WO2009123781A1 - System and method for deicing of power line cables - Google Patents
System and method for deicing of power line cables Download PDFInfo
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- WO2009123781A1 WO2009123781A1 PCT/US2009/031826 US2009031826W WO2009123781A1 WO 2009123781 A1 WO2009123781 A1 WO 2009123781A1 US 2009031826 W US2009031826 W US 2009031826W WO 2009123781 A1 WO2009123781 A1 WO 2009123781A1
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
- H02G7/00—Overhead installations of electric lines or cables
- H02G7/16—Devices for removing snow or ice from lines or cables
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60M—POWER SUPPLY LINES, AND DEVICES ALONG RAILS, FOR ELECTRICALLY- PROPELLED VEHICLES
- B60M1/00—Power supply lines for contact with collector on vehicle
- B60M1/12—Trolley lines; Accessories therefor
Definitions
- the present document relates to the field of overhead power transmission lines.
- it relates to systems and methods for preventing or removing excessive ice accumulation on cables of such power transmission lines to prevent damage due to weight of the excessive ice.
- Ice storms are fairly common in some parts of the United States. These storms result in an accumulation of ice on structures, including overhead power transmission lines and associated poles and towers; this ice may reach thicknesses of several inches. Such ice storms inevitably represent only a small percentage of the total operating time of a power transmission line, and any one power transmission line typically encounters such conditions only a few times per year.
- Some power transmission lines are trolley wires used to transmit power to electric vehicles. Since ice is not a good conductor, ice on trolley wires can interfere with power transmission to the vehicles.
- Power transmission lines are normally designed to have a constant, low, overall resistance, so as to avoid excessive power losses and operation of wires at high temperatures.
- wire reaches high temperatures, whether due to electrical self- heating, high ambient temperatures, or both, it tends to lengthen and weaken. This lengthening can cause the lines to sag between poles or towers, possibly causing hazard to persons or property on the surface.
- low resistance during normal operation is desirable to avoid excessive power losses - every kilowatt lost to heating of lines is a kilowatt that must be generated but does not reach a customer.
- excessive voltage drops in the transmission line due to high resistance may cause instability of the power grid system.
- 2003/0006652 and 2008/0061632 describe a system having load cells or other apparatus for detecting accumulated ice on a transmission line.
- this system when ice is detected one or more parallel conductors of a phase of a transmission line are disconnected by opening parallel mechanical and electronic switches, such that current flowing in the transmission line is diverted through and deices a selected one or a few of the parallel conductors. A pattern of open switches is then rearranged to divert current through a different one or a few of the parallel conductors.
- Other systems for deicing power transmission lines are known in the art.
- US Patent 4190137 to Shimada couples parallel lines of a trolley system into a loop, then superimposes a current around the loop upon power ordinarily transmitted through the loop to deice the lines.
- Shimada discloses DC trolley lines, with a superimposed AC current around a loop of the trolley lines for inducing joule heating to deice the lines.
- Power transmission lines do not carry the same amount of current at all times.
- Current transmitted over a line varies with a wide variety of factors including load conditions - which in turn vary with time of day and weather, a particular selection of power plants operating at a moment in time, and other factors.
- a power transmission line carrying power from a wind and solar farm into the power grid will carry current that may vary greatly with cloud, time of day, and wind conditions.
- Even conventional power plants, such as those having multiple units may provide transmission line current that will change with time, for example one unit of a two unit plant may be shut down for repairs,
- power transmission lines connecting energy storage systems, including pumped storage plants and battery storage plants to the power grid may conduct current intermittently.
- a system for deicing of power transmission lines having cables (one for each phase of a 3-phase line, or one for each polarity of a DC line) having at least three mutually insulated conductors.
- the system has switches that when closed place all three conductors in parallel for normal, low resistance, operation; and when opened place all three conductors electrically in series to deice the cable.
- the system operates under control of a system controller.
- a transmission line is a line providing electric power to an electric vehicle, such as a locomotive, a tramcar, or a trolley bus.
- an electric vehicle such as a locomotive, a tramcar, or a trolley bus.
- One of several conductors is in direct electric contact with a sliding mechanical linkage such as a pantograph or trolley wire.
- a conductor in contact with a pantograph is made of material having higher electrical resistivity but higher mechanical strength than the material of two other wires.
- a conductor for contacting pantographs can be made of steel, stainless steel, bronze, brass, or copper-clad or aluminum-clad steel while two parallel conductors are made of aluminum, aluminum alloy, or copper.
- an apparatus for monitoring temperature of the cables, and for returning the conductors to parallel should overheating of a cable be detected.
- a switchbox for switching conductors of a transmission line cable between a parallel configuration and a series configuration has an energy storage device with charger, a control signal receiver for receiving commands and at least one switch controlled by the control signal receiver for determining current flow through at least one conductor of the cable, and apparatus for overriding the control signal receiver and placing the cable conductors in a parallel configuration if a high temperature is detected on a conductor of the cable.
- the cable need not have multiple conductors, but has an electrically resistive strength core - such as steel wire — and at least one conductor, this system has a switchbox for diverting sufficient current from the conductor through the resistive strength core to deice the cable in a first operating mode, and wherein substantially all current passes through the conductor in a second operating mode.
- the switchbox diverts current through the strength core by placing or increasing an inductance in series with the conductor; the strength core is in parallel with the combined series inductance and conductor and takes an increased current because of the inductive reactance of the inductance.
- the switchbox has a transformer and a switch, the transformer bypassed in normal operation and operating as a step up transformer to divert power into the strength core during a deicing mode.
- the switchbox incorporates devices for monitoring a temperature of the cable and for reducing current in the strength core towards normal operating levels should high temperatures be encountered.
- a method is disclosed for deicing cables of a transmission line in which the cable has a section with several conductors between a first switchbox and a second switchbox. The section of cable has a normal operating mode where the conductors are electrically connected in parallel.
- the switchboxes are reconfigured to couple some of the conductors electrically in series thereby placing the section of cable in a high resistance deicing mode. Current flowing in the section of cable resistively heats and deices the section of cable. After deicing, the switches of the switchboxes are reconfigured to return the section of cable to the normal operating mode.
- a controller selects between several deicing configurations of the switches according to the current in the cable. Further, if current is too low for deicing, the controller may request an increase of current in the cable.
- FIG. 1 is a schematic diagram of a system for preventing or removing ice accumulation from a power transmission line.
- FIG. 2 illustrates an embodiment for preventing or removing ice accumulation from a trolley wire used to transmit power in a transportation system.
- FIG. 3 illustrates an alternative embodiment of a cable for use with the system of FIG. 2.
- FIG. 4 is an electrical schematic of one section of one cable of an alternative embodiment of the system for preventing ice accumulation having five conductors per cable.
- FIG. 5 is an electrical schematic of an alternative method of operating one section of cable of an alternative embodiment of the system for preventing ice accumulation having five conductors per cable.
- FIG. 6 is an electrical schematic of an alternative method of operating one section of cable of an alternative embodiment of the system for preventing ice accumulation having five conductors per cable.
- FIG. 7 is an electrical schematic of one section of one cable of an alternative embodiment of the system for preventing ice accumulation having six conductors per cable.
- FIG. 8 is an electrical schematic of one section of one cable of an alternative embodiment having seven conductors per cable.
- FIG. 9 is a cross sectional diagram of a cable having seven conductors and a steel strength member in thermal contact with each other.
- FIG. 10 is a block diagram of a solar-battery-powered switchbox for use in the system.
- FIG. 11 is a block diagram of an alternative switchbox for use in the system.
- FIG. 12 illustrates a system having multiple cable sections each capable of independent or sequential deicing or anti-icing operation.
- FIG. 13 illustrates a cross-section of a first cable for use with the system of FIG. 1.
- FIG. 14 illustrates a cross-section of a second cable for use with the system of FIG. 4.
- FIG. 15 illustrates a cross-section of a third cable for use with the system of FIG. 1.
- FIG. 16 illustrates an alternative embodiment having series connected switches.
- FIG. 17 illustrates a deicing system for power lines as proposed in PCT/US2004/27408.
- FIG. 18 illustrates a cross section of a cable having a steel strength core electrically insulated from an outer conductive layer.
- FIG. 19 illustrates a two-conductor, single-switch-per-section deicing system.
- FIG. 20 is a schematic diagram of an inductive switchbox suitable for use with the deicing system of FIG. 19.
- FIG. 21 is a schematic diagram illustrating an alternative core for use with the inductive switchbox of FIG. 20.
- FIG. 22 is a schematic diagram of an alternative single-switchbox- per-section deicing system having a step-up transformer to reduce voltage loss in the cable.
- FIG. 23 is a schematic diagram of an alternative embodiment having some features of FIGs. 1 and 15.
- FIG. 1 A system for electrically removing accumulated, or preventing accumulation of, ice on a power transmission line 100 is illustrated in FIG. 1. For simplicity, only one of the three cables 102 or phases of a typical three-phase AC line is shown.
- a cable 102 is constructed from three parallel conductors 104, 106, 108. The three conductors 104, 106, 108 are bundled together by insulating spacers 110 along cable 102.
- Cable 102 is suspended by insulators 112 from towers 114, or in an alternative embodiment from poles (not shown). At ends of a section of cable 102, a first switch box 116 and second switch box 118 are suspended from insulator 112 along with cable 102. Each switch box 116, 118 contains a switch 120 and a switch actuator-controller 122.
- the switch boxes 116, 118 are either in a first, switch-closed, state; or in a second switch-opened state. During normal operation, the switch boxes remain in the switch-closed state with all parallel conductors 104, 106, 108 of cable 102 connected electrically in parallel.
- switches 120 of boxes 116, 118 are placed in the switch-opened state.
- the switches 120 of switch boxes 116, 118 operate under control of a system controller 124.
- system controller 124 is located at a network operations center.
- system controller 124 is an automatic device capable of sensing local weather conditions including ice accumulation and attached to a tower 114 near a section of cable 102 subject to ice accumulation and having switchboxes 116, 118 under its control. In this way, switches of both switchboxes 116 and 118 can be opened or closed essentially simultaneously even if switchboxes 116 and 118 are located one or more miles apart.
- FIG. 1 is also applicable to a cable or a polarity of a DC transmission line or trolley power line, as illustrated in FIG. 2.
- FIG. 2 there are three parallel conductors 150, 152, 154 coupled into a serpentine configuration between two switchboxes 156, 158.
- One of the three conductors, the contact conductor 154, is arranged so that it is accessible to contact with pantographs 160 or other trolley- wire contacting apparatus of an electrically powered vehicle 162.
- Vehicle 162 may be an electric locomotive, or a streetcar unit as illustrated, with return path for vehicle current through a rail 164.
- two sets of parallel conductors 154 and switchboxes 156, 158 are provided with dual trolley- wire contacting apparatus 160, one for each phase or polarity of a DC or AC trolley- wire system, such that vehicle 162 connects to both phases or polarities.
- vehicle 162 may be a rubber- tired vehicle such as the electrically powered busses that have operated in San Francisco for many years.
- switches 168, 166 may be opened to enter deicing mode, and closed for normal operating mode. Opening of these switches 168, 166, causes current flowing through the conductors 154, 152, 150, such as current being drawn by vehicles 162 in later sections of the system, to pass through all three conductors 154, 152, 150 in sequence rather than in parallel, increasing current density and heating the conductors.
- the contact conductor 154 may, but need not, be fabricated from material different from that of the other or non-contact conductors 152, 150.
- the contact conductor may be a high-strength moderate-resistance bronze, brass, copper-clad steel, stainless steel, or aluminum-clad steel, with parallel conductors 150, 152 made of low resistance copper or aluminum.
- This embodiment has an advantage in that the high strength contact conductor may be better able to resist mechanical stresses due to contact with the pantograph or trolley- wire contacting apparatus 160. Further, while it can be advisable to deice the non- contact conductors 152, 150 to avoid weight and wind related damage, ice on the contact conductor 154 may interfere with power transfer from the contact conductor 154 to the pantograph or other trolley wire contacting apparatus 160.
- Higher resistance of the contact conductor 154 may help to ensure prompt and rapid deicing of the contact conductor 154 to ensure continued operation of the vehicle 162 during icing conditions.
- opening of switches 166, 168 for a brief time can deice contact conductor 154 to ensure continued operation, while opening of switches 166, 168 repeatedly or for a longer time can deice the non- contact conductors 152, 150 when ice accumulation threatens weight or wind related damage.
- non- contact conductors 150, 152 are separately strung from the contact conductor 154, or are nearby conductors 150, 152, 154 separated by spacers; in an alternative embodiment, as illustrated in FIG. 3, a contact conductor 154 may form a shell containing insulating material and non-contact conductors 150, 152.
- This system 100 differs from that of Couture in that direction of current in one conductor 104 of the cable 102 is reversed, and in that Couture deices only one or a few conductors at a time, while the system 100 deices all three of the conductors of a segment simultaneously - in the case of spaced- conductor cables Couture requires several sequential deicing operations to clear all conductors of a cable.
- the system 100 also differs from that of Couture in number and position of the switches. Couture places one set of switches at one point between two ends of a section, while in system 100 the switches are placed at both section ends. Couture's system for a three-conductor line would have 3 switches, while system 100 has only 2 switches.
- the alternative embodiment of the system 200 for removing or preventing ice accumulation of FIG. 4 has five instead of three conductors per cable 202.
- each switch box 204, 210 has two ganged switches 206, 207, 209 and actuator-controller 208.
- opening of switches 206, 207, 209 has the consequence of increasing the effective resistance of cable 202 by a factor of twenty- five; thereby increasing self-heating of cable 102 to melt accumulated ice and retard accumulation of additional ice.
- two conductors of the five carry current in a reverse direction while three conductors carry current in a forward direction.
- the effective length of total conductor in a segment of cable 102 is increased by a factor of five. Phase shift introduced by this increase of length will not cause significant effect on power flow in the transmission line when operated in a power grid when segments of a few miles in length are deiced since the wavelength of sixty-cycle powerline AC current is approximately three thousand miles and this will not cause significant phase shift. Further, because the length (and conductor resistance) may be increased simultaneously in all three phase-lines by operating switches in all three phases simultaneously, there should not be a significant phase shift added by deicing operations between the different-phase conductors of the transmission line.
- switches 206, 209 are opened to enter a deicing mode, while switch 207 is left closed.
- effective resistance of the cable segment is increased by a factor of five.
- switches 206, 207 are opened while switch 209 is left closed.
- the effective resistance of the cable segment is increased from one- fifth R to three R, an increase of resistance by a factor of fifteen.
- Embodiments having cables with six or more conductors may have even numbers of conductors.
- resistance of the cable segment is increased from one-sixth R to three-halves R, an increase by a factor of nine when the switches 206, 222 open.
- Other configurations of the system are possible, having other power increases in deice mode; for example if switch 222 is left closed while switches 206 open, resistance increases from one-sixth R to three- fourths R, an increase of four and a half.
- an alternative embodiment 250 may have seven conductors in each cable and three or four (as illustrated in FIG. 8) switches 252, 254, 256, 258, 260, 262, 264, 266 in each switchbox 268, 270.
- effective resistance of the cable is programmable according to which switches are open, as illustrated in FIG. 1, ranging up to forty-nine times the resistance of the cable with all switches closed.
- switches 266 and 252 are replaced by wire with minimal reduction in the resistance options provided.
- a system controller monitors current through the transmission line and determines a resistance required for deicing, selecting a deicing mode from minimum resistance, maximum resistance, and intermediate resistance modes as appropriate for the current in the transmission line.
- the system controller may also transmit a request to an energy storage system, generation system, or network operations center that current in the transmission line be increased to provide enough current for deicing.
- a transmission line system has phase cables 267 having multiple segments each of which corresponds to the schematic diagram of FIG. 8.
- the cables 267 have seven conductors 253, 255, 257, 259, 261, 263, 265, made of aluminum or copper, that are bound in thermal and mechanical contact to each other and to a central steel strength member 280, according to the cable cross section of FIG. 9.
- the seven conductors correspond to the seven conductors of FIG. 8.
- the phase cables are suspended from towers and equipped with a system controller 124 in manner resembling that of FIG. 1.
- controller 124 monitors current through the transmission line cables.
- the controller 124 determines a resistance increase that will provide adequate heating of the cable 267 to deice the cable, while avoiding damage to cable 267.
- the controller then automatically determines a configuration of open switches for switches 252, 254, 256, 258, 260, 262, 264, 266 of switchboxes 268, 270, and transmits that configuration to switchboxes 268, 270 to cause the system to enter deicing mode for a particular cable 267 segment.
- the switches are closed to return to normal operation.
- controller 124 may transmit a request to a grid management system to reconfigure the power grid such that enough power is carried through cable 267 to deice the cable 267. In the case of transmission lines connecting energy storage systems to the power grid, this may require that the storage system either store or release sufficient energy to deice the line.
- Resistance self-heating of a transmission line is proportional to current I through the transmission line squared, times the resistance R of the line (I *R).
- the resistance increases of Table 1 are calculated based upon an assumption that each conductor of the cable has equal resistance. Since there may be times when current in a transmission line is quite low, there may be transmission line systems in which it is desirable to have conductors of differing resistance such that a maximum resistance increase can be significantly higher than would be accomplished with conductors of equal resistance. For example, in a variant embodiment of the embodiment of FIG. 8, wires 263 and 265 have resistance ten times the resistance of the other, or low resistance, conductors 253, 255, 257, 259, 261.
- conductor 263 has resistance ten times that of each low resistance conductor 253, 255, 257, 259, 261
- conductor 265 has resistance thirty times that of each low resistance conductor 253, 255, 257, 259, 261.
- an intermediate increase to seventy R is available, and a maximal increase to two hundred twenty five times R is available.
- the controller 124 selects a switch configuration appropriate to provide adequate heating for deicing based upon the amount of current available in the line. This configuration is then transmitted to switchboxes 268, 270 which set their switches accordingly.
- Controller 124 may be a separate controller or may be integrated into a switchbox 268, 270.
- the transmission line segment 267 carries power from a solar or wind generation system having an energy storage subsystem.
- controller 124 may transmit a request to the energy storage subsystem requesting that some stored energy be released over the transmission line to provide current for deicing the line.
- Alternative embodiments may have additional wires, for illustration say N wires, each mutually insulated from each other in the cable.
- Each conductor of embodiments resembling that of FIG. 8 may be assembled from one or more of the N wires.
- M is less than or equal to N.
- the number of wires in each conductor may differ between conductors, conductors having greater resistance may have fewer wires than those conductors having lower resistance.
- While local power-distribution transmission lines often operate between 3,500 and 25,000 volts, many "high-tension" three-phase transmission lines operate at voltages between 60,000 and 1,200,000 volts. While embodiments having conventional construction may be suitable for use with some local distribution transmission lines, operation on high-tension transmission lines poses additional challenges.
- switchbox 204, 116, 118 is attached at the cable 202, 102 end of insulators 112 and is suspended with the cable.
- switchbox 204, 116, 118, 300 is powered by an internal energy store 302 such as an ultracapacitor or battery.
- energy store 302 is charged through charger
- control signal receiver 312 receives a correctly encoded
- switch actuator 314 may incorporate a solenoid, electromagnet, or an electric motor, and may incorporate additional springs for rapid opening and closing as known in the art of electrically-operated switching devices.
- switch 316 is an electronic switch; yet another embodiment has electronic switches in parallel with electrically-operated mechanical switches.
- actuator 314 operates to oppose the force of a spring 318 that tends to hold switch 316 closed.
- actuator 314 pulls switch 316 open by acting not against a case of switchbox 300, but through a fusible link 320 to a clamp 322 that is attached to one conductor, such as conductor 104, of cable 102 a short distance from switchbox 300.
- Fusible link 320 is adjacent to conductor 104, and is made of a low-melting metal or plastic such that it will break before conductor 104 reaches a temperature at which excessive sag or damage to cable 102 occurs and allow spring 118 to close switch 1 16. Therefore, should the system for ice removal or ice prevention fail, switches 116 fail into the closed (low resistance) condition.
- control signal receiver 312 normally switches cable 102, 202 between low and high resistance conditions by activating electrically actuated contactor modules 340.
- Contactor modules 340 may incorporate electromechanical switching devices or, since the maximum voltage seen across the switch is far less than the operating voltage of the transmission line, solid state relay devices, or both.
- electromechanical switching devices provide low switching resistance for transmission line currents that may be on the order of several hundred amperes and reduce self-heating of the solid state relay devices, while the solid state relay devices may suppress any contact arcing associated with opening and closing the electromechanical devices by being closed before the electromechanical devices close, and opened after the electromechanical devices open.
- contactor modules 340 are connected in parallel with safety switches 342 that are closed by spring 344 whenever fusible link 320 melts due to excessive heating in the conductor 346 to which clamp 322 is fastened. This effectively overrides both the control signal receiver 312 and switches 340 when conductor 346 reaches high temperatures. This will prevent excessive dip in, or overheat damage to, cable 102, 202 in the event of failed switchboxes, but poses some risk of ice damage to cable 102, 202 at a later time - especially if left unrepaired.
- a temperature sensor 324 (FIGs. 10 and 11) may be attached to clamp 322, temperature readings being transmitted by temperature transmitter 326 to system control 124 to indicate when, for example, deicing of a section is expected to be complete because temperature of a conductor 104 of cable 102 has significantly exceeding the freezing point of water.
- each cable 400 of the transmission line which may be hundreds of miles long and traverse a variety of terrain and climate zones, is divided into sections, such as section 402 and section 404, of from one tenth to ten miles length, for example.
- Each section has a first switchbox 406, 410, 414 and a second switchbox 408, 412, 416.
- the switchboxes 406, 408 of the first section 402 are activated to open the switches.
- switchboxes 410, 412 of the second section are activated to open the switchboxes, and so on in sequence until all iced-over sections of the cable 400 are deiced.
- division of cable 400 into sections permits deicing of those sections of the cable 400 that have been or are exposed to icing conditions, while allowing sections exposed to different weather to continue normal operation.
- Limiting voltage drop by sequentially deicing sections of the line helps maintain stability of the power grid and avoids voltage drops in the transmission line that may be noticed by customers.
- FIG. 13 illustrates a cross section of a cable suitable for use with a single-switch-per-switchbox, three-conductor cable of the present cable deicing system.
- a triangular spacer 502 which may be nonconductive plastic, ceramic, or metal with rubber insulators, is attached to each conductor 504 of the cable. Attachment of spacer 502 to the conductor 504 may be by molding, gluing a cap over cable and base part of the insulator, with screws securing a cap to an insulator base, or such other methods as known in the art of spaced-conductor cables.
- Each conductor 504 may be a conductive copper or aluminum shell, over an optional steel supporting center 506, or may be assembled from conductive copper or aluminum strands wrapped around a supporting center of multiple steel strands.
- Spacers 502 are positioned at regular distances along the cable, spacer spacing is chosen to be small enough to prevent direct electric contact between the conductors of the cable.
- each of the five conductors is of essentially equal ampacity.
- One, in the embodiment illustrated conductor 606, or all five conductors 602, 606 may have a steel core 608 to provide the strength needed for long spans between towers. Since all five conductors 602 carry current during deicing, all five will be deiced even if these conductors are not in thermal contact with each other.
- the 202 has three (illustrated), five, seven, or nine conductors 702, 704, 706 assembled around a strength core 708 which may be stranded steel.
- the conductors 702, 704, 706, which may be stranded copper or aluminum, are insulated from each other and coated with an extruded plastic insulation layer 710. [0091] With reference to FIGs. 13, 14, and 15, it is anticipated that the conductors 504, 602, 606, 702, 704, 706 and steel supporting cores 506, 608, 708 need not be solid; in most embodiments these are of stranded construction for flexibility and ease of installation as known in the art of transmission line cabling.
- the conductors and steel cores may be merged - these may be stranded conductors having multiple individual strands of conductor-coated steel, such as stranded Copperweld ⁇ (copper clad steel) wire.
- embodiments may have larger numbers of smaller insulated wires that are grouped into the conductors herein referenced; for example a transmission line cable may have six wires grouped into three groups of two wires each for purposes of deicing according to the present invention, and where each pair of wires are treated as a conductor for deicing as heretofore described.
- control signal transmitted from a system controller 124 to switchboxes 300. It is considered desirable that the control signals be transmitted in encrypted form, and encoded, to prevent accidental opening of switches of the switchboxes or sabotage of the system by unauthorized persons.
- an alternative switch configuration provides similar effect.
- a cable 802 has an odd number of conductors 810, 812, 814, 816, 818 greater than three running between two switchboxes 804, 805.
- switches 806 and 807 connected in series, connect conductors 812, 814, 816, and 818 in parallel to conductor 810 and the input 820 and to the output switchbox 805, where corresponding switches are closed.
- switchbox control and actuators 808 open switches 806 and 807, current is forced to flow through all five conductors 810, 812, 814, 816, 818 in series thereby causing resistive self-heating of these conductors.
- This configuration has effect of reducing the voltage seen across any one switch, at the expense of increasing current in the first switches (e.g. switch 806) in the series sequence.
- Deicing systems for transmission lines have been proposed where each of typically three phases is conducted over a cable 900, and that cable is divided into two conductors 904, 906, as illustrated in FIG. 17 and as disclosed in PCT/US2004/27408.
- a switch 908 at an end of a section 910 of the cable transitions between normal operation with the two conductors 904, 906 in parallel, and deicing operation with current flow in only one 906 of the two conductors 904, 906; the one conductor 906 used during deicing sized such that resistance of the cable is high enough to produce sufficient self-heating to deice the cable and prevent further ice accumulation, while the conductor 904 that is placed in parallel during normal operation is sized to provide suitably low resistance for low losses during normal operation.
- first conductor 904 is an outer layer of the cable physically close to the ice to be removed, while normal second conductor 906 is the central bulk of the cable, and may include any core of the cable.
- High-tension transmission line cables including modified cable 1000 (FIG. 18), generally have many strands 1002 of a conductor such as aluminum or copper surrounding a strength core having strands 1004 of a stronger but more resistive material such as steel, the steel serves to help support the cable allowing greater tower or pole spacing than otherwise possible.
- modified cable 1000 there is an added layer of insulation 1006 that prevents electrical contact between strength core strands 1004 and conductive strands 1002.
- a modified deicing system 1100 for power transmission cables as illustrated in FIG.
- Cable 1102 having a steel core 1104, an insulation layer 1106, and a conductive layer 1108, the insulation layer 1106 preventing contact between steel core 1104 and conductive layer 1108; each or steel core 1104 and conductive layer 1108 are typically formed of multiple strands. Additional layers, such as an outer insulation and weather protection layer, may exist. Cable 1102 is separated into sections 1110, at one end of a section 1110 is a switchbox 1114, at the other end is a short circuit connection 1116 between steel core 1104 and conductive layer 1108.
- switchbox 1114 maintains an electrical connection between conductive layer 1108 of each section of the cable 1102. In this normal mode, a majority of current through cable 102 pass through conductive layer 1108. To deice a section 1110 of cable 1102, a controller 1118 of the switchbox 1114 associated with that section 1110 of cable 1102 opens a switch 1120, thereby reducing or eliminating current in conductive layer 1108 and, since the cable is part of a transmission line that is continuing to conduct power, correspondingly increasing current in steel core 1104 of that section 1 110.
- the conductive layer has several conductors 702, 704, 706, as illustrated in FIG. 15, coupled with switchboxes similar to those of FIG. 1 or FIG. 4.
- the strength core 708 is electrically connected between switchboxes 1401, 1403 at each end of a segment of cable. When the switches 1402, 1404 open, effective resistance of the conductive layer 702, 704, 706 increases relative to that of the cable with closed switches, diverting more but not all current through the steel strength core 1104, 708.
- switchbox 1114 contains an inductor 1122.
- switch 1120 opens, the inductor is placed electrically in series with the low resistance outer conductive layer 1 108 of cable section 1110, this series connection of inductor 1122 and conductive layer 1108 is electrically in parallel with inner steel core 1 104 of that section; in consequence some but not all current in cable 1102 is diverted through steel core 1104; the amount of this current being substantially greater than that through steel core 1104 during normal operation with switch 1120 closed.
- Switchbox 1114 has powering arrangements and high-temperature override apparatus as previously described with reference to FIG. 10 and FIG. 11.
- switchbox 1200 suitable for use in place of switchbox 1114 has no switch 1120.
- switchbox 1200 has a power input connection 1202 connected to both the outer conductive layer 1108 and inner steel core 1104 of a preceding cable section, and to a power output connection 1204 for connection to the inner steel core 1104 of the cable section 1110; in some embodiments this connection may incorporate a locally bared steel core 1104 of the cable.
- FIG. 20 also has a coil 1206 having a few turns of high- ampacity wire, coil 1206 connected between power input connection 1202 and a second power output connection 1208 for connection to the outer conductive layer 1108 of the cable section 1110.
- Switchbox 1200 has an energy store 1212 with charging arrangements as previously discussed with reference to FIGs. 10 and 11, and a control signal receiver 1214.
- control signal receiver 1214 receives a command to deice the cable section 1 1 10
- receiver 1214 activates a motor actuator 1216 that pulls on a nonmagnetic cable 1218.
- Nonmagnetic cable 1218 runs over pulley 1220 to a magnetic core element 1222, activation of motor actuator 1216 draws core element 1222 into coil 1206.
- inductance of coil 1206 is increased thereby diverting a portion of current in cable 1102 through resistive inner steel core 1104
- Pulley 1220 is attached to a case of switchbox 1200 through a release catch 1224, and a spring 1226 having sufficient strength to overcome solenoid attraction of core element 1222 into coil 1206 is connected to draw core element 1222 from coil 1206.
- control signal receiver 1214 receives a command to discontinue deicing of cable section 1 110
- control signal 1214 commands motor actuator 1216 to unwind nonmagnetic cable 1218. This permits spring 1226 to draw core element 1222 from coil 1206 and return cable section 1110 to normal operation.
- a fusible link such as previously discussed with respect to fusible link 320 of FIG.
- safety actuator rod 1230 is drawn into switchbox 1200 by a spring 1232.
- Actuator rod 1230 being drawn into switchbox 1200 triggers release catch 1224 to release pulley 1220, which allows spring 1226 to draw core element 1222 from coil 1206 and return cable section 1110 to low-impedance operation; this effectively reduces current in strength core 1104 and reduces self-heating of the cable 1102.
- the switchbox incorporates circuitry such as the sensor 324 and temperature/status transmitter 326 of FIG. 11 such that system controller 124 (FIG.
- control signal receiver 1214 can monitor sensor 324 and attempts to return switchbox 1200 to normal operation by extracting core 1222 at a temperature lower than that required to melt fusible link 320.
- a two-piece core is used as illustrated in FIG. 21. In this embodiment, a first L-shaped core portion 1240 is fixed to the switchbox.
- a second L-shaped core portion 1242 is arranged such that it may be extracted from coil 1232 in a first position as shown as 1242 in FIG. 21 to give a low-inductance setting, or drawn into the coil 1232 to a second position 1244 shown by dashed lines in FIG. 21 to give a high-inductance setting.
- first and second L- shaped core portions 1242, 1240 form a loop for magnetic flux when the second core portion 1242 is in the high-inductance position.
- FIGs. 19 and 20 operate under control of a system controller 124 as previously discussed with reference to FIG. 1 ; in an embodiment some sections of cable are deiced as described with reference to FIGs. 19 and 20, while some other sections are deiced as described with reference to FIGs. 1 and 4.
- the embodiment of FIG. 22 also is a system 1300 for deicing transmission line cable, in this case by heating the cable 1302 by diverting a portion of cable power through a step-up transformer (windings 1304 and 1306) and through the steel supporting strands 1308 of cable 1302.
- steel strands 1308 are surrounded by insulation 1310, and then surrounded by stranded aluminum or copper conductive layer 1312.
- Switchbox 1313 has a switch 1314 open in normal operating mode, and 1316 closed, to allow current to flow through the conductive layer 1312 unimpeded.
- Switchbox 1313 also has a power store 1322 and command receiver 1324 similar to and having equivalent charging circuitry to the power store 302 and command receiver 312 described in reference to FIG. 11 ; as with other embodiments command receiver 1324 is in communication with system controller 124.
- command receiver 1324 receives a command and closes switch 1314 first to establish a current path through steel supporting strands 1308; then command receiver 1324 opens switch 1316 to apply considerable current to transformer primary winding 1306. Transformer secondary winding 1304 thereupon provides power to supporting strands 1308.
- Transformer primary 1306 has only a few turns, and transformer core 1318 is constructed of a saturable magnetic material, such that only a small proportion of the power available in the cable is applied to the supporting strands 1308; such as 100 to 300 watts per meter of cable - in a 600 kV transmission line drawing 1000 amps, the 150 kW required to heat all three cables of one mile of line at 300 watts per meter is less than a tenth of a percent of the total power flowing through the transmission line, and voltage drop across the primary winding 1306 may be held to a low level.
- the embodiment of FIG. 22 has apparatus (not shown in FIG.
- switch 1316 or an auxiliary switch (not shown) is closed to reduce current in cable core 1308 by bypassing transformer primary 1306; as in normal operating mode bypassing primary 1306 greatly reduces current in the cable core 1308 and reduces resistive heating of the cable 1302.
- Switchboxes of all embodiments herein described sense overtemperature conditions of the cable and switchboxes, as for example through temperature sensor 324, and attempt reversion from deicing to normal operation at temperatures below that required to melt fusible links such as fusible link 320.
- Mechanical sensing and return to low- resistance operation provided by fusible links 320 and associated apparatus is an overriding mechanical backup intended to prevent overheat damage to the transmission line and its cables should system control 124, electrical switch actuators 314, electrically actuated switches 340, 1120, 1316, motor actuator 1216, temperature sensors 324, or other components fail into the deicing mode.
Landscapes
- Suspension Of Electric Lines Or Cables (AREA)
- Control Of Resistance Heating (AREA)
- Remote Monitoring And Control Of Power-Distribution Networks (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
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EP09726680A EP2258030A1 (en) | 2008-04-02 | 2009-01-23 | System and method for deicing of power line cables |
JP2011502999A JP2011517267A (en) | 2008-04-02 | 2009-01-23 | System and method for deicing power line cables |
EA201071153A EA201071153A1 (en) | 2008-04-02 | 2009-01-23 | SYSTEM AND METHOD FOR THE PREVENTION OF ICEING OF WIRES OF ELECTRICAL TRANSMISSION LINES |
CA2720352A CA2720352A1 (en) | 2008-04-02 | 2009-01-23 | System and method for deicing of power line cables |
Applications Claiming Priority (4)
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US4187508P | 2008-04-02 | 2008-04-02 | |
US61/041,875 | 2008-04-02 | ||
US12/193,650 US20090250449A1 (en) | 2008-04-02 | 2008-08-18 | System And Method For Deicing Of Power Line Cables |
US12/193,650 | 2008-08-18 |
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WO2009123781A1 true WO2009123781A1 (en) | 2009-10-08 |
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PCT/US2009/031826 WO2009123781A1 (en) | 2008-04-02 | 2009-01-23 | System and method for deicing of power line cables |
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US (1) | US20090250449A1 (en) |
EP (1) | EP2258030A1 (en) |
JP (1) | JP2011517267A (en) |
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Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6018152A (en) * | 1999-04-13 | 2000-01-25 | Allaire; Marc-Andre | Method and device for de-icing conductors of a bundle of conductors |
WO2000035061A1 (en) * | 1998-12-04 | 2000-06-15 | Hydro-Quebec | Switching apparatus and method for an electric power transmission line section |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4190137A (en) * | 1978-06-22 | 1980-02-26 | Dainichi-Nippon Cables, Ltd. | Apparatus for deicing of trolley wires |
DE69932495D1 (en) * | 1999-02-11 | 2006-09-07 | St Microelectronics Srl | Semiconductor device with improved chip-to-conductor connections, and manufacturing method therefor |
CA2469778A1 (en) * | 2004-06-04 | 2005-12-04 | Pierre Couture | Switching modules for the extraction/injection of power (without ground or phase reference) from a bundled hv line |
-
2008
- 2008-08-18 US US12/193,650 patent/US20090250449A1/en not_active Abandoned
-
2009
- 2009-01-23 EP EP09726680A patent/EP2258030A1/en not_active Withdrawn
- 2009-01-23 EA EA201071153A patent/EA201071153A1/en unknown
- 2009-01-23 KR KR1020107023298A patent/KR20100130220A/en not_active Application Discontinuation
- 2009-01-23 CA CA2720352A patent/CA2720352A1/en not_active Abandoned
- 2009-01-23 WO PCT/US2009/031826 patent/WO2009123781A1/en active Application Filing
- 2009-01-23 JP JP2011502999A patent/JP2011517267A/en not_active Withdrawn
- 2009-02-02 RU RU2009103371/07A patent/RU2009103371A/en not_active Application Discontinuation
- 2009-02-18 CN CNA2009100095373A patent/CN101552444A/en active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2000035061A1 (en) * | 1998-12-04 | 2000-06-15 | Hydro-Quebec | Switching apparatus and method for an electric power transmission line section |
US6018152A (en) * | 1999-04-13 | 2000-01-25 | Allaire; Marc-Andre | Method and device for de-icing conductors of a bundle of conductors |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2010193618A (en) * | 2009-02-18 | 2010-09-02 | Toyota Motor Corp | Charging system |
CN102208791A (en) * | 2011-02-23 | 2011-10-05 | 苏州蓝特照明科技有限公司 | Defroster for high-tension transmission line |
CN102208791B (en) * | 2011-02-23 | 2014-01-15 | 苏州蓝特照明科技有限公司 | Defroster for high-tension transmission line |
RU2478244C2 (en) * | 2011-03-31 | 2013-03-27 | Закрытое акционерное общество "Группа компаний "Таврида Электрик" (ЗАО "ГК "Таврида Электрик") | MELTING METHOD OF GLAZE ICE ON 6( 10 ) kV OVERHEAD TRANSMISSION LINES |
RU2569318C1 (en) * | 2014-08-14 | 2015-11-20 | федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Южно-Российский государственный политехнический университет (НПИ) имени М.И. Платова" | Method for melting ice on wires of overhead electric line |
CN106898985A (en) * | 2017-03-17 | 2017-06-27 | 国家电网公司 | Multifunction power conducting wire deicing device |
CN106898985B (en) * | 2017-03-17 | 2024-02-06 | 国家电网公司 | Multifunctional electric power wire deicer |
CN108598967A (en) * | 2018-05-08 | 2018-09-28 | 淮阴师范学院 | A kind of power equipment snow-removing device |
Also Published As
Publication number | Publication date |
---|---|
JP2011517267A (en) | 2011-05-26 |
EA201071153A1 (en) | 2011-04-29 |
CA2720352A1 (en) | 2009-10-08 |
KR20100130220A (en) | 2010-12-10 |
US20090250449A1 (en) | 2009-10-08 |
RU2009103371A (en) | 2010-08-10 |
CN101552444A (en) | 2009-10-07 |
EP2258030A1 (en) | 2010-12-08 |
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