Dual-Circulant Modulation for Modular Multilevel DC/DC Converters With Inherent Balance Capability

• Modular multilevel dc/dc converters (MMDC) have emerged recently for medium-voltage dc applications. Under single-circulant modulation, the submodule (SM) capacitor voltages in MMDC are found to be evenly divided only at some specific modulation coefficients. To obtain the inherent balance capability under all modulation coefficients and expand the application range of circulant modulation, a simple dual-circulant modulation is proposed in this letter. On the basis of single-circulant modulation, the self-balancing of the SM capacitor voltages is realized by using the additional switching patterns generated by a simple circulant permutation method. The theoretical analysis of the proposed method is presented, and the inherent balance capability of MMDC under the dual-circulant modulation method is verified by experiments.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Annan elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Other Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Keyword

Dual-circulant modulation

inherent balance capability

medium-voltage

modular multilevel dc/dc converters (MMDC)

Publication and Content Type

ref (subject category)

art (subject category)