Micro-current excitation for efficient diagnosis of membrane electrode assemblies in fuel cell stacks: Error analysis and method optimization

•Identify ohmic resistance and update excitation model for precision upgrading.•Conduct systematic error analysis concerning decoupling algorithm and stack state.•Originally reveal condition sensitivity for identifying MEA inconsistency.•Validate adaptability to single excitation for a great advance in test efficiency.•Contribute to validity and reliability of MCE in stack-level MEA diagnosis.