Harmonic monitoring system via GPS-synchronized measurements - update and new developments

Abstract

This paper presents an update and extensions of New York Power Authority's (NYPA) harmonic measurement system (HMS) which has been deployed for over a decade. The HMS consists of hardware and software, which determine the harmonic state of a transmission system, in real time, and stores the acquired data in a historical harmonics database. The HMS hardware consists of global positioning system (GPS)-synchronized phasor measurement units (PMUs) installed at key substations. At present, the HMS consists of 180 measurements channels representing 60 phasors. The system performs synchronized waveform data acquisition every 15 minutes. The captured data are processed by on-site computers to correct for error from the non-ideal characteristics of the instrumentation, and to compute the harmonics. The computed harmonics (magnitude and phase) from various sites are packed and transmitted to a central location via a local area network where they can be utilized in the harmonic state estimation program to determine the harmonics level at any point in the represented portion of the power system. The HMS is available to both the NYPA and New York Independent System Operator (NYISO) staffs for viewing and analysis. The paper provides a review of the HMS hardware and software capabilities and examples of data captured. The initial implementation of the HMS introduced the capability to provide for corrections of errors from instrumentation channels and direct solution state estimation using GPS-synchronized measurements. Recent advances of these techniques are reported in this paper