1. Internal Resistance of a Source Definition: The resistance within a battery, or other voltage source, that causes a drop in the source voltage when there is a current. Definition: The resistance within a battery, or other voltage source, that causes a drop in the source voltage when there is a current. Lecture 3

5. Maximum Power Transfer Theorem

8. This table represents the values of the output power, the load current and load voltage

9. This plot shows the load power as a function of load resistance

10. This plot shows the variation of load voltage and current with load resistance

13. This leads to the fact that the best operating condition is that, when the load resistance equal to the internal resistance of the source, form the view point of maximum power transfer from source to load.

14. New and Renewable Energy Sources Photovoltaic Panel (PV) Panel And Wind Energy

15. The Solar Energy The Photovoltaic Panel is no more than an energy transducer. It has an ability to generate electric energy from solar energy. It is one of the renewable energy sources. It is cheap, clean and available. The most important property to be considered, is that “it has a non-linear internal resistance”. This property is shown in the figures below:

16. The V/I characteristics shows that this source has a nonlinear internal resistance as compared with that of the battery. Then its output power has a maximum value at one point only as shown in the P/V characteristics shown above.

17. PV Array characteristics at different irradiation levels Note: Such a source needs special arrangements in order to achieve the maximum power point. This is done by changing the value of the input load resistance continuously in order to follow the source internal resistance.