# Current at maximum power - PV cell

• Imperatore
In summary, it seems that the current calculated from the current-voltage characteristic does not match the current calculated from the P(Ushunt) characteristic. This is rather strange, as presumably the currents should be approximately equal.

#### Imperatore

Hello there !

I got question regarding PV cell.
The current at maximum power Im calculated from current-voltage characteristic doesn't equal to the one calculated from P(Ushunt, as you can see in the attached picture. http://prnt.sc/b864hx
Furthermore, the Im from P(U) characteristic is about 2 times greater.
This is rather strange result for me. I am of the opinion, that these currents should be approximately equal. Maybe I am wrong and you will say it's nothing weird about these results.I hope so :)

To understand the result you need to know how the graph was arrived at.

It is my graph ;)

The current from P(U) is the current through the shut resistance, and Im from current-voltage characteristic shows the current without shut resistance. It is that what you mean?
In here http://www.instsani.pl/images/PV8.ht4.jpg [Broken] you can see, that these currents are equal.
Little confused now.

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OK - compare the methodology: you should find you are measuring different things, or the same thing in different circumstances.

Simon Bridge said:
OK - compare the methodology: you should find you are measuring different things, or the same thing in different circumstances.

Imperatore said:
The current from P(U) is the current through the shut resistance, and I am from current-voltage characteristic shows the current without shut resistance. It is that what you mean?

Is it that difference?

Why not check and see if your results are consistent with standard models?

From that I get:
1) Characteristic U(I):
IL=ID+ISh and ISh= 0, so IL=ID=0,5
2) Characterisitic P(U):
0,5=IL=ID+1,17(it's measured ISh), so ID=-0,67 mA

sth wrong

aby book explainig that pheno? It is written in every book I' ve examined that these two currents should be approx the same, what in my case obviously is not met.

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## 1. What is the maximum power point of a PV cell?

The maximum power point (MPP) of a PV cell is the optimal operating point at which the cell generates the maximum amount of power. It is the point at which the voltage and current produced by the cell result in the highest power output.

## 2. How is the maximum power point of a PV cell determined?

The MPP of a PV cell is determined by the cell's characteristic curve, which plots the voltage and current produced by the cell at different operating points. The MPP occurs at the intersection of the cell's characteristic curve and the load line, which represents the external circuit connected to the cell.

## 3. What factors affect the maximum power point of a PV cell?

The maximum power point of a PV cell is affected by several factors, including the intensity and angle of sunlight, temperature, shading, and the type and quality of the PV cell. These factors can cause the cell's characteristic curve to shift, resulting in a different MPP.

## 4. Can the maximum power point of a PV cell change over time?

Yes, the maximum power point of a PV cell can change over time. Factors such as aging, degradation, and changes in environmental conditions can cause the cell's characteristic curve to shift, resulting in a change in the MPP.

## 5. How can the maximum power point of a PV cell be tracked and maintained?

The MPP of a PV cell can be tracked and maintained using a maximum power point tracking (MPPT) system. This system adjusts the operating point of the cell to constantly track the MPP, ensuring that the cell operates at its maximum power output. MPPT systems are commonly used in PV systems to optimize power generation and improve efficiency.