WEC Fault Modelling and Condition Monitoring: A Graph-Theoretic Approach

Yufei Tang, Yu Hang Yu Hang, Erica Lindbeck, Sam Lizza, James VanZwieten, Nathan Tom, Wei Yao

Research output: Contribution to journalArticlepeer-review

10 Scopus Citations


The nature of wave resources usually requires wave energy converter (WEC) components to handle peak loads (i.e., torques, forces, and powers) that are many times greater than their average loads, accelerating equipment degradation. Moreover, due to their isolated nature and harsh operating environment, WEC systems are projected to possess high operations and maintenance (O&M) cost, i.e., around 27% of their leveled cost of energy. As such, developing techniques to mitigate these costs through the application of condition monitoring and fault tolerant control will significantly impact the economic feasibility of grid connected WEC power. Toward this goal, models of faulty components are developed in the open source modeling platform, WEC-Sim, to estimate the performance and measurable states of a WEC operating with likely device and sensor failures. Two types of faulty component models are then applied to a point absorber WEC model with basic controller damping and spring forces. Resulting changes in device behavior are recorded as a benchmark, and a graph-theoretic approach is proposed for fault detection and identification utilizing multivariate time series. Simulation results demonstrate that these faults can greatly affect the WEC performance, and that the proposed method can effectively detect and classify different types of faults.

Original languageAmerican English
Pages (from-to)781-788
Number of pages8
JournalIET Electric Power Applications
Issue number5
StatePublished - 2020

Bibliographical note

Publisher Copyright:
© 2020 The Institution of Engineering and Technology.

NREL Publication Number

  • NREL/JA-5000-74822


  • condition monitoring
  • damping
  • electrical maintenance
  • fault location
  • fault tolerant control
  • graph theory
  • power generation control
  • power generation economics
  • power generation faults
  • power generation protection
  • power generation reliability
  • power grids
  • public domain software
  • renewable energy sources
  • springs (mechanical)
  • time series
  • wave power generation


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