Application of unknown input observers to locate forced oscillation source

Abstract

Summary In this paper, the problem of locating forced oscillation source at device level is addressed, using unknown input observer (UIO)‐based method to realize oscillation source isolation. Firstly, a linear power system model suitable for oscillation source detection and isolation is derived. Typical oscillation sources, namely, oscillation sources from prime movers and speed governors, excitation systems, are included in the model as unknown inputs. Then, a systematic method using UIOs and fault isolation scheme to locate oscillation source is proposed. Using the disparities between the model responses generated by UIOs and the recorded responses, the proposed method establishes a one‐to‐one relationship between a residual and an oscillation source. The location of oscillation source at device level is accomplished on the basis of the different sensitivities of residuals to oscillation sources from different devices. The detectability of oscillation source and the numerical check are also discussed. The effectiveness of the proposed location method is verified by several simulation examples. The results show that the location of oscillation source by the proposed method is effective and is accurate to control the device that the oscillation source originates from.

A novel method for locating the source of sustained oscillation in power system using synchrophasors data

“…An equivalent power system model in the frequency domain considering noisy PMU data and uncertain generator parameters is developed in [21] and a numerical procedure based on Bayesian framework is adopted to identify the source of FO. Reference [22] proposes a double stage mode decomposition technique, while [23] discusses an unknown input observer (UIO) based method to locate the source of FO. Initially, the linearized power system model considering the unknown oscillation sources from a prime mover, excitation system etc.…”

A harmonic vibration suppression approach in nonlinear induction motors

“…36. Low‐frequency oscillations in practical power systems could be induced by forced vibration sources caused by exogenous periodic disturbances 37 . Shaft oscillations in wind turbine generators could be also exhibited due to torsional vibrations of the shaft system 38 …”