Voltage Control Strategy to Mitigate Harmonic Components Caused by Capacitance Imbalance in Active Power Decoupling Circuits

초록

This paper proposes a voltage control strategy to mitigate the first-order harmonic component caused by capacitance imbalance in a split-capacitor-type active power decoupling circuit. This circuit can replace the electrolytic capacitors used in passive decoupling methods for suppressing second-order harmonic components, while also enhancing overall system power density. However, when the two film capacitors connected in series have unequal capacitance values, the midpoint voltage becomes unbalanced. This imbalance causes a fluctuation in the output current, leading to the generation of first-order harmonics, which degrade system performance and reliability. To address this issue, the proposed strategy employs an offset-based compensation method, resulting in a substantial reduction in dc-link voltage ripple. The effectiveness of the proposed voltage control strategy is verified through MATLAB/Simulink simulations and experimental results.

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