US-12618347-B2 - Hybrid vehicle rapid catalyst exhaust cooling

US12618347B2US 12618347 B2US12618347 B2US 12618347B2US-12618347-B2

Abstract

A hybrid electric vehicle (HEV) includes an internal combustion engine and a motor/generator configured to drive the engine or be driven by the engine to generate electricity to charge a high voltage (HV) battery and/or drive an electric traction motor. The HEV includes an exhaust system, a HV system electrically coupling the HV battery and the electric traction motors, and a control system including a controller for monitoring an underhood environment of the HEV and performing a cooling operation to cool the exhaust system. The controller is programmed to determine if a temperature of the underhood environment, the internal combustion engine, and/or the exhaust system is above a predetermined threshold indicating a potential degradation of HV system performance, and operate the internal combustion engine in fuel shut-off to generate a flow of air to the exhaust system for cooling of the exhaust system to thereby cool the HV system.

Inventors

Benjamin Dean

Assignees

FCA US LLC

Dates

Publication Date: 20260505
Application Date: 20230901

Claims (16)

1 . A hybrid electric vehicle (HEV), comprising: an internal combustion engine; a motor/generator configured to drive the internal combustion engine or be driven by the internal combustion engine to generate electricity to charge a high voltage (HV) battery and/or drive one or more electric traction motors; an exhaust system; a HV system electrically coupling the HV battery and the one or more electric traction motors; and a control system including a controller for performing a cooling operation to cool the exhaust system, wherein the controller is programmed to: determine if a temperature of an underhood environment of the HEV the internal combustion engine, and/or the exhaust system is above a predetermined threshold indicating a potential degradation of HV system performance; and operate the internal combustion engine in fuel shut-off to generate a flow of air to the exhaust system for cooling of the exhaust system to thereby cool the HV system, wherein the controller is configured to perform the cooling operation during a plug-in recharging of the HV battery.
2 . The HEV of claim 1 , wherein the controller is further programmed to determine if a plug-in charging rate is being limited due to thermal conditions of the HV system.
3 . The HEV of claim 1 , wherein the controller is further programmed to determine an engine spin speed setpoint to reduce the temperature of the underhood environment, the internal combustion engine, and/or the exhaust system below the predetermined threshold.
4 . The HEV of claim 3 , wherein the controller is further programmed to operate the internal combustion engine in fuel shut-off at the determined engine spin speed setpoint.
5 . The HEV of claim 1 , wherein the HV system includes an onboard charger, a plug-in interface, and HV cables.
6 . The HEV of claim 1 , wherein during the cooling operation, the motor/generator is powered by the HV battery.
7 . The HEV of claim 5 , wherein during the cooling operation, the motor/generator is powered by a grid charger plugged into the plug-in interface.
8 . The HEV of claim 1 , wherein the HEV is a series hybrid electric vehicle.
9 . A method of operating a hybrid electric vehicle (HEV) having an internal combustion engine, a motor/generator configured to drive the internal combustion engine or be driven by the internal combustion engine to generate electricity to charge a high voltage (HV) battery and/or drive one or more electric traction motors, an exhaust system, and a HV system electrically coupling the HV battery and the one or more electric traction motors, the method comprising: determining, by a controller having one or more processors, if a temperature of an underhood environment of the HEV, the internal combustion engine, and/or the exhaust system is above a predetermined threshold indicating a potential degradation of HV system performance; and operating, by the controller and the motor/generator, the internal combustion engine in fuel shut-off to generate a flow of air to the exhaust system to perform a cooling operation of the exhaust system to thereby cool the HV system, wherein the cooling operation is performed during a plug-in recharging of the HV battery.
10 . The method of claim 9 , further comprising determining, by the controller, if a plug-in charging rate is being limited due to thermal conditions of the HV system.
11 . The method of claim 9 , further comprising determining, by the controller, an engine spin speed setpoint to reduce the temperature of the underhood environment, the internal combustion engine, and/or the exhaust system below the predetermined threshold.
12 . The method of claim 11 , further comprising operating, by the controller, the internal combustion engine in fuel shut-off at the determined engine spin speed setpoint.
13 . The method of claim 9 , wherein the HV system includes an onboard charger, a plug-in interface, and HV cables.
14 . The method of claim 9 , wherein during the cooling operation, the motor/generator is powered by the HV battery.
15 . The method of claim 13 , wherein during the cooling operation, the motor/generator is powered by a grid charger plugged into the plug-in interface.
16 . The method of claim 9 , wherein the HEV is a series hybrid electric vehicle.

Description

FIELD The present application relates generally to hybrid electric vehicle systems and, more particularly, to systems for rapidly cooling an exhaust system of a hybrid electric vehicle. BACKGROUND Many hybrid electric vehicles (HEVs) include both an internal combustion engine and high voltage (HV) components packaged into the underhood environment. However, the engine can produce high underhood temperatures via residual heat from radiator, exhaust and catalyst systems. The HV components may be sensitive to such high temperatures, potentially resulting in reduced performance or functionality. Accordingly, while such conventional systems work well for their intended purpose, there is a desire for improvement in the relevant art. SUMMARY In accordance with one example aspect of the invention, a hybrid electric vehicle (HEV) is provided. In one example implementation, the HEV includes an internal combustion engine and a motor/generator configured to drive the internal combustion engine or be driven by the internal combustion engine to generate electricity to charge a high voltage (HV) battery and/or drive one or more electric traction motors. The HEV includes an exhaust system, a HV system electrically coupling the HV battery and the one or more electric traction motors, and a control system including a controller for monitoring an underhood environment of the HEV and performing a cooling operation to cool the exhaust system. The controller is programmed to determine if a temperature of the underhood environment, the internal combustion engine, and/or the exhaust system is above a predetermined threshold indicating a potential degradation of HV system performance, and operate the internal combustion engine in fuel shut-off to generate a flow of air to the exhaust system for cooling of the exhaust system to thereby cool the HV system. In addition to the foregoing, the described HEV may include one or more of the following features: wherein the controller is further programmed to determine if a plug-in charging rate is being limited due to thermal conditions of the HV system; wherein the controller is further programmed to determine an engine spin speed setpoint to reduce the temperature of the underhood environment, the internal combustion engine, and/or the exhaust system below the predetermined threshold; wherein the controller is further programmed to operate the internal combustion engine in fuel shut-off at the determined engine spin speed setpoint. In addition to the foregoing, the described HEV may include one or more of the following features: wherein the HV system includes an onboard charger, a plug-in interface, and HV cables; wherein the controller is configured to perform the cooling operation during a plug-in recharging of the HV battery; wherein during the cooling operation, the motor/generator is powered by the HV battery; wherein during the cooling operation, the motor/generator is powered by a grid charger plugged into the plug-in interface; and wherein the HEV is a series hybrid electric vehicle. In accordance with another example aspect of the invention, a method of operating a hybrid electric vehicle (HEV) is provided. The HEV includes an internal combustion engine, a motor/generator configured to drive the internal combustion engine or be driven by the internal combustion engine to generate electricity to charge a high voltage (HV) battery and/or drive one or more electric traction motors, an exhaust system, and a HV system electrically coupling the HV battery and the one or more electric traction motors. In one example implementation, the method includes determining, by a controller having one or more processors, if a temperature of an underhood environment, the internal combustion engine, and/or the exhaust system is above a predetermined threshold indicating a potential degradation of HV system performance; and operating, by the controller and the motor/generator, the internal combustion engine in fuel shut-off to generate a flow of air to the exhaust system to perform a cooling operation of the exhaust system to thereby cool the HV system. In addition to the foregoing, the described method may include one or more of the following features: determining, by the controller, if a plug-in charging rate is being limited due to thermal conditions of the HV system; determining, by the controller, an engine spin speed setpoint to reduce the temperature of the underhood environment, the internal combustion engine, and/or the exhaust system below the predetermined threshold; and operating, by the controller, the internal combustion engine in fuel shut-off at the determined engine spin speed setpoint. In addition to the foregoing, the described method may include one or more of the following features: wherein the HV system includes an onboard charger, a plug-in interface, and HV cables; wherein the cooling operation is performed during a plug-in recharging of the HV battery; wherein during the cooli