Coupled harmonic admittance identification based on measurement

This paper proposes an identification method of a coupled harmonic admittance model that is able to reflect the mutual relationships between harmonic voltage and current in all orders. In the proposed method, the elements of the admittance matrix can be derived from voltage and current measurements using least square estimation. The effectiveness of the method is verified through simulations for a grid-connected bridge converter. Compared with Norton modeling, the proposed method presents higher accuracy in terms of harmonic current estimation. In addition, to address the time-varying feature of the admittance, a recursive strategy is proposed, and its merits are well evidenced through simulations.