A Highly Efficient Multifunctional Power Electronic Interface for PEV Hybrid Energy Management Systems

Abstract

In the hybrid energy management systems of plug-in electric vehicles (PEVs), a power electronic interface (PEI) is required to connect the grid side dc link, the ultracapacitor bank, and the battery pack. To realize this PEI, the conventional method is deploying multiple independent dc/dc converters and it suffers from bulky size and high hardware cost. In this paper, an integrated multifunctional PEI is proposed to effectively mitigate those issues. The proposed PEI enables three functions-grid to vehicle (G2V), vehicle to grid (V2G), and PEV driving. It integrates the CLLC resonant topology with the bidirectional interleaved buck/boost topology, in which the former is utilized in the G2V and V2G modes, while the latter is in charge of the driving mode. Due to circuit reuse of the secondary side full-bridge structure, the system components count is reduced effectively. A synchronous rectification (SR) technique is developed to actively control the MOSFETs in CLLC rectification stage. Soft switching and SR techniques work in synergy to ensure a high conversion efficiency. An experimental prototype is designed, optimized, and tested for all three working modes. A peak efficiency of 98.27% for the G2V mode, 98.04% for The V2G mode, 98.56% for the PEV driving mode and good overall efficiency performances are reported. INDEX TERMS CLLC, interleaved bidirectional buck/boost converter, plug-in electric vehicles, power electronic interface, synchronous rectification.

E-Mobility — Advancements and Challenges

“…Some of these variations include a resonant LC half-bridge with the front-end PFC and the output buck converters operating in discontinuous conduction mode to reduce the magnetic material requirements [43] and a bidirectional LC resonant converter with a full-bridge front-end interface to support vehicle-to-grid as well as direct-charging from stationary battery banks [44]. Other resonant converters have been investigated to widen the operation range of the charger including an LLC resonant converter [45], LLC with a SEPIC front-end PFC [46], and an LC-LLC bidirectional converter with an interleaved output stage [47]. Phase-shifted dual-and triple-active-bridge (PSDAB and PSTAB) converters have been utilized due to their simpler design and wider operating range.…”

A Bidirectional LLCL Resonant DC-DC Converter With Reduced Resonant Tank Currents and Reduced Voltage Stress of the Resonant Capacitor

“…It indicates that QB and MB are also reversely correlated under the same k. Therefore, when k=0.333, to ensure this constraint from light to full load operations, according to Fig. 15(b), QB should meet (28) After the selection of k, the relation between QF and g can be determined by analyzing MF. Fig.…”

“…Compared with LLC, this topology is proposed in [25] by arranging an extra pair of capacitor and inductor in series on the secondary side of the HFT. Since LLC structure in both directions can be obtained, CLLC has been widely used in charging systems [26]- [28]. By using a superimposed output structure and integrating CLLC with a buck/boost circuit [29], the converter's voltage gain and dynamic performances are further enhanced.…”

A Bidirectional Versatile Buck–Boost Converter Driver for Electric Vehicle Applications

“…A detailed inverter loss model is developed in [ 13 ], where a variable DC-bus voltage closely related to the rotational motor speed significantly improves the inverter efficiency for voltages above the battery voltage. Despite proposals of using composite topologies for high step-up gain [ 14 ] or flying capacitors topologies to reduce inductor size [ 15 , 16 ], the most commonly used converter for this application has been the bidirectional half-bridge [ 12 , 13 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ] and boost [ 25 ] converters. In [ 18 ], the authors proposed a three-level version of this converter to use lower breakdown voltage MOSFETs.…”

“…An interleaved zero voltage switching (ZVS) version, included in multifunctional power electronic interface and operating at 60 kHz, is presented in [ 20 ], achieving high-efficiency measurements. Integration of this bidirectional converter in a new topology is proposed in [ 24 ] for a hybrid electric vehicle system.…”