Can VRC be used on high voltage power transmission lines?
Yes. VRC can be used on lines with voltage from 3kV to 1.250MV. Line voltage does affect performance or method. Control electronics deals with the voltage drop ALONG one deicing section, not with the voltage of the line. For instance, the line voltage (potential difference between different phases) can be 500kV, but the VRC switches will deal with 1kV voltage only.
This one of the great advantages of this VRC. This principle is detailed in this paper.
What is the cost of installing such device on a per mile basis?
VRC switches cost between $200 and $3600 per kilometer of line. VRC switches cost about $1.00 US Dollar per 1 kW of switched power. Assuming 200kW/km of heating power to quickly deice the stand, the cost of power electronics per 1km per strand is (200kW/km x $1/kW) = $200/km. A standard 500kV transmission line has 6 strands per phase and 3 phases (18 strands). ($200/km x 18) = $3600/km. Replacement (not required) composite (metal/dielectric) strands adds about $400/km.
By comparison, the conventional short-circuit deicing (SCD) cost over $100,000 per kilometer.
Does VRC add much weight?
Insignificant. VRC conductors weight the same or less than conventional power-line conductors. VRC switches range from 5-15kg depending on line current.
Where in the world has this device been installed and operational?
VRC technology was successfully tested on power transmission lines by Orenbourg Energo in the Ural Mountains of Russia. Video
Are there any installations in America or Canada and can we see it?
We are discussing installations with Hydro-Quebec, Canada/US.
When the variable-resistance conductors are connected as a series, would most of the heating energy (two-third of it in a 3 strands system) be dissipated on the variable conductors themselves rather than on the transmission line?
Stranded bundles are treated (heated) as a single phase. See Chinese language video separated stranded bundles.
Suppose this device is installed on one terminal, and you need a wire to connect this device to the other terminal, are there any limitation on how far can these two terminals be separated? If this device is operated on series-mode, it seems that a lot of heating energy be dissipated on that wire too. Is it correct?
I don't understand the question. What do you mean under the term of "terminal?" One section of power line to be deiced? In English, a terminal usually means a point (or port) of connection. For instance, a DC power supply has two terminals, "+" and "-". When VRC is activated the heating power in a range of 50W/m to 200W/m is evenly applied to every meter of the stands' length. The heating and losses at the points of strands' connections are minimal.
Please explain the installation process in more details.
That is completely depends on a particular line construction. But here is an example given for a line having 3 strands per phase:
Those line modifications are very well illustrated in the VRC Power-Point presentations (Chinese/English) See slides: 14 and 15.
a. Strand separators made of metal should be replaced with composite (metal/dielectric) separators (slide 14, FIG 3).
b. Termination dielectrics are replaced with modified ones (slide 14, figures 1 or 2).
c. Control boxes are installed at the ends of deicing sections (every 10km, for instance, slide 15).
On a three-phase line, do you need three power de-icing devices one for each phase?
We don't need "power devices". The heating power is taken from a line itself. We just need a small switch control box at each end of a deicing section. For instance,
a deicing section of 10km in length will need 3 (phase) x 2 (ends) = 6 control boxes of the type shown in figure 15 of the presentation.
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Can VRC be used on high voltage power transmission lines?
Yes. VRC can be used on lines with voltage from 3kV to 1.250MV. Line voltage does affect performance or method. Control electronics deals with the voltage drop ALONG one deicing section, not with the voltage of the line. For instance, the line voltage (potential difference between different phases) can be 500kV, but the VRC switches will deal with 1kV voltage only.
This one of the great advantages of this VRC. This principle is detailed in this paper.
What is the cost of installing such device on a per mile basis?
VRC switches cost between $200 and $3600 per kilometer of line. VRC switches cost about $1.00 US Dollar per 1 kW of switched power. Assuming 200kW/km of heating power to quickly deice the stand, the cost of power electronics per 1km per strand is (200kW/km x $1/kW) = $200/km. A standard 500kV transmission line has 6 strands per phase and 3 phases (18 strands). ($200/km x 18) = $3600/km. Replacement (not required) composite (metal/dielectric) strands adds about $400/km.
By comparison, the conventional short-circuit deicing (SCD) cost over $100,000 per kilometer.
Does VRC add much weight?
Insignificant. VRC conductors weight the same or less than conventional power-line conductors. VRC switches range from 5-15kg depending on line current.
Where in the world has this device been installed and operational?
VRC technology was successfully tested on power transmission lines by Orenbourg Energo in the Ural Mountains of Russia. Video
Are there any installations in America or Canada and can we see it?
We are discussing installations with Hydro-Quebec, Canada/US.
When the variable-resistance conductors are connected as a series, would most of the heating energy (two-third of it in a 3 strands system) be dissipated on the variable conductors themselves rather than on the transmission line?
Stranded bundles are treated (heated) as a single phase. See Chinese language video separated stranded bundles.
Suppose this device is installed on one terminal, and you need a wire to connect this device to the other terminal, are there any limitation on how far can these two terminals be separated? If this device is operated on series-mode, it seems that a lot of heating energy be dissipated on that wire too. Is it correct?
I don't understand the question. What do you mean under the term of "terminal?" One section of power line to be deiced? In English, a terminal usually means a point (or port) of connection. For instance, a DC power supply has two terminals, "+" and "-". When VRC is activated the heating power in a range of 50W/m to 200W/m is evenly applied to every meter of the stands' length. The heating and losses at the points of strands' connections are minimal.
Please explain the installation process in more details.
That is completely depends on a particular line construction. But here is an example given for a line having 3 strands per phase:
Those line modifications are very well illustrated in the VRC Power-Point presentations (Chinese/English) See slides: 14 and 15.
a. Strand separators made of metal should be replaced with composite (metal/dielectric) separators (slide 14, FIG 3).
b. Termination dielectrics are replaced with modified ones (slide 14, figures 1 or 2).
c. Control boxes are installed at the ends of deicing sections (every 10km, for instance, slide 15).
On a three-phase line, do you need three power de-icing devices one for each phase?
We don't need "power devices". The heating power is taken from a line itself. We just need a small switch control box at each end of a deicing section. For instance,
a deicing section of 10km in length will need 3 (phase) x 2 (ends) = 6 control boxes of the type shown in figure 15 of the presentation.
Are you absolutely sure you want to delete this article? This process cannot be undone and is permanent.
Yes, Delete This Article
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Yes, Remove This Article
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