Civil Engineering Reference
In-Depth Information
FIGURE 8-13
Shadow effect on one long pv string of an array. The power degradation is small until shadow
exceeds the critical limit.
FIGURE 8-14
Bypass diode in pv string minimizes the power loss under heavy shadow.
gets below operating voltage of the string, making the string current fall to
zero, losing all power of the string.
The commonly used method to eliminate the loss of string due to shadow
effect is to subdivide the circuit length in several segments with bypass
diodes (
Figure 8-14
)
. The diode across the shadowed segment bypasses only
that segment of the string. This causes a proportionate loss of the string
voltage and current, without losing the whole string power. Some modern
pv modules come with such internally embedded bypass diodes.
