A power feedback loop against grid frequency disturbances of virtual synchronous generators

Output active power and frequency transient oscillations of the virtual synchronous generators (VSGs) occur under external disturbances. Existing transient improvement strategies improve the power characteristics but deteriorate the power-frequency response characteristics during grid frequency disturbances. In this regard, this paper proposes the method of parallel low-pass power feedback in the control loop, which increases the degree of freedom of the VSG, makes the improvement of phase margin possible, and effectively resists the grid frequency disturbances. Finally, a 15 kW VSG simulation model verifies the proposed method has a better ability to resist grid frequency disturbances compared with the existing VSG transient oscillation suppression methods.