Performance Analysis of Front-end Push-Pull Converter in a Single-Phase Inverter for Battery Current Ripple Reduction

Abstract

This research focuses on decreasing the second-order ripple on the battery for telecommunications applications. A two-stage inverter (TSI) produces ripples in the input current, diminishing the battery's performance and lifespan. The active ripple reduction scheme is introduced to minimize or prevent the ripple created by the inverter. This work analyses dual closed-loop feedback in a push-pull converter for eliminating second-order harmonics at the input of a TSI inverter system. During the discharge of a battery, its voltage decreases while the DC-DC converter's pulse width modulation duty cycle approaches its maximum value. This creates an open loop in the existing closed-loop scheme that returns the second-order ripple at the battery input current. Introducing a battery voltage compensation stage in the existing system helps sustain the closed loop at a minimum operating voltage of the converter and maintains acceptable ripple levels. The proposed technique provides a viable solution for keeping the second-order ripple level at the entire operating range of the TSI inverter, even when the battery voltage decreases during discharge. Using the PSIM simulation tool, the proposed solution was validated in a push-pull converter, and the percentage of battery input current ripple was compared with the existing and proposed closed-loop control strategy. Finally, an 800 W/ 1 KVA prototype is built and tested, and the experimental results show that the proposed control techniques work to reduce ripples. The proposed control strategy has reduced the ripples from 10.2% to 1.4% at minimum operating voltage

DOI: 10.61416/ceai.v26i1.8735