Leakage current evaluation of a singlephase transformerless PV inverter connected to the grid
Leakage current evaluation of a singlephase transformerless PV inverter connected to the grid
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DOI：
10.1109/apex.2007.357623
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发表时间：
2007-05
期刊：
影响因子：
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通讯作者：
Ó. López;R. Teodorescu;F. Freijedo;Jesus DovalGandoy
中科院分区：
文献类型：
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作者：
Ó. López;R. Teodorescu;F. Freijedo;Jesus DovalGandoy
对于低功率并网应用，可以使用单相转换器。在光伏应用中，可以移除逆变器中的变压器，以减少损耗、成本和尺寸。由于接地寄生电容，无变压器系统中电网和直流电源的电流连接可能会引入额外的漏电流。该电流增加了传导和辐射电磁发射、注入公用电网的谐波和损耗。漏电流的幅度和频谱取决于转换器拓扑、开关策略以及由接地电容、转换器、交流滤波器和电网形成的谐振电路。本文在不同条件下测量了 1.5 kW 光伏装置的漏电流，并用于建立仿真模型。该装置包括一串 16 个光伏电池板、一个全桥逆变器和一个 LCL 滤波器。该模型可以研究逆变器注入的谐波对漏电流的影响。
For low-power grid connected applications a single phase converter can be used. In PV applications it is possible to remove the transformer in the inverter in order to reduce losses, costs and size. Galvanic connection of the grid and the DC sources in transformerless systems can introduce additional leakage currents due to the earth parasitic capacitance. This currents increase conducted and radiated electromagnetic emissions, harmonics injected in the utility grid and losses. Amplitude and spectrum of leakage current depends on the converter topology, on the switching strategy and on the resonant circuit formed by the ground capacitance, the converter, the AC filter and the grid. In this paper, the leakage current in a 1.5 kW PV installation is measured under different conditions and used to build simulation model. The installation includes a string of sixteen PV panel, a full bridge inverter and a LCL filter. This model allows studying the influence of the harmonics injected by the inverter on the leakage current.