Fig. 1. Configuration of the MMC: (a) Circuit diagram, (b) Submodule
Fig. 2. Phase-shifted PWM method for the MMC
Fig. 3. Conventional PWM method and 2-D model of DFS
Fig. 4. Equivalent circuit of the MMC
Fig. 5. Analytical results and simulation results: (a) Analyticalresults, (b) Simulation results with simulation timestep of 0.5 μs, (c) Simulation results withsimulation time step of 10 μs
Fig. 6. Voltage drop on arm inductor
Fig. 7. Distribution of harmonics versus number of levelsof MMC (fct = 3600 Hz). (a) 5-level MMC, (b) 11-level MMC, (c) 21-level MMC
Fig. 8. Total harmonic distortion versus number of levels ofMMC
Fig. 9. Distribution of harmonics versus total switchingfrequency (11-level MMC): (a) fct = 1800 Hz, (b) fct= 3600 Hz, (c) fct = 5400 Hz
Fig. 10. Total harmonic distortion versus total switchingfrequency
Fig. 11. Harmonic profile of 11-level MMC
Table 1. The parameters of MMC
Table 2. THDs of the ideal and real line-to-line voltages
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