Page 265 - Practical Power System and Protective Relays Commissioning
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262 Practical Power System and Protective Relays Commissioning
FIGURE 18.10.3 Balanced voltage system—external fault—relay should not operate.
FIGURE 18.10.4 Balanced voltage system, internal fault—relay will operate.
18.10.2 APPLICATION OF DIFFERENTIAL PROTECTION
1. Generator differential protection;
2. Transformer differential protection;
3. Switchgear-busbar differential protection;
4. Feeder pilot-wire protection.
18.10.3 DIFFERENTIAL PROTECTION OF HIGH-VOLTAGE
TRANSMISSION LINES (PILOT-WIRE PROTECTION)
In this type of protection that use the principal of balanced circulating cur-
rent scheme to compare the currents in the two ends of the high-voltage line
as shown in Fig. 18.10.5.
