An LCC/VSC Hybrid Structure And Its Coordinated Control In Medium-Voltage DC Distribution System

In order to reasonably exploit the advantages of line commutated converter (LCC) and voltage source converter (VSC), a coordinated LCC/VSC control strategy applicable to DC distribution network structures is proposed in this paper. In steady-state operation, LCC and VSC perform power distribution according to the set distribution ratio, and LCC can be put into operation or shut down at the right time according to power changes. This power distribution strategy fully exploits the advantages of LCCs large capacity, reduces the pressure on the transmission power of VSCs, and provides a feasible solution for the application of large-capacity LCC in DC distribution networks. Meanwhile, when power fluctuation occurs in the DC distribution network, DC voltage fluctuation spikes can be reduced by VSC/LCC under the action of the virtual direct current generator (VDG) control strategy. The simulation results of MATLAB/SIMULINK verify the feasibility and effectiveness of the method.