Abstract
This study describes method of regenerative breaking control for HEV with multispeed transmission. When a gear is shifted during regenerative breaking, almost all TMED HEVs in the world lose decelerate linearity or reduce regenerative breaking to get decelerate linearity. So fuel efficiency is get down. We made concept that is called regenerative breaking practical quantity. Regenerative breaking practical quantity solved problem of decelerate linearity. And this technology is used in all TMED HEVs of Hyundai motor group. Regenerative breaking practical quantity reflect a characteristic curves of motor, shifting process of multispeed transmission and following of hydraulic brake for cooperative control of HCU, MCU, TCU, AHB and so on. As a result of this technology, decelerate linearity is retained for sale the HEV. Furthermore fuel efficiency is improved about 8.4% because regenerative breaking quantity is increased about 28%.