# Small Magnus Wind Turbine: Modeling Approaches
## 5 Conclusions  
The technological level of today's industry and everyday life requires sustainable energy preservation and regeneration methods. Therefore, new and renewable energy sources should provide high efficiency in order to achieve that goal. MWT is one of the potential technologies that can contribute towards advanced control techniques (e.g., MPPT) being used. In the current research work, multiple goals required for developing an MPPT control for the MWT were achieved.  
Primarily, the literature analysis shows that, when compared to conventional wind turbines, MWT has inferior coverage from the scientific research groups. There were only three possible simulation models discussed in the literature, so all approaches to simulate of the power coefficient of MWT were studied. As a result, mechanical and aerodynamical models of the MWT were created.  
The conducted study showed the possibility of designing three simulation models for describing MWT power characteristics. The literature review showed the linear relationship between the generated power and power coefficient of a wind energy conversion system. Three analytical models--analytical, regression, and correlation, using the power coefficient--were created. The simulation results for the presented mathematical models were later validated by comparing them to the experimental data on mechanical torque of the rotor of the experimental wind generator. The analytical model in the comparison was the most accurate with experimental results. Other models have been shown to be highly dependent on the mechanical characteristics of the wind generator used. The final comparison has shown that the analytical model presents the most accurate results, and it was selected to be a base model for further research in the field of MPPT for MWT.  
All discussed in the paper models may be repeated by using the link given in the Data Availability Statement section.  
Moreover, a power curve was obtained using the chosen analytical model. This curve is to be used to determine the optimal approach to MPPT. Further work in the field of MPPT for MWT requires the implementation of electrical, electromechanical blocks to the developed model, and simulating different MPPT techniques.  
Figure 10: Principles of MPPT for wind generators.  
**Author Contributions:** Conceptualization, G.D. and A.R.; methodology, A.L.; software, A.L.; validation, D.L., T.V. and A.A.; writing--original draft preparation, A.L., G.D. and A.R.; writing--review and editing, T.V.; supervision, D.L. and A.A.; funding acquisition, A.R. All authors have read and agreed to the published version of the manuscript.  
**Funding:** The research has been supported by the Estonian Research Council under grant PSG453 \"Digital twin for propulsion drive of autonomous electric vehicle\".  
**Data Availability Statement:** Magnus effect-based wind turbine (MWT) simulation models presented in the paper are available via the link [[https://github.com/aelukin/MWT_model](https://github.com/aelukin/MWT_model)]([https://github.com/aelukin/MWT_model](https://github.com/aelukin/MWT_model)) (accessed on 4 January 2022).  
**Conflicts of Interest:** The authors declare no conflict of interest.  
**Nomenclature**  
\begin{tabular}{l l} BEM & Boundary Element Method \\ \(C_{p}\) & power coefficient of a wind energy conversion system \\ CSR & Cylinder speed Ratio \\ DC & Direct current \\ HIL & hill-climbing control algorithm \\ MPPT & Maximum Power Point Tracking \\ MWT & Magnus effect-based Wind Turbine \\ TSR & Tip Speed Ratio \\ \end{tabular}