The electrical parameters of these modules are reflected in the current-voltage characteristics determined at standard conditions i.e., when the power of solar radiation equal to 1000 Втм2 temperature elements - 25°C and solar spectrum - at latitude 45° figure 1. The point of intersection of the curve with the axis of the voltage is called open circuit voltage Vх.x. and with the axis of current - short-circuit current IK.z. On the same graph shows the power curve obtained from the solar cell depending on load. The nominal power of the module is defined as the maximum power under standard conditions. The voltage corresponding to maximum power is called the operating voltage V p and the corresponding current - operating current IP. The value of the operating voltage for a module consisting of 36 cells is approximately equal to 16-17V 045-047Вэлемент at 25°C. This headroom voltage needed to compensate for the decrease in the operating voltage for the heating of solar radiation. Temperature coefficient of open-circuit voltage for silicon is minus 04%degree. Temperature coefficient of current - plus 007 %degree. The open circuit voltage of the solar module varies little when changing the light, while the short-circuit current are directly proportional. The efficiency of the solar module is defined as the ratio of the maximum power of the module to the total radiation power falling on its surface under standard conditions and is 15-40%.
With the aim of obtaining the required power and operating voltage modules are connected in series or in parallel. So get a solar panel. The power of solar battery is always lower than the sum of the capacities of modules because of losses due to differences in the characteristics of similar modules of losses to the mismatch. The more carefully selected modules in the battery that is less than the difference in the characteristics of modules the lower the loss to the mismatch. For example a series connection of ten modules with variations in the characteristics of a 10% loss is about 6% and in the range of 5% reduced to 2%.
In the case of shading of one module or part of the elements in the module in a solar battery is a series connection there is an effect of hot spots is the shaded module or element begins to dissipate lit all produced modules or elements of power rapidly heats up and fails. To eliminate this effect in parallel with each module or part set the shunt diode. The diode needs connecting more than two modules. To every line of series-connected modules is also connected a blocking diode to equalize voltage lines. All these diodes usually