Vehicle Battery Polarization Control for Accurate SOC at Arrival
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to accurately calculate the state of charge (SOC) of electric power storage devices in vehicles, such as lithium-ion batteries, as polarization during charging or discharging causes terminal voltage deviations from open circuit voltage, making immediate SOC calculation difficult due to the need for electrochemical equilibrium, which takes a long time to achieve.
Innovation Solution
A vehicle control apparatus with a control system that executes a polarization eliminating mode by controlling the energization state of the electric power storage device while traveling, setting necessary times based on polarization state and travel conditions to permit or refrain from executing this mode, ensuring accurate SOC calculation upon arrival.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the vehicle waits for the electric power storage device to reach electrochemical equilibrium before SOC calculation, then the SOC calculation accuracy is improved, but the time required increases significantly
Solution Approach 1:
The patent applies preliminary action by executing a polarization eliminating mode during vehicle travel before the vehicle stops. The control system actively manages the energization state of the electric power storage device during movement to reduce polarization effects in advance, enabling accurate SOC calculation immediately after stopping without requiring prolonged equilibrium time. This transforms the post-stop waiting period into a productive pre-trip preparation phase.
2Loss of time
If the polarization eliminating mode is executed during vehicle travel, then the SOC calculation can be performed immediately after stopping, but the control system complexity increases
Solution Approach 1:
The control system leverages the existing motor generator, which serves dual functions: propelling the vehicle during travel and acting as a polarization eliminating device during operation. By controlling the motor generator's energization state during vehicle movement, the system achieves polarization reduction without requiring dedicated additional hardware, thus minimizing complexity increase while maintaining the multi-functionality of existing components.
3Productivity
If the vehicle arrives at destination with high polarization, then plug charging can start immediately, but the SOC calculation accuracy deteriorates
Solution Approach 1:
The system performs preliminary polarization elimination during vehicle travel by controlling the motor generator's energization state. This advance action ensures that when the vehicle arrives at the destination, both the polarization is reduced and the SOC calculation can proceed immediately with high accuracy, enabling plug charging to start right away without compromising measurement precision.
4Measurement precision
If the first necessary time exceeds the second necessary time, then polarization cannot be fully eliminated before arrival, but executing the mode anyway may waste energy
Solution Approach 1:
The control system dynamically adjusts the polarization eliminating mode execution based on real-time comparison between the first necessary time (calculated from polarization state) and the second necessary time (time to destination). When the first necessary time exceeds the second, the system refrains from executing the mode, avoiding unnecessary energy consumption. This dynamic decision-making optimizes energy usage while maintaining SOC calculation accuracy within acceptable limits.
Data Source
AI summary
A vehicle control apparatus includes a control system. The control system includes a processor and a memory that are communicably coupled to each other, and executes a polarization eliminating mode in which polarization is eliminated by controlling an energization state of an electric power storage device while a vehicle is traveling. The control system sets a first necessary time to eliminate the polarization based on a polarization state of the electric power storage device, acquires a second necessary time to an arrival of the vehicle at a destination, permits the polarization eliminating mode to be executed while the vehicle is traveling in a case where the first necessary time is shorter than or equal to the second necessary time, and refrains from permitting the polarization eliminating mode to be executed while the vehicle is traveling in a case where the first necessary time is longer than the second necessary time.