Abstract: This paper investigates the harmonic current suppression in full-power wind turbine converters under low carrier ratio conditions. With the expansion of offshore wind power capacity and increasing grid penetration, the 5th/7th harmonic voltages in the permanent magnet synchronous generator"s back-EMF induce non-integer frequency harmonic currents on the machine side, leading to grid power quality deterioration and semiconductor thermal stress risks. Traditional resonant controllers suffer performance degradation under low carrier ratios due to control delays and frequency implementation errors, while existing improved solutions often fail to balance dynamic response and harmonic suppression requirements. To address this, we propose a discrete-domain resonant controller construction method that enhances harmonic suppression through optimized digital implementation. Combined with active damping principles, a feedforward decoupling strategy is designed to establish a composite structure of fundamental PI controllers and discrete resonant controllers in the dq-axis frame. Simulation and experiments demonstrate that the proposed solution can nearly completely suppress 5th/7th harmonics in practical operations while achieving fast oscillation-free current control dynamics, providing an effective approach for high-reliability operation of wind power converters.