Capacitor charging method for I-V curve tracer and MPPT in photovoltaic systems
Capacitor charging method for I-V curve tracer and MPPT in photovoltaic systems
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DOI：
10.1016/j.solener.2015.06.032
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发表时间：
2015-09-01
期刊：
影响因子：
6.7
通讯作者：
Chiaberge, Marcello
中科院分区：
文献类型：
--
作者：
Spertino, Filippo;Ahmad, Jawad;Chiaberge, Marcello
电容器充电方法可在光伏 (PV) 系统中用于两种典型应用：一种非常简单且廉价的方法 (1) 跟踪任何尺寸的光伏发电机的 I-V 曲线；(2) 跟踪最大功率点 (MPP)，尤其是在发生部分阴影时。问题在于正确确定电容器的尺寸，以实现准确、均匀和平滑的结果。在第一个应用中，进行了简化计算以快速设计电容器。这仅根据光伏阵列的主要特性和光伏模块最重要的数据表参数来完成。然后，介绍了模块、串和阵列级别的 I-V 曲线跟踪器的设置：这些跟踪器可用于检测光伏系统的性能不佳。在第二个应用中，设计了基于电容器充电的 MPPT（MPP 跟踪器）电路，并在部分遮蔽条件下进行了仿真。在这些条件下，光伏阵列的功率-电压 (P-V) 曲线的特点是存在多个旁路二极管动作的最大值。 P-V 阵列与负载隔离的时间可忽略不计，并连接到外部电容器。在充电期间，所提出的电路跟踪全局 MPP。该电路实现简单，缩短了扫描阵列P-V曲线所需的时间。 (C) 2015 Elsevier Ltd. 保留所有权利。
The capacitor charging method can be used in Photovoltaic (PV) systems for two typical applications: a very simple and cheap way (1) to trace the I-V curve of a PV generator of whatever size and (2) to track the Maximum Power Point (MPP), especially when the partial shading occurs. The problem is the correct sizing of the capacitor in order to achieve accurate, uniform and smooth results. In the first application a simplified calculation to design quickly the capacitor is carried out. This is done only as a function of the main characteristics of the PV array and the most important datasheet parameters of the PV modules. Then, the setup of I-V curve tracers at module, string and array levels is presented: these tracers are useful in the detection of underperformance of PV systems. In the second application a MPPT (MPP Tracker) circuit based on capacitor charging is designed and simulated in partial shading conditions. In these conditions the Power-Voltage (P-V) curve of a PV array is characterized by the presence of multiple maxima for the bypass diode action. The P-V array is isolated from the load for a negligibly short period and is connected to an external capacitor. During the charging time, the proposed circuit tracks the global MPP. This circuit is easy to implement and shortens the duration needed for scanning the P-V curve of the array. (C) 2015 Elsevier Ltd. All rights reserved.