AN3432 datasheet(5/24 Pages) STMICROELECTRONICS

5 / 24 page

AN3432

Photocurrent production basics of silicon solar cells

Doc ID 019041 Rev 1

5/24

Equation 3

The open circuit voltage (Voc) is the voltage corresponding to the output current of solar cell

or panel set to 0. The photocurrent is equal to the current lost in the intrinsic element of the

cell, and Voc is equal to the intrinsic diode forward voltage (Vd).

Equation 4

Equation 5

In the following, for easier the reading, Voc is the open circuit voltage of the panel and Voc_u

the open circuit voltage of the solar cell. The relation between them is given in Equation 6.

Equation 6

where nb is the number of cells contained in one panel.

1.3.2

Voc and Isc variations with ambient temperature

The open circuit voltage is mainly linked with the parasitic diode forward voltage then it is

temperature dependent with a negative temperature coefficient (

αVoc). Then the maximum

value for Voc is the value at minimum junction temperature specified in the panel data sheet.

Strongly linked with the photocurrent, the short circuit current increases slightly with the

temperature (

αIsc>0).

Figure 3.

Temperature effect on Isc and Voc parameters

Isc ~ IL

IL = Io · (exp

Voc

·Voc)

- 1) -

(

Voc =Vd

Voc =

i = 1

Voc_u_i

I(V)

V (T2)

V (T1)

αV ~ -0.4% / C

I (T2)

I (T1)

αI ~ + 0.05% / °C

AN3432 Scheda tecnica(PDF) 5 Page - STMicroelectronics

AN3432 Scheda tecnica(HTML) 5 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Scheda tecnica Scarica

Link URL