US-12623652-B2 - Methods and system for hybrid vehicle adaptive motor utilization

US12623652B2US 12623652 B2US12623652 B2US 12623652B2US-12623652-B2

Abstract

A method for operating a hybrid vehicle that operates in charge depletion and charge sustaining modes is described. In one example, fractions of driver demand power that are generated via an internal combustion engine and an electric machine are adjusted in response to a rate of change in electric machine temperature and/or predicted electric machine temperature.

Inventors

Brendan Diamond
Joseph F. Kucharski
Keith Weston
Lars Niklas PETTERSSON
Rajib Saha
Andrew Brown

Assignees

FORD GLOBAL TECHNOLOGIES, LLC

Dates

Publication Date: 20260512
Application Date: 20240605

Claims (7)

1 . A method for operating a vehicle, comprising: increasing a first fraction of a driver demand torque generated via an internal combustion engine relative to a baseline fraction of torque generated via the internal combustion engine and decreasing a second fraction of the driver demand torque generated via an electric machine relative to a baseline fraction of torque generated via the electric machine in response to the driver demand torque increasing over a plurality of time intervals.
2 . The method of claim 1 , where increasing the first fraction and decreasing the second fraction is performed in further response to the vehicle being in a charge depletion mode.
3 . The method of claim 1 , where increasing the first fraction and decreasing the second fraction is performed in further performed response to a trailer being attached to the vehicle.
4 . The method of claim 1 , further comprising decreasing an amount of regenerative vehicle slowing power provided via the electric machine in response to a predetermined travel route of the vehicle.
5 . The method of claim 1 , where increasing in the first fraction and decreasing in the second fraction is performed in further performed response to a mass of the vehicle increasing.
6 . The method of claim 1 , where each of the plurality of time intervals is a different time interval than other time intervals included in the plurality of time intervals.
7 . The method of claim 1 , further comprising performing regenerative vehicle slowing solely in response to applying a pedal.

Description

FIELD The present description relates to methods and a system for adaptively controlling operation of an electric machine of a hybrid vehicle. The electric machine may slow or provide propulsive effort to the hybrid vehicle. BACKGROUND A hybrid vehicle may include an internal combustion engine and an electric machine to propel the hybrid vehicle. The electric machine may provide propulsive effort while the internal combustion engine is activated or deactivated. The electric machine and the internal combustion engine may operate according to predetermined operating conditions so that the internal combustion engine may operate near its most efficient operating conditions and fuel may be conserved. However, there may be times when operating the engine near its most efficient operating conditions may not be desirable. Therefore, it may be desirable to provide a way of operating an internal combustion engine and an electric machine in a way that allows the engine to deviate from baseline operation at times. It may be understood that the background above is provided to give some context to the systems and methods described in the detailed description. The background is not meant to identify key features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not constrained to implementations that solve any disadvantages noted in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a schematic diagram of an internal combustion engine; FIG. 2 shows a schematic diagram of an example vehicle driveline or powertrain including the internal combustion engine shown in FIG. 1; FIG. 3 shows an example vehicle operating sequence according to the method of FIG. 4; and FIG. 4 shows a flowchart of an example method for adapting operation of an electric machine of a hybrid vehicle. DETAILED DESCRIPTION The present description is related to adapting utilization of an electric machine so that there may be less possibility of de-rating the electric machine. As a result, the electric machine may increase its assistance to the engine during high load conditions. One way to reduce a possibility of de-rating the electric machine may be to operate the internal combustion engine away from its baseline operating conditions where engine efficiency is higher. In particular, torque output of the engine may be increased over torque output of the engine at baseline operating conditions where the engine and the electric machine combine to generate a driver demand torque. Since the engine provides a greater fraction of the driver demand torque, there may be less possibility of the temperature of the electric machine reaching a temperature where the electric machine is de-rated. An internal combustion engine is shown in FIG. 1. The internal combustion engine of FIG. 1 is included in a driveline of a hybrid vehicle as shown in FIG. 2. The driveline may be operated according to the method of FIG. 4 as shown in the sequence of FIG. 3. A method for operating a vehicle is shown in FIG. 4. A hybrid vehicle may include a relatively small displacement internal combustion engine so that the hybrid vehicle is fuel efficient when the engine is activated. The engine may be assisted by the hybrid vehicle's electric machine and the electric machine may be heavily utilized to ensure efficient vehicle operation. The electric machine may be useful to assist in propulsion when the vehicle is hauling a load (e.g., cargo) or towing a trailer. The electric machine may provide propulsion assistance when the vehicle is operating in a charge depletion mode where high voltage battery power is consumed or depleted. The electric machine may assist in vehicle to provide propulsive effort until the high voltage battery state of charge (SOC) is within a predetermined “sustain” range or until the electric machine is de-rated (e.g., the power output of the electric machine is constrained to be less than the rated output power of the electric machine by constraining electric power flow to the electric machine to be less than a maximum rated electric power flow to the electric machine at present electric machine operating conditions). If the electric power flow to the electric machine is constrained due to a temperature of the electric machine being greater than a threshold temperature, the hybrid vehicle may not be able to provide as much propulsive effort or vehicle slowing capability as may be desired. The inventors herein have recognized the above-mentioned issues and have developed a method for operating a vehicle, comprising: increasing a first fraction of a driver demand torque generated via an internal combustion engine relative to a baseline fraction of torque generated via the internal combustion engine and decreasing a second fraction of the driver demand torque generated via an electric machine relative to a baseline fraction of torque