Title |
THD Analysis of Output Voltage According to PWM Carriers in Single-Delta Bridge Cell MMC |
Authors |
Jae-Myeong Kim ; Jae-Jung Jung |
DOI |
https://doi.org/10.6113/TKPE.2022.27.6.526 |
Keywords |
Carrier wave; Full-bridge cell; MMC(Modular Multilevel Converter); PSPWM(Phase-Shifted Pulse Width Modulation); THD(Total Harmonic Distortion) |
Abstract |
The modular multilevel converter (MMC) has been widely applied to various industrial areas because of its various advantages and structural characteristics. Therefore, many methods for synthesizing the output voltage of MMC have been studied. Among these methods, phase-shifted pulse width modulation (PSPWM) is frequently used in MMC systems because it has diverse merits, such as excellent output qualities even with a small number of cells and uniform power distribution among cells. In this study, the total harmonic distortion (THD) of the output voltage is analyzed in accordance with the number of cells in one arm of a single-delta bridge cell MMC in order to compare PSPWM methods in terms of the THD of the output voltage. The physical characteristics of the triangle and sawtooth carrier waves used for the PSPWM and the mathematical modeling of output voltage are introduced. Then, the obtained results are verified through real-time simulation of a 1 MW single-delta bridge cell MMC system |