Selectivity of Zero-Sequence Current Backup Protection and Improvement Based on Wide Area Measurement System

摘要

Theoretical analysis and simulation studies showed that under the condition of internal ground fault on the double-circuit transmission lines, when the system zero-sequence parameters on the two sides of the double-circuit lines and the location of the fault point met certain conditions, both the protections of the adjacent lines on the two sides of the double-circuit transmission lines all had the possibility of unselective operation. Meanwhile improved method based on wide area measurement system proposed in this chapter can improve both the selectivity and the speed of the backup protection.