果为：燃气轮机的最佳容量为200 kW,热电结合是最优的运行模式。在该模式下综合能源三联供系统较传统供能系统(火用)损失率降低3.5%,年综合碳排量减少593.7 t,年经济成本节约29.8万元。该方法能够全面、客观地分析某容量、某种运行模式下的系统性能,为解决联供系统的运行规划问题提供参考。