In the vessel integrated power system (IPS), several common events, such as replacement of the aging batteries, isolation of fault modules, and launching of pulse loads, can make the state-of-charge (SOC) of energy storage elements (ESEs) inconsistent, which, consequently, requires different charging or discharging power commands for the ESEs to balance their SOC. Modular multilevel converter–bidirectional dc–dc converter (MMC-BDC) can be utilized in the vessel IPS to connect ESEs with the medium-voltage (MV) bus for its outstanding characteristics. However, the degree of imbalance in the module power of MMC-BDC is limited inherently, which can destabilize the system, but is usually neglected by the researchers. Therefore, this article investigates the unbalanced operating principle of a cascaded MMC-BDC. The imbalance boundary is studied. A control strategy is designed for the unbalanced operation to optimize the voltage stress of the components. A method of allocating unbalanced module power to the submodules (SMs) is raised on the basis of an imbalance boundary. A novel fast balancing charging strategy is proposed consequently. Finally, the proposed theory and strategies are verified through simulation and a 7.2-kW prototype.
Unbalanced Operation Principle and Fast Balancing Charging Strategy of a Cascaded Modular Multilevel Converter–Bidirectional DC–DC Converter in the Shipboard Applications
IEEE Transactions on Transportation Electrification ; 6 , 3 ; 1265-1278
01.09.2020
9391714 byte
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Modular multilevel converter for railway applications
British Library Online Contents | 2011
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