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

Unpredictable power fluctuation and fault ridethrough 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 currentsource 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 multifarious 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 SMESCSDC is implemented via a scaled-down experiment,and its effectiveness for DC-DFIG protection is verified by a large-scale DC power system simulation.