A Harmonic Current Suppression Method Based on Two-Dimensional Identification of Virtual Harmonic Back Electromotive Force for PMSM Drives

In permanent magnet synchronous machines (PMSMs), the harmonic currents induced by harmonic back electromotive force (BEMF) and the inverter nonlinearity are inevitable. Existing methods typically rely on the design of high-performance controllers for harmonic suppression, which inevitably requires complex parameter tuning. In contrast, parameter identification methods, widely used in machine control, can achieve high-performance control while avoiding complex parameter tuning. However, there is a lack of methods that apply parameter identification for harmonic suppression. Consequently, this article models the harmonic voltages caused by the inverter nonlinearity, dq circuit cross coupling, and harmonic permanent magnet flux linkage as the virtual harmonic BEMF. Furthermore, this article proposes a harmonic current suppression method based on the 2-D identification of virtual harmonic BEMF. The proposed method utilizes only two integral regulators to achieve static-errorless identification of the amplitude and phase of the virtual BEMF while simultaneously ensuring static-errorless suppression of the harmonic currents. Furthermore, this article also considers the impact of system delay and incorporates compensation. Finally, the effectiveness of the proposed method is verified experimentally.