Superconducting Magnetic Energy Storage Integrated Current-source DC/DC Converter for Voltage Stabilization and Power Regulation in DFIG-based DC Power Systems

Abstract

Unpredictable power fluctuation and fault ride-through capability attract increased attention as two uncertain major factors in doubly-fed induction generators (DFIGs) integrated DC power system. Present solutions usually require complicated cooperation comprising multiple modules of energy storage, current control, and voltage stabilizer. To overcome the drawbacks of existing solutions, this paper proposes a superconducting magnetic energy storage (SMES) integrated current-source DC/DC converter (CSDC). It is mainly composed of a current-source back-to-back converter, and the SMES is tactfully embedded in series with the intermediate DC link. The proposed SMES-CSDC is installed in front of the DC-DFIG to carry out its dual abilities of load voltage stabilization under multi-farious transient disturbances and power regulation under wind speed variations. Compared with the existing DC protection devices, the SMES-CSDC is designed on the basis of unique current-type energy storage. It has the advantages of fast response, extensive compensation range, concise hardware structure, and straightforward control strategy. The feasibility of the SMES-CSDC is implemented via a scaled-down experiment, and its effectiveness for DC-DFIG protection is verified by a large-scale DC power system simulation.