In this paper, the transient stability of droopcontrolled voltage source converters (VSCs) is studied. Firstly, according to the rotor motion equation of a synchronous generator (SG), the large-signal model of VSCs is established. On this basis, the mechanism of transient instability of the converter during short-circuit fault is revealed through the equal area criterion (EAC). In order to ensure that the converter has low voltage ride through capability, the control mode is switched to vector current control by an adaptive mode parallel switching method. In the process of fault, the output current of the converter can follow the current reference value well and provide reactive power support to the grid. Finally, simulation and experimental results verify the effectiveness of the theoretical analysis.
Low Voltage Ride Through of Voltage Source Converters With Droop Control Xing Zhang, Jilei Wang, Zixuan Guo, Feng Han, Xinxin Fu, Shaolong Chen