Conductor marking lights

Marker lamps for high -voltage power lines are special air safety navigation lights that are mounted on high-voltage lines and low-flying aircraft serve as a visual cue to the obstruction. The various methods are described since the 1930s in various patents.

General

Overhead lines with large spans, this is typical in high- voltage power lines, provide for low-flying aircraft such as helicopters poorly visible obstacles represents an opportunity to defuse the problem is the marking of the lines through warning lights.

A simple solution is to move the lamps directly on the lines. The time required for the operation of the warning lamp electrical power is taken directly from the power line, which avoids technical difficulties in the supply of power to the lamp. The disadvantage of this " self-sufficiency " is that if the high-voltage line is turned off, for example in the context of maintenance, the warning lights are not in operation.

Implementation principle

There are in principle two ways to be seen from a power line, the power required in the range of a fraction to a few Watt for operating the signal lamp.

Electrical coupling

The energy is taken from the electric field and the decrease of the electric field strength in the vicinity of the conductor. An example of this system is Balisor. The advantage of this method is that the power available through the cable, regardless of the current flow. The disadvantage is that the removable power is low and can only supply small gas discharge lamps such as neon lamps with low power. This is easily detected, is given only in darkness.

Warning lights with electrical coupling can only be applied in the field of high voltage networks in the field of 220 kV or 400 kV, because at lower voltage, the decrease of the electric field strength in the vicinity of the conductor is too low.

Inductive coupling

The energy is extracted from the magnetic field, since the magnetic flux density around the conductor propagates circular cable with a current-carrying overhead conductor. By a power converter, which serves at the same time the suspension of the light on the cable, which is necessary for the operation of the lamp power in the range of several watts of the line can be removed. The disadvantage is that the operation of the lamp a sufficiently high current must flow through the conductor wire. Although the transmission line is on, but does not flow or very little flow through the conduit, for example because little power is removed, the light precipitates.

Inductively coupled warning lights are independent of the voltage level, but are used for practical reasons only in the high voltage range. The method also uses AC ahead - on lines, the DC transfer as in high-voltage direct current (HVDC ), the use of inductively coupled warning lights is not possible.

Since the removable power is higher with this principle, the light of several bright shining light emitting diodes ( LED) can be made, which are controlled by an integrated electronic circuit and for example, flashing regularly. Important for the operation is a sufficiently high current flows through the conductor cable, which covers the range up to about 8 A around 1 kA. Inductive but warning lights must also use the high power losses that occur at high currents and surges, especially in an electrical short circuit, cope.