Characterizing dynamic behavior of PMUs using step signals

Abstract

SUMMARYEvaluating performance of PMUs to verify the consistency of phasor measurements is of a great importance since it promotes the interoperability among PMUs from different manufacturers. This paper presents a set of test methodology and tools for evaluating the dynamic performance of PMUs when exposed to a step change of input signals. A phasor estimation scheme is proposed to achieve high accuracy of reference phasors. An interleaving technique applied on output phasors can equivalently increase the reporting rate and can precisely depict the transient behavior of a PMU under the step input. Four types of tests with balanced and unbalanced three-phase step signals are performed as reference signals to characterize the step responses. Three commercial PMUs are selected to perform step tests using the dynamic test system developed at NIST. A set of programs are developed based the dynamic test system to automate step test procedures. The test results are outlined at the end.

Power system measurement data and their applications

“…The current IEEE C37.118-2005 synchrophasor standard only specifies the total vector error for steady-state performance. In the first paper, Ren et al [1] present a set of test methodology and tools for characterizing dynamic behavior of PMUs when exposed to step signals. The technique is then applied to three commercial PMUs in a US National Institute of Standards and Technology laboratory and the results are presented.…”

A new method of decision tree based transient stability assessment using hybrid simulation for real‐time PMU measurements

“…On the other hand, in order to quickly detect the erroneous part of time‐series measurements, we need to have a reliable knowledge in advance about the settling times for all PMUs in case of a given contingency [18, 19]. While the settling times, and , of any PMU are highly dependent on the characteristics of its input three‐phase signal (specially the size of abrupt changes), PMUs receiving input signals with similar changes both in magnitude and form would possess similar settling times [20–22].…”

“…These ripples persist for a few cycles and then die out over time. According to Figure 5(b), it can be seen that there is a phase difference between the outputs of PB simulator and outputs of HPE simulator which can be due to the filtering mechanisms being applied during the discrete Fourier transform (DFT)‐based phasor estimation process [20–22]. In Figure 5(c), there are some significant overshoots in the outputs of HPE, which are not seen in the outputs of PB simulator.…”

“…Studies show that phasor calculation algorithm of practical PMUs may become significantly impaired in off-nominal frequency conditions associated with the fault occurrence and fault clearance. The effects of these impairments make the measurements highly erroneous and uninformative in specific periods of time [20][21][22]. Therefore, the erroneous part of time-series measurements cannot be considered as valid indicators of power system dynamics and should be removed from the feature space in a proper way.…”

Improved Performance of M-Class PMUs Based on a Magnitude Compensation Model for Wide Frequency Deviations

“…On the other hand, some works that improve the performance of PMUs have been presented in the literature, where new phasor estimation algorithms, new adaptive filtering-based methodologies and several compensation strategies have been proposed [1,6,8,[21][22][23][24]. For instance, some remarks about the performance of PMUs under dynamic conditions for electric signals are presented in References [28][29][30]. Regarding the compensation strategies, the phase is compensated using input delays, due to the linear phase characteristics of the filters.…”