Line traps series VZ

Purpose

The line traps are used to attenuate the switching effects of high-voltage lines and equipment as well as to prevent signal losses (signals for remote control, voice communication, remote metering) transmitted along high-voltage lines (6-1150kV).

The line traps are filter-barriers, mounted in-line on phase conductors and could be configured for certain attenuation band range (16-1000 kHz).

Line traps characteristics

Main parameters of the line traps are as follows:

class of transmission lines;
frequency bandwith;
continious rated current;
rated short-time current;
emergency overload current;
main coil inductance.

IEC 60353 and STO 56947007 (Russian Standard) have set the following values for transmission lines resistance, blocking impedance, continuous rated current.

IEC and STO recommend the following values of the main coil inductance (mH):

0.2 - 0.25 - 0.315 - 0.4 - 0.5 - 1.0 - 2.0

IEC and STO recommend the following values for the short-time current and emergency overload current

Construction

Main components:

Main Coil is used to carry rated continuous power frequency currents of transmission lines with the line trap;
Protective Device is used to protect the main coil and tuning device from over voltages occurring on lines and distribution devices of substations (atmospheric and switching over voltages, from short circuits);
Tuning Device (together with the main coil) is used to adjust the blocking frequency or bandwith i.e. the frequency range over which the line trap can provide a certain specified minimum blocking impedance or resistance;
Sometimes the line traps are supplied without the tuning devices depending upon the special requirements.

Accessories:

Bird Barrier;
Corona Rings and Corona Caps;
Pedestal for vertical mounting.