Standard overcurrent protection schemes for passive radial systems assume single direction current flow. The addition of distributed generation (DG) presents issues for the protection scheme, as current can flow from multiple directions. This thesis investigates the impact of DGs on overcurrent protection designed for a radial system, and proposes solutions to address the issues. A realistic feeder system and its protection scheme are developed in PSCAD/EMTDC. A point-of-common-coupling (PCC) is identified, indicating the portion of feeder that can potentially operate as an island. One DG, with output adjusted to maintain a specified power flow at the PCC, is added to the feeder system. The performance of the overcurrent protection in the presence of line, ground, and three-phase faults is analyzed. A second machine, outputting full capacity at unity power factor, is added to the feeder system. The strategies used to develop the single-DG modified protection scheme are applied to the two-DG system. The functionality of the modified protection scheme is verified.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/25449 |
| Date | 15 December 2010 |
| Creators | Chang, Tim |
| Contributors | Iravani, Mohammad Reza |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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