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Acceptance Testing of a Satellite SCADA Photovoltaic-Diesel Hybrid SystemSatellite Supervisory Control and Data Acquisition (SCADA) of a Photovoltaic (PV)/diesel hybrid system was tested using NASA's Advanced Communication Technology Satellite (ACTS) and Ultra Small Aperture Terminal (USAT) ground stations. The setup consisted of a custom-designed PV/diesel hybrid system, located at the Florida Solar Energy Center (FSEC), which was controlled and monitored at a "remote" hub via Ka-band satellite link connecting two 1/4 Watt USATs in a SCADA arrangement. The robustness of the communications link was tested for remote monitoring of the health and performance of a PV/diesel hybrid system, and for investigating load control and battery charging strategies to maximize battery capacity and lifetime, and minimize loss of critical load probability. Baseline hardware performance test results demonstrated that continuous two-second data transfers can be accomplished under clear sky conditions with an error rate of less than 1%. The delay introduced by the satellite (1/4 sec) was transparent to synchronization of satellite modem as well as to the PV/diesel-hybrid computer. End-to-end communications link recovery times were less than 36 seconds for loss of power and less than one second for loss of link. The system recovered by resuming operation without any manual intervention, which is important since the 4 dB margin is not sufficient to prevent loss of the satellite link during moderate to heavy rain. Hybrid operations during loss of communications link continued seamlessly but real-time monitoring was interrupted. For this sub-tropical region, the estimated amount of time that the signal fade will exceed the 4 dB margin is about 10%. These results suggest that data rates of 4800 bps and a link margin of 4 dB with a 1/4 Watt transmitter are sufficient for end-to-end operation in this SCADA application.
Document ID
20010012162
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Kalu, A.
(Savannah State Univ. Savannah, GA United States)
Emrich, C.
(Florida Solar Energy Center Cocoa, FL United States)
Ventre, G.
(Florida Solar Energy Center Cocoa, FL United States)
Wilson, W.
(Florida Solar Energy Center Cocoa, FL United States)
Acosta, Roberto
Date Acquired
August 20, 2013
Publication Date
August 1, 2000
Publication Information
Publication: HBCUs/OMUs Research Conference Agenda and Abstracts
Subject Category
Spacecraft Design, Testing And Performance
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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