Detection and Estimation of Nonstationary Power Transients

  • Gerard Ledwich
  • Ed Palmer
  • Arindam Ghosh
Part of the Power Electronics and Power Systems book series (PEPS)


This chapter looks at issues of non-stationarity in determining when a transient has occurred and when it is possible to fit a linear model to a non-linear response. The first issue is associated with the detection of loss of damping of power system modes. When some control device such as an SVC fails, the operator needs to know whether the damping of key power system oscillation modes has deteriorated significantly. This question is posed here as an alarm detection problem rather than an identification problem to get a fast detection of a change. The second issue concerns when a significant disturbance has occurred and the operator is seeking to characterize the system oscillation. The disturbance initially is large giving a nonlinear response; this then decays and can then be smaller than the noise level ofnormal customer load changes. The difficulty is one of determining when a linear response can be reliably identified between the non-linear phase and the large noise phase of thesignal. The solution proposed in this chapter uses “Time-Frequency” analysis tools to assistthe extraction of the linear model.


False Alarm Power System Probability Density Function False Alarm Rate Instantaneous Frequency 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer Science+Business Media,LLC 2009

Authors and Affiliations

  1. 1.Faculty of Built Environment and EngineeringQueensland University of TechnologyBrisbaneAustralia

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