US 12,278,492 B1
Method and system of self-adaptive setting of closed-loop parameters for suppressing photovoltaic coupling harmonics
Yuanyuan Sun, Jinan (CN); Pengbo Shan, Jinan (CN); Yahui Li, Jinan (CN); Lei Ding, Jinan (CN); Kejun Li, Jinan (CN); Kaiqi Sun, Jinan (CN); Zhijie Liu, Jinan (CN); Yirou Lai, Jinan (CN); Zhijie Ma, Jinan (CN); and Qianqian Li, Jinan (CN)
Assigned to SHANDONG UNIVERSITY, Jinan (CN)
Filed by SHANDONG UNIVERSITY, Jinan (CN)
Filed on Dec. 16, 2024, as Appl. No. 18/982,070.
Claims priority of application No. 202311743428.0 (CN), filed on Dec. 19, 2023.
Int. Cl. H02J 3/01 (2006.01); H02J 3/38 (2006.01)
CPC H02J 3/01 (2013.01) [H02J 3/38 (2013.01); H02J 2203/20 (2020.01); H02J 2300/24 (2020.01)] 7 Claims
OG exemplary drawing
 
1. A method of self-adaptive setting of closed-loop parameters for suppressing photovoltaic (PV) coupling harmonics, comprising:
acquiring a node voltage and a node current of a PV grid-connected inverter to be set;
constructing a harmonic coupling admittance matrix of the PV grid-connected inverter to be set according to the acquired node voltage and node current;
calculating an amplitude of each element of the constructed harmonic coupling admittance matrix;
screening contribution sources of coupling harmonics generated by the PV grid-connected inverter to be set according to the calculated amplitude of the each element;
evaluating quantitatively a harmonic admittance of the PV grid-connected inverter to be set according to screened contribution sources; and
carrying out an optimization iteration for parameters of double-closed-loop proportional-integral (PI) control of inverter with an objective of minimizing the coupling harmonics of the PV grid-connected inverter to be set according to results of the quantitative evaluation of the harmonic admittance, to complete self-adaptive setting of closed-loop parameters for suppressing PV coupling harmonics;
wherein, in a process of screening the contribution sources of the coupling harmonics generated by the PV grid-connected inverter to be set, determining a relationship between control variables and an amplitude of the harmonic coupling admittance by comparing changes of the each element in the harmonic coupling admittance matrix before and after different controller parameters are changed, wherein determining a harmonic admittance amplitude change ratio (hereinafter referred to as HCE) to identify and screen the contribution sources of the coupling harmonics generated by the PV grid-connected inverter to be set; wherein,
the HCE is a ratio of difference between a harmonic coupling admittance value after the different controller parameters are changed and an original admittance value of preset parameters to the original admittance value of the preset parameters, HCE=(Yx,yII−Yx,yI)/Yx,yI×100%; where, Yx,yI is the original admittance value of the preset parameters, and Yx,yII is the admittance value after the preset parameters are changed; and
in response to the HCE exceeding an upper-limit of a threshold range, a controlled variable of the controller is a strong coupled variable;
in response to the HCE being within the threshold range, the controlled variable of the controller is a coupled variable; and
in response to the HCE not exceeding a lower-limit of the threshold range, the controlled variable of the controller is an uncoupled variable.