Method of inspecting solar cell module

A method of inspecting a solar cell module including a solar cell array and a bypass diode, the solar cell array including a plurality of clusters connected in series, the plurality of clusters each including a plurality of solar battery cells connected in series, the bypass diode being connected in parallel to the clusters to cause a current that is unable to flow through the clusters to bypass the clusters when an amount of current that is able to flow through the clusters decreases, the method comprising:

• a step of operating the bypass diode by reducing an allowable current of at least one of the solar battery cells in part of the plurality of clusters;
• a step of setting, as a threshold value, a sum of the reduced allowable current of one of the solar battery cells and a leakage current of the solar battery cells;
• and
• a step of determining that the solar cell module is abnormal when a current flowing through the clusters including the solar battery cells with the reduced allowable current is equal to or greater than the threshold value, or when a current flowing through another cluster that does not include the solar battery cells with the reduced allowable current is less than the threshold value, in a state where the bypass diode is in operation.

A method of inspecting a solar cell module for inspecting a solar cell module, the solar cell module comprising:

• a solar cell array that includes a first solar cell cluster, a second solar cell cluster, and a third solar cell cluster sequentially connected in series, the solar cell clusters each including a plurality of solar battery cells connected in series;
• a first terminal portion connected to an end of the first solar cell cluster;
• a second terminal portion connected to a connection between the first solar cell cluster and the second solar cell cluster;
• a third terminal portion connected to a connection between the second solar cell cluster and the third solar cell cluster;
• a fourth terminal portion connected to an end of the third solar cell cluster;
• a first bypass diode connecting the first terminal portion and the second terminal portion;
• a second bypass diode connecting the second terminal portion and the third terminal portion;
• and
• a third bypass diode connecting the third terminal portion and the fourth terminal portion, wherein the method includes:
• a step of measuring a reference current value flowing through the solar cell module without shielding the first solar cell cluster, the second solar cell cluster, and the third solar cell cluster;
• a step of measuring a first current value flowing through the first solar cell cluster, a second current value flowing through the second solar cell cluster, and a third current value flowing through the third solar cell cluster in a state where one of the solar battery cells included in the second solar cell cluster is shielded, and detecting an open fault in the first solar cell cluster or a short-circuit fault in the first bypass diode, an open fault in the second bypass diode, and an open fault in the third solar cell cluster or a short-circuit fault in the third bypass diode by comparing each of the first current value, the second current value, and the third current value with a threshold value obtained by adding an allowable current that is estimated based on a shielded state of the second solar cell cluster and the reference current value, to a leakage current of one of the solar battery cells;
• and
• a second fault detecting step of measuring a fourth current value flowing through the first solar cell cluster, a fifth current value flowing through the second solar cell cluster, and a sixth current value flowing through the third solar cell cluster in a state where at least one of the solar battery cells included in the first solar cell cluster and at least one of the solar battery cells included in the third solar cell cluster are shielded, and detecting an open fault in the first bypass diode, an open fault in the second solar cell cluster or a short-circuit fault in the second bypass diode, and an open fault in the third bypass diode by comparing each of the fourth current value, the fifth current value, and the sixth current value with a threshold value obtained by adding an allowable current estimated based on a shielded state of the first solar cell cluster and the third solar cell cluster and the reference current value to a leakage current of one of the solar battery cells.