With the development of modular multilevel converter(MMC)
improving the capacity and voltage level has become a research hotspot. In this paper
by establishing the MMC model based on insulated gate bipolar transistor(IGBT)series modular
the voltage harmonic distortion with carrier phase shift modulation strategy is studied along with the electromagnetic noise interference at switching frequency. The random zero-sequence component modulation(RZCM)mode is proposed and
based on the principle of random process
the power spectral densities in different random pulse width modulation(PWM)modes are compared. Then
the noise reduction of random PWM for MMC is treated based on theory and simulation. Simulation results show that the proposed method can appreciably reduce the noise of MMC with large capacity and high voltage.