A Bidirectional, Triple-Voltage DC-DC Converter for Hybrid and Fuel Cell Vehicle Power Systems

Conference · Mon Jan 01 04:00:00 EST 2007

OSTI ID:931311

Su, Gui-Jia ^[1]; Tang, Lixin ^[1]

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1. ORNL

Electrical power systems in future hybrid and fuel cell vehicles may employ three voltage (14V, 42V and high voltage (HV)) nets. These will be necessary to accommodate existing 14V loads as well as efficiently handle new heavy loads at the 42V net and an electrical traction drive on the HV bus. A low-cost bi-directional dc-dc converter was proposed in (10) for connecting the three voltage nets. The converter consists of two half-bridges and a high-frequency transformer; thus minimizing the number of switching devices and their associated gate driver components. One salient feature is that the half-bridge on the 42V bus is also utilized to provide the 14V bus by operating its duty ratio around an atypical value of 1/3. This eliminates the need for an additional 14V/42V converter. Moreover, it makes use of the parasitic capacitance of the switches and the transformer leakage inductance for soft-switching; no extra active switches or passive resonant components are required. The use of half-bridges makes the topology suitable for interleaved multi-phase 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 the atypical duty ratio on the transformer and a preferred multi-phase configuration to minimize capacitor ripple currents.

• Research Organization: Oak Ridge National Laboratory (ORNL); Power Electronics and Electric Machinery Research Facility
• Sponsoring Organization: EE USDOE - Office of Energy Efficiency and Renewable Energy (EE)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 931311
• Country of Publication: United States
• Language: English

Related Subjects

24 POWER TRANSMISSION AND DISTRIBUTION
30 DIRECT ENERGY CONVERSION
33 ADVANCED PROPULSION SYSTEMS
CAPACITANCE
CAPACITORS
CONFIGURATION
FUEL CELLS
HYBRID ELECTRIC-POWERED VEHICLES
INDUCTANCE
LEGS
POWER SYSTEMS
SIMULATION
SWITCHES
TOPOLOGY
TRANSFORMERS