is bypass diode will efeect in maximum power of a solar system under partial shading condition withdifferant irridations.

Hi sir, i am using four panels with different irradation conditions i.e., G=1000,800,600,600. for this i have simulated the model and measured the maximum power under two cases 1. by using bypass diode 2. without bypass diode in above two scenarios maximum power is getting same. is it correct. then what will be the effect of bypass diode under partial shading condition.

Answer 1

[Yusuf Iskoun]

Hello

the maximum power should be lower if you have used bypass diode (if there is no shading)

in partial shadding condition in low voltage the shaded module deliver less current the other modules

e.g array with one string and two panels : PV1 (non shaded) and PV2 ( shaded)

in low voltage (let's say V = V1 + V2 = 2 Volts )

PV1 may deliver 3 A and PV2 deliver 2A;

• if there are not bypass diode the total curent will be 2A ; PV will absorbe 1A from PV1 -throw its intern resistor-; and the voltage of PV2 will be negative ( let's say : V1=3 Volts and V2=-1 Volts )

• if there is bypass diode, the total curent will be 3A ; PV will deliver 2A (or more); and the voltage will be small ( let's say : V1=2 Volts and V2=0 Volts ) ; PV1 deliver 3A; and bypass diode let 1 A pass throw it.

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