The invention provides a multi-
inverter grid-connected
system broadband oscillation suppression method based on impedance collaborative reconstruction, and the method comprises the steps: firstly carrying out the
frequency domain small
signal modeling, and constructing a
station-level
system frequency domain impedance model on the basis of a single
machine; therefore, the design of an additional control
branch is expanded, a power
signal is superposed to the control
branch through an additional damping control
branch so as to realize the improvement of the impedance amplitude of the
inverter, and the phase improvement of a capacitive
frequency band is realized by adopting an active damping strategy based on a filter; secondly, constructing an impedance collaborative
reconstruction method under a multi-
inverter system, establishing a two-stage optimization structure, comprehensively solving the position and parameters of a control branch, and achieving the suppression of system oscillation. According to the invention, through collaborative optimization, conflicts of different control strategies are reduced, and the influence of a
coupling relationship is minimized; furthermore, through cooperation of the multiple inverters, dual optimization of damping in the space and the
frequency domain is achieved, and efficient suppression of
broadband oscillation of the multi-inverter grid-connected system is achieved.