Solar
Electric Power System
Sweet Sue on the benefits of owning a polycrystalline photovoltaic module.
For grid-connected systems, we discuss a mathematical model and simulation program.
In a remote installation, the electronics for charging the batteries must be able to extract the maximum power at minimum loss from the solar modules, as well as performing a number of functions such as battery protection from over and under charging, protection of the cells from reverse voltage, and powering a number of user devices from low voltage DC to the standard grid mains power, in our case, 240V AC.
Before tackling the electronics, which will come later, we take a look at how to obtain a good choice of the capacities of the solar cells and battery. This is helped by studying a mathematical model of the system of solar modules and batteries.
- Solar Module
Illumination Model. This model predicts the
maximum power that could be obtained from a solar module during the
course of a day at any time of year and any latitude. The model gives
an appreciation of the reduction in power output over the specified
power and how this will vary with latitude and time of year.
- Solar Module Model.
This
model predicts the actual power that
would be stored into a battery. This differs from the maximum power
calculated in the Illumination Model because the fixed battery voltage
would
prevent the
solar module from operating at its maximum power transfer point. The
model gives an appreciation of the loss due to the fixed battery
voltage.
- Electronics. To be
done. The aim is to develop a smart
regulator that could improve the overall efficiency of the system.