Fuel Cell Stack EIS Diagnosis for Hydrogen and Air Starvation

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Solution Overview

Problem

Existing methods for diagnosing gas starvation faults in fuel cell stacks are limited, often requiring lengthy real-time EIS measurements and failing to differentiate between hydrogen and air starvation faults, which necessitate different countermeasures.

Innovation Solution

An EIS-based gas starvation fault diagnosis method that collects impedance modulus and phase data at specific characteristic frequencies, allowing for real-time identification and differentiation between hydrogen and air starvation faults by comparing these values against reference thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If real-time EIS measurement is performed to diagnose gas starvation faults, then diagnostic reliability is improved, but measurement time increases and real-time monitoring capability deteriorates

Engineering Contradiction:
Improvefault diagnosis reliabilityVSAvoidmeasurement time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts only the critical frequency points from the full EIS spectrum that are most sensitive to gas starvation faults. By identifying and monitoring only these specific frequency points rather than the entire frequency range, the method achieves reliable fault detection while significantly reducing measurement time and enabling real-time monitoring.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies partial action by measuring EIS at selected characteristic frequencies rather than performing complete spectral analysis. This partial measurement approach focuses resources on the most diagnostic frequency points, achieving sufficient reliability for gas starvation detection without the time cost of full spectrum measurement.

Inventive Principle:
Principle #16Partial or excessive action

2Difficulty of detecting and measuring

If general EIS monitoring is used to detect gas starvation, then fault detection capability is improved, but the ability to differentiate between hydrogen starvation and air starvation deteriorates

Engineering Contradiction:
Improvefault detection capabilityVSAvoidfault type differentiation information
Core Design Contradiction:
Difficulty of detecting and measuringVSLoss of information

Solution Approach 1:

The patent applies local quality by assigning different monitoring functions to different frequency points. Specific frequency ranges are selected that are particularly sensitive to hydrogen starvation, while other frequency points are more sensitive to air starvation. This frequency-specific monitoring enables differentiation between fault types while maintaining overall detection capability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the EIS measurement into multiple discrete frequency point measurements, each targeting specific fault conditions. By dividing the monitoring task into frequency-specific segments, the method can identify which segment shows abnormal behavior, thereby differentiating between hydrogen starvation and air starvation faults.

Inventive Principle:
Principle #1Segmentation

3Measurement precision

If comprehensive EIS analysis is performed to identify fault types, then diagnostic precision is improved, but system complexity and measurement requirements increase

Engineering Contradiction:
Improvefault identification precisionVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential frequency points and parameters needed for fault identification, eliminating unnecessary measurement and analysis complexity. By focusing on key characteristic frequencies rather than comprehensive spectral analysis, the system achieves precise fault identification with simpler measurement and processing requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

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 method enables quick and reliable diagnostic results, allowing for appropriate control strategies to be implemented based on the identified fault type, thereby preventing damage and performance reduction in fuel cell stacks.

Implementation Method 1

a protic exchange membrane fuel cell stack

Methodology Applied
Scientific EffectElectrochemical reaction: Fuel Cell

Implementation Method 2

collecting, in real time, an impedance modulus Z1 at a first characteristic frequency f1 of the fuel cell stack

Methodology Applied
Scientific EffectElectrical impedance: Electrical Resistance

Data Source

PatentUS20250130190A1EIS-based Gas Starvation Fault Diagnosis Method for Fuel Cell Stack
Publication Date: 2025.04.24 ROBERT BOSCH GMBH
  • US20250130190A1 patent drawing
  • US20250130190A1 patent drawing
  • US20250130190A1 patent drawing

AI summary

An EIS-based gas starvation fault diagnosis method for a fuel cell stack is disclosed. The method includes (S1) collecting, in real time, an impedance modulus at a first characteristic frequency of the fuel cell stack, (S2) comparing the impedance modulus to a modulus reference value, and (S3) determining whether an absolute value of a difference between the impedance modulus and the modulus reference value is greater than a first threshold, if yes, identifying that a gas starvation fault occurs to the fuel cell stack, and if no, returning to step (S1) to continuously collect the impedance modulus at the characteristic frequency of the fuel cell stack. The gas starvation fault diagnosis method is capable of quickly and reliably obtaining diagnostic results and is capable of differentiating between hydrogen starvation and air starvation through different parameters.