A Cross-Decoupled Current Harmonics Suppression Method for IPMSM Based on Notch Filter and Second-Order Generalized Integrator

The second-order generalized integrator (SOGI) is widely applied for current harmonics suppression of interior permanent magnet synchronous motors (IPMSMs). However, SOGI is single-degree of freedom and exists a tradeoff issue between the dynamic convergence response and the stable convergence precision. Thus, the final performance of current harmonics suppression is influenced. In order to address this issue, a cross-decoupled current harmonics suppression method based on notch filter and SOGI (NF-SOGI) is proposed. First, according to the opposite characteristics of SOGI and NF, SOGI is applied to extract the target current harmonic, while NF is applied to extract all the nontarget current harmonics, and thus, the target current harmonic is decoupled with the nontarget ones. Second, through the cross-link between SOGI and NF, NF-SOGI is reconstructed as double-degree of freedom, and there are two coefficients to cope with the tradeoff issue, and thus, the convergence precision can be improved under the same convergence rate. Therefore, the suppression performance of current harmonics is enhanced. Finally, the effectiveness of the proposed scheme is validated on a 17.26-kW IPMSM drive platform.