Fuel Cell Assembly Voltage Regulation via Variable Resistor

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Solution Overview

Problem

Existing electric vehicle fuel cell systems face inefficiencies and increased complexity when operating in both low and high power modes, with parallel fuel cell stack arrangements risking fuel starvation and degradation, while series arrangements introduce inefficiencies and component stress.

Innovation Solution

A fuel cell assembly with two or more fuel cell stacks, one optimized for low power and the other for high power, arranged in parallel, with a regulation assembly including variable resistors and a controller to manage voltage and current, ensuring power is generated within a single desired voltage range and minimizing the risk of degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fuel cell stacks are arranged in parallel to provide both low power and high power modes, then power versatility is improved, but fuel starvation risk and component degradation increase

Engineering Contradiction:
Improvepower mode versatilityVSAvoidfuel starvation risk
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The fuel cell system is segmented into multiple stacks (first fuel cell stack and second fuel cell stack) that can operate independently or together. Each stack can be selectively activated based on power requirements, allowing the system to provide both low power mode (one stack operating) and high power mode (both stacks operating) while maintaining reliability through proper load distribution.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If power conditioning is used with series fuel cell stacks to meet voltage requirements, then voltage range compliance is improved, but system complexity and fuel consumption increase

Engineering Contradiction:
Improvevoltage range complianceVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system employs dynamic configuration where fuel cell stacks can be selectively connected or disconnected from the circuit based on power mode requirements. A switching mechanism dynamically reconfigures the electrical connection between stacks, allowing direct voltage matching for different power modes without requiring complex power conditioning electronics.

Inventive Principle:
Principle #15Dynamics

3Power

If fuel cell stacks operate in parallel, then power delivery capability is improved, but fuel maldistribution and stack variability increase

Engineering Contradiction:
Improvepower delivery capabilityVSAvoidfuel distribution uniformity
Core Design Contradiction:
PowerVSStability of the object's composition

Solution Approach 1:

Each fuel cell stack is equipped with dedicated fuel delivery components (fuel manifolds, flow distributors) that ensure uniform fuel distribution specific to that stack's requirements. The system acknowledges and accommodates stack variability by providing localized fuel management rather than assuming uniform performance across all stacks.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration enhances efficiency by reducing power consumption, minimizing the risk of fuel starvation and component damage, and simplifying electrical component requirements, while maintaining a stable voltage range across varying power modes.

Implementation Method 1

A fuel cell assembly with two or more fuel cell stacks, one optimized for low power and the other for high power

Methodology Applied
Scientific EffectFuel cell electrochemical conversion: Fuel Cell

Implementation Method 2

a regulation assembly including variable resistors and a controller to manage voltage and current

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2858159B1Regulation of a fuel cell assembly
Publication Date: 2022.12.21 HAMILTON SUNDSTRAND CORP
  • EP2858159B1 patent drawingFigure 1
  • EP2858159B1 patent drawingFigure 2
  • EP2858159B1 patent drawingFigure 3

AI summary

A fuel cell assembly (18) includes a first fuel cell stack (26) in series with a variable resistor (32) and a second fuel cell stack (28) in parallel with the first fuel cell stack (26) and in series with a contactor (36). A resistance level of the variable resistor (32) is adjusted in response to deactivating the contactor (36).