The Virtual Inertia Control of MMC-HVDC Considering the Effect of Active Power Loss of DC Line

Abstract

Modular multi-level converter based high-voltage Direct-Current (MMC-HVDC) grid integration is an effective measure to achieve offshore wind power grid integration of large-scale and long-distance. As the offshore wind farms get farther and farther offshore, the active power loss of their submarine DC cables has become a non-negligible part of offshore wind power's participation in frequency regulation. In this paper, on the basis of simulating the inertia of synchronous generator with DC capacitor energy, a virtual inertial control strategy considering the influence of active power loss of DC cable is derived. And, the influence on the frequency stability of the system after considering the active power loss of the DC cable is also analyzed at the same time. Finally, a model of offshore wind power grid-connected through MMC-HVDC is built on MATLAB/Simulink. The simulation results show that the virtual inertia control strategy considering the active power loss of the DC line can effectively improve the frequency stability of the power system.