Equivalent Electrical Circuit of PV Cell

Circuit of solar cell consists of current source (I_sh) in parallel with a diode. As in practical conditions no solar cell is ideal, so a shunt resistance and a series resistance is considered in the circuit as shown in figure. R_S is the series resistance and R_SH is the parallel resistance and I_D is the diode current.When terminals are short circuited, the output voltage becomes zero and the short circuit current (I_sc) becomes equal to current source (I_ph). When we open circuit the terminals output current becomes zero and source current (I_ph) becomes equal to diode current (I_d).

                       I = I_ph – I_o(  - 1) = I_ph – I_d                                        

                                              I_ph = qA x efficiency x photon flux                                                    

                                                          V_oc =  ln (  – 1)                                                

Where,

I = output current,

I_ph = photo current,

V = output voltage,

q = electron charge,

k = Boltzman contant,

T = operating temperature (kelvin),

I_d = diode current,

I_o = reverse saturation current of diode,

A = collector area.