Total volume evaluation of high‐power density non‐isolated DC–DC converters with integrated magnetics for electric vehicles

Abstract

One of the main problems in electric vehicles is the volume of their electrical systems because their bulky components carry additional mass and high cost to the total system. On this topic, interleaving-phases and magnetic coupling techniques have been reported as effective methods for increasing the power density of the DC-DC converters that work between the storage unit and the motor inverter. In that sense, a volume assessment of these topologies would provide a better understanding of the problems to be faced when an electric power train is designed. In this paper, a volume modelling methodology is introduced with the purpose of comparing four different DC-DC converters: Single-Phase Boost, Two-Phase Interleaved with non-coupled inductors, Loosely Coupled Inductor (LCI), and Integrated Winding Coupled Inductor (IWCI). The analysis considers the volume of magnetic components, power devices (conventional and next-generation), cooling devices and capacitors. The methodology can be used as a part of an optimization procedure to minimize the volume of DC-DC converters. Conclusively, LCI and IWCI were found effective to miniaturize power converters with a power density of 8.4 W/cc and 9.66 W/cc, respectively. Moreover, a maximum efficiency of 98.04% and 97.61% was obtained for a 1kW LCI and IWCI prototypes, respectively.

Parameter Extraction Technique for Evaluation of Inductive and Capacitive Elements of Three-Winding Coupled Inductor

“…Such number of turns and the ratio between external and central turns are selected based on the condition of not exceeding the maximum flux in each leg, which was found in Step 1. Detailed information about this step can be found in [44].…”

A new family of bidirectional DC-DC power converters with very low input and output ripples

“…The cascaded DC-DC power converters can also be simplified so that the number of active switching devices can be reduced [9]- [11]. The voltage ratio can also be extended by using coupled inductor [12]- [17]. The drawback of this method is leakage and resonant issues.…”

Nonlinear models of power inductors: A survey

“…6 SMPSs convert input power at a given voltage and current level to output power at a different voltage and current level, by storing energy in capacitors and inductors, converting that energy into packets using semiconductor switches, and then releasing packets to the output. Achieving a high power density (defined as the ratio between power and volume) is of paramount importance in the automotive and aerospace fields since smaller and therefore lighter converters contribute to lowering the overall vehicle power consumption, 4,5,[7][8][9] and size can be an issue especially in small vehicles. The reduction of inductor size is crucial also in other contexts, for example, for electromagnetic interference filters 10 or magnetic energy harvesters.…”