Mismatch of series solar cells
Since most solar PV modules are in series, series mismatch is the most common type. Among the two simplest types of mismatch considered (mismatch of short circuit current or open circuit voltage), the mismatch of short circuit current is more common, because it is easily caused by partial shadows of solar panels. This type of mismatch is also the most serious.
For two solar cells in series, the current through the two solar cells is the same. The total voltage generated is the sum of the voltages of individual solar cells. Since the currents must be the same, a current mismatch means that the total current configured is equal to the minimum current.
Photovoltaic solar panel
Open circuit voltage mismatch of series solar cells
The open circuit voltage mismatch of series solar cells is a relatively mild form of mismatch. Under the short-circuit current, the overall current of the solar panel is not affected. At the maximum power point, the overall power is reduced because poor solar cells produce less power. Since the two solar cells are connected in series, the current through the two solar cells is the same. The overall voltage can be found by adding two voltages under a specific current.
Short circuit current of series battery does not match
The short circuit current of the series solar cells does not match. According to the working point of the solar panel and the degree of mismatch, it will have a huge impact on the solar photovoltaic modules. Under open circuit voltage, the effect of short-circuit current reduction is relatively small. Because of the logarithmic relationship between the open circuit voltage and the short circuit current, the open circuit voltage will change slightly. However, since the current through the two solar cells must be the same, the total current from the combination cannot exceed the current of the different solar cells. Under the low voltage where this may happen, the additional current generation capacity of good solar cells will not be dissipated in each individual solar cell (usually in the event of a short circuit), but will be dissipated in poor solar cells.
In general, in a series configuration with mismatched current, if the current generated by the poor solar cell is less than the maximum power current of the good solar cell, there will be a serious power drop. If the combination operates under short circuit or low voltage, the high power dissipation of the poor solar cell will cause irreversible damage to the solar charging panel. If you want to know more about solar panels, please contact us.