一种考虑电流限制的构网型变流器稳定性增强策略OA

In response to the issues of overcurrent and insufficient transient stability in grid-forming converters(GFCs)under voltage sag conditions,this paper proposes a transient stability enhancement control strategy incorporating current limitation.First,the structure of the studied GFC is introduced,and the causes of overcurrent as well as the mechanisms by which conventional current limiting methods may lead to transient instability are analyzed.Second,an adaptive virtual impedance is introduced to limit overcurrent during both fault initiation and fault duration.Meanwhile,the reference power is adaptively adjusted through grid voltage detection,thereby improving power-angle stability.In addition,a method for detecting the magnitude of grid voltage dips based on internal controller variables is proposed,which eliminates the need for additional grid voltage measurements or line impedance estimation.Finally,the correctness and effectiveness of the proposed control method are verified through comparative simulation and experimental results.