The Virtual synchronous generator (VSG) is an inverter based generating unit that uses a synchronous generator model to insert virtual inertia to power system. In this research, the parameters of the VSGs of the multi-VSG system are tuned to obtain the desired response. First, the multi-VSG microgrid is introduced. Then Particle Swarm Optimization is implemented to tune the parameters of the VSG units in the microgrid. Further, the virtual inertia control is applied to the VSG units to improve its stabilization. The simulations in PS CAD are represented for three conditions of VSG parameters and the results are compared.

关键词：微电网；智能电网；虚拟同步发电机

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The TIG arc welding is the high-quality joining technology. However, the weld pool is shallow in the TIG welding because the heat transfer to anode is poor. So, the weld defect sometimes occurs. The pulsed arc welding and mixing oxygen are used in order to control the heat transfer and prevent the weld defect. However, few reports has reported the variation of heat transfer to anode and the physical arc phenomena. In this paper, the time variation of heat transfer to anode in pulsed arc welding mixed with oxygen was elucidated in order to know the welding depth for prevention of welding defect. The thermal conductivity of heat transfer in the case of pulsed arc is not same as that in the case of stable arc. The thermal conductivity of heat transfer gradually decreases with increasing the time. The thermal conductivity of heat transfer can not catch up with the current waveform. When the arc is the transient mode, the arc radius and temperature distribution can not catch up with the stable arc ones. However, the heat transfer from center to r=3.00 mm can catch up current waveform. Thus, the thermal conduction of heat transfer varies over r=3.00 mm. The variation of it with Ar-O_2 is larger than that with pure Ar. Because the specific heat increases, the arc temperature at center becomes high.

关键词：电弧焊；脉冲电弧；传播热量；电磁热流体仿真

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采用CFD Fluent6.3软件模拟了自主研发的低阶煤低温干馏炉对喷式低温燃烧室内温度场分布,并对其结构进行了优化.结果表明:在燃烧室内设计4个关于燃烧室中央轴对称的长度分别为800mm和500mm、旋转角度分别为±30°和±10°的直挡板后,燃烧室内横向、纵向平均温度满足褐煤低温热解需求(500~650℃);采用非预混模式、过量空气系数为1.25和煤气管径为50mm时,燃烧室的燃烧特性最佳;过量空气系数、煤气与空气预混方式、管径均会影响燃烧室内温度分布;Realizablek-ε湍流模型、P-1辐射模型和非预混燃烧模型适用于计算焦炉煤气和空气低温燃烧室内燃烧温度场分布;模拟计算结果与实验结果基本吻合,误差波动幅度为50~70℃,同时对燃烧后烟气的检测结果表明,烟气排放符合标准要求。

关键词：低阶粉煤；低温干馏炉；低温燃烧室；NOx排放；CFD模拟

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为减小涡轮机动叶顶部间隙泄漏造成的气动损失、提高叶顶冷却效率,提出在凹槽叶顶离散排布小隔板迷宫.根据某涡轮机动叶结构,设计了迷宫叶顶气膜冷却效率试验台,通过稳态液晶技术测量了间隙叶高比分别为1.0%,2.0%,3.0%和吹风比分别为1.0,1.5,2.0时隔板迷宫叶顶和凹槽叶顶的气膜冷却效率.结果表明:2种叶顶结构的平均冷却效率均随着叶顶间隙高度的增加而减小;在某间隙高叶比和吹风比范围内,隔板迷宫叶顶冷却效率最多比凹槽叶顶冷却效率高出63%;隔板迷宫显著扩大了叶顶的冷却范围,提高了冷却效率,使冷却效率的分布更加均匀。

关键词：燃气轮机；动叶叶顶；迷宫结构；间隙高度；气膜冷却

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Because of its minor environmental impact, electricity generation using wind power is getting remarkable. The further growth of the wind industry depends on technological solutions to the challenges in production and construction of the turbines. Wind turbine tower vibrations, which limit power generation efficiency and cause fatigue problems with high maintenance costs, count as one of the main structural difficulties in the wind energy sector. To mitigate tower vibrations auxiliary measures are necessary. The effectiveness of tuned mass damper is verified by means of a numeric study on a 5 MW onshore reference wind turbine. Hereby, also seismic-induced vibrations and soil-structure interaction are considered. Acquired results show that tuned mass damper can effectively reduce resonant tower vibrations and improve the fatigue life of wind turbines. This chapter is also concerned with tuned liquid column damper and a semiactive application of it. Due to its geometric versatility and low prime costs, tuned liquid column dampers are a good alternative to other damping measures, in particular for slender structures like wind turbines.

关键词：结构控制；调谐质量阻尼器；调液阻尼器

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In this study, we have conducted modeling of the energy demands and supply systems of an actual small-scale housing complex and evaluated the effect of CGS installation from the standpoint of environmental and the economic aspects. Then, we have developed a new CGS operational algorithm that controlled the CGS generator by following the temperature of the heat storage medium in the storage tank and we have demonstrated the advantageous effects of this method. In addition, we have discussed the appropriate heat storage tank capacity for the proposed method.

关键词：能源管理系统；热电联产系统；设施规划

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介绍了适用于低品位能源的有机朗肯循环余热发电、卡琳娜循环余热发电、温差发电、热声发电4种热发电形式的原理和特点,分析了有机朗肯循环工质对系统性能的影响和热声发电系统的转换效率,指出太阳能的综合利用具有良好的发展前景.提出了可有效利用太阳能的太阳能电池余热方案,即光伏光热联合发电的有机朗肯循环系统,该系统的两相升压装置将太阳能电池的余热转化为液轮机的电力输出,实现了将太阳能转化为电能的过程,提高了太阳能的综合利用率。

关键词：低品位能源；发电系统；有机朗肯循环；有机工质；太阳能；光伏光热

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提出了一种新型增压富氧焚烧垃圾近零排放电站的设计概念,采用液态排渣增压垃圾焚烧锅炉,增加制氧装置与烟气压缩净化回收系统.以日焚烧1100t城市垃圾的汽轮机发电机组为例,计算了炉膛压力分别为0.5,1.0,1.5 MPa下发电机组的经济性,并与常压富氧焚烧技术进行对比.结果表明:由于锅炉炉膛压力增高,烟气中水蒸气的凝结热可用于加热汽轮机低温凝结水,减少汽轮机抽汽量,增加汽轮机发电功率,发电机组输出功率可达到25MW左右;空气分离制氧电耗约占发电量的34%,CO2压缩电耗占发电量的5%,低于常压富氧焚烧.综合考虑电站其他辅机电耗后,0.5~1.5 MPa炉膛压力下的增压富氧焚烧垃圾发电机组的净效率可提高9.31%~9.90%。

关键词：垃圾焚烧发电；增压富氧燃烧；近零排放；净效率

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Titanium dioxide has been used as the white pigment since the ancient times.95% of its current usage in industry involves paints, cosmetics, plastics, paper, and food. However, in near future the economic impact of titanium dioxide seems to be controlled by energy related applications mostly. Therefore, this chapter projects a brief outlook on the added value provided by the titanium dioxide structures in new and emerging technologies of the energy sector. The applications focused are: solar fuels, solar cells, fuel cells, Li ion batteries and solid state lighting. In those applications, TiO_2 standouts with its chemical and thermal stability, morphology variety, position of conduction and valance band energy levels, optical properties and cost.

关键词：二氧化钛；新兴能源技术；聚焦

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Asymptotic solution for the shear stress distributions and velocity profiles of steady electroosmotic (EO) and magnetohydrodynamic (MHD) flows are obtained in a parallel flat plate microchannel. A fully-developed flow is considered and the fluid obeys a constitutive relation based in a simplified Phan-Thien-Tanner model. The effect of the following dimensionless parameters on the fluid flow control is predicted: the viscoelastic parameter and the Hartmann number. The momentum equation, boundary conditions and the constitutive rheological model are combined to formulating a nonlinear differential equation to solve the shear stress, which is expanded in a regular expansion series in powers of small Hartmann numbers. This limit of small Hartmann numbers and low electrical conductivity in the buffer solution correspond to the range where the electric and magnetic effects can be used to move a charged solution in the flow control and sample handling in biomedical and chemical analysis.

关键词：电渗流；磁流体流动；微通道；粘弹性流体

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