Line traps prevent transmission of these high frequency signals to unwanted directions without loss of energy at power frequency. Line traps are series-connected to the transmission lines, and are designed to withstand the rated power frequency current and the short circuit current to which the lines are subjected.
What is the function of line trap in the carrier current protection?
Line trap is an LC network inserted between the busbar and connection of coupling capacitors to the line and tuned to resonance at the high frequency and are used to confine the carrier currents to the protected section so as to avoid interference with or from adjacent carrier current channel.
Which device used to inject carrier current in transmission line?
To inject the carrier signal and to restrict it within the protected section of the line suitable coupling apparatus and line traps are used at both ends of the protected section.
Which type of protection is carrier current protection?
For long overhead lines the power line itself may be used as the interconnecting channel between the terminal equipments. Carrier-current protection is the most widely used scheme for the protection of Extra High Voltage (EHV) and Ultra High Voltage (UHV) power lines.
What is the function of line trap?
Line traps prevent transmission of these high frequency signals to unwanted directions without loss of energy at power frequency. Line traps are series- connected to the transmission lines, and are designed to withstand the rated power frequency current and the shortcircuit current to which the lines are subjected.
What is Carrier aided protection?
Carrier aided protection is used for the protection of transmission lines. The carrier currents with high frequency range are transmitted and received with the help of transmission lines for protection.
How does a line tuner work?
The line tuner/coupling capacitor combination provides a low impedance path to the power line by forming a series resonant circuit tuned to the carrier frequency. On the other hand, the capacitance of the coupling capacitor is high impedance to the power frequency energy.
Which relay is least affected by power surges fault resistance?
Distance relays are preferred to overcurrent reIays because they are not nearly so much affected by changes in short-circuit-current magnitude as overcurrent relays are, and, hence, are much less affected by changes in generating capacity and in system configuration.