Current Harmonic Suppression for GaN Totem-Pole PFC Converter Based on Adaptive Active Damping With Tabu Search Algorithm

Grid current harmonic suppression in GaN-based PFC converters remains challenging due to the limited adaptability of fixed virtual admittance methods. In this paper, an adaptive active damping method employing the tabu search (TS) algorithm for grid current harmonic suppression was proposed to address this issue. An input admittance model of the converter that considers the input-side LC resonance and control loop influence is established and the sensitivity of the admittance to operating conditions is analyzed. In order to obtain the optimal solution and improve the power quality within a wide power range, the TS strategy and aspiration criteria are incorporated, which can effectively avoid entrapment in local optima. Meanwhile, considering the virtual admittance is a vector, a method of alternating stepwise optimization of amplitude and phase is adopted to simplify the algorithm and achieve equivalent effects. Then, equivalent active damping is implemented through current command adjustment and duty-cycle feedforward, eliminating the need for additional hardware. The TS algorithm's step size and tabu list are tuned to balance precision and convergence. Finally, experimental results on a GaN totem-pole PFC platform demonstrate that the proposed method outperforms conventional approaches, reducing grid current harmonics significantly over a broad power range.