A Boost Converter Design with Low Output Ripple Based on Harmonics Feedback

Conventional boost converters are essential to connect low-voltage energy source such as battery with high voltage DC bus in Electric Vehicles due to its simple construction and high conversion efficiency. However, large output capacitor banks must be used in order to reduce the output voltage ripples when an inverter is connected to a boost converter. In a typical series hybrid electric vehicle powertrain, significant voltage and current perturbations will impact on battery system performance and result in considerable power loss. To address this issue, this paper proposes a new control strategy for ripple reduction in the dc-link of power electronic converters. In the proposed method, an observer is designed to adaptively estimate the dc-link voltage and current harmonics. The harmonic terms are multiplied by optimized gains to control the converter's duty cycle by negative feedback law. Entire control model for the proposed converter is illustrated and robustness is verified. Simulation and experiments show that original voltage and current ripple magnitude can be reduced significantly.