Monitoring power system disturbances based on distribution-level phasor measurements

Abstract

The Frequency Monitoring Network (FNET) takes GPS-synchronized wide-area measurements in a low-cost, easily deployable manner at the 120V distribution level with the data rate of 10 sps. Various advanced situational awareness tools have been developed using FNET wide-area measurements, including disturbance alert, event location triangulation, oscillation detection, etc. Since late 2010 the FDR deployment has gradually covered some worldwide areas, e.g. Europe, China. In this paper, firstly, the observability of power system disturbances by the FNET system in some worldwide areas is examined and compared with North American power grid, taking the European Power Grid as example. Secondly, this paper investigates the power system dynamics during several major disturbances in Eastern Interconnection and Western Interconnection captured by the FNET system in 2011. Important system parameters (e.g. frequency, phasor angle, voltage magnitude) taken by FDRs are examined and analyzed.

Discrete Fourier transform‐based parametric modal identification from ambient data of the power system frequency

“…The autocorrelation r [ m ] can be estimated from y w [ n ] over a finite number of data as the following r w [ m ] r w [ m ] can be obtained with more reduction of effect on w [ n ] as NT s is assigned to be a longer interval. In practice, LFOs of interarea modes generally last less than 30 s in the modern power system [20, 21]. For time reduction of the autocorrelation calculation, it is necessary to calculate r w [ m ], 0 ≤ m ≤ M w , where M w T s is the effective duration of the autocorrelation function and is set to be less than 30 s. Since w [ n ] is a white noise, r w [0] contains a lot of the noise power of w [ n ].…”

Observability of nonlinear power system dynamics using synchrophasor data

“…It is also noticed that even with same PMU numbers, the system can have different levels of observability. Consider a different 15-PMU placement scheme with PMUs at generator buses 1,2,5,6,7,8,9,10,11,12,15,16,22, 24 and 28. The system observability indices of the new placement scheme (scheme 2) are shown in Figure 10.…”

“…Real time measurements of power systems are essential for applications such as dynamic state estimation , wide‐area stability analysis , disturbance detection , modal analysis , fault location and emergency control . A phasor measurement unit (PMU) is a powerful tool for system dynamic monitoring because it provides synchronized and high resolution data .…”