Micro High Step-Up Converters for Energy Conversion of Ion Engines

Step-up converters play an essential role in the power plant of aircraft and vehicles. Among the components of converters, electrolytic capacitors (ECs) are prone to failure with shorter lifespans and high loss, and their sizes increase greatly with larger capacitance. This study proposes two EC-eliminating schemes of the quasi-switching boost dc–dc converter (QSBC). The two non-EC QSBCs (NEC-QSBCs) can achieve energy conversion while improving the voltage conversion performance, realizing better nonlinear response, and having high economic advantages at high power density. Besides, the NEC-QSBC in scheme B can realize extra voltage pumping and low component stress. Theoretical calculations and analysis with parameter design, voltage ripples, and prototype experiments of the proposed NEC-QSBCs are presented for proof of concept. The superiority of the proposed NEC-QSBCs is verified through extensive comparisons with traditional EC-based converters. Experimental results agree well with the theoretical analysis. The maximum efficiency of 93.27% is achieved by the proposed NEC-QSBCs. Power losses of the two NEC-QSBCs are lower than three other EC-based converters. Among them, the minimum switching loss is 0.35 W at
$V_{\mathrm {o}}$
= 100 V,
$P_{\mathrm {o}}$
= 50 W, and
$f_{\mathrm {s}}$
= 100 kHz. Meanwhile, the capacitance loss is 0.23 W, the inductor loss is 0.48 W, and the diode loss is 2.88 W. The proposed NEC-QSBCs have great potential as future electric energy conversion plants of ion engine aircraft.