Patent ID: 9748856
Date: 2017-08-29
CPC Classifications: H02M

Claim:
1. A modular multi-level converter, comprising: a plurality of sub-modules each comprising a plurality of switching elements; a plurality of sub-control units each configured to control at least one sub-module of the plurality of sub-modules; and a central control unit configured to determine switching operation conditions of the plurality of sub-modules and transmit control signals corresponding to the determined switching operation conditions to the plurality of sub-control units, wherein each of the plurality of sub-control units is further configured to acquire state information including switching history information related to the corresponding at least one sub-module and transmit the acquired state information to the central control unit, wherein the switching history information includes information related to a charging operation, a discharging operation and a bypassing operation performed by the corresponding at least one sub-module, wherein the central control unit is further configured to use the switching history information to determine a sub-module currently performing the discharging operation, a sub-module currently performing the charging operation, and a sub-module currently performing the bypassing operation.