In my thesis I created optimisation tool for an economic optimisation of a hybrid solar-aggregator system. The first part of the thesis I conducted a necessary research. Separately I have examined the elements of such a system and the parameters that are necessary for the optimisation. In addition to this, I examined the economic environment in which these systems work, here in Hungary and in Germany.
Starting with the main power source, the solar cells, their types, manufacturing and construction. Then I examined the required electronic solutions that are necessary because of the fluctuating power generation of the solar cells and their voltage-current characteristics. Divided according to the application I examined feed-in inverters and solutions without any grid. In the case of feed-in solutions, I have analysed the inverters' maximum power point tracking and the required waveform.
As island systems I discussed in detail the charge controllers used for smaller DC systems and topologies that provide power for consumers needing alternating current. Specifically I analysed inverters providing complex charge control, DC-AC conversion and other functions. In addition to this, I have shown the structure, electrical parameters and charging requirements for lead-acid batteries typically used in household applications. I have analysed aggregators that are commonly used as an emergency power supply in such systems.
The program runs in MatLab environment. As input parameters, load profile, local irradiation time series data and electricity sales and purchase prices are necessary. The optimisation is based on a genetic algorithm. It’s result is system layout that gives the best return rate with a given electricity market and system cost. Constrains guarantee that the optimisation results will be an applicable system in reality too. Based on the detailed task description, I have created three models which are basically based on each other. One is a simple feed-in topology with solar panels and an inverter. Second is a battery system where the grid is also at hand. And thirdly a battery system without grid just with a generator. All three of them give as a result the rated power of solar panels, inverter, battery inverter and also the battery capacity and size of the aggregator.