The main aim of this thesis was to evaluate the influence of 2997 Aristo Z stud horse in Czech horse breeding. The general database listed 357 offspring in the Czech and Slovak Warmblood Studbook, all born between 2009 and 2018. The relevant data has been collected on the websites of the Association of Czech Warmblood Breeders, Association of Slovakian Warmblood Breeders in the Czech Republic, and in the Central Register of Horses in Slatiňany. The database has been compiled manually in Mi-crosoft Office Excel 2016 and the acquired data were processed by the general linear model with the subsequent testing by the Tukey-B method, if the observed effect was proved to be statistically significant. In this process, the UNISTAT 6.5. Mathematical and Statistical Package was used. Collected data proves that stallion 2997 Aristo Z was the most favorite among the breeders in 2008. Furthermore, a comparison of stallions and mares body measurements was performed, as well as point measurements for class, type, exterior and performance in mares. It can be concluded, that from the exterior point of view, 2997 Aristo Z stal-lion has proper offspring, albeit very variable. His daughters demonstrate high class, type, exterior and performance score. When comparing his own jumping index with the indexes of his daughters and sons, he was evaluated as a worse. Furthermore, a general linear model was applied to find a statistically significant influence of year of birth and year of studbook registration to withers height stick. In this case, a statistically conclusive influence of sex on the jumping index and influence of performance points on stud-book listing has been proved. Subsequent Tukey-B testing proved that mares listed in the General studbook have statistically significantly higher performance points when compared to the mares listed in the studbook. Another Tukey-B test was aimed at the statistically significant influence of sex on the jumping index. It has been proved that mares have statistically significantly higher jumping index than stallions and geldings. All the conclusions listed above are evaluated and discussed in the thesis.

This thesis treats the subject of a complete steady state and dynamic model of the VSC-HVDC covering both the AC and DC system-side of the converter. The topology of the model is recreated after the scheduled transmission line in the south of Sweden, called SydVästlänken. The topology covers both a simple two terminal connection as well as a multi-terminal one. This model is to be implemented in the power system simulation program ARISTO. The main directive of the model is operation planning and education during real-time scenarios. The model is deliberately designed as a complete and complex model but with methods of reducing it's complexity to suit the users needs at the time for implementation. Further more the author have made sure that it is a complete generic model to suit the application of the program as the technology to the day of this study are unknown. Lastly, a method of controlling the converters are presented where Droop-control take a prominent roll as the AC and DC voltage regulator.

How long would modern society cope with a power outage, what would happen to vital systems that we today take for granted in modern society. The Nordic electricity grid is facing a major shift where electricity production from non-renewable sources are to be replaced increasingly by renewable sources. By increasing the penetration of wind and solar power the electric power system might be exposed to disturbances due to decreasing inertia as a result of the electricity transition. Currently the electric power system has different reserves to use to maintain frequency stability but there are other reserves that could help further in the fight for the balance between electricity production and consumption. This project examines whether the new reserve service, fast frequency reserve (FFR), can help the existing frequency containment reserve for disturbed (FCR-D) operation. Therefore, two experiments were conducted using the simulation tool ARISTO, addressing relevant issues involving frequency stability. Motivation for the hypothesis was to investigate if FFR could reduce the frequency transients and improve frequency variations by developing various setups and cases when inertia was retained and when the system inertia was reduced at different stages. The results of the experiments showed that the global minimum frequency, nadir, had increased for all test cases compared to the reference case when using FFR, this proved that the FFR in fact help reducing frequency transients. The results showed furthermore that when the FFR had a duration time of 30 seconds compared to only 5 seconds, the frequency variations could be improved for certain setups for experiment 2.