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Development of Electric Powertrain for CLARITY PLUG-IN HYBRID

Journal Article
ISSN: 2167-4191, e-ISSN: 2167-4205
Published April 03, 2018 by SAE International in United States
Development of Electric Powertrain for CLARITY PLUG-IN HYBRID
Citation: Yamagishi, T. and Ishikura, T., "Development of Electric Powertrain for CLARITY PLUG-IN HYBRID," SAE Int. J. Alt. Power. 7(3):323-333, 2018,
Language: English


Honda has developed the 2018 model CLARITY PLUG-IN HYBRID. Honda’s new plug-in hybrid is a midsize sedan and shares a body platform with the CLARITY FUEL CELL and the CLARITY ELECTRIC. The vehicle’s electric powertrain boosts driving performance as an electric vehicle (EV) over Honda’s previous plug-in hybrid.
The CLARITY PLUG-IN HYBRID’s electric powertrain consists of a traction motor and generator built into the transmission, a Power Control Unit (PCU) positioned above the transmission, an Intelligent Power Unit (IPU) fitted under the floor, and an onboard charger fitted below the rear trunk.
The PCU integrates an inverter that drives the traction motor, an inverter that drives the generator, and a DC-DC converter to boost battery voltage (referred to as a “Voltage Control Unit (VCU)” below). The VCU employs an interleaved circuit configuration and a coupled inductor and realizes approximately three times the rated continuous power and approximately three times the power density of a standard unit employed in a hybrid vehicle.
The IPU contains 17 kWh high-capacity battery modules and a 12 V DC-DC converter. A coolant-cooling method has been adopted to respond to the increased power of the battery, boosting cooling performance. The battery modules are positioned below the front and rear seats, and the high-voltage wiring is positioned between the modules, in the center of the vehicle. This layout has made it possible to fit the IPU below the floor of the vehicle, helping to enable the realization of a spacious and comfortable cabin seating five passengers, as well as a useful amount of trunk space.
The use of a high-power VCU and a high-capacity IPU has made it possible to realize EV operation in the high-speed range with no need to start the engine, giving the vehicle an adequate all-electric range (AER) for everyday use. During hybrid operation, increasing both the VCU power and the battery power helps ensure quietness while also allowing the engine to be downsized from 2.0 to 1.5 liters. The developed electric powertrain realizes a long AER of 47 miles and extremely quiet hybrid operation with a high level of fuel economy at 42 mpg.