I modeled a PV panel (Voc = 37.7V and Isc = 8.72A) in simulink with Rs and Rsh being dynamic. I tried to use it with a buck converter and a resistive load. The controlled current source cannot work without an input capacitor, I added a capacitor of 50*10^-6. It works fine but with an overshoot of 20A. Also, when I changing the load resistor a little bit , I get output current of 12A. You can see the picture below.
Did anyone face this issue?
Dear Fahad,
ASn important point to consider and which you did not talk about it, in the equivalent circuit of the solar cell panel there is a forward biased diode connected across the current source. If this diode is not present one may have to add a capacitor shunting the current source. In fact the forward diode acts as a resistance in parallel with the a capacitor.
So, please consider my comment and your circuit will work properly.
Best wishes
Dear fahad, salam
You are measuring both input capacitor and PV panel currents. Try to measure just PV panel current.
- Also, check you solar irradiance value it maybe more then 1000kw/m2.
You can contact me if steel there is a problem.
Good luck.
Abdelhalim Zekry , thank you very much for your reply Dr Zekry. So what I meant by my question is that this controlled current source represent the equivalent circuit of solar cell. So the current from this controlled current source is the current flowing through Rs, which is I considered to be included inside this controlled current source. I simulated this in discrete powergui and sometime I face errors like algebraic loops. What I did is I broke the algebraic loops by using a unit delay. I am not sure if this is the reason why it gives me wrong measurements.
Mohammed Bilal Danoune Thank you Dr Bilal for your reply, regardless of the current measurements of the input capacitor and PV , it should not give me an output current of about 12A. Since the max current coming out from the PV under all situations should not be close to 12A. I am think maybe the issue because I used a unit delay to break algebraic loops, which changes the dynamic behavior of my system, but I am not sure about this as well.
Seyed Majid Hashemzadeh , Thank you Mr Majid for your reply, I modeled the equations so that this controlled current source represent the equivalent circuit of the solar cell, where the current coming out is the current flowing through Rs. Note that Rs and Rsh are dynamic (changes as voltage and current change). Imagine replacing that equivalent circuit of the solar cell with this controlled current source where also the voltage across it is the output voltage of the panel.
Mr Fahad Abu Khald
-Check the equations of the PV model again(I will send you my Simulink model PV with buck converter).
-L and C of your converter have to be properly designed, you can refer to ''Power Electronics'' book by Daniel W. Hart to design your converter.
- Change the solver to ode15s(stiff/NDF) in the configurations of the simulink.
best wishes
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