Low-Voltage Battery Charging Control for Fuel Cell Vehicles
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Solution Overview
Problem
Conventional methods for controlling the charging voltage of low-voltage batteries in fuel cell vehicles often lead to unnecessary discharge, especially when the vehicle is parked, resulting in reduced startability and potential fuel efficiency issues.
Innovation Solution
A method and apparatus that dynamically adjust the charging voltage of a low-voltage battery based on its state-of-charge (SOC) and the vehicle's operation mode, using a controller to set a base charging voltage and offset voltage based on the SOC of both the low-voltage and high-voltage batteries, thereby preventing excessive discharge or overcharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional voltage control is applied to low-voltage battery charging, then charging voltage is maintained according to operation mode and high-voltage battery SOC, but the battery may be discharged when the vehicle is parked for long periods, leading to reduced startability
Solution Approach 1:
The patent implements dynamic voltage control by adjusting the low-voltage battery charging voltage based on the vehicle's operation mode (parking mode, driving mode, charging mode) and the SOC of the high-voltage battery. The controller dynamically modifies the charging voltage from a base voltage according to these conditions, preventing unnecessary discharge during parking while optimizing charging during operation.
Solution Approach 2:
The patent changes the charging voltage parameter based on operation mode and high-voltage battery SOC. Specifically, it applies voltage offsets (positive or negative) to the base charging voltage depending on the detected operation mode and high-voltage battery state, thereby optimizing the low-voltage battery charging characteristics for different scenarios.
2Productivity
If fixed base charging voltage is used for low-voltage battery, then charging control is simple, but it cannot adapt to different operation modes and high-voltage battery SOC levels, reducing overall system efficiency
Solution Approach 1:
The patent implements parameter changes by adjusting the charging voltage based on operation mode and high-voltage battery SOC. The controller modifies the base charging voltage with appropriate offsets depending on whether the vehicle is in parking mode, driving mode, or charging mode, and on the high-voltage battery's charge state, thereby optimizing fuel efficiency without excessive complexity.
Solution Approach 2:
The patent uses feedback from the operation mode detection and high-voltage battery SOC monitoring to adjust the low-voltage battery charging voltage. The controller continuously monitors system state and modifies charging parameters accordingly, creating a closed-loop control system that improves fuel efficiency through adaptive voltage control.
Data Source
AI summary
A method for controlling low-voltage battery charging may include determining a state-of-charge (SOC) of a low-voltage battery based on a voltage of the low-voltage battery. A base charging voltage is set according to the SOC of the low-voltage battery. A charging voltage of the low-voltage battery is set based on the base charging voltage, a vehicle operation mode, and a SOC of a high-voltage battery.