Historically, research on grid-connected inverters has mainly focused on voltage source inverters (VSI), and current source inverters (CSI) have received relatively less attention due to their slower dynamic response (Wang et al. in IEEE Transactions on Power Electronics 30:7019–7037, 2014) and the risk of stability loss caused by the voltage of feedback capacitors in CL filters when suppressing filter resonance or using them for inner loop control (Yang et al. in IEEE Transactions on Industrial Electronics 70:3549–3560, 2022). To address this issue, this chapter first utilizes duality to design parameters for a CSI-type predictive power decoupling (PPD) controller and uses virtual resistance to suppress CL filter resonance and optimize PPD controller parameters. Additionally, a multi-loop control strategy is implemented using the PPD controller as the inner loop controller to solve the instability caused by the feedback capacitor voltage in conventional closed-loop control, as well as the damping branch feedback capacitor voltage, thereby effectively improving the dynamic response and direct current utilization rate of the CSI.