MODULATION METHOD AND APPARATUS FOR CASCADED ENERGY STORAGE SYSTEM

A cascaded energy storage system comprises N sub-modules which are connected in cascade, wherein N is greater than or equal to 2. The modulation method comprises: in an odd period, according to a first correspondence, using N carriers to modulate waveform signals output by the N sub-modules; and in an even period, according to a second correspondence, using the N carriers to modulate the waveform signals output by the N sub-modules, wherein in the first correspondence and the second correspondence, the N carriers are in one-to-one correspondence with the N sub-modules, and the first correspondence is different from the second correspondence.