Method for controlling a dual-supercharged combustion engine

Patent metadata

Field	Value
Publication number	US-10054038-B2
Application number	US-201314648448-A
Country	US
Kind code	B2
Filing date	Oct 21, 2013
Priority date	Nov 30, 2012
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

The invention relates to a combustion engine equipped with a dual supercharging system in which a mechanical compressor is driven by an electric motor. The method controls a combustion engine with the electric motor being controlled by determining a rotational speed setpoint for positive-displacement compressor using a supercharge volume filling model.

First claim

The invention claimed is:

1. A method for controlling a combustion engine equipped with a supercharging system comprising a turbocharger and a positive-displacement compressor for compressing a gas mixture at an intake of the combustion engine and a by-pass circuit in parallel with the positive-displacement compressor, including a controllable by-pass valve, the positive-displacement compressor being driven by an electric motor, the method comprising:
a) acquiring a boost pressure setpoint;
b) constructing a filling model of a supercharged volume contained in the intake of the combustion engine between intake valves of the engine and the positive-displacement compressor and the by-pass valve;
c) converting the boost pressure setpoint to a rotational speed setpoint for the positive-displacement compressor using the filling model of the supercharged volume; and
d) controlling the electric motor according to the rotational speed setpoint for the positive-displacement compressor.

2. The method as claimed in claim 1 , wherein a pressure and a temperature are determined upstream from the positive-displacement compressor, a boost temperature is determined at the intake of the combustion engine and the filling model connects a boost pressure to a rotational speed of the positive-displacement compressor from the pressure and the temperature upstream from the positive-displacement compressor and the boost temperature.

3. The method as claimed in claim 2 , wherein the pressure and the boost temperature are determined by pressure and temperature detectors upstream from an intake manifold of the combustion engine.

4. The method as claimed in claim 3 , wherein the pressure and the temperature upstream from the positive-displacement compressor are by pressure and temperature detectors respectively arranged upstream from the compressor or by an estimator.

5. The method as claimed in claim 4 , wherein the filling model is defined by a filling equation of the supercharged volume defined by a flow rate conservation formula wherein:

P
.

sural

=

RT
sural

V
sural

⁢

(

D
cpr

-

D
bp

-

D
asp

)

with {dot over (P)} sural being the derivative of the boost pressure P sural with respect to time, R being the ideal gas constant, V sural being the supercharged volume, D cpr being flow coming from the positive-displacement compressor, D bp being flow from the by-pass valve that is a function of opening of the by-pass valve and D asp being the flow into cylinders of the engine.

6. The method as claimed in claim 3 , wherein the filling model is defined by a filling equation of the supercharged volume defined by a flow rate conservation formula wherein:

P
.

sural

=

RT
sural

V
sural

⁢

(

D
cpr

-

D
bp

-

D
asp

)

with {dot over (P)} sural being the derivative of the boost pressure P sural with respect to time, R being the ideal gas constant, V sural being the supercharged volume, D cpr being flow coming from the positive-displacement compressor, D bp being flow from the by-pass valve that is a function of opening of the by-pass valve and D asp being the flow into cylinders of the engine.

7. The method as claimed in claim 2 , wherein the pressure and the temperature upstream from the positive-displacement compressor are determined by pressure and temperature detectors disposed upstream from the compressor or by an estimator.

8. The method as claimed in claim 7 , wherein the filling model is defined by a filling equation of the supercharged volume defined by a flow rate conservation formula wherein:

P
.

sural

=

RT
sural

V
sural

⁢

(

D
cpr

-

D
bp

-

D
asp

)

with {dot over (P)} sural the derivative of the boost pressure P sural with respect to time, R being the ideal gas constant, V sural being the supercharged volume, D cpr being flow coming from the positive-displacement compressor, D bp being flow from the by-pass valve that is a function of opening of the by-pass valve and D asp being the flow into cylinders of the engine.

9. The method as claimed in claim 2 , wherein the filling model is defined by a filling equation of the supercharged volume defined by a flow rate conservation formula wherein:

P
.

sural

=

RT
sural

V
sural

⁢

(

D
cpr

-

D
bp

-

D
asp

Assignees

• Ifp Energies Now

Inventors

• Leroy Thomas
• Chasse Alexandre
• Chauvin Jonathan

Classifications

• F02M26/06

  Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor · CPC title

• F02D2200/0402

  the parameter being determined by using a model of the engine intake or its components · CPC title

• Y02T10/144

  Cross-Sectional Technologies · mapped topic

• F02B39/04

  Mechanical drives; Variable-gear-ratio drives (non-mechanical pump drives having variable gear ratio F02B39/08) · CPC title

• F02B39/10

  electric · CPC title