A control method of a hybrid vehicle includes determining, by a controller, whether a target maintaining SOC has been set to a maximum level in a battery maintaining driving mode, determining, by the controller, whether a vehicle speed is equal to or higher than a predetermined speed, when the target maintaining SOC determined is a maximum level, calculating, by the controller, an estimated recovery energy which can be recovered by regenerative braking of the vehicle when a current vehicle speed is equal to or higher than the predetermined speed, and updating, by the controller, the target maintaining SOC by subtracting a subtraction SOC equivalent to the estimated recovery energy calculated from the target maintaining SOC.

When a kickdown switch is turned off, a target rotation speed of an engine is set on the basis of a vehicle speed and a gear and the engine, the first motor, and the second motor are controlled such that the smaller driving force of an upper-limit driving force based on the target rotation speed and a required driving force is output to a drive shaft and the engine rotates at the target rotation speed. On the other hand, when the kickdown switch is turned on, the target rotation speed is set to be higher than that when the kickdown switch is turned off on the basis of the vehicle speed and the gear and the engine, the first motor, and the second motor are controlled such that the required driving force is output to the drive shaft and the engine rotates at the target rotation speed.

A vehicle hybrid system includes a transmission mechanically coupled with an engine, a drive shaft mechanically coupled with the transmission, a rotation-transmitting part coupled with the drive shaft, a power connecting-disconnecting part coupled with the drive shaft via the rotation-transmitting part, a motor generator mechanically coupled with the power connecting-disconnecting part, and a directional power transmission part for transmitting power in a direction from the motor generator to the engine to drive the engine and for not transmitting power in a direction from the engine to the motor generator to drive the motor generator. This vehicle hybrid system has high efficiency.

The invention relates to a method to start a combustion engine in a hybrid powertrain by a) disconnecting rotatable components of a first planetary gear from each other, b) disconnecting rotatable components of a second planetary gear from each other, c) preventing rotation of at least one gear pair, which is connected with the first planetary gear and an output shaft and at least one gear pair, which is connected with the second planetary gear and the output shaft, prevent rotation of the output shaft, and e) activating a first electrical machine connected to the first planetary gear, and/or a second electrical machine connected to the second planetary gear, so that the combustion engine starts.

A through-the-road (TTR) hybridization strategy is proposed to facilitate introducing hybrid electric vehicle technology in a significant portion of current and expected trucking fleets. In some cases, the technologies can be retrofitted onto an existing vehicle (e.g., a trailer, a tractor-trailer configuration, etc.). In some cases, the technologies can be built into new vehicles. In some cases, one vehicle may be built or retrofitted to operate in tandem with another and provide the hybridization benefits contemplated herein. By supplementing motive forces delivered through a primary drivetrain and fuel-fed engine with supplemental torque delivered at one or more electrically-powered drive axles, improvements in overall fuel efficiency and performance may be delivered, typically without significant redesign of existing components and systems that have been proven in the trucking industry.

A hybrid system includes a hybrid module that is located between an engine and a transmission. The hybrid system includes an energy storage system for storing energy from and supplying energy to the hybrid module. An inverter transfers power between the energy storage system and the hybrid module. The hybrid system also includes a cooling system, a DC-DC converter, and a high voltage tap. The hybrid module is designed to recover energy, such as during braking, as well as power the vehicle. The hybrid module includes an electrical machine (eMachine) along with electrical and mechanical pumps for circulating fluid. A clutch provides the sole operative connection between the engine and the eMachine. The hybrid system further incorporates a power take off (PTO) unit that is configured to be powered by the engine and/or the eMachine.

A hybrid vehicle includes powertrain components such as an engine, an automatic transmission, and a traction motor selectively coupled to the engine via a clutch and to the transmission. At least one controller is programmed to control these powertrain components. The vehicle is driven over a drive cycle that includes multiple engine starts and transmission gear shifts. An amount of fuel consumption used during these engine starts and transmissions gear shifts is stored on an on-board storage device. Subsequently, the engine is inhibited from starting and the transmission is inhibited from shifting gears based on the amount of fuel consumption associated with the engine starts and transmission gear shifts performed during the drive cycle as recalled from the storage device.

A control system for a hybrid electric vehicle comprises a transmission system configured to drive wheels, an engine power subsystem connected to the transmission system, a motor power subsystem connected to the transmission system and a control module. When vehicle's electrical power is on, the control module is configured to control operating mode of the hybrid electric vehicle through the engine power subsystem and the motor power subsystem. The operating mode comprises HEV-eco mode and HEV-s mode. When the hybrid electric vehicle operates in HEV-eco and the hybrid electric vehicle operates at low power or when the hybrid electric vehicle operates in HEV-s mode and when the vehicle speed is zero, the control module enables the hybrid electric vehicle to operate by idle start-stop strategy.

A drive unit for a hybrid-vehicle to realize a variety of drive modes for covering various running conditions. A first planetary gear unit is included of a first carrier, a first sun gear, and a first ring gear. A second planetary gear unit is included of a second carrier, a second sun gear, and a second ring gear. A first clutch connects the engine selectively with the first carrier. A first motor is connected with the first sun gear, the second motor is connected with the second sun gear, and the first ring gear and the second ring gear are individually connected with an output member. The drive unit is with a second clutch for connecting the first carrier selectively with the second sun gear. In the drive unit, a reverse stage fixing-mode to propel the vehicle backwardly while changes the output member speed in accordance with the engine speed.

A control process including the following steps is executed. The control process includes, at the time of switching from series-parallel mode to series mode, a step of reducing an engine torque, a step of releasing a clutch, a step of reducing a reaction torque of a first rotary electric machine and a step of increasing a torque of a second rotary electric machine, and, when synchronization is started and a step of increasing a positive torque of the first MG, a step of starting engagement of a clutch, and, when a rotation speed of the first rotary electric machine and a rotation speed of an engine are synchronous with each other, a step of engaging the clutch.