Name / Hunger Yuri / Session / Operation-control-protection
Company / ELSI GROUP / Block / Operation-Special operational conditions
Address / Sibirjakov-Gwardeitsev, 50 / Question n°
Novosibirsk, Russia, 630024 / Language used on the floor / English
Phone / +7-3832-534-662, 276-977 / Accompanying visuals on file ? / Yes
e-mail /
PREVENTIVE WARM-UP OF PHASE AND GROUND WIRES OF OVERHEAD POWER LINES BY LOADED DEVICES IN THE PERIOD OF GLAZE DANGER
Icingemergenciesare considered to be very dangerous for successful functioning of overhead lines. They may either destroy or damage a large number of supports, thus causing the complete failure of power supply on large territories.
On the screen you can see the impacts of a very strong ice storm to Odessa power system. As you can see many overhead lines were damaged.
The methodof the three-phasing short circuit,which is widely used in Russiaforoverhead lines de-icing,is very oftennot efficient. The preventive warm-up of phase and ground wires proves to be more effective. Icing prevention currents for aluminium/steel and steel wires are shown on the screen.
Icing of wires can be prevented by using additional load that must be switchedon in the chosen points of network. Here are the implementationvariantsof additional load. Such measures should be taken when weather conditions are the most contributingto icing.
Now I would like to illustrate the icing preventive measures with an example shown on the screen. This diagram demonstrates load current being used by consumers in 24 ours period (marooncolour) and additional load that increases current up to the non-icing level (bluecolour). Here are showndifferent ways of implementing additional load: to switchon some resistors to6-10 kV voltage ( that can be high voltage resistors,ground wires of overhead lines of 110-220 kV or powerful ground electrodes), to switchon the heating orlightingdevisesto 0,4 kVvoltage, to switchon overhead line of 6-10 kV into short circuit. The main advantage of this method is that it allows to protectnot a single line, buta whole group of overhead lines with various voltage.
On the screen there are two variants of additional load devises for different voltage.
As you see this method leads to increased power losses. However, they can be minimised due to the followingreasons shown on the screen.The minimisation is possible because,astherule,we have enough information about the time and location of icing.
Analysis of current levels in some Russian Power Companies showed that the preventive warm-up of phase and ground wires can be effectively used at overhead lines of 6 – 110 kV voltage and partly at lines of 220 kV.
Nowon the screen you can see the conclusions.
Thank you very match for your attention !
I would be happy to answer any of your questions !