New York Power Authority

About: New York Power Authority is a based out in . It is known for research contribution in the topics: Electric power system & AC power. The organization has 95 authors who have published 157 publications receiving 2795 citations.

Missing Data Recovery by Exploiting Low-Dimensionality in Power System Synchrophasor Measurements

Abstract: This paper presents a new framework of recovering missing synchrophasor measurements (erasures). Leveraging the approximate low-rank property of phasor measurement unit (PMU) data, we connect the problem of recovering PMU data erasures with recent advances in low-rank matrix completion methods. Since the existing analysis for matrix completion methods assumes an independent-erasure model that does not capture the correlations in PMU erasures, we propose two models to characterize the temporal and the channel correlations in PMU erasures and provide theoretical guarantees of a matrix completion method in recovering correlated erasures in both models. We also propose an online algorithm that can fill in the missing PMU measurements for real-time applications. Numerical experiments on actual PMU data are conducted to verify the effectiveness of the proposed methods.

A Phasor-Data-Based State Estimator Incorporating Phase Bias Correction

Abstract: With amplitude and phase information, time-synchronized measured phasor data of bus voltages and line currents can be used to calculate, without iterations, the voltage phasor on neighboring buses. In some phasor measurement units (PMUs), it has been observed that the voltage and current phasors exhibit phase biases, which can corrupt the conventional state estimator solution if it is augmented with such biased phasor data. This paper presents a new approach for synchronized phasor measurement-based state estimation, which can perform phasor angle bias correction given measurement redundancy. In this approach, polar coordinates are used as the state variables, because the magnitude and phase are largely independent measurements. The state estimation is formulated as an iterative least-squares problem, and its application to portions of the AEP high-voltage transmission system is illustrated.

Alewives Avoid High-Frequency Sound

Abstract: We studied the response of the alewife Alosa pseudoharengus to high-frequency sound to develop an acoustic system for preventing fish from entering power plant intakes. Four groups of alewives were subjected to different frequencies of sounds ranging from 110 to 150 kHz at sound pressure levels (SPLs, given in decibels [dB] in reference to 1 μPa) ranging from 125 to 180 dB. Each group of 20 or 25 fish was tested in a cage that was suspended in a flooded rock quarry. During the day, alewives schooled and strongly avoided pulsed tones (500 ms pulses, 1,000 ms apart) of 110 and 125 kHz at or above 175 dB, a continuous tone of 125 kHz at 172 dB, and pulsed broadband sound between 117 and 133 kHz at or above 157 dB. Although alewives habituated to tones, they avoided pulsed broadband sound at 163 dB more consistently. In one test, alewives did not habituate to this sound after 150 min of repeated exposure, The more consistent response to the broadband sound was probably due to the range of frequencies...

Adaptive nonlinear excitation control of power systems with unknown interconnections

Abstract: Adaptive nonlinear excitation control of large-scale power systems is considered in this paper. The approach used is an adaptive feedback linearizing control to enhance the robustness to unknown or varying interconnection parameters like equivalent reactances of the transmission lines. Control design based on external feedback linearization may not be robust to handle varying power-system configurations. Inexact cancellation of terms due to uncertainties may result in performance deterioration like inter-system oscillations. Adaptation in estimated parameters is utilized to achieve an asymptotically exact cancellation of terms. It is shown that the adaptive control results in bounded states and maintains the desired performance. The control scheme developed is applied to a power system with two generators and an infinite bus connected through a network of transformers and transmission lines. Simulation studies for unknown interconnections arising due to faults and subsequent line switchings in the transmission network are carried out. The performance using the nonadaptive feedback linearizing control is shown to degrade for network configuration variations arising due to transmission line faults. The response obtained using the proposed scheme is compared with that using a conventional IEEE Type I excitation control. The studies validate the fact that connective stability and robust performance is maintained for unknown interconnection topology using the adaptive feedback linearizing scheme. >