Electric Compressor Torque Management for Exhaust Temperature Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for reducing polluting emissions from heat engines, such as catalysts and nitrogen oxide traps, face inefficiencies at low temperatures and incur high fuel consumption during regeneration, while existing powertrain control systems struggle to quickly increase exhaust gas temperature and optimize torque delivery.

Innovation Solution

A powertrain control method that utilizes an electric compressor driven by an electric motor connected to the storage battery, allowing the electric machine to operate in generator mode to absorb torque differences and the electric compressor to compress fresh air, thereby relieving the turbine and increasing exhaust gas temperature efficiently, while also enabling the system to operate with a fully charged battery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the turbocharger is used to increase the pressure of air admitted into the cylinders to increase torque, then the torque delivered by the heat engine increases, but the temperature of the burnt gases decreases due to expansion in the turbine

Engineering Contradiction:
ImprovetorqueVSAvoidburnt gas temperature
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The invention separates the torque generation function from the burnt gas expansion function. The electric compressor provides air compression for torque generation without requiring turbine expansion, allowing the turbine to be relieved and thus maintaining higher burnt gas temperatures for regeneration purposes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electric compressor acts as an intermediary device that provides the necessary air compression for torque generation without involving the turbine. This intermediary component enables torque increase while preventing the temperature reduction that would otherwise occur through turbine expansion.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If fuel is injected into the exhaust line to regenerate the nitrogen oxide trap and particulate filter, then the temperature of burnt gases increases and fine particles are burned, but fuel consumption increases

Engineering Contradiction:
Improveemission treatment effectivenessVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention replaces the chemical regeneration method (fuel injection) with a mechanical approach (electric compressor-driven torque generation). By using the electric compressor to increase torque while relieving the turbine, the system achieves the necessary temperature conditions for regeneration without requiring additional fuel injection, thus reducing fuel consumption.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Temperature

If the battery is fully charged, the electric machine cannot operate in generator mode to absorb excess torque, limiting the ability to increase burnt gas temperature

Engineering Contradiction:
Improveburnt gas temperatureVSAvoidoperational flexibility
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

Instead of using the electric machine in generator mode to absorb excess torque (the conventional approach), the invention inverts the approach by using the electric compressor to generate torque while relieving the turbine. This inverted strategy achieves temperature increase without requiring the electric machine to operate in generator mode, thus maintaining operational flexibility even when the battery is fully charged.

Inventive Principle:
Principle #13The other way round (Inversion)

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 allows for rapid and efficient increase in exhaust gas temperature, reducing fuel consumption and enabling the powertrain to deliver greater torque than needed, thus improving the effectiveness of emission reduction systems and optimizing vehicle performance.

Implementation Method 1

the electric compressor is operated so that it compresses the fresh air

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

the reversible electric machine is operated in generator mode so that it absorbs the difference between the thermal torque and the drive torque

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

the turbine is unloaded using the unloading means

Methodology Applied
Scientific EffectGas expansion: Turbine

Implementation Method 4

This chemical reaction is very exothermic, so that the burnt gases leave the trap at a very high temperature

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Data Source

PatentEP3194744B1Method to control a powertrain equipped with an electrical compressor
Publication Date: 2020.08.26 RENAULT SA
  • EP3194744B1 patent drawingFigure 1
  • EP3194744B1 patent drawingFigure 2~3

AI summary

The invention relates to a powertrain (1) for a motor vehicle, comprising: a heat engine (2) which includes an engine block (10), a cold-air intake line (20), an exhaust line (80) for burnt gases which includes a treatment means (83) for treating burnt gases, and a turbocharger which includes unloading means (82) for unloading said turbine, as well as an electric machine (90) which is coupled to the crankshaft of the heat engine and which is connected to a storage battery. According to the invention, the heat engine also includes an electric compressor (26) which is mounted in the intake line and which is actuated by an electric motor connected to said storage battery.