One of the most important forms of energy today is electricity. The consumption of electricity is increasing more and more. The task of the distribution network is to provide high-quality, constant and reliable electricity to consumers, which also requires greater energy production or an increase in network capacity. Nowadays, due to the growing number of loads, such as heat pumps and increasingly popular electric vehicles, we observe a significant increase in the consumption of electricity, especially in the winter time. The network must be constantly adapted and upgraded so that it can provide consumers with a reliable supply of electricity and thereby ensure the uninterrupted operation of devices.
The trends in energy production are also changing, which is confirmed by the ever-increasing number of dispersed, environmentally friendly renewable sources of electricity which, as a rule, are connected to the distribution network (the exception is wind farms which are mainly connected to the transmission network) and consequently have a strong influence on the operation of the network. Dispersed sources have low powers. The contribution to the share of electricity is not constant because they strongly depend on external factors (solar radiation, wind, water level, etc.).
Both loads and dispersed sources contribute to the fluctuation of electricity or the discrepancy between production and consumption, which is a key problem in the operation of the network. Despite these influences, the network must also ensure a high-quality supply of electricity in the future which is why it must be properly managed and have the ability to adapt to new conditions.
The reality of today's time is battery storage systems which are an alternative to strengthening the existing network, which optimizes the operation of the devices, contributes to the quality of the voltage and extends the time of investing in a new, stronger network.
The purpose of the diploma thesis is to investigate possible voltage adjustments that enable optimal operation of the distribution network to ensure a safe, uninterrupted and high-quality supply of electricity. In addition, the adjustments must be appropriate and acceptable from an economic and social point of view. Several options for voltage regulation in the network are mentioned, such as installing switches, replacing network elements, adjusting the power of renewable sources (reducing it when the network elements does not need it) or using battery systems. In practice, they are all established but due to restrictions or the shortcomings of the first three, the battery system is offered as the most optimal solution - this is also the topic of the diploma thesis. The battery system provides more services (quality electricity, voltage control, load smoothing and frequency control) which is why it proves to be effective because immediate investment in a new network is not necessary. That somewhat delays the investment and enables the optimal use of the existing network elements.
The components of the battery system or the main battery technologies and their characteristics (lifetime, efficiency and approximate powers) are presented, as well as the design and operation of the converter.
In the second part of the diploma thesis, voltage regulation with utilizing battery storage is presented in more detail. Utilizing the Matlab programming environment, an example of the operation of the distribution network before and after the installation of the battery system is shown. When installing the battery, it is necessary to determine its connection power, capacity and charging/discharging time according to the capacities and network requirements (excess production/increased demand for energy). For adequate battery properties, it is necessary to provide power elements that will enable efficient conversion and reliable voltage storage. In the process, it is also necessary to take into account safety requirements and the presence of harmonic components and predetermined restrictions following certain standards. The battery helps regulate the voltage of the network and this extends the lifetime of the existing network because with the addition of current renewable sources of electricity, such as solar cells, the network is no longer capable of optimal operation.
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