Measurement of Damages at Bypass Diodes by Induced Voltages and Currents in PV Modules Caused by Nearby Lightning Currents with Standard Waveform
Measurement of Damages at Bypass Diodes by Induced Voltages and Currents in PV Modules Caused by Nearby Lightning Currents with Standard Waveform
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用标准波形测量附近雷电流引起的光伏组件中的感应电压和电流对旁路二极管的损坏
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发表时间：
2008
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通讯作者：
H. Häberlin
中科院分区：
文献类型：
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作者：
H. Häberlin
在1990-1993年和1998-2000年的一个欧盟项目期间，北京东方卫理公会光伏实验室对流入或靠近光伏组件框架的雷电电流进行了光伏组件的灵敏度测试[1]、[2]、[3]。冲击电流为imax≤120kA和di/dtmax≤40kA/μS。可以证明，即使在中等距离，这种闪电电流在模块中感应的电压也可能高达数千伏。这样的电压很容易破坏旁路二极管。由于单元尺寸和电流的增加，越来越多的肖特基二极管被用作旁路二极管，其反向额定电压仅在40V到100V之间相当低。在实际操作中，这种损坏实际上会发生，但通常只有在比肖特基二极管的反向额定电压高得多的峰值感应电压下才会发生。文[5]和[7]对这一问题进行了理论分析，并给出了一些短脉冲电流(约8μS/20μS)的初步试验结果。本文推广了理论分析，给出了2007年和2008年在不同模块和不同二极管类型下用约6μS/350kAμS(di/dtmax≤30kA/μS)的冲击电流波形进行的多次测量结果。
In 1990 – 1993 and during an EU project in 1998 – 2000, the PV laboratory of BFH-TI has carried out tests about sensitivity of PV modules against lightning currents flowing in or close to the frame of a PV module [1], [2], [3]. For these tests, impulse currents with imax ≤ 120kA and di/dtmax ≤ 40kA/μs were used. It could be shown that even at moderate distances the voltages induced in a module by such lightning currents may go up to several thousand volts. Such voltages can easily destroy bypass diodes. Due to increasing cell dimensions and currents, more and more Schottky diodes are used as bypass diodes, which have only quite low reverse voltage ratings between 40 V and 100 V. In practical operation, such damages actually occur, but usually only at considerably higher peak induced voltages than the reverse voltage rating of the Schottky diode. In [5] and [7] the problem was analysed theoretically and the results of some first tests with short impulse currents (about 8μs/20μs) were shown. In this paper, the theoretical analysis is extended and results of many measurements performed in 2007 and 2008 with impulse current waveforms of about 6μs/350μs (di/dtmax ≤ 30kA/μs) at different modules and with different diode types are presented.