摘要 |
The present disclosure provides a method for controlling a multilevel converter, the method including, detecting modulation state values and current directions of sub-modules, and designating, by one sub-module, an average number of switching for each period of an output waveform, wherein
the step of designating the average number of switching includes,
grouping the sub-modules according to being in ON state or in OFF state,
comparing the number of sub-modules in previous ON state and the number of sub-modules in OFF state to obtain a difference therebetween, and changing a state as much as the difference, comparing a sub-module of ON state having a high voltage as much as a predetermined value in charged state with a sub-module of OFF state having a low voltage value, and changing the compared states of sub-modules of ON state and OFF state, when the values of sub-modules of ON state are higher, and comparing a sub-module of ON state having a low voltage as much as a predetermined value in discharged state with a sub-module of OFF state having a high voltage value, and changing the compared states of sub-modules of ON state and OFF state, when the values of sub-modules of OFF state are higher. |