In order to optimize the electric energy quality of HVDC access point, a modular multilevel selective harmonic
elimination pulse-width modulation (MSHE-PWM) method is proposed. On the basis of keeping the minimum action frequency
of the power device, MSHE-PWM method can meet the requirement for accurately eliminating low-order harmonics
in the output PWM waveform. Firstly, establish the basic mathematical model of MMC topology and point out the
voltage balance control principle of single modules; then, analyze offline gaining principle and realization way of MSHEPWM
switching angle; finally, verify MSHE-PWM control performance on the basis of MMC reactive power compensation
experimental prototype. The experimental result shows that the proposed MSHE-PWM method can meet such performance
indexes as low switching frequency and no lower-order harmonics, and has verified the feasibility and effectiveness
thereof for optimizing the electric energy quality of HVDC access point.
An improved hysteretic PWM control with feed-forward and feedback
