CA1079346A - High-voltage network for areas with high rate of icing - Google Patents

Abstract

Abstract of the Disclosure The invention relates to a high-voltage network for areas with a high rate of icing. The network includes load current circuits including a generator, a transformer or an autotransformer, aerial power transmission lines and complex loads, at least one transformer or an autotransformer for melt-ing of ice coatings. The secondary winding of the transformer or autotransformer for melting of ice coatings is connected to conductors of one of the aerial power transmission lines. The primary winding of the transformer or autotransformer for melt-ing of ice coatings is, according to the invention, connected in series with the load current circuit.

Description

~7~3~

The pre~ent invention relates to electroenergetics, and more specifically to high-vol-tage net~works for areas with high rates of icing.
Known in the art is a high-voltage network for area~
with high rates o~ icing, the network comprising load current circuits, formed by generators, transformers or autotransformers, which are installed in substationc3, by aerial power transmission lines, complex loads, systems of collecting bars providing for connecting the elements, and at least one transformer or auto-transformer for melting ice coating3 on conductor~ and cables ofpower transmission line~ of the high-voltage network.
The primary winding of the transformer or an auto-transformer for melting of ice coating of the known high-voltage network, for areac~ with high rates of icing, is connected to high-voltage feed bars, the secondary winding of the transformer or autotransformer for melting of ice coating being connected to conductors or cables o-f the aerial power transmission line on which the ice coating should be melted. The process of melting i9 attained owing to heating of conductors or cables with electric current. Often with a view to reducing the installed capacity of the transformer or autotransformer for melting of ice coating in such high-voltage network~, the ~econdary winding of the trans-former or autotransformer is connected to the aerial power : transmiasion line via a high-voltage rectifierO In this case the conductors or cables of the aerial power transmission line are connected to direct current outlets of the high-voltage rectifier, which rectifier9 as a rule, is of an unregulated typ~.
All the known high-volt~ge lines for areas with high rates of icing are characterized by an invariahle or step~variable level of voltage providing for melting of ice coatings on wires of aerial power transmission lines of high-voltage networkO As a rule, the subc~ctations of a high-voltage network are provided ..

: :. . : . . . ~ . . .

~7~3~

with one transformer or autotransformer f-or melting of ice coatings. As for the characteristics of the aerial power transmission lines outcolning from a substation, namely the length of said lines and conductor cross-section dimensions, the characteristics vary. This being the case, the value of current required for melting ice coatings on conductors of aerial power transmission lines is ensured by assembling ~
special circuit for each of the lines. The make-up of the circuit is determined by the need for providing a circuit for melting ice coating~, the circuit being of a certain total resistance, said circuit providing for flow of electric current heating those conductors from which ice coatings must be removed.
The value of the total resistance is determined proceeding from conditions of permissible overloading of the transformer or auto-transformer for melting of ice coatings, and proceeding from permissible overheating of conductors.
The use of special circuits in each ~pecific case requires much time for operational switching~ needed for pre-paring the circuit, and, as a rule, requires much time for warm-up of eonductors them~elve~, the time losses resulting from impossibility of controlling the value of voltage at which melting of ice coatings is earried out, the latter being the main disadvantage of the known in the art high-voltage networks.
Another disadvantage of such high-voltage networks is that emergency operating conditions of the high-voltage ~; networks are accompanied by passage of overcurrents. Hence, while selecting the equipment for the high-voltage network this requirement; must also be taken into account, resulting in complicity of the networkO
It is an object of the invention to provide a high-voltage network for areas with high rates of icing providing for reduclng time required fGr warming-up of the conductors of

2 ;

3~6 aerial power tran~mi~sion lines, whereon the melting o~ ice coating is carried out, and providing for reduciny emergency overcurrents in elements of the lines.
The above and other objects are achieved by a high-voltage network for areas with high rates of icing compri~ing load current circuits including a generator, a transformer or an autotransformer, aerial power transmission lines and complex ..
loads, and at least one trans~ormler or an autotransformer for melting of ice coatings, the secondary winding of said trans-former being connected to conductors of one of the aerial power transmission lines, the primary winding of the transformer or autotrans~ormer for melting of ice coatings is, according to the invention, connected in series with the load current circuit.
It is expedient in a high-voltage network to connect .-the secondary winding of the transformer for melting ice coat-ings with the aerial power transmission line via a rectifier, a resonant circuit ~ormed by an ihductor and a capacitor con-nected in series, being coupled to direct current outlets of said rectifier. ; ~;
It is also expedient in a high-voltage network to connect the secondary winding o~ the autotransformer for melt-ing of ice coatings to tha aerial power transmission line via a rectifier, a resonant circuit formed by an inductor and a capacitor which are connected in series, being connected to direct current outlets of said rectifier.
It is also expedient in a high-volta~e network to : connect the secondary winding of the trans~ormer for melting : of ice coatings to the aerial power transmission line via a rectifier, and to connect a resonant circuit formed by an in-: ductor and a capaci or which are connected in series, in : parallel wlth said secondary winding.

~ 3 7~

It is also expedient in a high-voltage network to connect the secondary wincling of an ,lutotransformer for melt-ing of ice coatings to the aerial power tran~mission line via a rectifier and to connect a resonant circuit formed by an inductor and a capacitor, which are connected in series, in parallel with said secondary winding.
It is also expedient in a high-voltage network to connect the secondary winding of the transformer for melting of ice coatings to the aerial power transmission Line via a rectifier, a resonant circuit formed by an inductor and a capacitor, which are connected in series, being connected in parallel with the primary winding of the tran~former for melt-ing of ice coating.
It is also expedient in a high-voltage network to connect the secondary winding of an autotransformer for melting of ice coatings to the aerial power transmission line via a rectifier, a resonant circuit formed by an inductor and a capaci-tor which are connected in series, being connected in parallel .
with the primary winding of the autotransformer for melting of ice coating.
It is also e~pedient in a high-voltage network to connect the primary winding of a transformer for melting of ice - -coatings in series with the load current circuit between the :.
outlets of the generator and the outlets of the low-voltage winding of a trans~ormer.
.... ....... ..
It is:also expedlent in a high-voltage network to connect the pri~iary winding of a transformer for melting of ice : coatings in seri.es with:the load current circuit between the out-: lets of the generator and the~outlets of the ~ow-voltage winding of an autotransformer. : -.
It is also:expedient in a high-voltage network to con-: nec~ the primary winding of a transformer for melting of ice :
: 4 97~33~
coatings in series with the load current circuit between "earth"
or "ground" and -three neutral outlet~ of the hiyh-voltage wind-ing of a tran~former.
It is also expedient in a high-voltage network to connect the primary winding of an autotransformer ~or rnelting of ice coatings in serieq with th~e load current circuit bekween "earth" or "ground" and three neutral outlets of the high-voltage winding of a tran~former.
It is also expedient in a high-voltage network to connect the primary winding of a transformer for melting of ice coatings in series with the load current circuit between the high-voltage outlet of a transformer or an autotransformer and a pha~e of another aerial power transmission line.
It is al~o expedient in a high-voltage network to connect the primary winding of an autotransformer for melting of ice coatings in serie~ with the load current circuit between the high-voltage outlet of a tran~former or an autotran~former and a phase of another aerial power transmission line.
It is also expedient in a high-voltage network to connect the primary winding of a transformer for meltiny of ice coatings in series with the load current circuit between three neutral outlet~ of complex load and "~arth" or "ground".
It is also expedient in a high-voltage network to con-nect the primary windLng of an autotransformer for melting of ice coatings in series with the load current circuit between three neutral outlets of complex load and "earth" or "ground".

.

It iY also expedient in a high-voltage network to connect the primary winding of a transformer for melting of ice coatings in serie~ with a load current circuit between the com-.
plex load and outlets of the average voltage winding of anautotransformer.
It is also expedient in a high-voltage network to : ' 7~3~

connect the primaxy winding of an autotransformer for melting of ice coatings in series with the load current circuit between a complex load and outlets of the average voltage winding of an autotransformer.
It is also expedient in a high-voltage network, wherein the aerial power transmission line comprises two in-sulated groups of conductor~, said groups of conductors being equipotential as per working voltages thereof and the secondary winding of a single-phase autotransformer for melting of ice coatings is split into two sections, to switch said sections of the secondary winding of an autotransformer for melting of ice coatings and also said two insulated groups of conductors into a circuit, said sections of the secondary winding being switched into said circuit accordantly.
It i~ also expedient in a high-voltage network, wherein the aarial power transmission line comprises an insulated group of conductors, including two conductors, and a conductor, which are equipotential as per working voltages thereof, and the secondary winding of a single~phase autotransformer is split into two sections, to switch said sections of the secondary winding of an autotransformer for melting of ice coatlngs and also said isolated group of conductors and said conductor into a circuit, said sections of the secondary winding being switched into said circuit accordantly.
It is also expedient in a high-voltage network, wherein the aerial power transmission line comprises three insulated conductors in phase, to connect each phase of the secondary winding of a~threie-phase transformer for melting of ice coatings in series with respective ones of the insulated conductors of a phase of the aerial power transmission line.
It is also expedlent in a high-voltage network to connect two three-phase transformers for melting of ice coatings B

3~6 with the opposite ends of the aerial power tran~mission line, said line comprising four insulated conductors in phase, two different pairs of the insulated conductors of which are short-circuited from the opposite ends, the analogous phases o~ the secondary windings of both of the transformers for melting of ice coatings being connected to opposite pairs of the short-circuited insulated conductors, the two remaining phases of the transformers for melting of ice coatings to be connected to the two remaining insulated conductors.
It i8 also expedient in a high-voltage network, where-in the aerial power transmission line comprises two insulated groups of conductors being equipotential as per working voltages thereof, to switch into a circuit in series with the two insulat-ed groups of conductors single-phase converters fed from the secondary winding of a transformer for melting of ice coatings, said single-phase converters being switched into said circuit accordantly.
The invention is further described in exampl~s illustra-ting it~ various embodiments and in the accompanying drawi.ngs, 20 in which:
FIG. 1 shows a high-voltage network for areas with high rate of icing, comprising load current circuit~ and a transformer ~or melting of ice coating, the primary winding : of said transformer being inserted between the neutral outlets of the high-voltage winding of a transformer of the high-voltage network and "earth", according to the invention.
; FIG. 2 shows ~ high-voltage network for areas with high rate of icing, wherein the primary winding of an auto-.
transformer for melting of ice coating is inserted between :~

30 neutral outlets of the high-voltage winding of a transformer .

of the high-voltage network and "earth", according to ~he invention~ ..

FIG. 3 shows a high-voltage network for areas with high rate of icing, wherein the pri~ary winding of a transformer for melting of ice coating is inserted between the neutral out-lets of an autotransformer of the high-voltage nekwork and "earth", according to the invenkion.
FIG. 4 shows a high-volt;age ne-twork for areas with high rate of icing, wherein the primary winding of an auto-transformer for melting of ice coating is inserted between neutral outlets of the average-voltage winding of an autotransformer of the high-voltage network and "earth", according to the invention.
FIG. 5 shows a high-voltage network for areas with high rate of icing, wherein the primary winding of a transformer for melting of ice coating is inserted between an outlet of the high-voltage winding of a transformer and a phase of the aerial power transmission line, according to the invention.
FIG~ 6 shows a high-voltage network for areas with high rate of icing, wherein the primary winding of a transformer for melting of ice coating is inserted between an outlet of the hiyh-voltage winding of an autotransformer and a phase of the aerial power transmission line, according to the invention.
FIG, 7 shows a high-voltage network for areas with high rate of icing, wherein the primary winding of a tran~former for melting of ice coating is inserted between three neutral out-lets of the complex load and "earth", according to the invention, FIG. 8 shows a high-voltage network for areas with high rate of icing, wherein the primary winding of an auto-transformer for melting of ice coating is inserted between three neutral outlets of the complex load and "earth", accor~ing to the inventionO -- ;
FIG. 9 shows a high-voltage network for areas with high rate of icing, wherein the primary winding of a transformer for melting of ice coating is inserted between the complex load ~;

.

and the outlets of the average-voltage winding of an auto-transformer, according to the invention.
FIG. lO shows a high-voltage network for areas with high rate of icing, wherein the primary winding of a transformer for melting of ice coating is inserted between outlets of a generator and those of the low-voltage winding of the transformer, according to the invention.
FIG. ll shows a high-voltage network for areas with high rate of icing, wherein the primary winding of a transformer for mel~ing ice coating is inserted between the outlets of a generator and those of the low-voltaye winding of an auto-transformer, according to the invention.
FIG. 12 show3 a high-voltage network for areas with high rate o~ icing, wherein the primary winding of a transformer for melting of ice coating is switched into a load current circuit between three neutral outlets of an autotransformer and "earth", whereas the secondary winding of the transformer for melting of ice coating i9 connected to the aerial power transmission line via a rectifier, a circuit formed by an inductor and a capacitor connacted in series, being coupled to direct current outlets of said rectifier, according to the invention.
FIG~ 13 shows a high-voltage network for areas with high rate of icing, wherein the primary winding of a transformer for melting of ice coating is switched into a load current circuit between three neutral outle-ts of an autotransformer and "earth", whereas the secondary winding of the transformer for melting of ice coating is connected to the aerial power transmission line via a rectifier, a resonant circuit formed by an inductor and a capacitor connec1ed in s~eries, being coupled in parallel with -~
said secondary winding, according to the invention.
.
FIG. 14 shows a high-voltage network for areas with high rate of icing, wherein the primary winding of a transformer .
,~ ' , 9 - : ~

~7~3~6 for melting of ice coaking is inserted into a :Load current circuit between three neutral outlets of an autotransformer and "earth", whereas the secondary windi.ng of the transformer for melting of ice coating is connected to an aerial power transmission line via a rectifier, a resonant circuit formed by an inductor and a capacitor connected in series, being coupled in parallel with the primary winding of the transformer for melting of ice coating, according to the invention.
FIG. 15 show~ a high-vol.tage network for areas with high rate of icing, wherein the primary winding of an auto-transformer for Melting of ice coating is in~erted into a load current circuit between three neutral outletq of an autotrans former and "earth", whereas the secondary winding of the auto-transformer for melting of ice coating is connected to an aerial power transmission line via a rectifier, a resonant circuit formed by an inductor and a capacitor connected in series, being coupled to the direct current outlets of said rectifier, accord-ing to the invention.
FIG. 16 shows a high-voltage network for areas with high rate of icing, wherein the primary winding of an auto- .
transformer for melting of ice coating is inserted into a load current circuit between three neutral outlets of an auto-transformer and "earth"j whereas the secondary winding of the autotransformer for melting of ice coating is connected to an aerial power transmission line via a rectifier, a resonant cir-cuit formed by an inductor and a capacitor connected in series, :
being coupled in parallel with said secondary winding, acrording to the in~ention.
FIG. 17 shows a high-voltage network for areas with high rate of icing, wherein the primary winding of an auto- .
transformer for melting of ice coating is inserted into a load :.~
current circuit between three neutral outlets of the auto- ::
~, : " 10 :: -.

3~6 transformer and "earth", whereas the secondary winding of the autotransformer for melting of ice coating is connec-ted to an aerial power transmi~sion line via a rect:ifier, a resonant circuit formed by an inductor and a capacitor connected in series being coupled in parallel with the primary winding of the autotransformer for melting of ice coating, according to the invention.
FIG. 18 shows a high-voltage network for areas with high rate of icing, wherein high-voltage transmis~ion shunt-ing reactors are used as a complex load.
FIG. 19 shows a high-voltage networ]c for areas with high rate of icing, wherein conductors of an aerial power trans-mission line are used as a complex load.
FIG. 20 shows a high-voltage network for areas with high rate of icing, wherein a split secondary winding of an autotransformer for melting of ice coating is inserted into a circuit with two in~ulated groups of conductors, accordiny to the invention.
FIG. 21 shows a high-voltage network for areas with high rate of icing, wherein a split secondary winding of an autotransformer for melting of ice coating is inserted into a circuit with an insulated group of conductors and a conductor, according to the invention.
FIG. 22 shows a high-voltage network for areas with high rate of icing, wherein the aerial power transmission line comprises three insulated conductors in phase and each phase of ~-the secondary winding of the transformer for melting of ice coating is connected respectively in series with one of the insulated conductors of a phase of the aerial power transmission line, according to the invention.

FIG. 23 shows a high-voltage network for areas with high rate of icing, wherein transformers for melting of ice - - . . .............................. ..
., , . . . ~ . . . - ~ ..................... -,~ , . . ... . . . . . . .

79~

coating are connected to the aerial power transrnission line from the opposite ends thereof, said line comprising four insulated conductors in phase, according to the invention.
FIG. 24 shows a high-voltage network for areas with high rate of icing, wherein autotransformers for melting of ice coating are connected to the opposite ends of the aerial power transmission line, said line comprising four insulated conductors in phase, according to the invention.
FIG. 25 shows a high-voltage network for areas with high rate of icing, wherein one of the load current circuits of the aerial power transmission line comprises two insulated groups of conductors, said conductors being e~uipotential as per work-ing voltage thereof, single-phase converter fed from the secondary winding of the transformer for melting of ice coating, being accordantly connected with ~he circuit in series with said insulated groups of conductors, according to th~ invention.
Referring now to FIGo 1 a high-voltage network for areas with high rate of icing is in the nature of two load current circuits and includes in series connection a power source, generator 1, a step-up transformer 2, an aerial electric ;
power transmission line 3, a reducing autotransformer 4 and complex loads 5 and 6, fed from average-voltage and low-voltage windings of the autotransformer 4. The primary winding of a three-phase transformer 7 for melting of ice coating is connected in series with the load current circuit between three neutral outlets of the high-voltage winding of the transformer 2 of the high-voltage network and "earth"~ The secondary winding of the transformer 7 for melting of ice coating is connected to an aerial electric power transmission line 8, said line being short-circuited at the opposite end thereof.

A group of single-phase transformers may be used in-stead of the three-phase transformer 7 for melting of ice coating.

. . . .

~t7~

FIG. 2 shows a high-voltage network for areas with high rate of icing identical to that of FIG. 1, wherein instead of the transformer 7 (FIG. 1) for mel-ting of ice coating an autotransformer 9 (FIG. 2) is provided, said autotransformer 9 being inserted in a like manner.
FIG. 3 shows a hiyh-voltage network for areas with high rate of icing similar to that: of FIG. 1, wherein an auto-transformer 10 (FIG. 3) is used instead of the transformer 2 (FIG. 1)~
FIG. 4 shows a high-voltage network for areas with high rate of icing similar to that of FIG. 1, wherein auto-transformers 9 (FIG. 4) and 10 are used in place of the trans-former 7 (FIG. 1) for melting of ice coating and the transformer 2.
In the high-voltage network for areas ~ith high rate of icing the primary winding of the transformer 7 (FIG. 5) for melting of ice coating is inserted in series into the load current circuit between the high-voltage bushing of the trans-former 2 and the phase of the electric power transmission line 3.
The primary winding of the transformer 7 (FIG. 6) for melting of ice coating is similarly inserted in series with the load current circuit between the high-voltage bushing of the autotransformer 10 and the phase of the aerial electric power transmission line 3~ . ' In the high-voltage network for areas with high rate vf icing the primary winding of the autotransformer for melting of ice coating is connected similar to the above description in series with the load current circuit between the high-~oltage bushing of the transformer and the phase of the aerial electric power transmission line or in serie~ with the load current cir- ~ :
cuit,between the high-voltage bushing of the autotransformer and .~.d - 13 3~

the phase of the aerlal electric powe:r transml~3ion line~
FIG. 7 show-~ a high-voltage network for areas with high rate of icing similar to that of FIG. 1, wherein the primary winding of the transformer 7 for melting of ice coat-ing is connected in series with the load current circuit between three neutral outlets of the complex load 5 and "earth"~
In the high-voltage network of FIG. 8, the primary winding of the autotransformers 9 for melting of ice coating is connected in series with the load current circuit between three neutral outlets of the complex load 5 and "earth".
FIG. 9 shows a high-voltage network for areas with high rate of icin~ similar to that of FIG. 1, wherein the primary winding of the transform~r 7 for melting of ice coat- :
ing is connected in series with the load current circuit between the outlets of the average-voltage winding of the au~o~rans- : :
former 4 and the complex load 5. -The primary winding of the autotransformer for melt- .
ing Oc ice coating is also connected similarly in series with :
the load current circuit between the outlets of the average-- ~
voltage winding of the autotransformer and the complex load. ~:
: FIG. lO shows a high-voltage network for areas with :
high rate of icing similar to that of FIG. l, wherein the primary winding of the transformer 7 for melting of ice coat-ing is connected in series with the load current circuit between : the outlets of the generator l and those of the low-voltage winding of the 1ransformer 2.
The primary winding of the transformer 7 (FIG. ll~
: for melting of :ice coating is connected similarly in series with the load current circuit between the outlets of the : generator l and the outlets of the low-voltage winding of the autotransformer lO.
~ ~:
, ~ .
jV.. ~ 14 -~7~3~6 FIG~ 12 ~hows an embodiment of a high-voltage networ for areas with high-rate of icing, intended for melting of ice coating by the use of direct current on conductors of an aerial electric power transmission line 8, its conductors being removed from service. This being the case, a high-voltage rectifier 11, drawing current from the secondary wind-ing of the transformer 7 for melting of ice coating is con-nected via disconnectors 12 to bars 13, from which the aerial power transmission line 8, which is connected to the bars 13 via the disconnectors 14, takes its current. At the opposite end the aerial line 8 is connected via disconnectors 15 to a grounding circuit. The primary winding of the transformer 7 for melting of ice coating is connected with a load current circuit between three neutral outputs of the average-voltage winding of the reducing autotrans~ormer 4 of the high-voltage network and "earth". The autotransformer 4 is connected to feed bars 16 ~ia a switch 17. Feed bars 20 and 21 are con-nected to the average-voltage and to the low-voltage windings of the autotransformers 4 via switches 18 and 19 resp~ctively.
A shunting switch 22 is connected in parallel to the primary winding of the transformer 7 for melting of ice coat-ing. Additionally there is provided an arc short-circuiter 23, three electrodes of which are connected to the alternating current inlet3 of the recti~ier 11 (not shown in the FIG.)~
and two electrode~ of which are connected to direct current ~;
outlets 24 of said rectifier 11, a higher harmonic filter being connected to said outlets, said filter being embodied as a resonant circuit wbich includes a condenser 25 and an 1nductor 26 connected in ~3eries.
.
30 ~ FIG. 13 shows a high-voltage network for areas with high rate of icing similar to that of FIG. 12. This network ;is peculiar in that the circuit which includes the series .,_ ; .. - . . , ., ,. . , . . - . .. . . . . . .
- - : .: : . : - : . -: . : :, ., . , . . ~ ' :, ~ .
. ,: , . .

3~

connected condenser 25 and the inductor 26, is connected in parallel with the secondary winding of the transformer 7 for melting of ice coating.
FIG. 14 shows a high-voltage network for areas with high rate of icing similar to that of FIG. 12. A distinguish-ing characteristic of the network is in that the resonant circuit which includes the series connected condenser 25 and the inductor 26, is connected in parallel with the primary winding of the transformer 7 for melting of ice coating.
FIGS. 15 9 16 and 17 show high-voltage networks for areas with high rate of icing analogous to those of FIGS. 12, 13 and 14 respectively. The main distinguishing feature thereof is the use oE the autotransformer 9 as the trans-former for melting of ice coating.
FIG. 18 shows an embodiment of a high-voltage network for areas with high rate of icing, wherein shunting reactor3 27 of the high-voltage power transmission line are used as complex load, said reactors being connected with the generator 1 via a switch 28. The primary winding of the transformer 7 for meltin~ o~ ice coating is connected in series with the load current circuit between the shunting reactor 27 and "earth" or "ground". The shunting switch 22 is mounted in parallel with the primary winding of the transformer 7 ~or melting of ice coating. The high-voltage rectifier 11 is connected to the ~ secondary winding of the transformer 7 for melting of ice coat-; ings~ The higher harmonic filter is connected to the direct current outlets of the rectifier 11, said filter including the inductor 26 and the condenser 25 connected in series. The ~ rectifier 11 is connected to bars, said connection being con-ventionally marked by arrows in the drawing, which bars f2ed ; power to the aerial power transmission line short_circuited at the opposite end in the manner of the embodiment of FIG. 12.
~ B 16 -FIG. 19 shows an embodiment of a high-voltage network for areas with high rate of icing similar to that of FIG. 18.
The main distinguishing feature is the use of conductors of a short-circuited aerial power trans~ission line 29 a~ a complex load. The secondary winding of the transformer 7 for melting of ice coating is connected to conductors of aerial power trans-mis~ion line short-circuited at the opposite end, which connect-ion is conventionally marked in the drawing with an arrow.
FIG. 20 shows a high-voltage network for areas with high rate of icing, wherein the aerial power transm~ssion line, from the conductors of which an ice coating must be removed, comprises two insulated groups of conductors 30, whlch are equipotential as per working voltages thereof, borne in rnind -are circular and double-circuit aerial powar transmission lines, as well as a split phase aerial power transmission line. The network may include several such aerial power trans-mission lines. The insulated groups 30 of conductors are connected via a switch 31 with disconnectors 32 to bars 33 of a power supply substation. The secondary winding of a single- ~ -phase autotransformer 34 for melting of an ice coating i~ split into two sections 35, which together with the two insulated groups 30 of conductors are switched into a circuit, said sections 35 of the secondary winding of the autotransformers 34 for melting of ice coating being switched into said circuit accordantly.
The sections 35 are connected to the insulated groups 30 of conductors via disconnectors 36, whereas the primary wind-ing of the single-phase transformer 34 for melting of ice coat-ing i5 switched :Lnto the load current circuit in series between an outlet of the high-voltage winding of the autotransformer 4 and insulated groups 30 of conductors. The primary winding of the autotransformer 34 for melting of ice coating is connected :

- 17 - ~

.. . . ... . . . .. .

~6~'7~

to bars 37 of the ~ubstation via disconnector~ 38 and 39, a switch 40 and one more disconnector 39. The autotransformer 34 for melting of ice coating, together with the disconnectors 36 and 38 is shunted by mean~ of switches 41c The drawing~ show also the generator l connected to the bars 33.
FIG. 21 shows a high-voltage network for areas with high rate of icing ~imilar to that of FIG. 20. It is peculiar in that it is provided with only one insulated group of con-ductors comprising three conductors 42, said group 30 ofconductors and a conductor being equipotential as per working voltage thereof.
In a high-voltage network for areas with high rate of icing of FIG. 22 each phase 43 of the aerial power trans-mission line connected to bars 44 of a power supply substation comprises three insulated conductors 45. A network may com-prise several of such aerial power transmission lines. A
primary winding 46 of a three-phase three-winding transformer for melting of ice coating is switched in series into a load current circuit between three neutral outputs of the average~
voltage winding of the autotransformer 4 and "earth", saia autotransformer being connected to bars 47.
Each phase of the secondary winding 48 o~ a three-phase three-winding transformer for melting of ice coating is connected in sexies respectively to one of the three insulated conductors 45 or the phase 43 of the aerial power transmission line and to the bars 47. A tertiary winding 49 of the trans-former for melting of ice coating is delta-connected. A shunt- ;
ing switch 22 is connected in parallel with the primary winding 46 of the trans~ormer for melting of the ice coating. Each phase of the secondary winding 48 of the transformer for melt-ing of the ice coating is shunted with a switch 50. The draw-~.

n;~,~i 1 ~3 ~93~

ing also shows the generator 1 connecte~ to the bar~ 44.
FIG. 23 show~ a high-voltage network for areas with high rate of icing comprising an aerial power transmission line including four insulated conductors 51 in phase 52. The aerial power transmission line is connected to b~r~ 53 of the power supply substation via a switch 54 provided with dis-connectors 55 and to bars 56 of the receiving substation via a switch 57 with disconnectors 58. One of the autotransformers

4 of the high-voltage transmission line is connected to bars 53 via a switch 59 with disconnectors 60. Another autotransformer 4 is connected to bars 56 via a switch 61 with disconnectors 62.
The power supply and the receiving substations are provided with two three-phase transformers 7 for melting of an ice coating, which transformers are switched into the aerial power trans mission line from the opposite ends thereof. The primary wind-ings of the transformers 7 for melting of an ice coating are switched in series into the load current circuits betw~en three neutral bushings of the autotransformers 4 and "earth" or "ground". The unlike pairs of insulated conductors 51 in phase 52 are coupled from the opposite ends of the aerial power transmission line. These pairs are connected with like phases of the secondary windings of the transformers 7 for melting of the ice coating. The remaining two phases of each of the trans-formers 7 for melting of the ice coating are connected to the remaining non-conn~cted insulated conductors 51. Disconnectors 63 connect the insulated conductors 51 of ~he aerial line with ~ ~ bars 64, which bars are connected with the secondary windings ; of the transformers 7 for melting of the ice coating. At the receiving and the transmitting ends of the aerial power trans-mission line the!re are provided disconnectors 65 and 66, res-pectively. Shunting switches 22 with disconnectors 67 are mou~ted in parallel with the primary windings of the trans-,~ - 19 -.

' . . . . . ~ . . ! . ' . ' . , . '. . '.' ', . ~ ' '. ' ' ' ' . .' , ' ' ' .

7~3~;

formers 7 for melting of the ice coating.
The drawing also show~ the generators 1 connected ko the bars 53 and 56.
FIG. 24 shows a high-voltage network for areas with high rate of icing similar to that: of FIG. 23. The distinguish-ing feature of the network is in that the autotrans~ormers 9 are used in the network as transfc)rmers for melting of an ice coating.
FIG. 25 shows a high-voltage network for areas with high rate of icing similar to that of FIG. 20, the aerial power transmission line including two equipotential insulated groups 30 of conductors as per the working voltages thereof. Single-phase converters 68 are connected accordantly in ser.ies with each of the insulated groups 30 of conductors of the aerial power transmission line, which converters 68 are fed from a split secondary winding 69 of a transformer 70 for melting of ice coating. The converters 68 are built around a rectifier 71 arranged in a single-phase bridge circuit. A higher harmonic filter and two of the three electrode~ o~ a discharger 72 are .:
between the insulated groups 30 of the conductors of the aerial power transmission line, said filter being a resonant circuit which includes a condenser 25 and an inductor 26 connected in series. The third electrode of the discharger 72 is connected to a common point 73 of connection of the unlike poles of the converterq 68, w,hich point is connected also with the primary winding 74 of thle transformer 70 for melting of ice coatings, the winding being connected to the bars 37 via the circuit bre`aker 40 with the disconnectors 39. The single~phase con- ;
verters 689 the transformer 70 for melting of ice coatings, and also the higher harmonic filter and the discharger 72 are shunted with the switch 41.

The process of melting of ice coatings on conductors .
~ _ 20 -~'7~3~

of aerial power transmi~ion lines of the high-voltage network for areas with high rates of icing, shown in FIG. 1, i3 as follows: The aerial power transml~sion line 8 on which the ice coating is to be melted, is connected directly to the secondary winding of the tran~former 7 for melting of the ice coating and is short-circuited at the opposite end thereof.
The current passing through the conductors of the aerial power transmission line 8 heats said conductors resulting in melting of the ice coating on the conductors and in removal of the ice therefrom.
Cwing to the fact that the capacity transmitted through the load current circuit exceeds the power con~umed for melting the ice coating on the conductors of the aerial power transmission line 8 by one order of magnitude, the change of voltage in the load current circuit may be ignored. Now the operating conditions of the transformer 7 for melting of ice coatings are close to those of the current source. The maximum value of the voltage at which the ice coatings on the conductors of the aerial power transmission line 8 melt and, consequently, the maximum length of the warmed-up aerial power transmission line 8, are limited by saturation of the magnetic circuit of the tran~former 7 for melting of ice coatings.
It is important that short-circuits in the warmed-up aerial power tr~nsmission line do not result in overcurrents, but in reduction of voltage applied to the primary winding of the transformer 7 for melting of ice coatings. This feature ;~
makes it possible to place less stringent requirements upon equipment of the high-voltage network.
The above-described features are al~o applicable to the embodiments of the high-voltage networks of FIGSD 2-11.
To ret~uce the power consumed while melting ice coatings, it is advisable to connect the secondary winding ~ -, ~ . ~ . . . .

~) ;,93~

of the transformer 7 ~FIG. 12) for melting of ice coatings to the aerial power transmission line 8 vi.a the rectifier llo In this case melting the ice coati.ng is effecte~ on dis-connected conductors of the aerial power transmission line 8.
The described procedure of melting of i.ce coatings on the conductors of the aerial power transmission line 8 with rectified current incorporates distinguishing featuresl the nature of which is in that an alternating current flowing from the side of the inlets of the rectifier 11 is of a strictly preset form. Unless special measures are provided, such feature results in pulsation in the rectified current of the converter 11, practically irrespective of parameters of the circuit in which the current for melting of ice coating is flowing, said feature, in its turn, resulting in overvoltage across elements of the converter 11.
With a view to eliminating dangerous overvoltages across elements of the converter 11, there is provided a higher harmonic filter embodied as a resonant circuit compris-ing a condenser 25 and an inductor 26 connected in ~eries.
With the aim of limiting ovexcharges occurring atemergency conditions of operation down to permissible values, there is provided an arc short-circuiter 23 The transformer 7 forlthe melting of ice coatings is brought into operation and removed from operation by the use of a shunting switch 22. As the ice coating is being melted, the shunting switch 22 is disconnected, while disconnectors 12, 14, 15 and a switch 17 are switched on.
The currents of the common part of the windings of the autotransformer 4 prior to start of the process of melting were bridged through t~e shunting switch 22. A~ter the switch 22 i9 iD off po~ition, the load current of the common part of ..

~75~3~i the wi.ndinys of the autotransformer 4 is bridged throuy~ the primary winding of -the transformer 7 Eor melting the ice coat-ing. The presence of load current in the primary winding o~
the transformer 7 for melting of i.ce coatings causes generation of currents in the secondary windi.ng, the difference in value between the secondary and the primary currents being equal to the ratio of transformation of the! transformer 7 for melting of ice coatings. The secondary currents, being rectified by the use of the converter 11, are closed in a circuit formed by the rectifier 11, by the conductors of the aerial power transm:ission line 8 and "earth" or "ground". "Earth" can be additionally employed to obtain the return of direct current. The process of melting in the embodiments o~ a high-voltage network shown ..
in FIGS. 13 - 17 is similar to that described above.
FIG. 18 shows an embodiment of a high-voltage network for areas with high rates of icing, wherein a shunting reactor 27 or high voltage transmission line is used as a complex load~
The` bringing of the transformer 7 ~or melking of ice coatings into operation and removal of the transformer from operation are provided by the usa of the shunting switch 22, simiIarly to above described case. :~.
FIG. 19 shows an embodiment of a high-voltage network for areas with high rates of icing similar to the above described network wherein conductors of the short-circuited aerial power transmission line 29 are used as a complex load.
While melting the ice coating without disconnecting the aerial power transmission line 9 for example, by the use of the analogous phases of double-circuit, circular aerial power .. ..
transmission lines or by insulating 5eparate conductors o~ a split phase, like in the given case, it is advisable to connect the primary wind:in~ of an autotransformer 34 (FIG. 20) for melting of ice coatings in series with the insulated groups 30 of the conductors of the aerial power transmi~ion line and with the outlets of the high-voltage winding of the au-to-tran~former 4. The connection of the secondary windings 35 of the autotransformer 34 for melting of ice coatings to the insulated groups 30 of conductors is provided by the use of the disconnectors 36. The insulated groups 30 of conductor~
are connected to the bars 33 of a power supply substation via the switch 31 with the disconnectors 32 and to the bars 37 of a receiving substation via the switch 40 with the disconnectors 39. The autotransformer 34 for melting of ice coating~ is brought into action by cutting off or shunting the switches 41. The switching of the primary winding of the autotransformer 34 for melting of ice coatings into the load current circuit is provided by the use of the disconnector 38.
For simplicity, with aerial power transmission lines having three conductors 42 (FIG. 21) in phase, it is advisable to insulate only one of the three conductors 42 of the aerial power transmission line. This being the case, the current may be increased in modulus threefold simultaneou41y in all the three conductors 42. me current-distribution between the conductors 42 and the windings of the autotransformer 34 for melting of ice coating is shown in FIG. 21 by arrows "J" -current.
With the aim of balancing out the assymetry under operating conditions of melting of ice coatings when three insulated conductors 45 (FIG. 22) of the phase 43 are avail-able, as well as to increase the current for melting of ice coatings more than threefold as compared to that of rated operating conditions, the three-phase secondary winding 48 of a three-phase, three-winding transormer for melting of ice coatings i5 connected in series with three insulated conductors 45 of the phase 43 of the aerial power transmission line, and 3~
the neutral outlet of the winding 48 is connected ~ith the bushing of the autotransformer 4. The transformer for melting of ice coatings is brought into operation by cutting off the shunting switches 22 and 50. The tertiary winding 49 of the transformer for melting of ice coatings, delta-connected, serves to bridge currents of third harmonic.
With four insulated conductors 51 (FIG. 23, 24) in the phase 52 of the aerial power transmission line, an equal current can be developed in each of them. However, it should be pointed out that equality of currents in all the four con-ductors 51 of the aerial power transmission line is achieved at the expense of certain assymetry of the power supply. Prior to the beginning of the process of melting of ice coatings the switches 54 and 57 with the disconnectors 55 and 58 are closed~
The neutral wires of the autotransformers 4 are earthed or grounded by the use of switches 22 with the disconnectors 63.
The disconnectors 67 are cut off. The disconnectors 65 and 66 are switched in prior to the beginning of the process of melt-ing of ice coatings. The switches 59 and 61 with the dis-connectors 60 and 62 are closed. While melting the iCQ coatings,the switches 54 and 57 are switched off and the circuits thereof taken apart. After that, the disconnectors 65 and 66 at the receiving and transmitting ends of the aerial power tran3mission line are cut off~ The disconnectors 63 are switched on. m e switches 54 and 57 being switched off, there are two equivalent load current circuit~ existing in the receiving and the trans-mitting system~. me load current circuits of the transmittin~
and recelving sy~3tems are formed by the generators 1, the bars 53 and 56, the switches 59 and 61, the autotransformers 4 and the load. The currents of the common portion of the windings of the autotransformers 4 prior to the start of process of melting of ice coatings were bridged through the shunting . .

: . .:~ . . .. - : . . .

3~

switche~ 22. AEter the shunting switches 22 are switched of~
both from the receiving sub~tation and from the transmitting ~ubstation, the load current of the common portion of the winding of the autotransformer 4 will be bridged through the primary winding of the tr~nsformer 7 for melting of ice coat-ings. The current sets up magnetizing ampere-turns, which causes their associated magnetic flux in the magnetic circuit of the transformer 7 for melting of ice coatings. Under the effect of electromotive force of the secondary winding~ an electric current starts flowing through the insulated conduct-ors 51 of the phase 52 of the aerial power transmission line.
To reduce the power consumed for melting of ice coatings, the single-phase converters 68 (FIG~ 25) are used even in case the aerial power transmission lines are in operation. With the aim of eliminating diversion of current through dead earthed or grounded neutral wires and in ~eries with each of the insulated groups 30 of conductors of the aerial power transmission line 9 there are accordantly connected the single-phase converters 68, which are fed from the second-ary winding 69 of the transformer 70 for melting of ice coat-ings. Prior to the start of melting of ice coatings the switches 41 are closed. The switches 31 and 40 with the dis-connectors 32 and 39 are also closed.
For melting ice coating the shunting switches 41 are switched open resulting in setting up load current in the primary winding 74 of the transfGrmer 70 for melting of ice coatings. The load current generated in the primary ~inding 74 causes setting up currents in the split secondary winding 69, its currents being different from those in ~he primary winding by the coefficient of transformation of the transformer 70 for melting of ice coatings~
The secondary currents, being rectified by the con-~.~7~3~
verters 68, are closed in a circuit formed by tha converter 68 and the insulated groups 30 of conductors. Since load current is generated in concluctors of the insulated groups 30 besides melting current, the form of elec-tric current in the secondary winding 69 of the transformer 70 for melting of ice coating is dlstorted, resulting in setting up of constant component point in each section of the split secondary winding 69~ The avail-ability in different sections of the secondary winding 69 of constant components, which are equal in modulus but opposite in sign results in practically full compensation of the magnetizing ampere-turns and, in consequence, results in absence of constant component in the magnetic flux of the magnetic circuit of the transformer 70 for melting of ice coatings. The whole alternat-ing component of the rectified current is bridged through the higher harmonic filter. With the aim of bringing overvoltages occurring under emergency operating conditions down to permis-sible values, there is provided the arc short-circuiter 72.
Each of the converters 68 is protected therewith by one of the electrode couples of the three-electrode arc short-circuiter 72.
The present invention provides for reducing the time required for warming up conductors of aerial power transmission lines, on which melting of ice coatings is carried out and for reducing emergency overcurrents in elements of a high-voltage network for areas with high rates of icing.

.
,.

Claims (36)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, a first transformer, aerial power transmission lines and complex loads, a second transformer for melting of ice coatings with its prim-ary winding being connected in series with a load current cir-cuit and the secondary winding of said second transformer being connected to conductors of one of said aerial power transmission lines.

2. A high-voltage network as claimed in claim 1, wherein said secondary winding of said second transformer for melting of ice coatings is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant circuit comprising an inductor and a condenser connected in series being coupled to direct current outlets of said rectifier.

3. A high-voltage network as claimed in claim 1, wherein said secondary winding of said second transformer for melting of ice coatings is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant circuit comprising an inductor and a condenser connected in series being coupled in parallel with said secondary winding.

4. A high-voltage network as claimed in claim 1, wherein said secondary winding of said second transformer for melting of ice coatings is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant circuit comprising an inductor and a condenser connected in series being coupled in parallel to said primary winding of said second trans-former for melting of ice coatings.

5. A high-voltage network for areas with high rates of icing, comprising: load current circuits including a generator, an autotransformer, aerial power transmission lines and com-plex loads a transformer for melting of ice coatings the primary winding of which is connected in series with a load current cir-cuit, whereas the secondary winding of said transformer is con-nected to conductors of one of said aerial power transmission lines.

6. A high-voltage network as claimed in claim 5, wherein said secondary winding of said transformer for melting of ice coatings is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant circuit comprising an inductor and a condenser connected in series being coupled to direct current outlets of said rectifier.

7. A high-voltage network as claimed in claim 5, wherein said secondary winding of said transformer for melting of ice coatings is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant circuit comprising an inductor and a condenser connected in series being coupled in parallel with said secondary winding.

8. A high-voltage network as claimed in claim 5, wherein said secondary winding of said transformer for melting of ice coatings is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant circuit comprising an inductor and a condenser connected in series being coupled in parallel to said primary winding of said transformer for melting of ice coating

9. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, a transformer, aerial power transmission lines and complex loads, an autotransformer for melting of ice coatings with its primary winding being connected in series with a load current circuit, whereas the secondary winding of said autotransformer is conn-ected to conductors of one of said aerial power transmission lines.

10. A high-voltage network as claimed in claim 9, wherein said secondary winding of said autotransformer for melting of ice coatings is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant circuit comprising an inductor and a condenser connected in series being coupled to direct current outlets of said rectifier.

11. A high-voltage network as claimed in claim 9, wherein said secondary winding of said autotransformer for melting of ice coatings is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant circuit comprising an inductor and a condenser connected in series being connected in parallel with said secondary winding.

12. A high-voltage network as claimed in claim 9, wherein said secondary winding of said autotransformer for melting of ice coating is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant circuit comprising an inductor and a condenser connected in series being coupled in parallel with said primary winding of said auto-transformer for melting of ice coatings.

13. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, a first autotransformer, aerial power transmission lines and complex loads, a second autotransformer for melting of ice coat-ings with its primary winding being connected in series with a load current circuit, whereas the secondary winding is connected to conductors of one of said aerial power transmission lines.

14. A high-voltage network as claimed in claim 13, wherein said secondary winding of said second autotransformer for melt-ing of ice coatings is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant cir-cuit comprising a series connected inductor and a condenser being coupled to direct current outlets of said rectifier.

15. A high-voltage network as claimed in claim 13, wherein said secondary winding of said second autotransformer for melt-ing of ice coatings is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant cir-cuit comprising an inductor and a condenser connected in series being coupled in parallel with said secondary winding.

16. A high-voltage network as claimed in claim 13, wherein said secondary winding of said autotransformer for melting of ice coatings is connected to conductors of one of said aerial power transmission lines via a rectifier, a resonant circuit comprising an inductor and a condenser connected in series, being coupled in parallel with said primary winding of said second autotransformer for melting of ice coatings.

17. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, a first transformer, aerial power transmission lines and complex loads; a second transformer for melting of ice coatings with its primary winding being connected in series with a load current circuit between outlets of said generator and those of a low-voltage winding of said first transformer, whereas the secondary winding of said second transformer for melting of ice coatings is connected to conductors of one of said aerial power transmission lines.

18. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, an autotransformer, aerial power transmission lines and complex loads; a transformer for melting of ice coatings with its prim-ary winding being connected in series with a load current cir-cuit between outlets of said generator and those of a low-voltage winding of said autotransformer, whereas the secondary winding of said transformer is connected to conductors of one of said aerial power transmission lines.

19. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, a first transformer, aerial power transmission lines and complex loads; a second transformer for melting of ice coatings with its primary winding being connected in series with a load current circuit between "earth" and three neutral outlets of a high-voltage winding of said first transformer, whereas the secondary winding of said second transformer for melting of ice coatings is connected to conductors of one of said aerial power trans-mission lines.

20. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, an autotransformer, aerial power transmission lines and complex loads; a transformer for melting of ice coatings with its prim-ary winding being connected in series with a load current cir-cuit between "earth" and three neutral outlets of a high-vol-tage winding of said autotransformer, whereas the secondary winding of said transformer is connected to conductors of one of said aerial power transmission lines.

21. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, a transformer, aerial power transmission lines and complex loads;
an autotransformer for melting of ice coatings with its primary winding being connected in series with a load current circuit between "earth" and three neutral outlets of a high-voltage winding of said transformer, whereas the secondary winding of of said autotransformer is connected to conductors of one of said power transmission lines.

22. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, a first autotransformer, aerial power transmission lines and complex loads; a second autotransformer for melting of ice coat-ings with its primary winding being connected in series with a load current circuit between "earth" and three neutral outlets of a high-voltage winding of said first autotransformer, whereas the secondary winding of said second autotransformer is connected to conductors of one of said aerial power transmission lines.

23. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, a first transformer, aerial power transmission lines and complex loads; a second transformer for melting of ice coatings with its primary winding being connected in series with a load current circuit between a high-voltage bushing of said first transformer and the phase of an aerial power transmission line, whereas the secondary winding of said second transformer is connected to conductors of another aerial power transmission lines.

24. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, an autotransformer, aerial power transmission lines and complex loads; a transformer for melting of ice coatings with its primary winding being connected in series with a load current circuit between a high-voltage bushing of said autotransformer and the phase of one aerial power transmission line, whereas the secon-dary winding thereof is connected to conductors of another of said power transmission lines.

25. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, a transformer, aerial power transmission lines and complex loads; an autotransformer for melting of ice coatings with its primary winding being connected in series with a load current circuit between a high-voltage bushing of said transformer and the phase of an aerial power transmission line, whereas the sec-ondary winding of said autotransformer is connected to conductors of another of said aerial power transmission lines.

26. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, a first autotransformer, aerial power transmission lines and complex loads; a second autotransformer for melting of ice coat-ings with its primary winding being connected in series with a load current circuit between a high-voltage bushing of said first autotransformer and the phase of an aerial power transmission line, whereas the secondary winding of said second autotransformer is connected to another of said aerial power transmission lines.

27. A high-voltage network for areas with high rates of icing comprising: load current circuits including aerial power transmission lines and complex loads; a transformer for melt-ing of ice coatings with its primary winding being connected in series with a load current circuit between three neutral outlets of a complex load and "earth", whereas the secondary winding of said transformer is connected to conductors of one of said aerial power transmission lines.

28. A high-voltage network for areas with high rates of icing comprising: load current circuits including aerial power transmission lines and complex loads; an autotransformer for melting of ice coatings with its primary winding being connected in series with a load current circuit between three neutral outlets of a complex load and "earth", whereas the secondary winding of said autotransformer is connected to conductors of one of said aerial power transmission lines.

29. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, an autotransformer, aerial power transmission lines and complex loads; a transformer for melting of ice coatings with its prim-ary winding being connected in series with a load current circuit between a complex load and outlets of an average-voltage wind-ing of said autotransformer, whereas the secondary winding of said transformer is connected to one of said aerial power trans-mission lines.

30. A high-voltage network for areas with high rates of icing comprising: load current circuits including a generator, a first autotransformer, aerial power transmission lines and complex loads; a second autotransformer for melting of ice coat-ings with its primary winding being connected in series with a load current circuit between a complex load and outlets of an average-voltage winding of said first autotransformer, whereas the secondary winding of said second autotransformer is conn-ected to conductors of one of said aerial power transmission lines.

31. A high-voltage network for areas with high rates of icing comprising: load current circuits including aerial power transmission lines, at least one of said lines comprising two insulated groups of conductors, which are equipotential in work-ing voltage thereof, and a single-phase autotransformer for melting of ice coatings with its primary winding being connec-ted in series with a load current circuit, whereas the second-ary winding of said autotransformer is split into two sections, which sections together with said two insulated groups of con-ductors are switched into a circuit, said sections of said second-ary winding being switched into said circuit accordantly.

32. A high-voltage network for areas with rates of icing comprising: load current circuits including aerial power trans-mission lines, at least one of said lines having an insulated group of conductors comprising two conductors, and a conductor, which are equipotential in working voltage thereof, a single-phase autotransformer for melting of ice coatings with its primary winding being connected in series with a load current circuit, whereas the secondary winding thereof; is split into two sections, which sections together with said insulated group of conductors and said conductor are switched into a circuit, said sections of the secondary winding being switched into said circuit accordantly.

33. A high-voltage network for areas with high rates of icing comprising: load current circuits including aerial power transmission lines, at least one of said lines comprising three insulated conductors in phase, and a three-phase transformer for melting of ice coatings with its primary winding being connected in series with a load current circuit, whereas each phase of the secondary winding of said transformer is connected in series respectively with one of said insulated conductors of the phase of an aerial power transmission line.

34. A high-voltage network for areas with high rates of icing comprising: load current circuits including aerial power transmission lines, at least one of said lines comprising four insulated conductors in phase, two unlike pairs of insulated conductors of the line being short-circuited from the opposite ends thereof, and two three-phase transformers for melting of ice coatings with the primary windings of said transformers being connected in series with said load current circuits, whereas the secondary windings of said transformers are connec-ted to said aerial power transmission lines from the opposite ends thereof, line phases of the secondary windings of both said transformers for melting of ice coatings being connected there-with to unlike said pairs of the short-circuited insulated con-ductors, whereas two remaining phases of said transformers for melting of ice coatings are connected to two remaining insulated conductors.

35. A high-voltage network for areas with high rates of icing comprising: load current circuits including aerial power transmission lines, at least one of which comprises four insulated conductors in phase, two unlike pairs of said insulated conductors being short-circuited from the opposite ends thereof, and two three-phase autotransformers for melting of ice coatings with the primary windings of said autotransformers being connected in series with said load current circuits, whereas the secondary windings of said autotransformers are connected to said aerial power transmission lines, the connection being made from the opposite ends of the line, the like phases of said secondary windings of both said autotransformer for melting of ice coatings being connected to unlike said pairs of the short-circuited in-sulated conductors, whereas two remaining phases of said auto-transformers for melting of ice coatings are connected to two remaining said insulated conductors.

36. A high-voltage network for areas with high rates of icing comprising: load current circuits including aerial power transmission lines, at least one of which comprises two in-sulated groups of conductors, which are equipotential in working voltage; a transformer for melting of ice coatings with its primary winding being connected in series with a load current circuit; single-phase converters fed from the secondary wind ing of said transformer for melting of ice coatings and which converters together with said two insulated groups of conductors are connected in series into a circuit, said single-phase con verters being connected into said circuit accordantly.