## 6 Conclusions  
This work presents three key current-source inverter modulation techniques: VSI-derived CSI SVM, direct CSI SVM, and direct duty ratio CSI PWM. It also includes extensive simulation models and analyzes the fundamentals of each modulation strategy in detail. These models address a significant gap in the availability of simulation models for CSI modulation and the existing theory, a complexity sometimes overlooked in comparison to the  
Figure 21: The relationship between modulation index and (**a**) THD, (**b**) efficiency for VSI-derived CSI SVM, direct CSI SVM, and DDPWM modulation techniques.  
relatively simple VSI method. For those working with CSI technology, the straightforward models and comprehensive simulations presented here constitute a great resource.  
The modular structure of the blocks presented in this study will allow engineers and researchers to adapt them easily to similar applications. This study shows how to analyze the performance of CSIs in practice and how to achieve even better results when the calculations and predictions, in theory, are combined with the necessary mathematical approaches.  
Table 3 and Figure 21 demonstrate that each modulation technique has its own unique advantages. VSI-derived SVM is suitable for simplicity (94% efficiency, 1.72% THD), direct SVM is suitable for balanced performance (95% efficiency, 1.1% THD), and DDPWM is suitable for optimal metrics (97% efficiency, 0.42% THD). The simulation results show that all three methods comply with the THD grid standards below 5%. This shows the ability of these techniques to improve the efficiency and reliability of power electronic systems, particularly in high-power conditions, where CSIs are increasingly implemented. By providing models for all three approaches, this work enables both academic research and industrial applications to benefit from the practical applicability of the models, which is further improved by the inclusion of comprehensive parameter selection advice and waveform comparisons.  
Future work will focus on experimental validation of these techniques at different power levels. Integration with wide-bandgap devices and application-specific optimizations for renewable energy systems are also valuable directions. This detailed study provides the necessary tools for its wider use in power electronics systems.  
Conceptualization, G.E. and E.N.; methodology, G.E. and E.N.; software, G.E. and E.N.; validation, G.E. and E.N.; formal analysis, G.E. and E.N.; investigation, G.E. and E.N.; resources, G.E. and E.N.; writing--original draft preparation, G.E. and E.N.; writing--review and editing, G.E. and E.N.; visualization, G.E. and E.N.; project administration, G.E. and E.N. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
The raw data supporting the conclusions of this article will be made available by the authors on request.  
The authors gratefully acknowledge Plexim GmbH for providing a sponsored academic license of PLECS software to Bilecik Seyh Edebali University, which facilitated the simulations presented in this work.  
Author [PERSON] was employed by the company Data Technologies Inc. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.  
The following abbreviations are used in this manuscript:  
\begin{tabular}{l l} CSI & Current-source inverter \\ DDPWM & Direct duty ratio pulse-width modulation \\ FSM & Full Wave Symmetrical Modulation \\ PLL & Phase-locked loop \\ PWM & Pulse-width modulation \\ SPTT & Single-Pole Triple-Throw Switch \\ SOPWM & Synchronous Optimal Pulse-Width Modulation \\ \end{tabular}  
Figure A2: Detailed switching sequences for symmetrical SVM implementation of the CSI. Sector 1–3 patterns, Sector 4–6 patterns, showing gate signals (S1–S6) and current paths.  
Figure A3: Sector selector and the state machine.