High-performance front end PFC controller design for light electric vehicle charger application

Abstract

Power factor correction (PFC) boost converters operating in CCM (continuous conduction mode) typically utilize average current mode (ACM) control alongside a LPF (low-pass filter) to reduce the impact of double line frequency ripple on the current loop. However, the LPF limit the voltage loop bandwidth in ACM-regulated converters, resulting in sluggish dynamic response. Additionally, zero-crossing distortion (ZCD) often occurs in the current control loop due to inaccuracies in tracking the reference current at the zero crossing point of the waveform. To address these challenges, this paper proposes a feed-forward control strategy that utilizes supply voltage and output current, effectively eliminating the need for an LPF and enhancing transient response. The voltage loop is tuned using the conventional Z-N method, while the Grey Wolf Optimization (GWO) technique is employed to optimally tune the gain parameters of the current controller (K_Pi and K_Ii). This approach effectively reduces reference tracking errors and mitigates ZCD, offering a balance between simplicity and performance. The proposed method is simple, offering fast transient and steady-state response, low THD, near-unity PF, and tight voltage regulation under fluctuating conditions. The effectiveness of this approach is validated through MATLAB/Simulink simulations, and hardware verification is conducted using a 500 W laboratory prototype controlled by a dSPACE 1104 digital controller.