Research on Low Voltage Ride Through capability of wind farms grid integration using VSC-HVDC

摘要

With the capacities of wind generators in power system rapidly increasing, wind farms has impact on the AC grid obviously. So the problem which is to improve Low Voltage Ride Through (LVRT) capability of wind generators needs to be solved urgently. Base on the design of controllers of DFIG and controllers of VSC-HVDC system, the wind farms connected to the AC grid by two different methods of AC and VSC-HVDC are modeled in the paper. When there is a three-phase short-circuit fault in system side, the LVRT capability of wind farm that integrates by two different ways is analyzed. For wind farm connected to AC grid through VSC-HVDC system, if VSC-HVDC system has chosen right dc-capacitors, the dc-capacitors can temporarily store energy during system fault which can ensure the LVRT requirements of wind turbines.