Optimization of Bidirectional Modular DC/DC Converter for Low and High Power Operation in Aircraft Applications

Abstract

This paper presents a multi-objective optimization method for DC/DC converters used in More Electrical Aircrafts applications. Very high efficiency associated with high power density requires the use of wide bandgap devices, such as SiC semiconductors. Results show that, due to the use of SiC devices, the designed converter produces lower losses at hard-switching (HS) modulation than at soft-switching (SS) modulation. Furthermore, we show that there is an optimal number of small converters in parallel, which provides high efficiency even at low power as well as high reliability, compared to a single converter.

Stability and Control for Buck–Boost Converter for Aeronautic Power Management

“…The soft-switching modulation is instead characterized by the simultaneous switching of the two legs. As detailed in [31], where a similar application is investigated with a focus on the network parameters optimization, both modulation strategies have their pros and cons; however, hard-switching is preferred over soft-switching modulation because of its lower losses. For this reason, also in this work hard-switching modulation is considered.…”

“…Consider system (24), the sliding function defined in (26), and the auxiliary system (27), with uncertain dynamics defined as in (28)- (29), where the variable v is defined as in (14). Consider regions Ω 1 and Ω 2 defined in (30)- (31), and the two-stage control law defined as…”

“…Indeed, during boost mode, the active controller is the SOSM control algorithm described in Theorem 3, while for current control in buck mode, a two-stage control algorithm has been designed. If the state trajectory belongs to the set Ω 1 indicated in (30), then the monotonic SOSM control algorithm presented in (37) is adopted, while if the state trajectory belongs to the set Ω 2 indicated in (31), then the feedback-based monotonic control algorithm (38) is adopted. This recalls the need for a higher-level controller, i.e., a supervisory controller, responsible for the selection of the required controller according to the value of the converter state.…”