太阳光发电系统介绍课件.ppt

太陽光發電系統介紹;Solar cell 種類;Solar Cell 製作;;PV Module Performance Rating;1. Power Output：一天內產生之peak power or avg power。 (watts) 2. Energy Output： (Wh) 在一定之週期下評估以上3項目 3. Conversion efficiency： 　　　　　　　　　　　　energy output from array energy input from sun 評價單位：1EEE、ASTM (American Society for Testing and Materials);影響日照的因素;光波頻譜;V;I;;Power is a function of position along the VI characteristic. At the intercepts, it is minimum - zero - increasing to a max near the knee of the curve. ; Set #1: ISC , PMAX , VOC ;The short circuit current ISC is a linear function of sunlight intensity. The open circuit voltage VOC is not. (VOC is weakly dependent on temperature.) Recall from Part I that sunlight intensity is measured in terms of a solar constant with units such as mW/cm2.;I = ISC;I = 0;; Set #2: RS , RSH ;Questions: 1. Which resistance is higher, the measurement at ISC or the measurement at VOC ? Remember: R = ?V/?I ! 2. Physically, what do you think these resistances represent? 3. As a solar cell designer, what is your preferred ideal value?;Answers to Questions #1 - #3: The resistance at ISC is extremely high. In an equivalent circuit model of a solar cell, it represents a shunt resistance. The resistance at VOC is extremely low. In an equivalent circuit model of a solar cell, it represents a series resistance. Both of these resistances are internal, and represent energy dissipation mechanisms in the cell. Ideally, a designer would like zero series resistance and infinite shunt resistance.;ISC;ISC;ISC; Notice that the area under the rectangle = PMAX for the ideal cell. For this cell, PMAX = VOC ? ISC ;ISC;Questions: 1. What is the ideal fill factor