共查询到19条相似文献,搜索用时 250 毫秒
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文章对带工频隔离变压器的单相光伏并网逆变器产生偏磁进行了分析,为解决输出的直流偏磁对逆变器的不良影响,提出一种通过对调制波进行直接处理的全数字化基于脉宽处理的偏磁抑制方法,为验证其有效性,在3 kW单相光伏并网逆变器的样机上进行了试验验证,采用单极性倍频的SPWM调制方式。试验结果表明,该偏磁抑制方法能有效地抑制变压器的直流偏磁。 相似文献
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日前,国际权威机构——德国T譈V莱茵检测认证机构向阳光电源股份有限公司颁发了系列500 kW,630 kW光伏并网逆变器的认证证书。这是继100 kW,250 kW产品通过认证后,阳光电源的大功率光伏并网逆变器再次通过国际权威的TV认证。其中,630 kW是目前国内通过该项权威认证的最大功率等级光伏逆变器。作为全球最重要、最成熟的光伏发电市场,欧洲各国对相关产品的准入要求十分严格,只有在取得相关产品的安全 相似文献
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受电网电压畸变等问题的影响,单相光伏并网逆变器输出电流中存在大量谐波,严重降低了该逆变器输出电能的质量。针对上述问题,提出一种基于扰动补偿器与矢量比例积分控制器的单相光伏并网逆变器谐波抑制方法。该方法借助扰动补偿器倍频次谐波的抑制能力实现高频谐波电流的有效补偿,利用矢量比例积分控制器实现工频交流电流的无静差跟踪。文章利用额定功率为5 kW的单相光伏并网逆变器样机进行稳态运行实验。实验结果表明,文章所提出的控制算法能够大幅度降低单相光伏并网逆变器输出电流的总谐波畸变率,从而提升该逆变器的并网电能质量。 相似文献
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基于电网电压前馈的光伏并网逆变器的仿真与实现 总被引:1,自引:0,他引:1
介绍了光伏并网逆变器的基本原理和拓扑结构;提出了一种基于电网电压前馈和电流跟踪控制技术的并网控制方法;建立了仿真模型;给出了系统控制的软件和硬件设计.在一台10kHz,3kW的实验样机上对该方案进行了实验,实验结果验证了该方法的有效性. 相似文献
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In photovoltaic (PV) applications, a maximum power point tracking (MPPT) module is necessary to extract the whole energy that the PV module can generate depending on the instantaneous conditions of the PV system. A PV module is obtained by connecting a number of solar cells in series and parallel, which causes voltage and current to increase at module terminations. The present work is based on a three-phase grid-connected inverter designed for a 100 kW PV power plant that uses an MPPT scheme based on fuzzy logic controllers. The whole system presented is simulated in MATLAB. The fuzzy logic-based MPPT controllers show accurate and fast responses and are integrated into the inverter, so that the there is no requirement for a dc–dc converter. The inverter allows full control of reactive power. 相似文献
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3 kW光伏并网逆变器 总被引:5,自引:0,他引:5
阐述了3kW光伏并网逆变器的关键技术。通过对光伏并网逆变器最大功率点跟踪、孤岛效应和并网控制等问题的分析,提出了具体的解决方案。并且通过对最大功率跟踪算法的改变及变压器切换的控制,使逆变器在轻载的条件下,依然可以获得较好的工作效率。 相似文献
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Resource optimization is a major factor in the assessment of the effectiveness of renewable energy systems. Various methods have been utilized by different researchers in planning and sizing the grid-connected PV systems. This paper analyzes the optimal photovoltaic (PV) array and inverter sizes for a grid-connected PV system. Unmet load, excess electricity, fraction of renewable electricity, net present cost (NPC) and carbon dioxide (CO2) emissions percentage are considered in order to obtain optimal sizing of the grid-connected PV system. An optimum result, with unmet load and excess electricity of 0%, for serving electricity in Makkah, Saudi Arabia is achieved with the PV inverter size ratio of R = 1 with minimized CO2 emissions. However, inverter size can be downsized to 68% of the PV nominal power to reduce the inverter cost, and hence decrease the total NPC of the system. 相似文献
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针对弱电网下光伏并网逆变器可能发生的失稳现象,提出一种光伏并网逆变器的数字H∞鲁棒控制器设计方法。首先建立传统控制策略下光伏并网逆变器的控制模型,并分析其在弱电网条件下的稳定性。为了提高LCL型光伏并网逆变器对电网阻抗变化的鲁棒性,考虑数字控制延时的影响,通过建立离散域下光伏并网逆变器的标准H∞控制模型,并设计加权函数,求得光伏并网逆变器的数字H∞控制器。与传统的双闭环控制策略相比,理论分析与仿真和实验结果均表明,所设计的数字H∞控制器可显著增强弱电网条件下光伏并网逆变器的稳定性。 相似文献
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Optimum PV/inverter sizing ratios for grid-connected PV systems in selected European locations were determined in terms of total system output, system output per specific cost of a system, system output per annualised specific cost of a system, PV surface orientation, inclination, tracking system, inverter characteristics, insolation and PV/inverter cost ratio. Maximum total system output was determined for horizontal, vertical and 45° inclined surfaces for a low efficiency inverter for sizing ratios of 1.5, 1.8 and 1.3, respectively; and for a medium efficiency inverter with sizing ratios of 1.4, 1.5 and 1.2. PV surface orientation and inclination have little impact on the performance of a high efficiency inverter. For different PV tracking systems and for different inverter characteristics, the optimum sizing ratio varied from 1.1 to 1.3. The PV/inverter cost ratio and the PV and inverter lifetimes have significant impact on the optimum PV/inverter sizing ratio. A correlation relating optimum sizing ratio and PV/inverter cost ratio has been developed; the correlation coefficients were found to be functions of insolation and inverter type. The impact of PV/inverter sizing ratio on PV array performance was less when PV array has a much higher cost than the inverter. The optimum sizing ratio for PV/inverter cost ratio of 6 and low efficiency inverter system varied from 1.4 to 1.2 for low to high insolation sites. For a high efficiency inverter system, the corresponding variation was from 1.3 to 1.1. 相似文献
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光伏逆变器在弱电网下运行时,不均匀的线路阻抗使微电网控制系统功率因数下降、带宽变窄、控制性能减弱、跟踪误差变差,甚至导致逆变器系统退出运行等现象。为此,首先在双闭环控制方式下,通过电压环振荡处理引入瞬时无功控制手段与电压前馈控制方式来减少无功输出,提高逆变器控制系统并网电流质量。其次采用锁相环与锁频环复合同步手段优化跟踪质量,提高控制系统功率因数以及抗干扰能力。最后通过搭建两台2 kW同型号的单向并网逆变器并联运行的实验平台验证了该控制方法的正确性与实用性。 相似文献