Page 266 - Practical Power System and Protective Relays Commissioning
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Protection Relays Chapter | 18 263
FIGURE 18.10.5 Merz-price differential protection.
FIGURE 18.10.6 Practical pilot wire differential protection.
Refer to the unit pilot-wire differential protection in Fig. 18.10.6.
There are different methods to transfer the current signals over the line as
follows:
Pilot wires;
Power line carrier (PLC);
Radio link;
Optical fiber; and
Pilot wires.
This system can be used for short lines less than 10 km.
18.10.4 POWER LINE CARRIER
This system is used to transfer the tripping and protection acceleration signal
to the remote end of the line along with the voice signal. Refer Fig. 18.10.7.
