PROJECT TITLE :

Analysis of the Performance of MMC Under Fault Conditions in HVDC-Based Offshore Wind Farms

ABSTRACT:

This paper analyzes the behavior of a modular multilevel converter-high-voltage direct-current (MMC-HVDC)-connected offshore wind power plant (WPP) throughout dc faults. For that purpose, detailed models of the dc cable, MMC stations, and transformers are utilized in order to get reliable results. The influence of the WPP management technique within the short-circuit behavior of the HVDC link has additionally been studied. Results show that the dynamics of the WPP contribution to pole-to-ground faults are slightly slower than those of the wind turbines current management loops. Thus, the wind turbine front-finish converters can be used to scale back the peak and average value of the fault current in such a system. Moreover, it has been found that ferroresonant oscillations can appear in the offshore ac grid when the WPP delivers constant power throughout faults.