Chopper controlled resistors in VSC-HVDC transmission for WPP with full-scale converters

Abstract

Large and distant offshore wind power plants can be efficiently connected to the onshore power grid network using VSC-HVDC (Voltage Source Converter based HVDC) transmission. Chopper controlled resistors can be used to limit the DC line over-voltage when there is a fault on the onshore AC grid and power transfer to the grid is obstructed. Considering the development of full scale converter based wind turbine generators (WTG), use of unit rated chopper controlled resistors for each of the full scale AC-DC-AC converter system of the individual turbines has been proposed in place of the one on the HVDC line side. Both the cases have been simulated and their performances are found to be similar. Thus, it justifies that the chopper resistors in the full scale converters are sufficient to handle the low voltage fault ride through (LVRT) conditions.