Global resonance suppression method and system of LCL type inverter multi-machine parallel system

The invention relates to a global resonance suppression method and system for an LCL type inverter multi-machine parallel system, and the method comprises the steps: S1, obtaining an inverter multi-machine parallel system equivalent model through a single-inverter system equivalent model, and obtaining the resonance characteristics of a multi-inverter parallel system; s2, based on a QPR controller, forming double-loop control which takes a capacitance current proportion as a current inner loop and takes grid-side current feedback as a current outer loop; s3, adding optimization control of a power grid voltage feed-forward series lead compensation link on the basis of the step 2, and suppressing harmonic resonance caused by a low-frequency disturbance component of the power grid voltage; and S4, PCC point high-frequency component feedback compensation is introduced on the basis of the step 3, a virtual admittance coefficient can be set and adjusted according to the size of the power grid impedance under the we