Investigation of potential islanding of dispersed photovoltaic systems
Photovoltaic sources feed power back to a utility through static power converters (SPCs) during normal operation. The SPCs are designed to shut down when the utility grid is abnormal; however, it has been shown that they continue to operate or ''run-on'' under certain abnormal conditions. This research was designed to establish the conditions of load vs generation under which run-on would occur. Computer simulations were made of a TESLACO self-commutated SPC and of a Gemini line-commutated SPC. The results of the simulations were verified by laboratory and field tests. Run-on was found to occur only when there was a very close match between PV generation (SPC output) and connected load. For the TESLACO, under matched-load conditions, run-on was limited to 4 seconds, due to destabilizing circuits and internal trip mechanisms. For the Gemini, external VAR support, necessary for matched-load conditions, allows the unit to run-on indefinitely. The addition of internal trip mechanisms based on sensing frequency and voltage, available from the Gemini manufacturer, reduced run-on to an extremely low probability event. The research did not reveal any dynamic interaction among multiple TESLACOs, multiple Geminis, or among TESLACOs and Geminis within an island that would cause the island to persist longer than it would for a single SPC. 29 refs., 117 figs.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA); Southern Electric International, Birmingham, AL (USA); Auburn Univ., Montgomery, AL (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 6721835
- Report Number(s):
- SAND-87-7024; ON: DE89002827
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
14 SOLAR ENERGY
POWER POOLING
COMPUTERIZED SIMULATION
ELECTRONIC CIRCUITS
FLOWSHEETS
NUMERICAL DATA
PHOTOVOLTAIC POWER SUPPLIES
POWER CONDITIONING CIRCUITS
POWER GENERATION
DATA
DIAGRAMS
ELECTRONIC EQUIPMENT
EQUIPMENT
INFORMATION
POWER SUPPLIES
SIMULATION
SOLAR EQUIPMENT
200300* - Electric Power Engineering- Power Transmission & Distribution- (-1989)
140600 - Solar Energy- Photovoltaic Power Systems