EP2761637A1 - Coupe-circuit à commutation - Google Patents

Coupe-circuit à commutation

Info

Publication number
EP2761637A1
EP2761637A1 EP12834648.3A EP12834648A EP2761637A1 EP 2761637 A1 EP2761637 A1 EP 2761637A1 EP 12834648 A EP12834648 A EP 12834648A EP 2761637 A1 EP2761637 A1 EP 2761637A1
Authority
EP
European Patent Office
Prior art keywords
shuttle
commutating
circuit breaker
stator
electrode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP12834648.3A
Other languages
German (de)
English (en)
Other versions
EP2761637B1 (fr
EP2761637A4 (fr
Inventor
Roger W. Faulkner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alevo International SA
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US13/366,611 external-priority patent/US8890019B2/en
Application filed by Individual filed Critical Individual
Priority to PL12834648T priority Critical patent/PL2761637T3/pl
Publication of EP2761637A1 publication Critical patent/EP2761637A1/fr
Publication of EP2761637A4 publication Critical patent/EP2761637A4/fr
Application granted granted Critical
Publication of EP2761637B1 publication Critical patent/EP2761637B1/fr
Not-in-force legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/59—Circuit arrangements not adapted to a particular application of the switch and not otherwise provided for, e.g. for ensuring operation of the switch at a predetermined point in the ac cycle
    • H01H33/596—Circuit arrangements not adapted to a particular application of the switch and not otherwise provided for, e.g. for ensuring operation of the switch at a predetermined point in the ac cycle for interrupting dc
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C10/00—Adjustable resistors
    • H01C10/04—Adjustable resistors with specified mathematical relationship between movement of resistor actuating means and value of resistance, other than direct proportional relationship
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C10/00—Adjustable resistors
    • H01C10/16—Adjustable resistors including plural resistive elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/04—Means for extinguishing or preventing arc between current-carrying parts
    • H01H33/16—Impedances connected with contacts
    • H01H33/161—Variable impedances

Definitions

  • This disclosure relates to a circuit breaker.
  • the inductive energy stored in the magnetic fields due to the flowing current must be absorbed; it can either be stored in capacitors or dissipated in resistors (arcs that form during opening the circuit are in this sense a special case of a resistor). Because of the rapid inrush of current in a short circuit, the inductive energy can easily be much greater than just the inductive energy stored in the system at normal full load; if the current goes to five times the normal full load amps before being controlled, the inductive energy would be up to twenty-five times as large as in the circuit at normal full load (depending on the location of the short).
  • HVDC high voltage DC
  • MJ megajoules
  • Arc chute breakers (US patents 2,270,723; 3,735,074; 7,521,625; 7,541,902 for example) are effective to break DC currents up to 8000 amps (8.0 kA, kiloamps) at 800 volts (0.8 kV, kilovolts) DC, or 4000 amps at 1600 volts (1.6 kV).
  • arc chute breakers The concept behind arc chute breakers is to spread the arc current out into many small arcs over a large surface area between parallel metal plates. Since the arc is quite hot, the higher surface area of the many small arcs implies far greater radiative cooling. As the arcs cool, the resistance goes up so high that the arc current is ultimately quenched; this process takes a while: 50-300 milliseconds (ms) is a typical time between striking the arc and arc extinction in a megawatt (MW) scale arc chute breaker.
  • ms milliseconds
  • US patent 3,534,226 describes a particular way to insert resistance and capacitance into a DC circuit, to open the circuit; this patent is included herein by reference in its entirety.
  • the basic concept of switching in resistors to reduce the current in a stepwise manner so as to control the magnitude of voltage transients during opening of a DC circuit is well described in US patent 3,534,226, which envisions using many individual switches and resistors.
  • the method of patent 3,534,226 involves two different kinds of switches that must be opened in a precise sequence: first a low resistance mechanical switch (through which most of the power flows when the circuit breaker is closed) is opened. This is a conventional switch in which the electrical contacts are separated.
  • a plasma arc may briefly form between the separating electrodes of the low resistance switch, this arc is quickly extinguished as the current is commutated onto a parallel path through the resistors, which are switched via fast acting switches.
  • the initial resistance in the resistive network must be quite low for the initial arc to extinguish and commutate to the parallel resistive path.
  • the current has been reduced to less than 10% of its maximum value (which implies that >99% of the magnetic energy has been dissipated), which allows the final capacitor snubber to be relatively small and economical compared to the size it would have to be if it had to absorb most of the magnetic energy stored in the circuit at the time of initial opening.
  • US patent 3,534,226 forms the basis for several subsequent patents, including US patents 3,611,031 and 3,660,723 (both of which also use a low-loss mechanical switch to commutate the current to a resistive network based on fast electronic switches), and US patent 6,075,684 which uses a fast electronic switch in place of the commutating mechanical switch.
  • Commutating circuit breakers work by switching increasing resistance into a circuit in a predetermined sequence until the current is sufficiently reduced so that a final circuit opening can be performed using a relatively small snubbing circuit such as a varistor or a capacitor to absorb the last bit of stored magnetic energy.
  • the resistance needs to increase slowly enough that the inductive energy can be quenched without creating voltage spikes that are above the maximum voltage that the system can tolerate.
  • the sequential switching of resistance into the circuit is accomplished by the motion of a shuttle. As the shuttle moves, the resistance increases because of one of these three "Cases":
  • the resistance across the circuit breaker increases as a commutating shuttle commutates the current over a sequence of stationary resistors; or,
  • a commutating variable resistance shuttle is used to commutate over a sequence of
  • the current flows between a first Pole A through a first stator electrode (stator electrode #1) to a first shuttle electrode on the shuttle; this part of the current path from Pole A of the circuit breaker on to the shuttle can be accomplished by any workable means, either via a commutating connection or a stable continuous connection; the stable continuous connection can be accomplished by a flexible wire, a telescoping tube, or a slip ring, for example.
  • the current is on the shuttle, it flows to a second shuttle electrode which connects to one or a series of second stator electrodes to complete the circuit to Pole B in such a manner that electrical resistance increases as the shuttle moves.
  • a variable resistance portion of the shuttle connects Pole A of the commutating circuit breaker to Pole B through stationary stator electrodes.
  • Motion of the shuttle could be linear or it could be rotary.
  • the points of electrical connection between the stationary stator electrodes and the moving shuttle electrodes include at least one discrete stator electrode along which the shuttle slides during operation of the circuit breaker, through which the current is transferred.
  • the other connection of the shuttle to the circuit can also be a sliding contact, but may also be a flexible wire connection or a telescoping tube that remains attached to the shuttle as it moves (on only one side of the shuttle circuit).
  • the lower mass of a commutating shuttle compared to a variable resistance shuttle implies less momentum needs to be transferred to accelerate the shuttle, which minimizes the jolt due to acceleration of the shuttle, and also reduces shock, vibration, and fatigue for the structure that holds the commutating circuit breaker.
  • a commutating variable resistance shuttle as in Case #3 above is useful for snubbing arc currents that might otherwise arise as the trailing edge of a commutating stator electrode leaves its electrical connection to a particular moving shuttle electrode.
  • Making the last part of a shuttle electrode lower in conductivity compared to the first part can suppress arcing while still preserving a low resistance path through the first part of the shuttle electrode to conduct electricity efficiently when the circuit is closed, or to connect to the next stator electrode in the sequence of stator electrodes contacted by the moving shuttle electrode.
  • This same type of resistivity gradient is also desirable on the trailing edges of the stator electrodes where the stator electrodes link to external resistors.
  • Making the trailing edge of an electrode much more resistive than a metal implies placing a portion of the resistance insertion of a commutating circuit breaker on board the shuttle in the trailing portion of the shuttle electrodes, or within the trailing portion of the stator electrodes, or both.
  • the trailing edge resistive gradient is primarily limited to the stator electrodes because adding said gradient on the trailing edge of the shuttle electrodes increases shuttle mass, which makes the launching mechanism heavier, and the momentum transferred to accelerate the shuttle greater. Grading the resistivity on the trailing edges of both the shuttle electrodes and the stator electrodes provides the best possible arc suppression as a particular stator electrode loses contact with a particular shuttle electrode.
  • the graded resistivity on the trailing edges of the electrodes connecting through Path A commutates the current to a different higher resistance electrical Path B through next neighbor electrodes that share a parallel connection with the separating electrodes.
  • the resistance through Path A has increased to at least ten times the resistance through parallel Path B, and this may be accomplished by graded resistivity in the trailing edges of the separating Path A electrodes.
  • This zone may commutate the power from a shuttle electrode through a series of electrically separated stationary stator electrodes onto paths having increasing resistance, or the stator commutation zone may comprise a stack of electrically series connected stationary stator electrodes such that the path length through the resistor stack increases, leading to increased inserted resistance as the commutating shuttle moves, or the movement of a variable resistance shuttle may simply place greater resistance between Pole A and the stator electrode that links to Pole B.
  • MVDC Medium voltage DC
  • MVAC Medium voltage DC
  • MVDC enables microgrids with many different generators, power demands, and storage units tied into a single grid, whereas this is far more difficult to do with AC power.
  • MVDC allows efficient power distribution in industrial facilities (especially factories and processing plants that use a lot of variable speed motors); on board ships; and at mine sites and other isolated off-grid sites.
  • the provision of DC power to many different variable speed motor drives saves both capital and energy costs compared to the normal mode of operation in which each motor controller for a variable speed drive must first produce DC power from AC power within the drive, then either drive a DC motor or convert to AC at a controlled frequency to drive the variable speed motor.
  • Variable speed drives are less expensive and more efficient if they are powered by MVDC, which has previously been impractical due to the lack of fast, efficient, economical MVDC circuit breakers.
  • High voltage DC (HVDC) power transmission is the most efficient way to transmit high power levels, over one gigawatt (GW) for example, for distances greater than 1000 km.
  • GW gigawatt
  • DC power lines can readily go underground or undersea, and for these reasons HVDC is the most efficient and feasible way to transmit vast amounts of renewable electricity from distant wind farms and solar arrays to cities and economical remote energy storage sites, as will be needed to build an efficient energy economy based on renewable energy.
  • HVDC power transmission was strictly via "line commutated converters" (LCC) which only work as point-to-point power lines, connecting two or a few nodes of the AC grid, with LCC converters at each connection point to the AC grid.
  • LCC line commutated converters
  • VSC voltage source converters
  • the commutating circuit breaker is a breakthrough in terms of capital cost and operating characteristics (long life, low switching transients) that will enable DC grids all the way from the modest voltage relevant for data centers (-400 volts) to MVDC for microgrids, ships, factories and processing plants, to HVDC for long distance power sharing.
  • Figure 1 shows a linear motion ballistic circuit breaker with variable resistance shuttle having step changes of resistivity in the shuttle; two stator electrodes are arranged in a circularly symmetrical manner to avoid a Lorentz force torque.
  • Figure 2 shows a container for a resistor that is sometimes called a "Can" herein. This Can is filled with a potted disc shaped resistor to form a resistor cell.
  • Figure 3 shows a stack of resistor cells as in Figure 2 that are series connected in such a way as to facilitate commutation by a moving shuttle that fits around the stack as in Figure 4.
  • Figure 4 Linear motion commutating circuit breaker with a pipe-shaped commutating shuttle that fits around a stationary column of disc-shaped resistors.
  • Figure 5 Linear motion multistage commutating circuit breaker with four commutation zones in two stages.
  • Figure 6 Rotary Motion Multistage commutating circuit breaker with six commutation zones.
  • Figure 7 Quenching of current and energy for an optimized 18-stage commutating circuit breaker of Figure 6 and Table 1.
  • Figure 8 Single stage commutating shuttle with electrical stress control behind moving electrode; circuit shown just prior to actuating motion of the commutating shuttle.
  • Figure 9 Single stage commutating shuttle with electrical stress control behind moving electrode; circuit shown at the end of the motion of the commutating shuttle.
  • FIG. 10 Shuttle electrode/stator electrode interface with increased resistivity trailing edges.
  • Figure 11 Commutating circuit breaker with flexible wire lead from Pole A to the shuttle.
  • Figure 12 Commutating circuit breaker with shuttle having the shape of a rod, tube, or wire.
  • Figure 13 Variable resistance shuttle with elastomer sleeve for voltage stress control.
  • Figure 14 Elastomer sleeve for voltage stress control following stator electrode.
  • Figure 15 Hybrid commutating circuit breaker with parallel fast switch.
  • Figure 16 Pipe-shaped commutating shuttle.
  • Figure 17 Rotary commutating circuit breaker, with two commutation zones and external resistors.
  • Figure 18 Simplified rotary fast-acting commutating circuit breaker in which the stator electrodes and resistors make up wedge-shaped keystone sections of the stator wall.
  • Figure 19 shows the drive and control mechanism for a large diameter rotary commutating circuit breaker designed for high voltage.
  • Figure 20 Rotary commutating circuit breaker mounted on base plate, with torque driver, bearings, fast actuated release, and arresting brake.
  • Figure 21 Semi logarithmic plot comparing current versus time in a worst case dead short (no voltage sag, no resistance) versus a circuit with internal resistance.
  • the shuttle can be either a variable resistance shuttle as in Case #1, or a commutating shuttle as in Case #2, or a blending of these cases in which part of the insertion of variable resistance occurs on the shuttle, and part via stationary resistors, as in Case #3.
  • Commutating circuit breakers for relatively low power circuits of less than about one hundred kilowatts (kW) can be made with a variable resistance shuttle (Case #1) that connects between two sets of contacts, as in Figure 1.
  • the variable resistance shuttle must withstand high acceleration loads, and must have a surface that slides on the stator electrodes without excessive wear.
  • Figure 1 is a partially exploded view of a commutating circuit breaker 100 in which the inserted resistance is on board the shuttle.
  • a spring 101 is under tension, pulling on the shuttle through a non-conductive rod 103; this rod extends to the back end of the shuttle and is connected to permanent magnet 119, the "shuttle magnet.”
  • Shuttle magnet 119 is in contact with stator magnet 121 when the circuit breaker is closed, prior to triggering the breaker.
  • Electromagnet coil 123 is oriented to repel the shuttle magnet and to trigger opening of the circuit breaker by the spring when a DC current passes through the coil.
  • Figure 1 shows a variable resistance portion 110 of the shuttle having step changes of resistivity in the shuttle core segment layers 111, 112, and 113.
  • Stator 107 has electrodes 105 and 115 that are arranged in a circularly symmetrical manner to avoid torque on the shuttle by Lorentz forces.
  • the two circular stator electrodes 105 and 115 are at a set distance apart, far enough to prevent arcing during opening of the circuit breaker.
  • stator electrode 115 During the time that a single resistivity layer is exiting stator electrode 115, the resistance increases smoothly due to insertion of a greater length of resistive segments between Pole A and Pole B as the shuttle moves left. As each resistive material boundary passes out of contact with stator electrode 115, there is a discontinuity in the resistance versus time curve, which in turn generates change of slope in the resistance vs. time curve, but no step changes in resistance.
  • the shuttle in Figure 1 is shown in its closed circuit position, but an exploded view is applied to the stator magnet 121 and the electromagnet trigger 123 to make it easier to depict.
  • the closed circuit power flows from Pole A to the stator electrode 115, then through the portion of the shuttle 109 to stator electrode 105; 109 is composed of a good electrical conductor with low resistivity ⁇ 10 "8 ohm-meter. After the shuttle begins to move, the resistance increases as the boundary between material 109 and material 111 exits the left side of stator electrode 115; this is the first commutation.
  • FIG 2 shows a single resistor cell of a stacked resistor column (shown in Figure 3) in which a disc-shaped resistor 127 is potted into a Can that facilitates stacking and commutation.
  • Resistor 127 is desirably an alumina/carbon resistor, such as those available from HVR Advanced Power Components of Cheektowaga, NY, USA. These resistors can handle pulsed power very well, as is needed during operation of a Commutating Circuit Breaker, and are available over three orders of magnitude in resistivity.
  • the physical properties of this class of resistor (especially density and strength) would not be desirable for a design such as Figure 1 in which the resistor per se is accelerated to accomplish the circuit opening, and the stator electrodes ride on the surface of the resistor.
  • the Can of Figure 2 is comprised of a conductive lower portion 129, an insulating upper portion 133, and an insulating sleeve portion 135.
  • Said Can provides a nesting site for a discshaped resistor 127 (or 137, 138, 139, 140, or 141, as shown in Figure 3) which is attached by conductive adhesive 131 to the bottom of the Can 129.
  • the conductive adhesive 131 is desirably a metal brazing compound, a solder, or a conductive adhesive that is lower in volume resistivity than the resistive material that comprises disc resistor 127.
  • Said bottom of the Can 129 is metallic and has a metal lip that extends part way up along, but some distance away from the sides of the disc resistor 127, 137, 138, 139, 140, or 141.
  • an insulating sleeve 135 is inserted between the common inner radius of the upper lip of the metallic portion of the Can 129 and the insulating upper portion of the Can 133 and the outer radius of the disc resistor 127, 137, 138, 139, 140, or 141; this sleeve guarantees that current flows vertically from top to bottom of each resistor, so that I R resistive heat generation is distributed over the entire volume of the disc resistor such as 127.
  • the resistors (127, 137, 138, 139, 140, or 141 ) are potted into six Cans that each contain components 129, 131, 133, and 135 with a void-free insulating polymeric system (as is commonly practiced in potted transformers, for example) to form the final potted resistor cell, as in Figure 2.
  • Six resistor cells similar to the one shown in Figure 2 are then stacked as in Figure 3 to form the base of a stator; the entire outside radial wall of each Can and the entire stator formed by stacking the Cans plus a special top cell is a concentric sliding surface that is smooth.
  • the bottom resistor cell contains disc resistor 127; the next cell up contains disc resistor 137; the next cell contains disc resistor 138; the next cell contains disc resistor 139; the next cell contains disc resistor 140; the next cell contains disc resistor 141; the resistivity levels of each disc resistor increases in the order 127 ⁇ 137 ⁇ 138 ⁇ 139 ⁇ 140 ⁇ 141.
  • resistor cell that differs from the other cells in that it is comprised of a metal base plate 145, and on top of that is a graded resistivity cermet element 143 that has resistivity at the bottom that is approximately equal to the resistivity of disc resistor 141, with resistivity that increases until it is an excellent insulator at the top, with resistivity > 10 12 ohm-meter (ohm-m). All these cells are mechanically and electrically bonded together, so that the metal base of each cell is attached to the entire upper surface of the disc resistor below it in the stack.
  • Figure 4 shows how the stack of resistor segments of Figure 3 is combined with a commutating shuttle 147, which in this case takes the form of a metallic sleeve that fits over the column of resistor segments, a conductive slip ring 149 that is connected to Pole A and to commutating shuttle 147, and a conductive base plate 151 that is connected to Pole B to form a commutating circuit breaker.
  • Figure 4 shows an intermediate state that occurs during opening of the commutating circuit breaker of Figures 2, 3, 4; in this intermediate state three resistor cells containing disc resistors 127, 137, and 138 are in a series-connected state between the moving commutating shuttle 147 and the base of the resistor stack 151.
  • the metallic sleeve commutating shuttle 147 is lower in mass than the column of resistor segments, and therefore takes less force 150 to accelerate than would be required to accelerate the resistor stack at the same rate.
  • the connection of the commutating shuttle to Pole A could also be via a wire in principle.
  • the commutating shuttle 147 When the circuit breaker of Figure 4 is triggered, the commutating shuttle 147 is rapidly accelerated upwards, causing the current to pass first through resistor 127, then 127 + 137, then 127 + 137 + 138 (this is the state illustrated in Figure 4), and so on. The commutating shuttle continues to move upwards until it has moved beyond the last metallic portion of the resistor stack column, 145 of Figure 3, after which the final small remaining current is quenched by the graded resistivity cell 143.
  • a semiconductive or insulating sleeve 153 that fits closely around the resistor column to suppress arcing when the conductive portion of the commutating shuttle 147 pulls apart from one of the metallic parts 129 found at the bottom of each resistor shell.
  • Said sleeve 153 is desirably semiconductive where it touches the commutating shuttle 147, but has a resistivity gradient such that it becomes a high dielectric strength, high resistivity material (greater than 10 12 ohm-meter) at the opposite end (lower end in Figure 4).
  • Said sleeve 153 can be made of a variety of materials; a particularly desirable composition is a high strength fabric-reinforced elastomer with a slippery inner surface.
  • a particularly desirable composition is a high strength fabric-reinforced elastomer with a slippery inner surface.
  • Not shown, but optionally present on the inner surface of the commutating shuttle 147 are flexible electrodes that facilitate better electrical contact between the commutating shuttle 147 and the outer surface of the stack of resistors shown in Figure 3.
  • Figure 5 is a two-stage commutating circuit breaker that has a commutating shuttle 158 that moves a distance 205 to open the circuit.
  • the commutating shuttle contains two shuttle electrode pairs comprised of 210, 211, and 212 (shuttle electrode pair #1), and 215, 216, 217 (shuttle electrode pair #2), both of which are embedded in a structural insulator 159.
  • stator electrodes 166, 168, 170, and 172 there are four stator electrodes; for example commutation zone 161 contains stator electrodes 166, 168, 170, and 172; stator electrode 166 connects through low resistance conductor 174 to Pole A. Stator electrode 168 connects to Pole A through resistor 176; stator electrode 170 connects to Pole A through resistors 178 and 176 in series; stator electrode 172 connects to Pole A through resistors 180, 178, and 176 in series; and similarly for the other commutation zones.
  • Commutation zone 162 contains stator electrodes 181, 183, 185, and 187. Stator electrode 181 connects to stator electrode 189 through low resistance conductor 182.
  • Stator electrode 183 connects to low resistance conductor 182 through resistor 184; stator electrode 185 connects to low resistance conductor 182 through resistors 186 and 184 in series; stator electrode 187 connects to low resistance conductor 182 through resistors 188, 186, and 184 in series.
  • Commutation zone 163 contains stator electrodes 189, 190, 192, and 194.
  • Stator electrodel89 connects to stator electrode 181 through low resistance conductor 182; stator electrode 190 connects to low resistance conductor 182 through resistor 191; stator electrode 192 connects to low resistance conductor 182 through resistors 191 and 193 in series; stator electrode 194 connects to low resistance conductor 182 through resistors 195, 193, and 191 in series.
  • Commutation zone 164 contains stator electrodes 196, 198, 200, and 202.
  • Stator electrode 196 connects to Pole B through low resistance conductor 197.
  • Stator electrode 198 connects to Pole B through resistor 199;
  • stator electrode 200 connects to Pole B through resistors 201 and 199 in series;
  • stator electrode 202 connects to Pole B through resistors 203, 201, and 199 in series.
  • Pole A connects through conductor 174 to stator electrode 166 to shuttle electrode 211, which then connects through insulated conductor 210 to shuttle electrode 212, which then connects to stator electrode 181 and from there through conductor 182 to stator electrode 189, then to shuttle electrode 216, then through insulated conductor 215 to shuttle electrode 217, then to stator electrode 196, then through conductor 197 to Pole B.
  • the commutating shuttle in this case is essentially a rigid body that maintains a set geometric relationship between the four shuttle electrodes 211, 212, 216, and 217 as it moves to the right to open the circuit.
  • Said timing may be accomplished by adjusting both the spacing between the shuttle electrodes and the stator electrodes; or, a standard spacing can be adopted between the shuttle electrodes, with all the timing control being done by adjusting the trailing edge positions of the stator electrodes only. It is optimal to insert the twelve resistors at controlled time intervals. After the twelve resistive insertions implied by Figure 5, the current is low enough so that the shuttle electrodes can move beyond their last connection through resistors without damaging arcs as the then greatly diminished current is cut off. It is desirable to grade the resistivity of the trailing edges of the stator electrodes, especially the particular stator electrode that does the final power shutoff. In Figure 5, the final shutoff occurs when shuttle electrode 211 loses its connection to stator electrode 172, which is the last electrode in Zone 1.
  • stator electrode 172 is the one to open the circuit, it is highly desirable to grade the resistivity of the trailing edge of this electrode all the way from semiconducting to high resistivity to provide a soft final shutoff of the residual current still flowing after the twelfth commutation of the commutating circuit breaker of Figure 5.
  • a long multistage chain of commutating circuit breakers as in Figure 5 can be used to break an arbitrarily high voltage.
  • it is desirable to use multiple drives along the length of the commutating shuttle such as multiple springs positioned to accelerate the shuttle between the commutating zones, or multiple linear motors acting between the commutating zones.
  • a long multistage breaker with embedded permanent magnets can be driven by known electromagnetic means, for example (however, greater force can be exerted with springs or electromagnets than by coupling to permanent magnets).
  • a combination of drive mechanisms can also be used to achieve greater acceleration than can be produced by one means alone.
  • a variety of triggers and releases can be deployed in such a multistage linear breaker, as is discussed in more detail later.
  • Figure 6 represents a notional rotary multi-stage commutating circuit breaker designed for one pole of a medium to high voltage DC or AC power circuit breaker.
  • 221-229 comprising shuttle electrode 221; stator electrodes 222, 223, 224, and 225; conductive lead 226; and resistors 227, 228, and 229)
  • 231-239 comprising shuttle electrode 231; stator electrodes 232, 233, 234, and 235; conductive lead 236; and resistors 237, 238, and 239
  • 241-249 comprising shuttle electrode 241; stator electrodes 242, 243, 244, and 245; conductive lead 246; and resistors 247, 248, and 249)
  • 251-259 comprising shuttle electrode 251; stator electrodes 252, 253, 254, and 255; conductive lead 256; and resistors 257, 258, and 259)
  • 261-269 comprissing shuttle electrode 261; stator
  • the first commutating zone (defined by 221-229 in Figure 6) is closest to Pole A, and is linked via insulated conductor 220 to the second commutating zone (defined by 231-239 in Figure 6); the first commutating zone and the second commutating zone together with insulated conductor 220 form the first of three commutation stages in the commutating circuit breaker of Figure 6.
  • the other two stages include components 240-259 and 260-279.
  • a stage is defined as a complete circuit that moves power on to the commutating shuttle and then off of the shuttle. In Figure 5 there are two stages, and in Figure 6 there are three stages.
  • the multistage rotary commutating circuit breaker of Figure 6 works in much the same way as the linear multistage commutating circuit breaker of Figure 5, except that actuation is via rotation of a cylindrical commutating rotor 280 rather than linear motion of a commutating shuttle as in Figure 5, and there are three stages rather than two as in Figure 5.
  • “commutating rotor” is a special case of a “commutating shuttle;” a “shuttle electrode” refers to any moving electrode, whether it moves linearly as in Figure 5, or via rotation, as in Figure 6.
  • the circuit breaker of Figure 6 has six commutation zones, each of which works in the same way as does each of the four linear motion commutation zones of Figure 5. In this case, the commutating shuttle rotates about 18.2 degrees counterclockwise to open the circuit, then a further 7.9 degrees to a final open circuit position, so that the total rotation during actuation of the rotary
  • the commutating circuit breaker is 29.1 degrees (281).
  • the rotor is composed of strong, electrically insulating materials such as a fiberglass reinforced polymer composite, an engineering grade thermoplastic compound, or a polymer-matrix syntactic foam, except for the shuttle electrodes 221, 231, 241, 251, 261, and 271 and the insulated conductive paths shown with heavy black lines (220, 240, and 260) within the shuttle that connect pairs of shuttle electrodes (such as 221 and 231).
  • the shaft is desirably metallic, but electrically insulated from the conductors 220, 240, and 260.
  • the entire rotating part is surrounded by a stator 290 in which the stator electrodes are mounted.
  • the resistors are preferably outside the stator to facilitate heat removal after the circuit breaker trips.
  • the view in Figure 6 is an end-on view of a commutating shuttle which has the shape of a cylinder.
  • the length of the cylinder (perpendicular to the cross-section shown in Figure 6) can be adjusted to keep the normal full load amps per cm 2 of electrode contact area within design limits; thus, depending on the current, the cylinder 280 can look like a disc or a barrel.
  • circumferential insulated distance between stator electrodes can be adjusted to deal with the voltage gradient at each commutation; in principle, both the width of each stator electrode and the distance between each next neighbor pair of stator electrodes would be adjusted to reach an optimum design. Neither the distances between stator electrodes, nor the width of the stator electrodes, nor the composition of different stator electrodes needs to be the same for any two stator electrodes.
  • multiple series-connected commutating circuit breakers such as that of Figure 6 can be mounted on a single shaft, to create more commutation stages (6, 9, etc.). In this case, each of the switch contacts 221, 231, 241, 251, 261, and 271; and their mating contacts 222, etc. only span a fraction of the length of the drive shaft separated by intervening insulating sections.
  • the on-state stator electrodes 222, 232, 242, 252, 262, and 272 are desirably liquid metal electrodes; these are the only stator electrodes which carry high current in the on state.
  • Liquid metal electrodes are about 10 4 times as conductive as sliding solid metal electrodes in terms of contact resistance. Liquid metal electrodes can therefore also be narrower than sliding solid contact electrodes, which is a major advantage for the first few commutation steps of a commutating circuit breaker.
  • the liquid metal stator electrodes 222, 232, 242, 252, 262, and 272 can be one tenth as wide as the solid stator electrodes 223, 224, and 225 for example, and still have one thousandth of the contact resistance of the solid stator electrodes.
  • the commutating rotor of Figure 6 is a 31.5 cm diameter barrel-shaped commutating shuttle designed for 30 kV DC or AC power.
  • a consideration when using liquid metal electrodes is to avoid oxidized solid metal contacts to connect with the liquid metal electrode.
  • One way to avoid oxidation at the shuttle electrode surface that mates with the liquid metal electrode is to enclose the circuit breaker in a sealed oxygen free environment; in this case, conventional copper- or silver-based shuttle electrodes can be used with a liquid electrode, as long as the liquid metal electrode does not react with copper or silver.
  • Another known method is to use a "noble metal" such as gold, platinum, or palladium in air.
  • a particularly desirable solution is to use a molybdenum-surfaced electrode, since molybdenum does not oxidize in air below 600° Celsius; even though molybdenum has low conductivity for a metal (resistivity 85 times higher than copper), a thin coating of molybdenum on a substrate metallic electrode results in an oxide-free surface that couples very well with liquid metal electrodes, without the added resistance due to an oxide layer; the resistance through the molybdenum per se is negligible if it is only a mm or less thick on the electrode, as may be easily obtained by plasma spray or various PVD (physical vapor deposition) processes.
  • PVD physical vapor deposition
  • Liquid metal electrodes typically comprise a sintered porous metal structural component formed by a powdered metallurgy processes that is wetted and flooded by a liquid metal such as gallium or a low melting gallium alloy.
  • a liquid metal such as gallium or a low melting gallium alloy.
  • Sodium, sodium/potassium eutectic, and mercury have also been used in liquid metal electrodes, but are less desirable than gallium-based based liquid metal electrodes.
  • Gallium, gallium alloys, sodium, or sodium/potassium eutectic will oxidize, so such electrodes must be protected within an oxygen-free container which may contain gas, liquid, or vacuum in addition to the solid movable parts of the rotary motion multi-stage commutating circuit breaker of Figure 6.
  • the added cost of the gas-tight containment structure in order to be able to use gallium or sodium based liquid electrodes is well justified in the case of high power circuit breakers, such as that of Figure 6.
  • the non-liquid-metal electrodes include all the shuttle electrodes and all but one of each commutation zone's stator electrodes); in such a design the sliding electrode surface could be based on an copper, nickel, chromium or silver pure metal or alloy, or a cermet composite containing one of these metals or an alloy thereof, rather than molybdenum.
  • an oxidation-resistant surface on the electrodes that contact the liquid metal electrodes in the on state may be important to make it convenient to fabricate the device without having to maintain an oxygen-free environment between the time that the electrodes are manufactured and the circuit breaker is fabricated.
  • the commutating rotor of Figure 6 is a 31.5 cm diameter barrel-shaped commutating shuttle designed for 30 kV DC or AC power.
  • the barrel-shaped rotary commutator 280 in this particular example is 99 cm in circumference and contains 6 conductive shuttle electrodes that are 1.25 cm wide in the circumferential direction (occupying 4.55 degrees at the outer radius of the commutating rotor). The shuttle electrodes are wide enough to be touching two stator electrodes at all times except for the final commutation; all the shuttle electrodes are embedded in an insulating polymeric material.
  • stator electrodes 223, 224, and 225 are metallic electrodes that can be, for sake of demonstration 1.0 cm wide, with 0.25 cm of an insulator between each, so that the 1.25 cm wide shuttle electrodes are in full contact with the next stator electrode at the moment that contact is lost with a given stator electrode.
  • the first stator electrode 222 is only .25 cm wide, and is a liquid metal electrode, followed by an insulating gap that is 0.25 cm wide between stator electrodes 222 and 223; this means that the commutating rotor only needs to rotate 0.91 degrees to the first commutation in zone 1.
  • shuttle electrode 221 is in full contact with electrode 223; and at the moment that electrode 223 loses contact with shuttle electrode 221, said shuttle electrode is in full contact with electrode 224; and so on.
  • the trailing edges of the conductive electrodes of Figure 6 may be graded in terms of composition and electrical resistivity to reduce the chance that an arc will initiate at the time the electrodes separate.
  • trailing edge resistivity gradient can be in only the shuttle electrodes, only in the stator electrodes, or in both the shuttle and stator electrodes. This is discussed more generally elsewhere; in the specific case of the Figure 6 commutating circuit breaker a single graded resistivity zone at the trailing edge of one of the stator electrodes could easily absorb the last bit of magnetic energy in the flowing current after the last commutation of Table 1 , or a capacitor may be more economical to absorb this last bit of inductive energy.
  • the outermost surface of the shuttle electrodes is best made from a highly conductive metal or composite which is also wear resistant, and which does not oxidize, recrystallize, or interdiffuse with the facing on state stator electrodes during use. Oxidation can either be prevented by excluding oxygen, or by using an oxidation resistant metal such as gold, platinum, or
  • molybdenum where oxygen is excluded, a particulate hard particle/soft metal matrix composite with good electrical conductivity, such as silver- or copper-impregnated porous structures based on sintered metals; for example chromium powder as in US patent 7,662,208, or tungsten powder, as in commercial electrodes from Mitsubishi Materials C.M.I Co. Ltd. are suitable.
  • Aluminum/silicon carbide electrodes are also suitable in an oxygen-free environment.
  • molybdenum is a favored contact surface for all the non-liquid-metal electrodes; molybdenum that is plasma sprayed onto aluminum/silicon carbide electrodes is especially favorable.
  • the total resistance of the path from Pole A to Pole B in Figure 6 would be at most 2.5E-4 ohms. This low a resistance is only feasible with liquid metal on state electrode junctions. Achieving lower resistance entails using a more massive rotor, which requires more torque to accelerate; there exists an optimum design basis on-state resistance target that will be somewhat different for each particular case; in some cases, higher heat production than one kW may be well justified in combination with fan or liquid cooling, which makes it easier to make a working commutating circuit breaker without resorting to liquid metal electrodes for the on state electrode connections.
  • the spring or other driver used to cause the counterclockwise radial acceleration of Figure 6 may accelerate the rotor throughout the time of the commutations, or alternatively, a very stiff spring could impart an initial acceleration using up only a small part of the 18.2 degrees of radial motion that the commutating rotor moves during commutation. In this scenario, the commutating rotor is in free flight during most of the time that the commutating circuit breaker rotor is moving and causing commutations.
  • the first commutation of Table 1 inserts 50 ohms, which is based on limiting the voltage and current at the design basis maximum (500 kV and 10 kA); this first commutation needs to occur within 2.667 milliseconds (ms) in order to hold the fault current to no more than 10 kA (starting from normal full load of 2 kA at time zero).
  • I is the current when the resistance R (in ohms) is first inserted
  • L is the inductance (0.10 Henry in this example)
  • t refers to time (in seconds) since resistance R is first inserted.
  • Resistance R is repeatedly reset during the operation of the commutating circuit breaker (as in Table 1); this is a highly efficient way to absorb inductively stored magnetic energy during opening of a DC circuit with a lot of stored magnetic energy.
  • commutations can be timed precisely by adjusting the exact angles of rotation at which each of the first six separations of stator electrode and shuttle electrode occur, as the trailing edge of a shuttle electrode moves away from the trailing edge of a particular stator electrode.
  • This fine timing adjustment capability for the first switching event in each of the six commutation zones can be determined down to the microsecond time scale by careful design of the structure of the rotating commutating shuttle 280 and the mating commutating stator 290; however, after that the needed minimum spacing between stator electrodes to maintain electrical isolation creates limitations on timing subsequent commutations in each commutating zone.
  • the range of voltage from 500kV to 360kV is an unusually narrow control range for voltage excursions during opening of a circuit breaker (voltage switching transients), which is enabled in this case by the eighteen small commutation steps of Table 1 that the design of Figure 6 allows.
  • the final open circuit condition occurs when one of the shuttle electrodes slides past the last of that zone's sequence of stator electrodes into its highly insulating final resting zone.
  • Figure 6 shows the shuttle electrodes on the outer radius of the commutating shuttle, it is equally possible to put the shuttle electrodes on the flat ends of the shuttle. Both designs have advantages and disadvantages.
  • the design of Figure 6 is analogous to a drum brake, where the brake pads have an analogous role to that of the stator electrodes, and the drum is analogous to the rotary commutating shuttle.
  • the alternative design with the shuttle electrodes on the ends of the commutating shuttle is analogous to a disc brake.
  • the needed separation distance between next neighbor commutating electrodes depends mainly on the voltage change that occurs during the commutation step as current flowing through one resistive path is shunted to the next path when the separation of the shuttle electrode and stator electrode occurs.
  • the voltage difference between these two alternate paths carrying the same current is a reasonable estimate of the actual voltage difference driving arc formation as two electrodes separate; this driving force to form an arc has little to do with the medium surrounding the electrodes (vacuum, gas, or liquid) but whether an arc actually does form also depends on the dielectric strength of the fluid surrounding the separating conductors. This in turn depends on such factors as the pressure and chemical composition of the fluid and the dissolved gases present in the fluid if it is a liquid.
  • Particularly desirable fluids to surround the separating shuttle electrode and stator electrode include paraffinic hydrocarbons, including mineral oil and kerosene; vegetable oils; methyl esters of fatty acids; perfluorocarbon fluids; and liquid or gaseous sulfur hexafluoride (including gas mixtures), and a high vacuum.
  • paraffinic hydrocarbons including mineral oil and kerosene; vegetable oils; methyl esters of fatty acids; perfluorocarbon fluids; and liquid or gaseous sulfur hexafluoride (including gas mixtures), and a high vacuum.
  • Sulfur hexafluoride- containing gas mixtures are well known in the prior art for their high dielectric strength (for a gas) and excellent arc quenching properties, but liquid phase sulfur hexafluoride is not used commercially at present as far as I know as an intentional liquid dielectric.
  • the low liquid volume required in rotary design commutating circuit breakers such as that of Figure 6 make it feasible to use SF 6 in the
  • commutating shuttles containing pairs of shuttle electrodes which are connected to each other electrically but are insulated from each other at the surface of the commutating shuttle are required.
  • Said insulating material can comprise a polymer, an inorganic glass, a ceramic, a cementitious material, or a composite of two or more of these components.
  • Specific examples of insulators that may be used to insulate around the shuttle electrodes include:
  • fiber-reinforced composites based on a matrix phase curing polymer such as fiberglass- epoxy, polyaramid-epoxy, boron fiber-epoxy, fiberglass-polyester, etcetera;
  • engineering-grade moldable plastics defined as polymers with tensile modulus > 2.5 GPa and tensile strength > 40MPa, which may be unreinforced polymers; or polymers reinforced by non-conductive reinforcing fillers;
  • cement composites including fiber-reinforced and polymer latex toughened cement
  • polymeric syntactic foam low density and high compressive and shear strength
  • Each shuttle electrode aligns with several different stator electrodes as the shuttle moves, and in most cases each shuttle electrode is also connected to a second shuttle electrode at a different location on the commutating shuttle, such that the two shuttle electrodes are insulated from each other on the surface plane.
  • the shuttle electrodes of a multi-zone commutating shuttle occupy less than half of the total surface area of the commutating shuttle, and in most cases occupy less than 10% of the surface area of the commutating shuttle.
  • the commutating shuttle can be fabricated from previously formed metallic and insulative components; or, the commutating shuttle can be obtained by overmolding an insulator onto a metallic core. Overmolding can be accomplished via reaction injection molding (RIM) of fast-polymerizing systems, by casting of slow-polymerizing systems, or by thermoplastic injection molding, for example.
  • RIM reaction injection molding
  • Figures 8 and 9 depict a single stage commutating circuit breaker with commutating shuttle 310 (which includes a highly conductive shuttle electrode 335, a semiconductive transition plug 312, an insulating plug 311, and an insulating sleeve 347 that surrounds part of a highly conductive connecting rod 337).
  • Connecting rod 337 attaches the shuttle electrode 335 to Pole B through a conductive slip ring 345 and a wire lead 346.
  • Shuttle electrode 335 connects the various stator electrodes 321, 322, 323, 324 to Pole B as the shuttle electrode 335 moves to the right.
  • stator electrodes are connected through paths of varying resistance to Pole A of the commutating circuit breaker; in the on state ( Figure 8), stator electrode 321 connects through low resistance lead wire 331 to Pole A; as the commutating shuttle moves to the right, stator electrode 322 connects shuttle electrode 335 through resistor 332; next, the connection is through stator electrode 323 through resistors 333 and 332 to Pole A; then the connection is through stator electrode 324 through resistors 334, 333, and 332 in series.
  • the commutating shuttle 310 is actuated by pressure P (301) behind the commutating shuttle insulating plug 311, which causes the commutating shuttle to move from the closed (on) state shown in Figure 8 to the open (off) state shown in Figure 9.
  • Insulating plug 311 must be long enough to lie over all the stator electrodes (321, 322, 323, 324) at the end of travel of the commutating shuttle, and to overlap with insulating layer 340, as in Figure 9, in the fully open state to create a total resistance between Pole A to Pole B greater than 10 8 ohms in the fully open state.
  • Figures 8 and 9 depict a simplified commutating circuit breaker with just one commutation zone; these simplified depictions of a single commutation zone with only three resistance insertions prior to opening the circuit make it easier to describe and discuss certain aspects of commutating circuit breakers.
  • the commutating circuit breaker of Figures 8 and 9 has only 5 primary resistance levels. Power is linked from Pole B through slip ring 345 to the shuttle electrode 335, and from there through a series of different stator electrodes connected to increasing resistances given approximately by:
  • Resistance Level One is shown in Figure 8: current flows with minimal resistance
  • Resistance Level Two current flows primarily through stator electrode 322 and then
  • Resistance Level Three current flows primarily through stator electrode 323 and then through resistances 332 + 333 to the opposite Pole A of the circuit breaker.
  • Resistance Level Four current flows primarily through stator electrode 324 and then
  • Resistance Level Five is the open circuit condition shown in Figure 9 in which total resistance > 10 ohms (see Figure 9).
  • Actuation of the circuit breaker begins with the commutating shuttle 310 (composed of components 311, 312, 335, 337, and 347) in the closed circuit state of Figure 8 ; the resistance through the commutating circuit breaker in the closed circuit case is also known as the "on-state resistance" of the circuit breaker.
  • the on-state resistance of the circuit breaker of Figure 8 is actually comprised of two component resistances Rl and R2 through parallel circuits:
  • Rl is resistance of slip ring 345 + lead resistances 346 + 337 + contact resistance
  • R2 is resistance of slip ring 345 + lead resistances 346 + 337 + contact resistance
  • Rl resistive path
  • shuttle electrode 335 Because contact resistance scales with 1 /(contact area)].
  • desired commutation can be forced to occur well before the two electrodes lose contact with each other.
  • a semiconductive trailing portion of shuttle electrode 335 is provided by transition plug 312.
  • transition plug 312 As the commutating shuttle 310 moves to the right from the initial position of Figure 8, there will also be an electric current path through transition plug 312 to a sequence of stator electrodes (321, 322, 323, and 324). This means that at some points during the opening of the circuit breaker there will be electrical paths through three different stator electrodes, with the leftmost connections being through the semiconductive transition plug 312.
  • shuttle electrode 335 When shuttle electrode 335 leaves contact with stator electrode 321, there is a sudden increase in resistance through 321 and 331 as current through this path must then pass through the transition plug 312 after the metal electrodes 335 and 321 separate, which quickly commutates the current to the path through R2, but much more softly than if the trailing (left) edge of shuttle electrode 335 would abut an insulator such as 311 rather than semiconducting transition plug 312.
  • a consideration during this commutation is that current through the semiconducting transition plug 312 must not cause melting or damage to the material used to create semiconducting transition plug 312. This can be avoided by making the resistivity of transition plug 312 high enough so that only a minor portion of the current flows through transition plug 312 in every commutation except the last one.
  • semiconducting transition plug 312 performs the final quench of the last of the inductive energy.
  • shuttle electrode 335 moves to the right of stator electrode 324, the only electrical connection remaining between Pole A and Pole B goes through the
  • transition plug 312 Because of the graded resistivity in transition plug 312, a soft shut off can be provided if current and voltage is low enough to not damage the
  • Lpath refers just to the inductance of the current path from the point where the current turns from another alternative path to go through the given path, such as L331, which is the inductance from stator electrode 321 through connector 331 to Pole A, or L332, which is the inductance from stator electrode 322 through resistor 332 and its lead wires to Pole A. It is thus desirable in particular that resistors 332, 333, and 334 have relatively low inductance, as will be familiar to a person skilled in the art of electrical engineering.
  • Stepping through the actuation process for the device of Figures 8 and 9 pressure 301 creates force 300 by acting on the surface area of insulator 311 ; the force 300 moves the shuttle to the right inside the barrel 302, for a total distance 305; the electrical resistance increases in stages:
  • dielectric insulating plug 311 Three particularly desirable kinds of material for dielectric insulating plug 311 are:
  • a highly insulating elastomeric plug which is compressed when pressure is applied to drive the commutating shuttle forward may also be used for insulating plug 311 ; in the case where elastomeric plugs are employed for insulating plug 311 or semiconductive transition plug 312, the interface between these plugs and the wall 302 should be well lubricated, and the inner surface of the tube 302 should be quite smooth and have low friction with the elastomer plugs.
  • Elastomers are desirable for at least a portion of transition plug 312, both because of the convenience of preparing chemically similar elastomer layers with controlled resistivity, and because compression of an elastomer layer such as transition plug 312 results in a pressure against the wall which facilitates tight contact with the stator barrel 302, which inhibits arcing between the plug 312 and the tube wall 302.
  • the relative convenience of creating a stack of layers of elastomer compounds which are mutually cure compatible, mechanically similar and all with good sliding properties makes it fairly inexpensive to process, mold and fabricate cured elastomer plugs such as may be used in transition plug 312 with graded resistivity from 10 "2 to 10 ohm-m; it is much easier than creating all those layers in a plastic, for example.
  • Two compatible elastomer masterbatches can be used to create the graded resistance portion of transition plug 312.
  • This elastomeric portion of the transition plug may be bonded to a more conductive material, such as amorphous carbon or a sintered alnico layer for example, to cover the range of resistivity from 10 '4 to 10 "2 ohm-m, which may be desirable at the leading edge of transition plug 312, where it abuts against shuttle electrode 335.
  • thermoplastic polymer discs It is difficult to create intimate electrical contact between two separately molded semiconductive thermoplastic polymer discs, or between a thermoplastic, semiconductive polymer and a metal or ceramic surface, but the high compliance of elastomers facilitates better electrical connection to a surface, as long as the elastomer/metal interface is under pressure.
  • This interfacial lubricating layer between the shuttle and the stator barrel 302 can be thinner if the mating surfaces of the shuttle and the stator are smooth, and match each other's shape. Insofar as the surfaces of the shuttle and the rotor are not perfectly smooth, the boundary layer can also be thinner if the stator is somewhat flexible and is pressed against the rotor.
  • a useful design feature of a commutating shuttle or a variable resistance shuttle is to use a polytetrafluoroethylene (PTFE) coated elastomer on some of the sliding surfaces between the shuttle and the stator such as on the outside of an elastomer cylinder like 311.
  • PTFE polytetrafluoroethylene
  • Pure or formulated PTFE can be sintered and then skive cut to create a PTFE film which can then be used to create a sleeve.
  • PTFE and/or PTFE compounds can also be ram-extruded to form a thin-walled tube that can then be cut in lengths to use as a sleeve.
  • Such a sleeve may then be adhered to an elastomer by first chemically etching it, for example with FluoroEtch® available from Acton Technologies, Inc., and then co-molding it with a curing elastomer. It is however not nearly as easy to vary the resistance level of a PTFE layer as is the case for ordinary elastomers, so PTFE coating of elastomer surfaces is more desirable in the arc suppressing insulative sleeve of Figure 4 (153) or in purely insulating segments, such as 311 of Figures 8 and 9, rather than for the semiconductive components such as transition plug 312 of Figures 8 and 9.
  • Figure 10 shows diagrammatically a sliding connection between two stator electrodes and one moving shuttle electrode; 355, 370, and 371 are highly conductive metallic electrodes, while 360, 375, and 376 are semiconductive electrodes that are functionally similar to 312 of Figures 9
  • Components 375 and 370 together form the stator electrode, and 371, 376 together form the j th stator electrode, with stator insulator 380 between and surrounding them; the i th stator electrode connects through resistance 372, while the j th stator electrode connects through resistance 373, which is higher resistance than 372.
  • a sliding shuttle electrode (composed of the two layers 355 and 360) is electrically connected to both the i th and the j th stator electrode at the moment shown in Figure 10.
  • the shuttle electrodes 355 and 360 are surrounded by highly insulating regions of the shuttle 365.
  • the shuttle electrode slides to the left (indicated by 350) below the stator electrodes and the trailing edge of the highly conductive portion of the shuttle electrode 355 is about to lose electrical connection to the highly conductive first portion of the i th stator electrode 370.
  • This event will not completely open the circuit connection through the i th stator electrode through resistor 372, since the circuit is still open through the semiconductive electrode portions 360 and 375.
  • the final opening of the circuit through resistor 372 occurs, when the two semiconductive electrodes 360 and 375 separate, the current flowing through Bl will have been reduced to less than one ampere.
  • Figure 10 illustrates another case for how electrical smoothing layers may be implemented on the trailing edges of electrodes, showing the case where electrical smoothing elements (360, 375, and 376) are connected to the trailing edges of both a shuttle electrode 355 and two stator electrodes (370, 371).
  • electrical smoothing elements 360, 375, and 376 are connected to the trailing edges of both a shuttle electrode 355 and two stator electrodes (370, 371).
  • materials that may be used to modify the resistivity of electrodes as is useful in this invention:
  • Nichrome alloys resistivity ⁇ 1.5 x 10 "6 ohm-meter) or another high resistivity metallic alloy or composite;
  • Alnico alloy #8 resistivity ⁇ 4.7 ⁇ 10 "3 ohm-meter
  • Amorphous carbon resistivity ⁇ 10 "4 to 10 "2 ohm-meter
  • Conductive filled elastomer layers resistivity ⁇ 10 "2 to 10 12 ohm-meter
  • variable resistivity layer 360 is part of the moving shuttle, and so needs to be stronger than the stationary graded resistivity layers 375 and 376 at the trailing edges of the stator electrodes 370 and 371.
  • Appropriate materials for the shuttle electrode graded resistivity feature 360 include cermets, quasicrystalline metal alloys, or highly loaded, stiff, slippery polymers, whereas transition plugs 375 and 376 can be made of weaker materials. It is also desirable to keep the stiffness and wear rate of all the layers that are engaged in frictional relative motion in a commutating circuit breaker approximately equal (for long device life).
  • a particular stator electrode is relevant to minimizing on-state heat generation due to ohmic losses only if a major portion of the on-state current flows through that particular stator electrode when the circuit is fully closed and the shuttle is stationary in the on state (such as electrode 321 in Figure 8).
  • the stator electrodes that carry the main current in the closed circuit on state such as 321 should be highly conductive (like copper or silver, or a liquid metal electrode as discussed previously), but the other stator electrodes such as 322, 323, 324 can be made of a variety of metals and/or cermets, chosen more for friction, wear, cost, and corrosion resistance properties rather than especially low resistivity.
  • Nickel and/or nickel alloys are particularly useful electrode materials, for stator electrodes that only carry current for a short time.
  • Figure 11 shows the case where electric power is delivered to the shuttle of a commutating circuit breaker by a flexible wire 417 from Pole A.
  • a commutating shuttle design with sharp conductor/insulator boundaries is depicted, but variable resistance electrodes as in Figures 8, 9, and 10 can also be used with a tethered wire attachment mechanism as in Figure 11.
  • the connecting wire 417 must have high strength and very good fatigue resistance.
  • Total movement of shuttle electrode 425 to the right is such that at the end of its travel 445 the electrode is surrounded by a high dielectric strength, high resistivity tube 430.
  • a shock absorbing insulating element 427 is at the end of the travel of the front (right hand) face of electrode 425.
  • the actuator of motion 400 could be any suitable fast acting device; the thrust delivered by the actuator passes through a metal shaft 405 to an electrical isolation coupling 410, and from there via a non-conductive shaft 413 to the coupling 415 which links the metal shaft 420 to Pole A of the circuit breaker via the wire lead 417.
  • Shaft 420 is surrounded by an insulating sleeve 423 that aligns and supports the shaft within the non-conductive stator barrel 430, though which the stator electrodes 431, 432, 433, and 434 are installed.
  • Figure 12 shows a variant on the simple commutating circuit breaker concept shown in Figure 4.
  • a cylindrical shaped stack of hollow disc resistors 460 with metal washers 451 between each pair of next neighbor disc resistors (such as 450) is bonded together by some suitable means such as conductive adhesive, soldering, or brazing.
  • This is simpler and less expensive to implement than the disc resistor stack of Figure 3, based on a metal Can to hold each disc resistor as shown in Figure 2.
  • the metal washers 451 are very simple examples of stator electrodes, and preferably have a slightly smaller hole through them than the hole 455 through the disc resistors themselves (such as 450), so that the washers protrude into the central cavity through the resistors; this protects the inner surfaces of the disc resistors from damage via direct contact with the moving shuttle electrode 465, which in this case is simply a metal rod or tube that extends clear through the stack of resistors 460.
  • an optional end 466 of the commutating shuttle 465 which may function as an electrical stress control device with a similar function to 312 in Figures 8 and 9, but which may also have additional functionality as described below, by providing a gripping surface to hold back the rod 465 in the on (closed circuit) state.
  • electrical connection to Pole A is made by low resistance stator electrode 490 which can be a high conductivity metal electrode or a liquid metal electrode that mates with the end of commutating shuttle 465.
  • the upper end of the commutating shuttle 475 is a feature for connecting to a force 480 that pulls the commutating shuttle out of the disc resistor stack 460 to open the circuit.
  • Figure 12 shows all the disc resistors as having the same outside diameter, that is not necessarily the case; in particular, because the first disc resistors inserted into the circuit absorb far more inductive energy than subsequent resistors. It is desirable that the lowest disc resistor in Figure 12 (this is the first one inserted into the circuit) should have the greatest mass and therefore the largest outside diameter. It is important that the metal discs such as 451 cover the entire face of the resistors to which they are attached, so that the current can flow evenly through the entire volume of each disc resistor.
  • the circuit breaker of Figure 12 has several unique features. It uses the simplest possible commutating shuttle, a metal rod or tube.
  • the maximum force 480 that can be applied to the rod or tube depends on the strength of the material, and the cross-sectional area of the rod or tube wall. If all the force on the commutating shuttle originates from acceleration, then the maximum acceleration that is possible for any given material is strictly a function of the strength/density ratio of the material forming the commutating shuttle, and the length of the commutating shuttle.
  • Results from this equation appear in Table 2 for a 2 meter long column of metal pulled from one end as in Figure 12; maximum feasible acceleration varies from less than 1000 m/s 2 for sodium to 114,000 m/s 2 for aluminum matrix alumina-fiber wire.
  • Table 2 also shows the mass of various materials at 20° C that are needed to create a 2 meter long 25 micro-ohm column of material; at this loss level the 2 meter long notional commutating shuttle would transmit 2000 amps with 100 watts of I 2 R waste heat production.
  • the best overall solution for a commutating shuttle 465 as in Figure 12 depends on the relative cost for conductive material versus mechanical structure (including springs and triggers and the structural supports that maintain 465 in a stressed state, or apply stress to it), and critically, on the needed acceleration.
  • the structural cost scales with the mass of conductor that must be accelerated times the acceleration. Acceleration determines time to the critical first commutation, so there is a good reason to push towards high acceleration in order to minimize the time to first commutation, if and where that is important (it is more important to get to the first commutation very fast if the system inductance in a fault is low than if the system inductance in a fault is high).
  • Simply pulling a conductive tube so fast that one comes to the engineering limit for maximum tensile strength of the material is the fastest theoretical way to accelerate a linear motion commutating shuttle.
  • the fastest actuation commutating circuit breaker of Figure 12 using a material from Table 2 would be based on the highest strength/density ratio material, aluminum matrix alumina-fiber wire.
  • This cermet wire is the mechanical strength element (replacing steel in the more standard ASCR aluminum steel core reinforced wire) in 3MTM Aluminum Conductor Composite
  • commutating shuttle 465 from a high strength titanium alloy shell with sodium inside.
  • pure aluminum and pure magnesium have essentially equal mass to meet the 25 micro-ohm resistance target, but pure aluminum is stronger and so is a better solution for commutating shuttle 465.
  • the penultimate column in Table 2 is a dimensionless figure of merit M
  • This figure of merit M is indexed to a reference value for annealed copper of 1.00; of the single component materials (not composites or fabricated structures) shown in Table 2, cold worked copper has a modestly improved figure of merit M (1.257) compared to copper, and all the forms of magnesium and aluminum examined also have slightly higher M value than annealed copper, ranging from 1.147 to 4.411 for high strength aluminum alloy 6061 -T6.
  • the highest figure of merit M in Table 2 (43.4) is for a cermet wire, composed of alumina glass fibers in a matrix of pure aluminum. Similar wires that are comprised of carbon fiber reinforced aluminum have also been reported, but are much more difficult to prepare, and are not (as far as I know)
  • Such a cermet wire can serve as both conductor and actuator of the motion of the commutating shuttle 465 in Figure 12.
  • the modulus of the cermet wire (core wire of 3M ACCR) is so high (4550 MPa), stretching it just a few percent can store a large amount of elastic energy (comparable to a very stiff spring) that could supply force 480 while obviating the need for slip ring 470.
  • This design could be used for a very fast actuating design capable to very high voltage.
  • the feature 466 can be a stiff, strong rod that is held in place by a ring of piezoelectric thrusters that hold the wire end 466 in place via a normal force that can be released within 20 microseconds (the needed normal force can be reduced if part of the restraint to motion of 466 can be due to correlated magnetic domains on the surface of 466 that match up with similar domains that are imprinted on the surface of sleeve 490);
  • the wire 465 or a wire end 466 can be cut with high explosives
  • Fracture of the wire per se or a wire end 466 can be initiated with pulsed lasers.
  • a commutating circuit breaker of Figure 12 can be reset if piezoelectric grips are used to hold the bottom end of the commutating shuttle 465, through the abutting rod-shaped gripping surface provided by feature 466 in Figure 12.
  • Figure 12 minimizes the mass of non-essential parts of a commutating shuttle, by eliminating most of the insulation attached to the commutating shuttle and minimizing the mass of the trailing edge electric field control technology described elsewhere in this disclosure. Only the conductor is absolutely required for the breaker of Figure 12; the optional graded resistivity trailing edge component 466 is not a requirement, though it is expected to reduce arcing inside the core of the resistor stack during operation, and so is a desirable feature.
  • This design can also be deployed with a high vacuum, or with an arc-quenching gas mixture containing sulfur hexafluoride surrounding the commutating shuttle 465 and the resistor stack 460.
  • a major consideration in accelerating and decelerating the shuttle of a commutating circuit breaker is the mechanical integrity of the shuttle under a given acceleration.
  • the setups shown in Figures 1, 4, and 13 accelerate the commutating shuttle linearly strictly with a pulling force; in such a method of acceleration of the shuttle, there is no tendency for the shuttle to buckle, regardless of the slenderness ratio of the shuttle (length/diameter for a circular cylindrical commutating shuttle). Note though, that during deceleration the long, slender shuttles of Figures 1, 4, and 12 would have a high tendency to buckle if braking force is applied at the front, which would limit the maximum deceleration to a lower value than the maximum acceleration.
  • Buckling of a long slender commutating shuttle such as 465 in Figure 12 can be prevented by surrounding the commutating shuttle with a strong stiff stator; however making the stator perform a mechanical function in addition to its primary electrical function (greatly reducing the volume where arcing can occur) will make the entire device more expensive.
  • This is one major advantage of a rotary motion commutating circuit breaker such as that of Figure 6 versus a design in which the shuttle moves linearly.
  • long slender commutating shuttles have distinct advantages in terms of cost at very high power levels (Figure 12), it is useful to discuss options for braking a linear motion shuttle from the rear.
  • the feature 466 at the end of the conductive rod 465 may comprise permanent magnets, as indicated for feature 119 in Figure 1, which may both restrain the rod 465 from moving in the on state and which can also provide a braking force (generated by inducing a current in metal, a well known means of braking) after the commutating circuit breaker has completed its motion through the stack of resistors.
  • Other types of mechanical constraints including a non-conductive rope attached to the end of the commutating shuttle, for example at the position 466 in Figure 12, and attached at the other end to a mechanical brake that can arrest the forward motion of the commutating shuttle after the circuit has been opened, or friction brakes that only engage with feature 466 at the end of travel, are also viable options to brake from the rear.
  • Figure 13 shows a variable resistance shuttle design of the commutating circuit breaker in the on state, in which a highly conductive material 540 bridges between the two stator electrodes 505 and 510.
  • a highly conductive material 540 bridges between the two stator electrodes 505 and 510.
  • FIG. 1 illustrates the case of a moving resistive core 110 with well-defined
  • FIG. 13 shows the case of a variable resistance core 530 that is a continuously graded cermet that has resistivity increase smoothly from right to left, with no sudden changes in resistivity.
  • Cermet resistors with stratified resistivity ranging from low to high resistivity can be prepared by known means (see for example, "Functionally Graded Cermets," by L. Jaworska et al, Journal of Achievements in Materials and Manufacturing Engineering; Volume 17, July- August 2006). Substituting a continuously graded resistor for step changes in resistance eliminates switching transients, so this is a desirable implementation of the invention that is feasible either with resistors on the shuttle (as in Figure 13), or stationary resistors.
  • stator electrode trailing edge elastomeric sleeve 500 which is functionally similar to the trailing edge feature 153 shown in Figure 4.
  • Said trailing edge elastomeric sleeve 500 overlaps with electrode 505, and occupies region 535 to the right of electrode 505.
  • Figure 14 shows a close-up view of stator electrode trailing edge elastomeric sleeve 500, which is attached to stator electrode 505 as shown in Figure 14.
  • the sleeve 500 inhibits arcing and makes it possible to operate the commutating circuit breaker of Figure 13 in open air at a higher voltage differential between stator electrode 505 and downstream stator electrode 510 than would be possible in the absence of sleeve 500.
  • the variable resistance material 530 is exposed to the air upon exiting elastomeric sleeve 500, the voltage gradient at that point is greatly reduced compared to what the voltage gradient is upon exiting electrode 505.
  • the maximum voltage gradient can be higher under the elastomer sleeve 500 without causing electrical breakdown compared to the voltage gradient that could be sustained without breakdown at an air interface at the trailing edge of 505 if the variable resistance portion of the commutating shuttle 530 exits the end of the metallic stator electrode 505 into air.
  • the downstream stator electrode 510 does not need a sleeve like 500, because the current only flows between Pole A and Pole B.
  • the total movement of the shuttle core 550 is far enough so that the highly insulative portion of the commutating shuttle 533 fills a zone that extends from left to the right of stator electrode 505, to somewhere under elastomer sleeve 500.
  • Figure 13 also provides an example of actuation of motion of the shuttle with gas pressure 525.
  • the sleeve 500 fits around the circular cross-section of the tube-shaped stator electrode 505, and has a lip feature 555 to attach the elastomer sleeve 500 to the trailing edge of said stator electrode.
  • the shape of 500 as molded will be substantially different than how it looks in the deformed state shown in Figure 14. As will be familiar to one skilled in the art of design of rubber boots for mechanical devices (steering boots and the like), it is possible to work backwards from the final deformed shape of the elastomer sleeve ( Figure 14) to calculate the dimensions of the mold to make the rubber sleeve.
  • extension ratio ⁇ (which is the ratio of diameter in the deformed state to diameter as molded) at the interface between the elastomer sleeve and the shuttle at location 556 to about 1.1 to 1.25. It is desirable that the inner surface of elastomeric sleeve 500 be coated by PTFE, and that the sleeve is made of a strong elastomer with a low rate of stress relaxation. In the case of sleeve 500, stress must be maintained for the life of the elastomer part, so slow relaxing elastomer types, such as peroxide cured elastomers with carbon-carbon crosslinks are preferred.
  • sleeve 500 has electrostatic dissipative resistivity between about 10 5 to 10 9 ohm-meter.
  • the sleeve of Figure 14 will have to last many years in a potentially high ozone environment around electrical equipment, in an extended state. Therefore this sleeve also must be highly ozone resistant; for these reasons, peroxide crosslinked HNBR (hydrogenated nitrile-butadiene elastomer), EPR (ethylene-propylene rubber), and EPDM (ethylene-propylene-diene monomer) are particularly appropriate as base elastomers for sleeve 500.
  • HNBR hydrogenated nitrile-butadiene elastomer
  • EPR ethylene-propylene rubber
  • EPDM ethylene-propylene-diene monomer
  • Commutating circuit breakers can also be deployed in a hybrid circuit breaker design such as Figure 15, in which the critical first commutation is done by a very fast switch 605; this fast commutation switch is connected to a common buss bar 601 that connects both fast switch 605 and commutating circuit breaker 610 to Pole A.
  • Buss Bar 615 connects both 605 and 610 to Pole B through a no-load disconnection switch 602, which is normally closed (but which is shown as open in Figure 15). In the on state, switches 602, 605 and commutating circuit breaker 610 are all closed, and current flows through both connections.
  • fast switch 605 When fast switch 605 opens, the full current is rapidly commutated to the commutating circuit breaker, which then finishes opening the circuit over a period of ⁇ 10 ms. After the current is quenched, no-load switch 602 is also opened, which facilitates re-setting of both fast switch 605 and the
  • the hybrid switch of Figure 15 still has the soft circuit opening capability of a stand-alone commutating circuit breaker, but can get to the first resistance insertion much faster than a purely electromechanical commutating circuit breaker.
  • the hybrid circuit breaker design of Figure 15 can relax the requirement of very low on state resistance through the commutating circuit breaker 610, since in the on state, most of the current flows through the parallel path through the fast switch 605.
  • the resistor insertion sequence of Table 1 is modified so that the on state resistance of the commutating circuit breaker (prior to actuation) is equal to the first inserted resistance of Table 1 (50 ohms in this example).
  • the fast switch carries most of the on state current.
  • the fast commutating switch shown in Figure 15 can be:
  • a type II (ceramic) superconducting shunt that is designed so that resistance goes very high when current exceeds a pre-determined limit.
  • ceramic superconductors are used in superconductive fault current limiters (SFCLs)]; this is the fastest and preferred option where control of short circuit over-current is the primary risk, and is intrinsically failsafe even for low inductance short circuits);
  • a semiconductor switch such as a GTO, IGBT, or IGCT (although this implies high on state losses compared to a mechanical switch);
  • the initial resistance of the commutating circuit breaker (prior to any movement of the rotor) would be 50 ohms, which could be spread out among the six commutation zones equally by making the resistance of each of the six lowest resistance electrical links (226, 236, 246, 256, 266, and 276 in Figure 6) 8.33 ohms each, for example.
  • the 50 ohms initial resistance could also be divided between five of the six commutation zones; the remaining commutation zone with low resistance will then be the zone where the second commutation occurs (this second commutation is the first commutation caused by movement of rotary commutating shuttle 280 of Figure 6); according to Table 2, this second inserted resistance would be 19.4 ohms (inserted in series with the previous 50 ohms, so that total resistance goes to 69.4 ohms). From this point forward, all subsequent commutations and resistance insertions would be handled by the commutating circuit breaker 610.
  • the fast switch 605 can in some cases commutate power to the commutating circuit breaker in less than one microsecond, and then the commutating circuit breaker shuttle begins to move and may take 5-50 ms to fully open the circuit, but is instantaneously able to clamp the current inrush due to a dead short to protect the connected components, such as a VSC (voltage source converter), or a transformer for example.
  • VSC voltage source converter
  • This fast commutation feature is particularly important in a multi-terminal HVDC grid.
  • superconducting fault current limiters and cold cathode vacuum tubes are especially desirable for fast switch 605.
  • Figure 16 illustrates a simple method to create a linear motion commutating shuttle that is functionally similar to a single stage 157 of the two stages of the linear actuated commutating circuit breaker shown in Figure 5.
  • the design of Figure 16 is based on a piece of metallic or metal-matrix cermet pipe 620, onto which conductive sleeves 625, 626, and insulating sleeves 630, 631, and 632 are fitted and/or attached.
  • Said conductive sleeves 625 and 626 correspond to shuttle electrodes 211 and 212 in Figure 5, and are metallic sliding electrodes.
  • Sleeves 630, 631, and 632 are electrically insulating sleeves that correspond to the insulating material 159 surrounding conductor 210 in Figure 5.
  • Said sliding metallic electrodes can be mechanically and electrically bonded to the pipe-shaped core 620 by a friction fit based on assembling accurately machined parts at different temperatures (shrink fit); by using solder or brazing; or by plasma or flame sprayed metal applied directly to the pipe-shaped core 620.
  • the electrically insulating sleeves can be glazed onto the metallic substrate 620 as a glass; a preformed insulating sleeve that is accurately machined can be placed over the pipe-shaped core 620 by a friction fit based on assembling accurately sized parts at different temperatures (shrink fit); by plasma or flame sprayed ceramic insulation applied directly to the pipe-shaped core 620; or, an insulating, adherent polymer coating can be applied to the metallic substrate 620 to insulate it everywhere except at the sliding electrodes 625 and 626.
  • the commutating shuttle of Figure 16 can be prepared by lathe cutting a conductive pipe so as to leave raised ridges behind to form the two shuttle electrodes 625 and 626, followed by coating the remaining portion of the pipe with an insulator, such as epoxy or polyurethane resin, or by insert molding using a thermoplastic. After forming the conductive and insulating sleeves, smoothing the surface of the coated pipe so that the outer radius of the insulating sections 630, 631, and 632 is equal to the radius of the two electrodes 625 and 626, and there are no sharp edges at the boundaries between conductive sleeves and insulating sleeves is important.
  • an insulator such as epoxy or polyurethane resin
  • Figure 17 depicts a single stage, two zone rotary commutating circuit breaker with external resistors that is well suited to high current, medium voltage DC (MVDC) applications.
  • Figure 17 is similar to Figure 6 in that it depicts an end-on view of a circular rotary commutating shuttle and the mating parts of the stator, but it is designed to have a smaller and simpler rotating commutating shuttle, to push up the speed of actuation.
  • MVDC medium voltage DC
  • the compact circular cross-section of the outermost surface 670 of the commutating rotor (comprising major components 650, 671, 672, 673) of Figure 17 is smooth on its outer surface, which enables it to fit snugly inside a stator assembly 652, not shown in detail, which holds all the stator electrodes (675, 680, 690, 700, 710, 676, 720, 730, 740, 750).
  • the stator electrodes 680, 690, 700, and 710 connect to external resistors 681, 691, 701, and 711; similarly stator electrodes 720, 730, 740, and 750 connect to external resistors 721, 731, 741, and 751 as shown.
  • the two on state stator electrodes 675 and 676 are liquid metal electrodes that connect via low resistance lead wires to Pole A and Pole B of the commutating circuit breaker.
  • the entire stator assembly 652, including the inner surfaces of the stator electrodes has a smooth inner surface in contact with the rotary commutating shuttle (650, 671, 672, 673).
  • the entire stator surface other than the stator electrodes is composed of a highly insulating material, such as a polymer or polymer composite.
  • a lubricating interfacial film (not shown in Figure 17) desirably resides between the rotor outer surface 670 and the stator 652.
  • the stator electrodes are desirably held against the shuttle with a uniform pressure, which can originate from an elastic force, a pressure on the outside of a flexible stator, or both.
  • the commutating rotor core 650 is desirably composed of an aluminum-matrix SiC composite shaft or some similar low density, low thermal expansivity, high electrical conductivity material which is coated on its outer perimeter with an adherent electrically insulating shell 671, for example a ceramic such as plasma-sprayed alumina, aluminum nitride, quartz glass, or a polymer, except that the insulating shell is interrupted in the two shuttle electrode regions 672, 673 where the metallic tube is coated with a thin layer of conductive metal that is the same thickness as the insulating layer, but which is conductive and has good properties as a sliding electrode; two particularly desirable metals for the major part of shuttle electrodes 672, 673 are silver, nickel, and/or molybdenum.
  • an adherent electrically insulating shell 671 for example a ceramic such as plasma-sprayed alumina, aluminum nitride, quartz glass, or a polymer, except that the insulating shell is interrupted in the two shuttle electrode regions 672, 6
  • the shuttle electrodes 672 and 673 are wide enough to make full connection to the first two stator electrodes in the on state.
  • the timing of the commutations can be set by varying the width of the two on state electrodes 675, 676 and adjusting the gaps 682 and 692 between said on state stator electrodes and the next two stator electrodes 680 and 720.
  • Figure 18 depicts an end-on view of a single stage, two zone rotary commutating circuit breaker 800 with resistors that are incorporated into the stator, but which is otherwise similar to the rotary commutating circuit breaker of Figure 17.
  • hollow keystone-shaped stator electrode resistors (811, 821, 831, 841, 861, 871, 881, 891) act as both stator electrodes and resistors; these keystone-shaped stator electrode resistors actually form part of the inner walls of the stator and contact the commutating rotor (which is in this case a strong metallic hollow or solid shaft 855, selected to allow very high torque for maximum radial acceleration and very fast actuation).
  • stator electrode resistors 811 and 861 are also electrically connected to stator electrode resistors 821 and 871 and so on, up to the final stator electrode resistors 841 and 891.
  • Figure 18 shows all the stator electrode resistors as having the same outer diameter
  • the outer diameter of the various stator electrode resistors can vary according to the amount of energy each stator electrode resistor is expected to absorb during normal operation of the commutating circuit breaker; the first resistors to be switched into the circuit (811, 861) absorb far more energy than the last resistors (841, 891), and so should have higher mass. This can be accomplished by increasing the outer radius of 811 and 861.
  • the outer radius of the intermediate stator electrode resistors (821, 831, 871, 881) would then be intermediate in terms of outer diameter between the diameters of the first resistors (811, 861) and the last resistors (841, 891).
  • the outer surface of the rotor shaft 855 is coated with an insulating ceramic, glass, or polymer layer 803, 853 over most of its surface, but also is coated in two shuttle electrode regions 802 and 852 with suitable metals, as previously described.
  • the outer wall of the commutating rotor extends out to radius 804, and is polished smooth so that there is at most only a very small unevenness in going from an insulating part of the wall (803, 853) to the neighboring conductive parts of the wall (802, 852).
  • a tight clearance is maintained between the outer edges of the rotor and the keystone-shaped pieces forming the inner part of the stator (801, 811, 821, 831, 841, 826, 851, 861, 871, 881, 891, and 825), which occurs at radius 804; there may be a liquid or dry non-conductive lubricant at this interface.
  • multistage commutating circuit breakers which can be either large diameter rotors or long axial motion devices, are desirable. It is highly desirable to drive such large commutating shuttles from multiple areas on the surface of the commutating shuttle rather than by applying force at one or both ends of a long axial motion multi-stage breaker, or to the shaft of a large diameter rotary breaker.
  • a three stage rotary commutating breaker with six commutation zones along its outer surface as in Figure 6
  • the rotor will likely have to be more than a meter in diameter to allow adequate insulation between alternative electrical paths through the rotor.
  • Figure 19 illustrates an actuation mechanism that is particularly well suited to drive a large diameter multistage rotary commutating circuit breaker similar to Figure 6.
  • Multiple flat or gently curved springs 905 are disposed around the outer radius of the commutating rotor 900. Each spring engages with the rotor via a matching feature 910 attached to the rotary
  • the commutating shuttle is held in place via quick release brakes 915 that restrain the rotor from moving until a signal from controller 925 traveling through control signal wires 920 releases the brakes.
  • the brakes are desirably based on piezoelectric actuators that apply a normal force against polished surfaces to resist movement by friction.
  • the controller 925 causes the piezoelectric actuators 915 to quickly change shape so as to relieve the normal force, the commutator rotates to open the circuit breaker.
  • Figure 20 shows a general setup of a shaft-driven rotary commutating circuit breaker assembly.
  • 930 is a torque drive that applies torque to the shaft 945, which drives the rotation of the rotary commutating circuit breaker 940 when the fast brake 950 is released.
  • Rotary commutating circuit breaker 940 can be of a variety of designs, such as Figures 7, 18, or 19 for example. All components are mounted on a strong base plate 960 (which could also take the shape of a pipe or a truss that surrounds the commutating circuit breaker assembly).
  • Torque source 930 can be a torsion spring, a ring of flat springs acting on a drive wheel, as in Figure 19, an electromechanical or fluidic drive, or even a length of twisted shaft.
  • the rotary commutating circuit breaker 940 is between two bearings 935.
  • the fast release brake 950 is on the opposite side of rotary commutating circuit breaker 940 from the torque drive, which holds the torque from the torque drive 930 in the on state of the circuit breaker, so that the torque that is applied to the shaft 945 is held back by the fast release brake 950; as soon as the fast brake is released the shaft and the rotary circuit breaker rotate to an open position.
  • the base plate 960 In the on state there is an equal and opposite torque on the base plate 960 between the torque drive 930 and the fast release brake 950.
  • the shaft 945 extends beyond the fast release brake 950 to an arresting brake 955 that is mounted to the shaft by a spline so that it does not encumber motion of the shaft until after the opening of the circuit by the commutating circuit breaker is complete, after which the arresting brake quickly stops the rotation of the shaft while also preventing rebound and reversal of the shaft rotation.
  • a no-load electrical switch 965 is opened, which de-energizes the rotary commutating circuit breaker so that it can safely be reset.
  • the arresting brake 955 also incorporates a feature for re-setting the rotary commutating circuit breaker, by twisting the shaft back to its initial position after the rotary commutating circuit breaker has opened. After the shaft is reset to its initial on state position, the fast acting brake is reset, then the arresting brake is returned to its normal on state position and locked so that it cannot rotate with respect to the base plate. Finally, the no-load switch 965 is reclosed to return the rotary commutating circuit breaker assembly to its original on state, ready to again carry current from pole A to pole B, while also being able to rapidly open again as needed.
  • the fast brake can be a variety of different prior art mechanical releases, or a piezoelectric brake as described elsewhere in this disclosure, or a combination of correlated magnetic domains to hold back part of the applied torque, combined with a piezoelectric brake to enable very fast actuation. It is possible to apply the principle of matching printed magnetic domains to hold a commutating shuttle stationary while stress is applied, either in a rotary mode of actuation or a linear mode of actuation. This is based on a method of accurate positioning that is being developed by Correlated Magnetics of New Hope, AL (see for example, US patent 8,098,122).
  • a "fingerprint" pattern of matching magnetic domains can be created on the commutating shuttle and the mating stator of commutating circuit breaker 940, or on a shaft and sleeve that form a part of the fast brake 950 that is capable of restraining the rotation of the commutating shuttle in respect with the stator because of a large aggregate attractive force between the correlated magnetic domains; let us assume that the matching magnetic domain patterns can prevent rotation of the shuttle out of the "magnetic energy well" up to an applied torque of Tc.
  • Correlated magnetic domains have the additional important feature that they can accurately position the commutating shuttle rotor in a precise relationship to the commutating stator (within 10 microns). This is especially important in versions of commutating circuit breakers that use thin liquid metal electrodes, which must be accurately aligned in the on state. It is easy to arrange things so that once the commutating shuttle begins to move, the magnetic domains do not restrain the motion significantly, and yet a second set of correlated magnetic domains can arrest the commutating shuttle in a desired off state at the end of its rotation.
  • the principle of matching printed magnetic domains to hold a commutating shuttle stationary while stress is applied, via matching "magnetic fingerprints" is also capable of restraining linear motion of a commutating shuttle of a variable resistance shuttle.
  • the matching magnetic domain patterns can prevent motion of the shuttle out of the "magnetic energy well” up to an applied force of Fc.
  • Fc fast-acting linear motion commutating circuit breaker.
  • fast- acting springs are deployed which apply a force below that which would release the shuttle from the magnetic energy well, for example 0.95(Fc); the magnetic domains are in this case adequate to restrain motion of the shuttle out of the magnetic energy well.
  • a relatively small additional force of only 5% or more of the spring force can be applied to knock the commutating shuttle out of its "magnetic energy well" after which it will be rapidly accelerated by the springs.
  • This additional force could be applied electromagnetically, by piezoelectric actuators, or by gas pressure for example.
  • the second way to use correlated magnetic domains in a fast commutating circuit breaker is to combine the braking effect of piezoelectric actuators with correlated magnetic domains that are not quite able to restrain motion of the shuttle by themselves (as was discussed in relation to rotary motion in the discussion of Figure 20 above).
  • an applied force that is greater than the maximum that can be restrained by the correlated magnetic domains alone, for example 1.l(Fc) is applied to the shuttle of a commutating circuit breaker that is partially restrained by correlated magnetic domains, and partially by piezoelectric actuators that apply force
  • This method has the advantage that if control power is lost, the circuit breaker will open automatically, so its failure mode is far less dangerous than the other method previously described above to restrain motion using correlated magnetic domains, in which spring force per se is not adequate to knock the shuttle out of the magnetic energy well if the control circuit power is lost.
  • the motion of the variable resistance shuttle or the commutating shuttle implies rapid acceleration, which will cause a mechanical jolt unless two opposed motions with equal and opposite momentum changes are combined into a single circuit breaker.
  • Three mechanisms to contain the momentum effects of commutating circuit breaker actuation within the stator are possible: 1. accelerating two linear variable resistance shuttles or commutating shuttles in opposite directions within a common stator housing (which is capable of absorbing the shock loading that will result when the shuttle cores reach the end of their travel and must be arrested) which will contain the momentum effects of two symmetrical and balanced cylinders which move axially in opposite directions;
  • momentum component can be a mass that is not a commutating circuit breaker per se.
  • the commutating circuit breakers of the present invention work best when the ratio of system voltage V (in volts) to inductance L (in Henries) is less than 40 million at most; more preferably the ratio of V/L should be less than or equal to 8 million.
  • Commutating circuit breakers for relatively low power circuits may desirably incorporate the resistors into the moving variable resistance shuttle, such as Figures 1 and 13; this principle may also be used in rotary commutating circuit breakers, by using a variable resistance rotor.
  • Commutating circuit breakers for relatively high power circuits are preferably made with a commutating shuttle that connects the current through a sequence of increasing resistance paths by making sequential contacts through stator electrodes connected with multiple stationary resistors, as in Figures 4, 5, 6, 8, 9, 11,12, 17, and 18.
  • a snubber circuit integrated into the commutating circuit breaker that has the effect of minimizing the voltage spike that occurs when the contacts slide off the connection (whether direct or indirect) to one set of resistors onto the next set of resistors of higher resistivity.
  • Case #4 has no voltage sag due to internal resistance (a worst case assumption, similar to a large capacitor bank); Case #5 has the current come from a large battery bank with realistic internal resistance of .36 ohms);
  • Table 3 shows calculated times to go from full load (2kA) to maximum overload (lOkA) in two different overload cases:
  • Figure 21 shows a plot of these two equations for an intermediate inductance case (150 microhenries); up to normal full load of 2kA, the two plots are nearly the same, but they diverge significantly at higher current, longer time.
  • L minimum system inductance
  • dl/dt change of current with time in a dead short
  • Time to the first resistance insertion is an important attribute of a commutating circuit breaker, because the first resistance reverses or greatly slows the increase of current; this is true whether it is a standalone commutating circuit breaker or a hybrid design as in Figure 15; or indeed for any DC circuit breaker based on sequential insertions of resistance.
  • the selected resistance for the first insertion is just high enough to clamp the current and reverse dl/dt, but without causing voltage to increase above 12kV.
  • Table 1 which relates to a high inductance transmission system
  • Adding in extra inductance Lx slows down not only the inrush of current in the short (as in Equations 3 and 4), but also extends the time until the circuit is opened (since current decays as exp[-t(R/L)], as the following examples will show.
  • the fast switch is a cold cathode vacuum tube of the type disclosed in US patent 7,916,507.
  • a tube has an on-state voltage drop of about 10 volts, which implies energy loss of about 10/6000 or -.17% of transmitted power (better than an IGBT and not needing water cooling), for the basis assumptions cited above.
  • This kind of tube can switch in less than 0.1 microsecond, easily commutating power to the commutating circuit breaker before the current inrush passes the 1 OkA maximum level, even at one microhenry inductance, provided of course that it can be triggered fast enough.
  • the vacuum tube is doing the first commutation, and if the system inductance is only one microhenry, then there is very little inductive energy to dissipate: only 100 joules if the current is interrupted at lOkA, so that a small capacitor or varistor could be used to absorb this energy.
  • the advantages offered by the commutating circuit breaker would be negligible in this case, except if (as is often the case) the inductance of the fault could be highly variable depending on its location.
  • the commutating circuit breaker can be optimized for the maximum expected inductance, so as to minimize voltage spikes during opening of the circuit breaker.
  • voltage spikes can be kept below the voltage that would be experienced if a varistor were used to absorb the inductive energy.
  • the entire rotor which contains the 10 cm long rotary commutator is assumed to be equivalent to a 20 cm long titanium beta-C alloy shaft, 4 cm in outside diameter and 20 cm long, and weigh 1.214 kg.
  • the internal resistance delays the crossing of lOkA in a dead short, so that 283 microseconds is available to reach the first commutation (after the 50 microseconds allowed for fault detection and release of the piezoelectric brakes); this reduces the needed angular acceleration to 2.5 million radians per second and the required torque to 606 newton-meters, which is just barely within the strength limitations of the assumed solid titanium alloy rotor. This is not a practical design, but it does show that it is technically feasible to reach the first commutation within 333 microseconds using the rotary design of Figure 18.
  • the other eight stator electrodes are not liquid metal electrodes, and as a consequence have to be wider than the liquid metal electrode in order to carry the fault current safely and without damage to the electrodes.
  • the optimum interval between commutations also changes as the current and stored inductive energy are quenched by repeated resistance insertions. I have not taken the step to couple the equation of motion of the rotor 650 with optimized times for resistance insertion (as in Table 1 and Figure 7 for a different specific case), so as to calculate the optimal width of each particular stator electrode for the assumed worst case fault (lOkA, zero system resistance).
  • Figure 17 illustrates this principle by the fact that the first two metal sliding stator electrodes 680 and 720 are wider (one cm wide in the circumferential direction) than either the initial liquid metal stator electrodes 675, 676 (which are 0.2 cm wide) or the three subsequent stator electrodes 690, 700, 710, 730, 740, 750 (which are 0.6 cm wide).
  • the two sets of stator electrodes (those from 720-750 and those in from 680-710 are equal in size to their counterpart electrode in the opposite commutation zone.
  • Syncopation of switching between commutating zone 760 and 770 is accomplished by making the width of the first insulating gap 682 between liquid metal stator electrode 675 and stator electrode 680) 0.45 cm, whereas all the other insulating gaps (including the insulation gap 692) are 0.30 cm; this offsets the
  • the best available conductors near room temperature are silver and copper; silver-matrix electrodes in which silver is infiltrated into a sintered porous metal substrate of chromium or tungsten are well known, for example. If silver or copper is used in contact against liquid metal electrodes, it can react; silver reacts with gallium and mercury, so even if one made silver- mercury electrodes for example, the surface of the silver electrode will be a silver-mercury amalgam. Silver can be used with the sodium-potassium low melting eutectic, but this introduces safety concerns.
  • a particularly desirable surface for the shuttle electrodes 672, 673 so that the electrode surface is compatible with mercury or a gallium alloy is to cold spray silver onto a non- oxidized aluminum or aluminum composite substrate in a moderate thickness layer 100-1000 microns thick, and then to polish the surface smooth before applying a molybdenum layer, which can desirably be accomplished by physical vapor deposition (PVD) methods to lay down a fairly thin film (1-5 microns) on the polished silver surface, which PVD-applied film reflects the surface finish of the silver substrate below, and does not require further polishing.
  • PVD physical vapor deposition
  • Plasma spray techniques can also be used to apply a thicker molybdenum surface layer on a copper, silver, aluminum/SiC composite, or chromium substrate in principle.
  • Plasma co-spraying of a substrate metal and molybdenum can be used to create a fuzzy boundary layer between silver and molybdenum (for example) to reduce the chance of delamination.
  • a thick layer of molybdenum on a silver, copper, or aluminum substrate is intrinsically unstable due to the difference in thermal expansivity of the molybdenum compared to the substrate, and is therefore less favored than a thinner coating of molybdenum applied by PVD.
  • the reason to apply a surface film of molybdenum is to coat the solid electrode with a non-oxidizing metal (below about 600° C) which does not react with gallium or mercury to form an amalgam.
  • the electrode layers 672, 673 on the surface of the commutating rotor 650 of Figure 17 are relatively thin (less than one mm), and also for simplicity of manufacturing, it is desirable for the entire thickness of the electrodes to be composed of molybdenum that is plasma sprayed onto the substrate metal tube 651.
  • the insulating layer 670 could logically be a plasma sprayed alumina layer (the surface of the commutating rotor would in this case be ground smooth after plasma spaying). Because molybdenum and alumina both have low thermal expansivity compared to conductive metals, it is desirable to minimize the thermal expansivity of the substrate conductive tube or shaft 650 in the commutating circuit breaker of Figure 17. Two potential materials for the core of a rotary commutating circuit breaker such as that shown in Figure 17 were considered:
  • AlSiC-9 is an aluminum- infiltrated silicon carbide composite from CPS Technologies that has 8-9 ppm (parts per million per degree Celsius) thermal expansivity from 30° C to 200° C (less than half the thermal expansivity of aluminum), and titanium has 8.6 ppm (parts per million) thermal expansivity from 30° C to 200° C. Both materials form bonds with plasma sprayed alumina and molybdenum which are more resistant to thermomechanical fatigue than similar thickness plasma-sprayed alumina or molybdenum layers on aluminum, copper, silver, or their alloys.
  • the titanium tube wall thickness (pure titanium) that matches the moment of inertia of a solid AlSiC-9 solid shaft (outside diameter of both is 4.00 cm), is only 0.149 cm thick.
  • the resistance between the two shuttle electrodes would be about 88.5 micro-ohms, which implies on state losses at maximum full load (2000 amps) around 350 watts just from resistance heating of the 10 cm long titanium shaft section between electrodes 672 and 673.
  • a very strong, shock resistant material as the substrate for the commutating rotor of Figure 17 or 19, such as titanium or a titanium alloy tube electrically bonded to an aluminum alloy core.
  • a very strong, shock resistant material such as titanium or a titanium alloy tube electrically bonded to an aluminum alloy core.
  • AlSiC-9 will be a more appropriate material for the core of a rotating shuttle such as 650 of Figure 17, and aluminum alloy tubes may also be used on some cases.
  • minimum system inductance is taken to be five times higher than the minimum inductance of Example 3 (3.75 mH). According to Table 3, this allows 5 ms to the first commutation in Case #4, or 8.13 ms to the first commutation in Case #5.
  • the necessary acceleration of the shuttles can be done in such a way that a paired set of commutating circuit breakers are simultaneously triggered so that the momentum effect due to accelerating and decelerating the shuttle mass of the first commutating circuit breaker is counteracted by the momentum effect of accelerating and decelerating the shuttle mass of the second commutating circuit breaker so that the momentum that must be transferred to the mounting system for the pair of commutating circuit breakers is greatly reduced.
  • the two stage axial circuit breaker of Figure 5 can readily be modified to break two circuits simultaneously by eliminating the connection between the two stages 182 and wiring the two now electrically independent halves to break the circuit on the positive side and the negative side of the DC circuit simultaneously.
  • a rotary commutating circuit breaker can also be designed to open two circuits simultaneously.
  • Such a rotary 2-pole circuit breaker cannot use a conductive shaft that is in the circuit as in Figures 17 and 18, but would instead need to maintain electrical separation between the stages, similar to Figure 6.
  • the three commutating stages in Figure 6 can also be adapted to interrupt all three phases of a three phase AC circuit simultaneously, by eliminating the series-connecting wires 236 and 256 and instead connecting each stage to one phase of the three phase circuit.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Arc-Extinguishing Devices That Are Switches (AREA)

Abstract

Coupe-circuit à commutation, fonctionnant en insérant progressivement une résistance croissante dans un circuit par un mouvement physique d'un coulisseau relié au circuit par un ensemble de contacts électriques de glissement sur le coulisseau qui branche électriquement, par l'intermédiaire du coulisseau en mouvement, une suite de parcours résistifs différents de résistance croissante ; le mouvement du coulisseau peut être soit linéaire soit rotatif. L'invention est caractérisé en ce qu'à aucun moment les électrodes du coulisseau ne sont séparées des électrodes fixes correspondantes de stator de façon à générer un arc puissant. Au lieu de cela, le courant est commuté d'un parcours résistif à l'autre avec à chaque étape des variations de résistance suffisamment faibles pour contrecarrer l'amorçage d'arcs. La résistance variable peut se trouver à l'intérieur du coulisseau en mouvement ou le coulisseau peut être constitué d'un coulisseau de commutation qui fait parcourir au courant une série de résistances fixes.
EP12834648.3A 2011-09-30 2012-10-01 Coupe-circuit à commutation Not-in-force EP2761637B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PL12834648T PL2761637T3 (pl) 2011-09-30 2012-10-01 Komutacyjny wyłącznik

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US201161541301P 2011-09-30 2011-09-30
US13/366,611 US8890019B2 (en) 2011-02-05 2012-02-06 Commutating circuit breaker
US201261619531P 2012-04-03 2012-04-03
PCT/US2012/058240 WO2013049790A1 (fr) 2011-09-30 2012-10-01 Coupe-circuit à commutation

Publications (3)

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EP2761637A1 true EP2761637A1 (fr) 2014-08-06
EP2761637A4 EP2761637A4 (fr) 2015-03-18
EP2761637B1 EP2761637B1 (fr) 2016-12-07

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Application Number Title Priority Date Filing Date
EP12834648.3A Not-in-force EP2761637B1 (fr) 2011-09-30 2012-10-01 Coupe-circuit à commutation

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EP (1) EP2761637B1 (fr)
CN (1) CN104115250B (fr)
AU (1) AU2012315502B2 (fr)
CA (1) CA2850601C (fr)
ES (1) ES2613669T3 (fr)
HK (1) HK1200240A1 (fr)
PL (1) PL2761637T3 (fr)
WO (1) WO2013049790A1 (fr)

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CN105723489B (zh) 2013-08-05 2019-06-04 英诺锂资产公司 具有阻断半导体的换向开关
CN106849599B (zh) * 2017-04-23 2023-04-07 吉林大学 一种电磁摩擦压电复合式能量采集器
CN107564761B (zh) * 2017-10-20 2019-12-17 国网新疆电力公司阿勒泰供电公司 自动化负荷开关及其控制系统及断路态和导通态方法
CN207367899U (zh) * 2017-11-07 2018-05-15 施耐德电气工业公司 能够检测预定状态的低压配电装置
CN108963998B (zh) * 2018-06-05 2022-04-15 中国电力科学研究院有限公司 旋转式液态金属限流器
EP4068326B1 (fr) * 2019-11-29 2024-02-28 Kabushiki Kaisha Toshiba Disjoncteur à courant continu

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2066129A (en) * 1933-05-08 1936-12-29 Schweitzer & Conrad Inc Fuse
US3534226A (en) 1967-11-09 1970-10-13 Hughes Aircraft Co Sequential switching circuit breaker for high power ac or dc power transmission circuits
US3611031A (en) 1970-06-11 1971-10-05 Hughes Aircraft Co Series sequential circuit breaker
US3660723A (en) 1971-03-09 1972-05-02 Hughes Aircraft Co Current transfer circuit as part of high voltage dc circuit
SE361379B (fr) 1972-03-21 1973-10-29 Asea Ab
US4433608A (en) * 1981-12-03 1984-02-28 Westinghouse Electric Corp. Electromagnetic projectile launcher with an augmented breech
US4598332A (en) * 1984-07-20 1986-07-01 Westinghouse Electric Corp. Current limiting apparatus utilizing multiple resistive parallel rails
US4822961A (en) * 1988-03-07 1989-04-18 Hugin Peter E Soft break switch
FR2677485A1 (fr) * 1991-06-07 1992-12-11 Stopcircuit Sa Appareil de coupure en charge pour circuit electrique.
AU742180B2 (en) * 1997-01-29 2001-12-20 Dieter W. Blum Dynamo-electric machines and control and operating system for the same
US6075684A (en) 1998-03-23 2000-06-13 Electric Boat Corporation Method and arrangement for direct current circuit interruption
JP3799924B2 (ja) * 2000-01-11 2006-07-19 株式会社日立製作所 電力用遮断器および発電所電気回路装置
CN100481297C (zh) * 2003-11-04 2009-04-22 三菱电机株式会社 断路器
EP1630841B1 (fr) * 2004-08-23 2010-10-06 ABB Technology AG Chambre de commutation et disjoncteur-limiteur
DE102006004811A1 (de) * 2006-01-26 2007-08-09 Siemens Ag Elektrisches Schaltgerät mit Potentialsteuerung
EP1939908A1 (fr) * 2006-12-29 2008-07-02 ABB Technology Ltd Procédé de conception d'antennes réseau
KR101503955B1 (ko) * 2007-09-10 2015-03-18 에이비비 테크놀로지 아게 시작 저항기와 맞물리기 위한 스위치를 갖는 고전압 전력 스위치
US8445978B2 (en) * 2008-11-26 2013-05-21 Freescale Semiconductor, Inc. Electromechanical transducer device and method of forming a electromechanical transducer device

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CA2850601A1 (fr) 2013-04-04
AU2012315502B2 (en) 2016-06-30
CA2850601C (fr) 2018-12-11
CN104115250B (zh) 2017-11-03
EP2761637B1 (fr) 2016-12-07
WO2013049790A1 (fr) 2013-04-04
HK1200240A1 (en) 2015-07-31
EP2761637A4 (fr) 2015-03-18
CN104115250A (zh) 2014-10-22
AU2012315502A1 (en) 2014-04-17
PL2761637T3 (pl) 2017-06-30
ES2613669T3 (es) 2017-05-25

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