Method for improving the audio susceptibility and input impedance of stacked boost converters

Stacked boost converter (SBC) is widely adopted in aerospace applications because of the superiority of high efficiency, continuous current and easily controlled system. In the SBC with three-capacitor, the resonance of the stray inductance of stacked branch and output capacitors worsen the closed-loop input impedance and audio susceptibility. In order to eliminate the resonance, three-capacitor is optimised as single-capacitor in this study. An accurate model considering the parasitic parameters is also developed to analyse the loop gain, output impedance, input impedance and audio susceptibility under two types of capacitor structures. The calculated and experimental results demonstrate that single-capacitor is more suitable for SBC.