REEV Battery SOC Targeting for Road Load and Towing Torque Reserve
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional range-extended electrified vehicles (REEVs) experience noticeable range depletion during long-distance and towing scenarios, leading to a shift to engine power, which can be audibly and perceptually less capable compared to conventional vehicles.
Innovation Solution
An intelligent battery charge depletion system that monitors state of charge (SOC), estimated road load, and gross combined vehicle weight (GCVW) to adjust the SOC setpoint dynamically, maintaining a torque reserve and allowing for selective engine recharging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional charge depletion strategy is used to minimize instantaneous fuel consumption, then fuel efficiency is improved, but driving capability and perceived performance deteriorate during high-load scenarios
Solution Approach 1:
The patent applies dynamics by making the SOC setpoint adjustable rather than fixed. The controller dynamically modifies the charge sustaining SOC setpoint based on real-time operating conditions including road load estimates, vehicle weight, ambient temperature, and altitude. This allows the system to adapt battery charge management to varying driving scenarios, maintaining adequate torque reserve during high-load conditions while optimizing fuel efficiency during normal operation.
Solution Approach 2:
The patent changes the parameter of SOC setpoint from a conventional fixed value to a dynamically modified value. The controller calculates modifications to the charge sustaining SOC setpoint based on multiple parameters including estimated road load, gross combined vehicle weight, ambient temperature, and altitude. This parameter change enables the system to maintain appropriate torque reserve under varying conditions, resolving the contradiction between fuel efficiency and driving capability.
2Length of moving object
If battery charge is depleted quickly during long-distance scenarios, then electric range is maximized initially, but engine activation occurs sooner causing audible noise and reduced perceived capability
Solution Approach 1:
The patent applies preliminary action by proactively adjusting the charge sustaining SOC setpoint before the vehicle encounters high-load conditions. The controller estimates road load, vehicle weight, and environmental conditions in advance, then modifies the SOC setpoint accordingly. This preliminary adjustment ensures adequate torque reserve is maintained, delaying engine activation and preventing the harmful effects of early engine engagement.
Solution Approach 2:
The patent implements feedback by continuously monitoring operating conditions including road load estimates, vehicle weight, ambient temperature, and altitude. The controller uses this feedback to dynamically adjust the charge sustaining SOC setpoint, creating a closed-loop control system that maintains optimal torque reserve and delays engine activation until necessary, thereby reducing audible noise and maintaining perceived capability.
Data Source
AI summary
An intelligent battery charge depletion system for an electrified powertrain of a range-extended electrified vehicle (REEV) determines a modified state of charge (SOC) setpoint based on an estimated road load and an estimated gross combined vehicle weight (GCCW) of the REEV. The modified SOC setpoint is different than a charge sustaining SOC setpoint and is for a battery system having an SOC and that is configured to power an electric motor of the electrified powertrain. The estimated road load is for a road segment that the REEV is traversing. The system also controls the electric motor based on the modified SOC setpoint and the battery system SOC to maintain a torque reserve that the electric motor and the battery system can use when needed; and controls an engine of the electrified powertrain to selectively recharge the battery system.