Impedance remodeling strategy for alternating-current micro-grid composed of VSG and CPL

The invention discloses an impedance remodeling strategy for an alternating current micro-grid composed of a VSG and a CPL. The method comprises the specific steps of establishing a dq impedance model of a VSG and a constant power load, analyzing influence factors and an instability mechanism of microgrid stability through the impedance model, and performing impedance remodeling on the VSG and the constant power load based on a passivity theory. The amplitude of the output impedance of the VSG in the middle-frequency band is high, and the amplitude of the impedance of the constant-power load in the middle-frequency band is low, so that the VSG and the constant-power load are easy to interact in the middle-frequency band and lose stability. Active damping is added to a VSG inner ring, LC resonance is inhibited, and output impedance of a middle frequency band is reduced. A series lead correction link is added to a current inner ring of the constant power load to compensate phase lag caused by the sampling low-p