Improvement of VSG Transient Performance Based on Power Feedforward Decoupling Control

Abstract

The suppression of power grid frequency fluctuation, the inhibition of output active power oscillation, and the coupling of active and reactive power at the output of the virtual synchronous generator (VSG) are all investigated in this work. The connection between VSG output active power oscillation inhibition and grid frequency fluctuation suppression is explored, as well as the difficulties of achieving both power oscillation suppression and frequency fluctuation suppression for VSG at the same time. To overcome this problem, a control approach incorporating notch filter power feedforward decoupling and modifying virtual damping coefficient is presented, it is called power feedforward decoupling control (PFDC). The virtual resistance will worsen the P/Q coupling, whereas the virtual inductance will have no effect, according to the results of the P/Q coupling analysis. It can be demonstrated that the suggested solution does not jeopardize P/Q decoupling performance for VSG active power oscillation suppression and grid frequency fluctuation suppression. The understanding of VSG transient performance is deepened by the comprehensive investigation of the three issues. Finally, simulation is used to verify the soundness of the theoretical analysis and proposed strategy, while VSG's transient performance is increased even more.