Harmonic monitoring system via synchronized measurements

The New York Power Authority (NYPA), and the other Empire State Electric Energy Research Corporation (ESEERCO) member utilities, initiated deployment of a high voltage transmission harmonic measurement system (HMS) in 1992. 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 harmonic database. The HMS hardware consists of GPS synchronized digital event recorders linked to on-site computers, and a master station computer. The present installation includes instrumentation for a total of 150 measurements of which 138 are three phase quantities (voltages or currents) resulting in 46 phasors. The system performs synchronized waveform data acquisition every 15 minutes. The captured data are processed at the on-site computers to correct for error from the nonideal characteristics of the instrumentation, and to compute the harmonics. The computed harmonics (magnitude and phase) are transmitted to the master station computer where the system wide harmonic flow is constructed, using a harmonic state estimation technique. This paper describes the HMS hardware and software as well as HMS applications.