Method and devices for operating an internal combustion engine having a supercharging system
AssigneeVolkswagen Aktiengesellschaft
InventorsSebastian Heinken, Javier Bartolome, Florian Frese, Sebastian Keich
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Abstract
A method and device for operating an internal combustion engine having a supercharging system that has an exhaust turbocharger and an electrically driven compressor. An output of the exhaust turbocharger is adjustable by a control element. A boost pressure setpoint is determined for achieving an increased engine torque setpoint. The supercharging system is adjusted to build up the actual boost pressure in accordance with the boost pressure setpoint and a positive scavenging gradient in a cylinder of the internal combustion engine is adjusted as the overriding command variable for driving the supercharging system.
Claims12
A method for operating an internal combustion engine with a supercharging system that has an exhaust turbocharger and an electrically driven compressor, an output of the exhaust turbocharger being adjustable via a control element, the method comprising:
- determining a boost pressure setpoint for achieving an increased engine torque setpoint;
- adjusting the supercharging system to build up an actual boost pressure, in accordance with the boost pressure setpoint, by adapting the output of the exhaust turbocharger via the control element;
- and
- adjusting a positive scavenging gradient in a cylinder of the internal combustion engine as an overriding command variable for driving the supercharging system,
- wherein the positive scavenging gradient is a pressure difference across the cylinder between an intake manifold pressure upstream of the cylinder and a pressure that is present within an exhaust gas line of the internal combustion engine downstream of the cylinder,
- wherein the positive scavenging gradient is achieved in that the electrically driven compressor and the exhaust turbocharger are operated as a function of one another,
- wherein the electrically driven compressor is operated in accordance with a first control variable, and the exhaust turbocharger is operated in accordance with a second control variable, wherein the first reduction factor and the second reduction factor are determined as a function of an actual scavenging gradient, of a valve overlap, of a capacity of an energy storage device, and of an ignition angle.
An internal combustion engine comprising:
- a supercharging system that has an exhaust turbocharger;
- an electrically driven compressor;
- and
- a controller, an output of the exhaust turbocharger being adjustable via a control element,
- wherein the internal combustion engine is configured to:
- adjust the supercharging system to build up an actual boost pressure, in accordance with the boost pressure setpoint, by adapting the output of the exhaust turbocharger via the control element;
- and
- adjust a positive scavenging gradient in a cylinder of the internal combustion engine as an overriding command variable for driving the supercharging system,
- wherein the positive scavenging gradient is a pressure difference across the cylinder between an intake manifold pressure upstream of the cylinder and a pressure that is present within an exhaust gas line of the internal combustion engine downstream of the cylinder,
- wherein the positive scavenging gradient is achieved in that the electrically driven compressor and the exhaust turbocharger are operated as a function of one another,
- wherein the electrically driven compressor is operated in accordance with a first control variable, and the exhaust turbocharger is operated in accordance with a second control variable,
- wherein the first control variable is determined based on a first reduction factor and the second control variable is determined based on a second reduction factor, and
- wherein the first reduction factor and the second reduction factor are determined as a function of an actual scavenging gradient, of a valve overlap, of a capacity of an energy storage device, and of an ignition angle.
Dependencies are inferred from the claim text.