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针对传统光伏发电系统只采用组件峰值功率进行主要电气设备选型,造成设备利用率低,且没有考虑系统效率的缺点,从实际运行电站的发电量数据分析得出光伏系统效率,以此提出两种优化方案。并与传统方案在经济性和运行可靠性方面进行对比和论证,得出优化方案不仅可满足运行可靠性的要求,在降低成本的效果也非常明显。结合风电和电力电子技术的发展趋势,分析两种优化方案的差距,得出主要电气设备的功率等级越大,系统集成度越高,降低成本的经济性优势越突出,将有利推动光伏发电技术的应用和推广。: 相似文献
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光伏发电是可再生能源中最有发展前景的一种新能源发电形式。高密度分布式光伏发电系统接入配电网可能引起电压偏差越限的问题。建立了考虑分布式光伏发电系统多点接入的馈线电压偏差计算模型,并分别分析了过电压及低电压条件约束条件下不同型号架空及电缆线路光伏电源的准入容量及最大渗透率,根据建立的计算模型采用PSS/E软件进行仿真计算,计算结果表明:利用光伏电源的调压作用可防止过电压,减短馈线长度可防止低电压;电缆线路的光伏电源准入容量主要受过电压因素的限制,而架空线路主要受低电压因素的限制。 相似文献
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为评价光伏水泵系统的供水可靠性,首先根据定义日辐射峰值强度和统计方法建立太阳辐射强度概率分布模型。然后,基于建立的日照分布模型,通过试验揭示了日出水量与日照峰值的关系,从而可准确地获得光伏水泵系统出水量的输出特性。最后,引入失负荷概率(LOLP),研究日需水量QD、储水箱体积V和日照概率分布密度参数对LOLP的影响,对光伏水泵系统的供水可靠性进行评价。结果表明,可以通过基于日辐射峰值强度建立的日照分布概率模型准确预测光伏水泵系统长期出水量;当储水箱体积V大于日需水量QD的2倍时,储水箱体积V对LOLP已无影响。当中间变量G-max分布的标准差在150 W/m2以内时,可根据日照峰值的平均值来设计光伏水泵系统。 相似文献
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纵观当下时期,国内科技水平已遥遥领先,不同地区的行业发展规模渐渐朝着专业型、智慧型、科技型方向前行,在很大程度上充实了人类物质和精神生活.伴随国民经济水平的显著加强,电力行业在其中扮演着重要角色,因此受到社会各界人士的关注.如今,人们对用电量需求持续增长,增加了电力系统的供应压力.基于此,为了满足人们用电需求,急需拓宽... 相似文献
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直流输电系统是实现高电压、大容量、远距离送电和区域电网互联的一个重要技术手段,对于大规模新能源发电的跨区域消纳具有重要的作用。以大规模光伏发电发电接入西北某电网为对象,建立光伏电站模型,分析光伏电站不同运行方式及电网扰动情况下对直流系统的影响,并提出为保证大规模光伏发电接入后直流系统稳定运行的措施与建议。 相似文献
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文章对光伏发电站在不同接入系统下,从光伏电站至用户端之间的线路输变电环节存在的主要电能损耗进行分析,阐明光伏发电远距离输电的利用效率比较低,其中从电站发送端到用户受电端之间各级变压器变电效率的影响是一个主要的因素,在现有技术条件下,实现光伏发电高效利用的主要方式依然是就地消纳。 相似文献
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As non-controllable power sources, photovoltaics (PV) can create overvoltage in low voltage (LV) distribution feeders during periods of high generation and low load. This is usually prevented passively by limiting the penetration level of PV to very conservative values, even if the critical periods rarely occur. Alternatively, one can use active power curtailment (APC) techniques, reducing the amount of active power injected by the PV inverters, as the voltage at their buses increase above a certain value. In this way, it is possible to increase the installed PV capacity and energy yield while preventing overvoltage. This paper investigates a number of approaches for sizing and controlling the PV power generated by 12 net-zero energy houses equipped with large rooftop PV systems in a typical 240 V/75 kVA Canadian suburban radial distribution feeder. Simulations of a one year period with typical solar irradiance and load profiles are conducted with PSCAD to assess the performance of the different approaches in terms of overvoltage occurrence, sharing of the burden for overvoltage prevention per house and total energy yield of the residential PV feeder. 相似文献
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Hasmaini Mohamad Hazlie Mokhlis Ab Halim Abu Bakar Hew Wooi Ping 《Renewable & Sustainable Energy Reviews》2011,15(8):3952-3962
Hydro power generation is the oldest generation and provides the largest contribution among the renewable energy types of generation. In distribution system, most of the distributed generation (DG) is small scale hydro generation of which utilizes the natural flowing water of the river. This generation requires governor and excitation control unit to control and sustain the power generation when subjected to any changes of load behavior. More advanced control strategy is critically expected when considering the recent interest in distribution system to perform islanding operation of DG. Many of the literature have clearly highlighted this issue, but only a few have discussed on the islanding operation of small hydro generation. This paper therefore reviews this topic and relates the discussion with the controller designed for other type of turbines interfaced with synchronous generator. To strengthen the knowledge on islanding operation, the background of islanding is also presented in this paper. 相似文献
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In stand-alone photovoltaic (PV) systems, when the battery is fully charged, the excess generated power is wasted. To solve the problems of wasted excess power, a distributed flexible network photovoltaic (DFNPV) system is studied. It incorporates many PV subsystems each consisting of PV panel, DC/DC converter, and load, and are connected to each other with shared batteries. The excess generated power of the subsystem is transferred between PV subsystems to compensate the lack of power in other subsystems.The control method of transferring power is based on simple voltage control of the subsystems. The output voltage in a given subsystem decreases if a transient excessive load is larger than the generated power; as a result excess power is transferred from another subsystem that has sufficient power and higher voltage output. In this study, this proposed operation method is demonstrated by simulation of power transfer between two subsystems and among four subsystems. Furthermore, to estimate the size of the DFNPV system within an acceptable voltage drop, the relationships between cable length, power loss, and cable types are discussed. 相似文献