Analysis and Controller Design for Positive Output Boost Converter With Low Current Stress on Output Capacitor

A nonisolated positive output fifth-order dc-dc boost converter is proposed in this article. This topology is developed from the existing fourth-order boost converter (FOBC) by appropriately inserting a charge-pump cell. Compared to FOBC, the proposed topology offers enhanced voltage gain with reduced switch voltage stress. The proposed converter has an advantage of continuous output-port current over existing boost topologies, which reduces the output capacitor current stress. The voltage conversion ratio and L-C design equations in terms of their ripple quantities are formulated by time-domain analysis. Thereafter, a summary of comparison between the proposed converter and existing boost topologies is presented. The duty-to-output voltage transfer function obtained through the average state-space model shows minimum phase behavior. A PID type voltage-mode controller is designed using the dominant pole placement technique to ensure predefined time-domain specifications along with sufficient dominance factor. Maximum sensitivity (Ms) is adopted as a measure to ensure the required robustness of the closed-loop system. The analysis and voltage-mode controller design are verified through experimental results. The dynamic performance and robustness of the closed-loop system tested experimentally are in agreement with the desired requirements.