Graphical tools for generating qualitative redundant relations

To perform fault diagnosis for multi‐energy systems, the causal graph‐based methods are well‐suited for modelling and monitoring purposes. The present paper is concerned with the merging of the quantitative model (bond graph) and the qualitative reasoning (signed directed graph) and its subsequent is introduced as a new causal graph framework. The integrated model can be involved to generate qualitative fault signatures matrix deduced from the qualitative redundant relations. Compared with the classical bond graph‐based monitoring, the proposed mechanism can reduce the number of redundant relations which depend on the qualitative state of known variables and enhance the process monitoring in normal situations as well as in the presence of failures without any need of numerical calculations. The performance of the developed approach is explained using two illustrative examples (systems with single and coupled energies) and discussed in detail with the existing bond graph method.