Photovoltaic inverter leakage current detection

How to eliminate leakage current in solar PV array system?

There are two distinct methods to eliminate the leakage current in the solar PV array system: (i) obstruct the leakage current, (ii) reduce the variation/constant common-mode voltage. The additional diodes/switches are incorporated in the system to obstruct the leakage current by disconnecting the PV array from the grid side network.

Does a solar inverter detect leakage current?

Standard and detection of leakage current According to the 7.10.2 regulation of NB32004-2013 standard, in any case where the solar inverter is connected to the AC grid and the AC breaker is turned off, the inverter should provide leak current detection.

Why does the photovoltaic system generate leakage current?

Leakage current of the photovoltaic system, which is also known as the square matrix residual current, is essentially a kind of common mode current. The cause is that there is parasitic capacitance between the photovoltaic system and the earth.

What is leak current detection?

Leak current detection should be able to detect the total (including the DC and AC parts) effective value current, continuous residual current. If the continuous residual current exceeds the following limits, the inverter should be disconnected and send a fault signal within 0.3s:

What happens if a PV system leaks?

This can flow through a human body and pose serious risks if exceeding a specific value. Also, the leakage current can cause efficiency reduction, harmonic injection, and increased total harmonic distortion (THD) in the grid current [ 8 ]. Figure 1 shows an overview of the PV system, including the inverter, output inductor and grid.

How to reduce leakage current in a grid-connected photovoltaic system?

Grid-connected photovoltaic system Many topologies have been proposed in the literature to reduce leakage current. The most prominent topologies are the full-bridge structure with bipolar switching method, H5 structure [ 9 ], H6 [ 10, 11 ], and HERIC [ 12] etc.