A given solar cell has the following specifications:
Isc=4A
Voc=0.7V
36 identical cells with the above specifications are to be interconnected to create a PV module.
1- What is the open-circuit voltage (in V) of the PV module if all the solar cells are connected in a series configuration?
X=.........
2- What is the short-circuit current (in A) of the PV module if all the solar cells are connected in a series configuration?
Y=...........
3- Now suppose that the PV module mentioned above is set up using a series connection of solar cells with the above mentioned specifications. Two of the solar cells have gone faulty (completely stopped generating power), but fortunately you have bypass diodes connected across the faulty solar cells. Assume that the bypass diodes are ideal (has a 0 voltage drop when conducting).
What is the measured open-circuit voltage (in V) of the above PV module with the faulty solar cells?
Z=.........
1. X = 36 * 0.7 = 25.2 Volts
2. Y = 4A
3. Voc = 34 * 0.7 = 23.8 Volts.
1- The open-circuit voltage (Voc) of the PV module when all solar cells are connected in a series configuration (36 cells) would be:
X = Voc × Number of Cells = 0.7V × 36 = 25.2V
2- The short-circuit current (Isc) of the PV module when all solar cells are connected in a series configuration would remain the same as Isc of a single cell, which is 4A.
Y = Isc = 4A
3- When two solar cells have gone faulty, but bypass diodes are connected across them, the open-circuit voltage of the PV module remains the same as before.
Z = X = 25.2V
So, even with faulty cells, the open-circuit voltage of the PV module with bypass diodes remains unchanged.
1- In a series configuration, the voltage of the PV module will be the sum of the voltages of each solar cell. Since there are 36 cells with a voltage of 0.7V each, the open-circuit voltage of the PV module will be:
X = 0.7V * 36 = 25.2V
Therefore, the open-circuit voltage of the PV module is 25.2V.
2- In a series configuration, the current of the PV module will be equal to the current of a single solar cell. Since each solar cell has a current of 4A, the short-circuit current of the PV module will also be:
Y = 4A
Therefore, the short-circuit current of the PV module is 4A.
3- In a series configuration, the open-circuit voltage of the PV module will be affected by faulty cells. However, with bypass diodes connected across the faulty cells, the open-circuit voltage will remain the same as in question 1. Therefore,
Z = X = 25.2V
Therefore, the measured open-circuit voltage of the PV module with the faulty solar cells is 25.2V.
To answer these questions, we need to understand how solar cells are interconnected and how their specifications affect the PV module.
1. Open-Circuit Voltage of the PV module in series configuration:
In a series configuration, the solar cells are connected one after another, resulting in the sum of their voltages. Therefore, the open-circuit voltage (Voc) of the PV module will be the sum of the Voc of each individual cell.
Since each cell has Voc=0.7V and there are 36 cells in series, the open-circuit voltage (X) of the PV module can be found by multiplying the Voc of a single cell by the number of cells:
X = 0.7V * 36 = 25.2V
So, the open-circuit voltage of the PV module is 25.2V.
2. Short-Circuit Current of the PV module in series configuration:
In a series configuration, the total current (Isc) flowing through the PV module is the same as the current flowing through each individual cell.
Since each cell has Isc=4A, the short-circuit current (Y) of the PV module will be the same as the Isc of a single cell:
Y = 4A
So, the short-circuit current of the PV module is 4A.
3. Open-Circuit Voltage of the PV module with faulty cells and bypass diodes:
When two solar cells become faulty and stop generating power, the open-circuit voltage (Voc) of the PV module will change. However, with the presence of ideal bypass diodes, the faulty cells are bypassed and have no effect on the overall voltage.
Therefore, the measured open-circuit voltage (Z) of the PV module will remain the same as before, which is 25.2V.
So, the measured open-circuit voltage of the PV module with faulty cells and bypass diodes is 25.2V.