Hybrid Gearshift Torque Control Using Regenerative Power Transfer
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Solution Overview
Problem
Hybrid vehicles experience noticeable torque interruptions during gear changes, leading to an unpleasant 'power gap' felt by drivers and passengers, which existing technologies struggle to mitigate without compromising vehicle performance or electrical architecture.
Innovation Solution
A control method that increases the power supplied by the first electric machine during thermal transmission ratio changes by operating the second electric machine in regenerative mode, temporarily boosting the supply voltage to compensate for torque reductions, using existing components without architectural adaptations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the thermal engine torque is interrupted during gear changes, then the gear change can be executed, but the driver and passengers feel torque loss and power gap
Solution Approach 1:
The patent uses the first electric machine as an intermediary to compensate for the torque interruption of the thermal engine during gear changes. When the thermal engine torque is interrupted, the first electric machine provides compensating torque to the wheels, acting as a mediator that smooths out the power gap and prevents the driver from feeling the torque loss.
Solution Approach 2:
The patent dynamically adjusts the torque output parameters of the first electric machine based on the gear change state. During thermal gear changes, the control system increases the torque contribution of the first electric machine to compensate for the thermal engine torque interruption, thereby maintaining overall torque delivery and reducing perceived power gap.
2Power
If the power available from the main electrical engine is increased during gear changes, then the torque break can be compensated, but the vehicle's electrical architecture is compromised
Solution Approach 1:
The patent makes the second electric machine multi-functional by using it both for its primary function (assisting acceleration) and for voltage regulation during gear changes. By controlling the second electric machine to operate in regenerative mode during thermal gear changes, the system temporarily boosts the electrical network voltage without requiring additional voltage regulation equipment or architectural modifications.
Solution Approach 2:
The patent enables the electrical system to self-regulate voltage during gear changes by having the second electric machine operate in regenerative mode. This self-service mechanism temporarily boosts the electrical network voltage to support increased power delivery from the first electric machine without requiring external voltage regulation systems or architectural changes.
3Power
If the voltage of the on-board network is increased during shifts, then the wheel torque can be maintained, but additional system components or resizing are required
Solution Approach 1:
The patent uses the second electric machine as an intermediary voltage regulator. By controlling the second electric machine to operate in regenerative mode during gear changes, it acts as a mediator that temporarily boosts the electrical network voltage, enabling the first electric machine to deliver increased torque to the wheels without requiring additional voltage regulation equipment.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Maintains wheel power at a higher level during gear changes, reducing acceleration loss and the perceived 'power gap' by up to 50%, ensuring a smoother driving experience without requiring additional system components or resizing.
Implementation Method 1
operating the second electric machine (HSG) in regenerative mode. All the electrical power of the latter is then transmitted to the first
Data Source
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Figure 2
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AI summary
A method for controlling the torque available during the ratio changes of a drive train consisting of a heat engine (Mth) connected to a first input shaft (4) of a gearbox (1) that can transmit the torque of same to the wheels at different transmission ratios, a first electric machine (ME) connected to a second input shaft thereof, and a second electric machine (2) connected alternately to the first or second input shaft of the gearbox, characterised in that, during the changes in the transmission ratio of the heat engine (Mth), the second electric machine (2) operates in regenerative mode and transmits all of the electric power of same to the first electric machine (ME) that uses it to compensate for the reduction in torque at the driven wheel resulting from the temporary decoupling of the heat engine during the change in ratio of same.