Dc Fault Current Clearance At The Source-side Of Hvdc Grid Using Hybrid Mmc

DC FAULT CURRENT CLEARANCE AT THE SOURCE-SIDE OF HVDC GRID USING HYBRID MMC

Abstract:

            In this project, a control technique is presented for clearing a source-side DC fault current for HVDC grids under DC short-circuit faults. The technique consists of  half-bridge sub-modules (HBSM) and full-bridge  sub-modules (FBSMs) based hybrid MMC. The DC fault current behaviors of the HVDC grid is revealed as a primary criterion for the proposed approach. The additional degrees of freedom for control of hybrid MMC are incorporated into the HVDC grid to interrupt the fault current feeding at the source side. Reactive power is compensated  during the fault ride-through process. This control technique doesn't require DC circuit breakers (DCCBs) since the current in the fault line can be controlled to zero. The primary and backup protection schemes for hybrid MMC-HVDC grid are proposed. The performance of the proposed technique is examined by simulations on MATLAB/SIMULINK software.