Gas insulated grounding switch

Abstract

A circuit breaker apparatus has a housing, electrical power inlet, electrical power outlet, a main circuit breaker, a grounding switch, and a mechanical linkage. The main circuit breaker and the grounding switch each have a pair of contactors therein. The mechanical linkage is movable between a pair of positions in which one of the positions causes the pair of contactors of the main circuit breaker to close and the pair of contactors of the grounding switch to open and another position in which the pair of contactors of the main circuit breaker are open and such that the pair of contactors of the grounding switch are closed. The housing has an interior that is filled with an isolating gas.

Claims

1. A circuit breaker apparatus comprising: a housing; an electrical power inlet; an electrical power outlet; a main circuit breaker positioned in said housing, said main circuit breaker having a pair of contactors therein, one of said pair of contactors electrically connected or interconnected to said electrical power inlet and to said electrical power outlet; a grounding switch positioned in said housing, said grounding switch having a pair of contactors therein, one of said pair of contactors of said grounding switch being electrically connected or interconnected to ground, said grounding switch being in non-longitudinal relation to said main circuit breaker; and a mechanical linkage movable between a first position and a second position, said first position actuating said main circuit breaker such that the pair of contactors of said main circuit breaker are closed and such that the pair of contactors of said grounding switch are open, said mechanical linkage movable to said second position actuating said main circuit breaker such that the pair of contactors of said main circuit breaker are open and such that the pair of contactors of said grounding switch are closed, said mechanical linkage comprising: an actuator that is movable between a first position and a second position, said actuator movable from the first position to the second position upon detection of a fault in electrical power from said electrical power inlet; and a yoke connected to said actuator, said yoke connected to one of said pair of contactors of said main circuit breaker and to one of said pair of contactors of said grounding switch, a movement of said actuator to the second position causing the pair of contactors of said main circuit breaker to open and the pair of contactors of said grounding switch to close.

2. The circuit breaker apparatus of claim 1, said housing having an interior that is void of air.

3. The circuit breaker apparatus of claim 2, said interior being filled with an isolating gas.

4. The circuit breaker apparatus of claim 1, said electrical power outlet being a main bus having at least a portion positioned in said housing, said main circuit breaker electrically connected to said main bus when the of contactors of said main circuit breaker are closed.

5. The circuit breaker apparatus of claim 4, further comprising: a switch disconnect positioned in said housing, said switch disconnect movable between a first position which electrically connects said main circuit breaker to said main bus and a second position electrically isolating said main circuit breaker from said main bus.

6. The circuit breaker apparatus of claim 1, said grounding switch extending in generally transverse relationship to said main circuit breaker.

7. The circuit breaker apparatus of claim 1, said yoke being pivotally mounted within said housing.

8. The circuit breaker apparatus of claim 1, said yoke having a generally L-shape, said actuator having an arm connected adjacent to one end of the L-shape, the one of the pair of contactors of said grounding switch connected to a portion of the L-shape away from the one end of the L-shape, the one of the pair of contactors of said main circuit breaker connected to an opposite end of the L-shape.

9. The circuit breaker apparatus of claim 8, said actuator having a rod connected to said arm at a location away from the one end of the L-shape, said rod being resiliently mounted so as to move downwardly upon the detection of the fault in the electrical power from the electrical power inlet, so as to cause said rod to move said arm so as to pivot said yoke in order to open the pair of contactors of said main circuit breaker and close the pair of contactors of said grounding switch.

10. The circuit breaker apparatus of claim 1, said main circuit breaker having a vacuum bottle in which the pair of contactors of said main circuit breaker are positioned, said grounding switch having another vacuum bottle in which the pair of contactors of said grounding switch are positioned.

11. The circuit breaker apparatus of claim 1, said electrical power inlet comprising: a cable extending to or into said housing; a conductor connected to said cable through a busing; and a conductive plate positioned in said housing adjacent to said main circuit breaker, said main circuit breaker being electrically connected to said conductive plate.

12. The circuit breaker apparatus of claim 1, further comprising: a grounding bus coupled to another of the pair of contactors of said grounding switch, said grounding bus connected to ground so that the electrical power passes to ground when the pair of contactors of said main circuit breaker are open and when the pair of contactors of said grounding switch are closed.

13. The circuit breaker apparatus of claim 1, one of the pair of contactors of said main circuit breaker being movable and another of the pair of contactors of said main circuit breaker being fixed, one of the pair of contactors of said grounding switch being movable and another of the pair of contactors of said grounding switch being fixed.

14. The circuit breaker apparatus of claim 1, said electrical power inlet passing power of three phases, said main circuit breaker being three main circuit breakers respectively connected to the three phases, said grounding switch being three grounding switches respectively connected to the three phases, the mechanical linkage being connected to the three main circuit breakers and the three grounding switches.

15. A switchgear having a plurality of the circuit breaker apparatuses of claim 1.

16. The switchgear of claim 15, the electrical power outlet being a main bus extending between the plurality of the circuit breaker apparatuses.

17. A circuit breaker apparatus comprising: a housing having an interior that is void of air; an electrical power inlet; an electrical power outlet; a main circuit breaker positioned in said housing, said main circuit breaker having a pair of contactors therein, one of the pair of contactors electrically connected or interconnected to said electrical power inlet and to said electrical power outlet; a grounding switch positioned in said housing, said grounding switch having a pair of contactors therein, one of the pair of contactors of said grounding switch being electrically connected or interconnected to ground; and a mechanical linkage movable to a first position and a second position, said first position actuating said main circuit breaker such that the pair of contactors of the said main circuit breaker are closed and such that the pair of contactors of said grounding switch are open, said mechanical linkage movable to said second position actuating said main circuit breaker such that the pair of contactors of said main circuit breaker are open and such that the pair of contactors of said grounding switch are closed, said mechanical linkage comprising: an actuator that is movable between a first position and a second position, said actuator movable from the first position to the second position upon detection of a fault in electrical power from said electrical power inlet; and a yoke connected to said actuator, said yoke connected to one of said pair of contactors of said main circuit breaker and to one of said pair of contactors of said grounding switch, a movement of said actuator to the second position causing the pair of contactors of said main circuit breaker to open and the pair of contactors of said grounding switch to close.

18. The circuit breaker apparatus of claim 17, said interior being filled with an isolating gas.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) FIG. 1 is a block diagram showing the operation of a prior art circuit breaker system.

(2) FIG. 2 is a block diagram showing the prior art circuit breaker system of U.S. Pat. No. 7,724,489.

(3) FIG. 3 is a side interior view of the circuit breaker of the prior art in accordance with U.S. Pat. No. 7,724,489.

(4) FIG. 4 is a frontal elevational view of the circuit breaker of the prior art of U.S. Pat. No. 7,724,489.

(5) FIG. 5 is an illustration of the mechanical interlock of the prior art of U.S. Pat. No. 7,724,489 in a first position.

(6) FIG. 6 is an illustration of the operation of the mechanical interlock of the prior art of U.S. Pat. No. 7,724,489 with the mechanical interlock in a second position.

(7) FIG. 7 is a frontal elevational view of the circuit breaker apparatus of the present invention.

(8) FIG. 8 is an interior frontal view of the circuit breaker apparatus of the present invention.

(9) FIG. 9 is a cross-sectional and diagrammatic view showing the mechanical linkage in a first position.

(10) FIG. 10 is a cross-sectional and diagrammatic view of the mechanical linkage and a second position.

(11) FIG. 11 is a interior side view of the circuit breaker apparatus of the present invention.

(12) FIG. 12 is a frontal view showing the circuit breaker apparatus of the present invention configured as a switchgear.

DETAILED DESCRIPTION OF THE INVENTION

(13) Referring to FIG. 7, there is shown the circuit breaker apparatus 200 in accordance with the present invention. The circuit breaker apparatus 200 includes a housing 202 in which the components are contained. The exterior of the housing 200 into has a control system 204 for the operation of the switch disconnect mechanism (to be described hereinafter). Another controller 206 is located on the housing 202 into. Controller 206 is adapted for controlling and reporting the operation of the actuating mechanism of the circuit breaker apparatus. The controller 206 is connected to the electrical power inlet. Suitable sensors are provided therein so that when a fault occurs in the electrical power inlet, the actuating mechanism is actuated so as to break the circuit and to prevent power from flowing between the electrical power inlet and the electrical power outlet.

(14) FIG. 8 shows an interior view of the housing 202 of the circuit breaker apparatus 200. Importantly, in the circuit breaker apparatus the present invention, there is an interior 208 which is generally sealed. The interior 208 will be free of air and contain an isolating gas. In the preferred embodiment of the present invention, the isolating gas is sulfur hexafluoride. However within the concept of the present invention, the isolating gas can be any other gas or gaseous mixture comparable to sulfur hexafluoride. This isolating gas is installed into the interior 208 by opening a valve such that the isolating gas is introduced into the interior 208 while air from the interior 208 is evacuated through another valve. After the isolating gas fills the interior 208, the valves are suitably close so that the interior 208 is void of air and is filled with the isolating gas. The isolating gas is important since it decreases electrical distances and serves as a dielectric improvement. The isolating gas avoids arcing between the various components within the interior 208. As such, this allows the main circuit breaker 210 and the grounding switch 212 to be placed in relatively close non-longitudinal alignment. In FIG. 8, the main circuit breaker 210 and the grounding switch 212 are in generally transverse relationship. The isolating gas assures that there will be no arcing between the main circuit breaker 210 and the grounding switch 212.

(15) FIG. 8 shows the electrical power inlet 214. Electrical power inlet 214 is divided into the separate phases 216, 218 and 220. The three phases are placed in relatively close alignment. The isolating gas assures that there will be no arcing between the phases. In general, FIG. 8 shows the configuration of the circuit breaker apparatus 200 in association with one of the three phases. For the purposes of illustration, the circuit breaker apparatus 200 will be described in association with the phase 216 of the electrical power inlet 214.

(16) An input power bus 222 extends from the electrical power inlet 214. The input power bus 222 is in electrical connection with a conductive plate 224. Conductive plate 224, in the preferred embodiment, is an aluminum plate. A copper flexible foil 226 is in electrical connection with the conductive plate 224 and is also in electrical connection with the main breaker switch 210 and the grounding switch 212. An insulated support 228 serves to secure the conductive plate 224 in a proper position within the interior 208 of the housing 202. A mechanical linkage 230 is provided in the interior 208 of the housing 202. The mechanical linkage 230, as will be described hereinafter, is movable between a first position and a second position. The first position actuates the main circuit breaker such that the pair of contactors in the main circuit breaker are closed and such that the pair of contactors of the grounding switch 212 are open. The mechanical linkage 230 is also movable to a second position so as to actuate the main circuit breaker such that the pair of contactors of the main circuit breaker 210 are open and such that the pair of contactors of the grounding switch 212 are closed. In particular, the mechanical linkage 230 includes an actuator 232 that is movable between a first position and a second position. The actuator 232 is movable from the first position to the second position upon detection of a fault in the electrical power from the electrical power inlet 214. A yoke 234 is connected to the actuator 232. The yoke 234 is pivotally mounted within the interior 208 of the housing 202. The yoke is connected to one of the pair of contactors of the main circuit breaker 210 and one of the pair of contactors of the grounding switch 212. A movement of the actuator 232 to the second position causes the pair of contactors of the main circuit breaker 210 to open and the pair of contactors of the grounding switch 212 to close.

(17) It can be seen that the yoke 234 has a generally L-shape. The actuator 232 is connected adjacent to one end of the L-shape of the yoke 234. One of the pair of contactors of the grounding switch is connected to a portion of the L-shape away from that one end of the L-shape. One of the pair of contactors of the main circuit breaker 210 are connected to an opposite end of the L-shape. The actuator 232 includes a rod 236 that is connected to the arm 238 at a location from one end of the L-shape of the yoke 234. The rod 236 is resiliently mounted so as to move downwardly upon the detection of a fault in the electrical power from the electrical power inlet 214. The downward movement of the rod 236 causes of the rod 236 to move the arm 238 in order to pivot the yoke 234 in order to open the pair of contactors of the main circuit breaker 210 and close the pair of contactors of the grounding switch 212.

(18) It can be seen that the main circuit breaker 210 is a vacuum bottle in which the pair of contactors are positioned. The grounding switch 212 is another vacuum bottle in which the pair of contactors of the grounding switch 212 are positioned.

(19) A main bus 240 is located in an upper portion of the housing 212. An isolator, namely switch disconnect 242, is cooperative with the main bus 240. The main bus 240 has at least a portion positioned in the housing 202. The main bus can extend outwardly of the housing 202 so as to connect with other circuit breaker apparatus, such as circuit breaker apparatus 200. As such, it can be used so as to form a suitable switchgear (as will be shown in FIG. 13). The main circuit breaker 210 is electrically connected to the main bus 240 when the pair of contactors of the main circuit breaker 210 are closed. The switch disconnect 242 is positioned in the housing 202. The switch disconnect is movable between a first position in which the main circuit breaker 210 is electrically connected to the main bus 240 and a second position in which the main bus 240 is electrically isolated from the main circuit breaker 210. In particular, there is a shaft 244 which can be manually or mechanically operated so as to move the switch disconnect 242 between the first position and the second position. A rotation of the shaft 244 in one direction will separate the switch disconnect 242 so that the switch disconnect 242 is in the second position. The shaft 244 can be rotated in an opposite direction so as to urge the switch disconnect 242 upwardly so as to electrically connect with the main bus 240. An insulated support 246 maintains the main circuit breaker 210 in a proper position within the interior 208 of the housing 202.

(20) FIG. 9 shows the specific operation of the mechanical linkage 230 relative to the main circuit breaker 210 and the grounding switch 212. It can be seen that the main circuit breaker 210 has a contactor 250 that is in a fixed position and is connected to a line 252. There is a second contactor 254 which is movable. In FIG. 9, the second contactor 254 contacts with the first contactor 250 so that an electrical connection is established between the line 256 and line 252. In this configuration, electrical power from the electrical power inlet 214 can flow to the main bus 240 (assuming the switch disconnect 242 is closed). When the pair of contactors 250 and 254 of the main circuit breaker 210 are closed, the mechanical linkage 230 automatically serves to keep open the contactors 258 and 260 of the grounding switch 212. As such, power from the electrical power inlet 214 will not flow to ground 262. It can be seen that the main circuit breaker 210 is in transverse relationship to the grounding switch 212.

(21) FIG. 10 shows what happens when there is a pivoting of the mechanical linkage 230 which is caused by a fault in the electrical power from the electrical power inlet 214. In this arrangement, the first contactor 250 of the main grounding switch 210 is opened relative to the second contactor 254. As such, current will not flow from line 256 to line 252. Simultaneously, the contactor 260 is closed upon contactor 258 of the grounding switch 212. As such, upon a fault in the electrical power from the electrical power inlet 214, the power will flow to ground 262 through line 264. In this configuration, the present invention assures that the transfer of power to ground and the disconnection of power to the main bus is automatic, immediate and simultaneous upon the detection of a fault.

(22) FIG. 11 shows the circuit breaker apparatus 200 of the present invention as used in association with the three phases of power. Initially, the power supply from a wind or solar farm can be connected to the electrical power inlet 214. A cable 270 extends from the electrical power inlet into the housing 202. Cable 270 then extends through a bushing 272 and into the interior 208 of the housing 202. The cable 270 is then divided into the separate phases 216, 218 and 220. Each of the phases 216, 218 and 220 is directed to separate main circuit breakers 210 and separate grounding switches 212. A shock absorber 274 is connected to one end of a shaft 276. Shaft 276 is part of the mechanical linkage 230 and, in particular, acts on the arm 238 (as shown in FIG. 8). The shaft 276 extends through a bushing 278 and into the actuating mechanism 230. The actuating mechanism has rod 236 extending downwardly so as to act on and rotate the shaft 276. As such, a small cam 280 located in the controller 206 moves the rod 236 downwardly so as to rotate shaft 276 in order to move the arm 238 and thereby up move the yoke 234 between the first and second positions (in the manner described herein previously).

(23) The shaft 244 associated with the switch disconnect 242 can be rotated manually or electromechanically through the controller 204. The rotation of the shaft 244 will move the switch disconnect 242 between the first position and the second position.

(24) FIG. 12 shows the circuit breaker apparatus 200 in the form of switchgear 310. As can be seen the circuit breaker apparatus 200 is joined to another circuit breaker apparatus 312 by way of the main bus 240. Main bus 240 will extend through the interior of the circuit breaker apparatus 312 and eventually into the interior of the circuit breaker apparatus 314. As such, the circuit breaker apparatuses 200, 312 and 314 can operate in unison so as to deliver power to the grid. As such, the housings 202 can be arranged next to one another in a very small footprint and of a very small size.

(25) Unlike the subject matter of U.S. Pat. No. 7,723,489, it is important to note that the switch disconnect 242 and main bus 240 are located within the interior of the housing. As such, the bushings associated with the prior art are avoided in the present invention along with the complex arrangement of the switch disconnects and the main bus at a location above the circuit breaker apparatus. As such, the present invention provides a very compact configuration. This reduces size, transportation costs, manpower required for assembly, materials, along with a variety of other cost savings.

(26) Since the interior of the housing 202 is maintained in an air-free environment, and within an isolating gas, there is minimal risk of corrosion. As such, the present invention can be used in an offshore environments or other corrosive environments. The isolating gas allows the various electrical components to be placed in very close relationship within the interior 208 of the housing 202. As such, unlike the subject matter of U.S. Pat. No. 7,724,489, the main circuit breaker 210 and the grounding switch 212 are placed in non-longitudinal alignment and the three phases of power can be placed in close proximity to each other. As such, the height and the width of the housing are greatly reduced and the space required for the operating mechanisms within the housing are also significantly reduced. In view of the reduced corrosion affecting the components within the interior 208 of the housing 202, the circuit breaker apparatus 200 will have a longer life.

(27) Simulation shows that the circuit breaker apparatus of the present invention resolves both issues of temporary overvoltage and incident energy where delays are not needed for clearing the fault from the plant. The present invention completely operates within nearly fifty milliseconds to open, clear the fault, close, and ground the affected collection circuit. As such, it collapses the voltage. When closed to ground, the present invention results in a very low impedance in the cable. There is a very clear change in impedance as it operates. Generators can detect such a change and act on it. The temporary overvoltage duration is minimized by the combination of the fast transition state of the present invention and the lightning arrestors. The present invention significantly lowers the energy burden on lightning arrestors and protects them. The present invention relieves the lightning arrestor and keeps the resulting temporary overvoltage below the duty curves. Without the present invention, the arrestors could be destroyed by other protection schemes. If they are destroyed and not replaced, expensive collection circuit equipment could be damaged thereinafter.

(28) The circuit breaker apparatus the present invention signals the wind generators in a fraction of the 150 ms required by PRC-024-1 and PRC-024-2 when the fault is inside the plant. This provides the generators with valuable information in which to allow the decision to be made to shut down. The present invention signals the generator that the fault is inside the plant and shuts them down for events that the turbines should not ride through. This provides a valuable discriminatory function that standard circuit breakers would not. The present invention forms a three-phase bolted ground and provides a zero reference closer to the generators than the zero reference that forms with the three-phase bolted ground at the point of interconnection. The difference in impedance between internal faults and external faults is basically the impedance of the main plant transformer. At near full power for the wind or solar power plant, the delta in voltage between the two fault locations is approximately eight percent. As a result, each generator can detect and discriminate between each fault location. Because the present invention can help differentiate between internal and external faults, generators will know via, the voltage measured at their terminals, that the fault is outside the plant and keep it running. As a result, the present invention provides designers and engineers with the ability to distinguish between external and internal faults. As such, the generators may be set to trip if the fault is in the plant or ride through the fault if the fault is outside the plant. The present invention does not require the use of fiberoptic installations that link the substation with the turbines to send shutdown signals to the generator. As such, the present invention is extremely cybersecure. The shutdown signal goes from the present invention to all of the generators of the collection circuit faster than any other means and the signal is transmitted to all of the generators at the same time.

(29) The present invention protects solar/wind power plants by reducing incident energy and eliminating temporary overvoltage. Elimination of the temporary overvoltage is an important feature of the present invention. Through the present invention, the lightning arrestors are operated below their prior duty curve, insulation coordination of the feeder circuit is maintained, and the equipment becomes more reliable. The present invention has an anti-island functionality. Unlike the prior art, the present invention avoids the islanding effect.

(30) The foregoing disclosure and description of the present invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction can be made within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.