Title :
A Multiphase, Modular, Bidirectional, Triple-Voltage DC–DC Converter for Hybrid and Fuel Cell Vehicle Power Systems
Author :
Su, Gui-Jia ; Tang, Lixin
Author_Institution :
Nat. Transp. Res. Center, Oak Ridge Nat. Lab., Knoxville, TN
Abstract :
Electrical power systems in future hybrid and fuel cell vehicles may employ three voltage [14 V, 42 V, and high voltage (HV)] nets. These will be necessary to accommodate existing 14-V loads as well as efficiently handle new heavy loads at the 42-V net and a traction drive on the HV bus. A low-cost DC-DC converter was proposed for connecting the three voltage nets. It minimizes the number of switches and their associated gate driver components by using two half-bridges and a high-frequency transformer. Another salient feature is that the half bridge on the 42-V bus is also utilized to provide the 14-V bus by operating at duty ratios around an atypical value of 1/3. Moreover, it makes use of the parasitic capacitance of the switches and the transformer leakage inductance for soft switching. The use of half bridges makes the topology well suited for interleaved multiphase modular configurations as a means to increase the power level because the capacitor legs can be shared. This paper presents simulation and experimental results on an interleaved two-phase arrangement rated at 4.5 kW. Also discussed are the benefits of operating with an atypical duty ratio on the transformer and a preferred multiphase configuration to minimize capacitor ripple currents.
Keywords :
DC-DC power convertors; bridge circuits; fuel cell power plants; fuel cell vehicles; high-frequency transformers; hybrid electric vehicles; hybrid power systems; switching convertors; traction motor drives; bidirectional triple-voltage DC-DC converter; fuel cell vehicle power systems; half-bridge circuit; high-frequency transformer; hybrid vehicle power systems; interleaved multiphase modular configuration; power 4.5 kW; soft switching; traction drive; transformer leakage inductance; voltage 14 V; voltage 42 V; EV/HEV power management; interleaved multiphase dc–dc converter; interleaved multiphase dc--dc converter; multivoltage-bus dc–dc converter; multivoltage-bus dc--dc converter; soft switching;
Journal_Title :
Power Electronics, IEEE Transactions on
DOI :
10.1109/TPEL.2008.2005386