Fuel Cell Stack Voltage Control for Individual Cell Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuel cell stacks experience deterioration due to voltage differences among individual cells, even when the overall stack voltage is within a predetermined limit, leading to reduced durability and performance.
Innovation Solution
A method and system that dynamically control the voltage of a fuel cell stack based on individual cell voltages and the state of charge of a battery, reducing the stack voltage when maximum cell voltages exceed a threshold and adjusting the reduction amount based on battery charge levels, while also monitoring charging current to adjust output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the reference value of fuel cell stack voltage is reduced to protect individual cells, then individual cell voltage is controlled better, but the output power of the fuel cell stack decreases
Solution Approach 1:
The patent dynamically adjusts the reference voltage value based on real-time monitoring of individual cell voltages and battery state of charge. Instead of using a fixed conservative reference value that would limit power output, the system adapts the reference value dynamically - reducing it only when necessary to protect individual cells while maintaining higher values when cells are safe, thus optimizing both protection and power output.
Solution Approach 2:
The patent changes the reference voltage parameter based on operating conditions, particularly battery state of charge and individual cell voltage levels. When the battery is highly charged, the reference value is reduced more aggressively to protect cells. When the battery has lower charge, the reference value is maintained higher to preserve power output, creating an adaptive parameter adjustment strategy.
Data Source
AI summary
A method of controlling voltage of a fuel cell includes steps of: determining whether a mode is a high-voltage avoidance mode of the fuel cell; controlling a fuel cell stack voltage to be at a predetermined reference value or less when the mode is the high-voltage avoidance mode of the fuel cell; monitoring individual cell voltages of the fuel cell and determining whether a maximum value of the monitored individual cell voltages exceeds a predetermined individual value; reducing a reference value of the fuel cell stack voltage when the maximum value of the monitored individual cell voltages exceed the predetermined individual value; and controlling the fuel cell stack voltage at the reduced reference value or less. The method and system for controlling fuel cell voltage is provided to secure durability and performance of individual cells of a fuel cell stack.