الفهرس | Only 14 pages are availabe for public view |
Abstract Certain -faults occur in terrestrial photovoltaic modules at the begining of operation and through -field experience. These faults lead to array power degradation and heating problems such as generation o-f a localised hot-spot. In studying hot-spot causes, one of the most import¬ant parameters which has to be determined is how fast the cell temperature reachs the critical temperature Tc (out-gassing temperature). This can be estimated through the knowledge of RTfe (rate of temperature increase due to dissi¬pated power) and RTS (rate of temperature increase due to light). The results obtained from averaging several measure¬ments are found to be 2.5 D.CELC. / W and 4.1 D.CELC. / W consequently. The combined effects of the shunt resistance and the amount of active area reduction (simulated by artificial partial shadowing) on the operating cell temperature are analysed and discussed. The results obtained clearly reflect that the cell with low shunt resistance and low photocurrent may not cause any problem during service contrary to those cells with high values of shunt resistance. Thus the amount of reverse power depends not only on the amount of active area reduction but also on the behaviour of the solar cell under reverse condition®. |