Active Damping Injection Output Voltage Control with Dynamic Current Cut-Off Frequency for DC/DC Buck Converters

Abstract

With regard to DC/DC buck converter applications, the objective of this study is to expand the admissible range of the output voltage cut-off frequency while lowering the steady-state current cut-off frequency as possible. This study fortifies the inner loop by incorporating the novel subsystems such as an auto-tuner (for the dynamic current cut-off frequency) and active damping injection invoking the pole-zero cancellation nature with the particular designed feedback gain structure. The outer loop active damping control renders the closed-loop speed transfer function to be a first-order low-pass filter with the cooperation of the specially structured design parameters; in addition, it provides time-varying disturbance attenuation. The experimental results obtained for a 3-kW buck converter validate the feasibility of the proposed technique by showing a 34% performance enhancement (at least) compared with the recent active damping controller.

Keywords

• DC/DC converter
• dynamic current cut-off frequency
• auto-tuner
• active damping