Hybrid Electric Machine Torque Limiting for High Demand

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In hybrid vehicles, high torque demands exceeding the capacity of the thermal engine can lead to conflicts between power draws by the front electric machine, reducing the power available to the wheels, resulting in inadequate torque delivery.

Innovation Solution

A method that limits the torque absorbed by the first electric machine by adjusting the electrical power delivered for recharging, ensuring the thermal engine can meet the driver's torque demand by offloading power intended for the energy storage device and maintaining constant power supply to the on-board network.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the front electric machine draws high torque to recharge the energy storage device, then the energy storage device is recharged, but the torque available to the wheels is reduced

Engineering Contradiction:
Improveenergy storage device rechargingVSAvoidtorque delivered to wheels
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The system dynamically adjusts the torque demand of the first electric machine based on real-time operating conditions. When high torque is needed at the wheels, the controller reduces the torque absorbed by the first machine for recharging. This dynamic adjustment allows the system to optimize the balance between recharging needs and wheel torque delivery, resolving the contradiction between energy storage recharging and power delivery to wheels.

Inventive Principle:
Principle #15Dynamics

2Power

If the thermal engine operates at high torque to meet driver demand, then the torque demand is satisfied, but the power available for electric machine recharging is reduced

Engineering Contradiction:
Improvetorque delivered to wheelsVSAvoidenergy storage device recharging
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The control system continuously monitors thermal engine torque output and dynamically adjusts the torque demand of the first electric machine accordingly. When the thermal engine is operating at high torque to meet driver demand, the system reduces the recharging torque to preserve power for wheel delivery. This dynamic coordination resolves the contradiction between satisfying driver torque demand and maintaining recharging capacity.

Inventive Principle:
Principle #15Dynamics

3Use of energy by moving object

If the first electric machine absorbs high torque for recharging, then the energy storage device charge level increases, but the overall vehicle performance is degraded

Engineering Contradiction:
Improveenergy storage device charge levelVSAvoidvehicle performance
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The system dynamically adjusts the torque absorption of the first electric machine based on real-time vehicle performance requirements. When high vehicle performance is needed, the controller reduces the torque absorbed for recharging. This dynamic adjustment ensures that recharging operations do not degrade overall vehicle performance while still progressing toward energy storage replenishment.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system changes the torque parameter of the first electric machine based on operating conditions. By adjusting the torque absorption parameter dynamically, the system optimizes the balance between charge level increase and vehicle performance maintenance, resolving the contradiction between these two objectives.

Inventive Principle:
Principle #35Parameter changes

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

This method optimizes fuel consumption and maintains performance and safety by preserving torque delivery to the wheels, ensuring the thermal engine meets the driver's demand while minimizing the torque absorbed by the electric machine.

Implementation Method 1

a first electric machine (12) coupled to a thermal traction engine (2) of a hybrid vehicle (1), said vehicle comprising a second electric traction machine (20) powered by an electrical energy storage device (16), said first machine (12) being provided for supplying current to the on-board network of the vehicle, being able to recharge the energy storage device (16)

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a thermal traction engine (2) of a hybrid vehicle (1)

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP2885146B1Method for limiting the torque of an electric machine of a hybrid vehicle, in case of a high torque request
Publication Date: 2016.08.17 PEUGEOT CITROEN AUTOMOBILES SA
  • EP2885146B1 patent drawingFigure 1~2
  • EP2885146B1 patent drawingFigure 3~4

AI summary

A method for limiting the torque drawn by a first electric machine (12) coupled to a traction combustion engine (2) of a hybrid vehicle, said vehicle comprising a second traction electric machine (20) powered by an electrical energy storage device (16), said first machine, designed to supply current to the onboard network (18) of the vehicle, also being able to charge the energy storage device (16), characterised in that, in case of a high torque request made by the driver and exceeding the capabilities of the combustion engine (2), it limits the torque absorbed by the first machine by adjusting the electrical power delivered for said charging, in order to meet said torque request.