HIGH VOLTAGE CIRCUIT BREAKER

Abstract

An improved circuit breaker is disclosed herein. The improved circuit breaker includes one or more main contacts and only one resistor contact. The only one resistor contact is connected in parallel with at least one of the one or more main contacts.

Claims

1. An improved circuit breaker comprises: one or more main contacts; and one and only one resistor contact, wherein the one and only one resistor contact is connected in parallel with at least one of the one or more main contacts.

2. The improved circuit breaker of claim 1, wherein each main contact of the one or more main contacts comprises at least one first fixed terminal and at least one first moving terminal.

3. The improved circuit breaker of claim 2, wherein the one and only one resistor contact comprises at least one second fixed terminal and at least one second moving terminal.

4. The improved circuit breaker of claim 3, further comprising: at least one breaker tank.

5. The improved circuit breaker of claim 4, wherein the at least one breaker tank comprises a plurality of links.

6. The improved circuit breaker of claim 5, wherein the plurality of links is in contact with the at least one first moving terminal.

7. The improved circuit breaker of claim 6, wherein the plurality of links is in contact with the at least one second moving terminal.

8. The improved circuit breaker of claim 7, wherein the one and only one resistor contact comprises at least one resistive component.

9. The improved circuit breaker of claim 8, wherein the one or more main contacts are enclosed in one or more interrupter units.

10. The improved circuit breaker of claim 8, wherein the one and only one resistor contact is enclosed in one and only one closing resistor unit.

11. The improved circuit breaker of claim 7, wherein the one or more main contacts are enclosed in one or more interrupter units.

12. The improved circuit breaker of claim 7, wherein the one and only one resistor contact is enclosed in one and only one closing resistor unit.

13. The improved circuit breaker of claim 1, wherein the one and only one resistor contact comprises at least one resistive component.

14. The improved circuit breaker of claim 1, wherein the one or more main contacts are enclosed in one or more interrupter units.

15. The improved circuit breaker of claim 1, wherein the one and only one resistor contact is enclosed in one and only one closing resistor unit.

16. The improved circuit breaker of claim 1, further comprising: at least one breaker tank.

17. The improved circuit of claim 16, wherein the at least one breaker tank comprises a plurality of links.

18. The improved circuit breaker of claim 17, wherein the plurality of links is in contact with at least one first moving terminal of a main contact of the one or more main contacts.

19. The improved circuit breaker of claim 18, wherein the plurality of links is in contact with at least one second moving terminal of the main contact.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present disclosure is further described hereinafter with reference to illustrated embodiments shown in the accompanying drawings, in which:

[0020] FIG. 1 illustrates a high voltage circuit breaker in accordance with the state of the art.

[0021] FIG. 2 illustrates a circuit diagram of the high voltage circuit breaker of FIG. 1 in accordance with the state of the art.

[0022] FIG. 3 illustrates an improved circuit breaker in accordance with an embodiment.

[0023] FIG. 4 illustrates a circuit of the improved circuit breaker of FIG. 3 under breaker open condition in accordance with an embodiment.

[0024] FIG. 5 illustrates the circuit of the improved circuit breaker of FIG. 3 under closing resistor closed condition in accordance with an embodiment.

[0025] FIG. 6 illustrates the circuit of the improved circuit breaker of FIG. 3 under breaker closed condition in accordance with an embodiment.

[0026] FIG. 7 illustrates the circuit of the improved circuit breaker of FIG. 3 under normal condition in accordance with an embodiment.

DETAILED DESCRIPTION

[0027] Various embodiments are described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident that such embodiments may be practiced without these specific details.

[0028] FIG. 3 illustrates an improved circuit breaker 300 in accordance with an embodiment. The improved circuit breaker 300 includes two interrupter units 302, 304 and a closing resistor unit 306. The improved circuit breaker 300 also includes a breaker tank 308, an incoming terminal 318, and an outgoing terminal 320. The breaker tank 308 including mechanical links 310, as illustrated in FIG. 3. During normal operation, current is flowing through the improved circuit breaker 300 from the incoming terminal 318 to the outgoing terminal 320 through the incoming interrupter unit 302 and the outgoing interrupter unit 304. A flow of current from the terminal 318 to terminal 320, as described in FIG. 3, is merely for demonstration purposes. In other embodiments, the current may flow from the terminal 320 to the terminal 318. The interrupter units 302, 304 include main contacts 312, 314 respectively, and the resistor closing unit 306 includes a resistor contact 316, as illustrated in FIG. 3. The shape and functionality of the main contacts 312, 314 are the same as the shape and functionality of the main contacts 118, 120 of the high voltage circuit breaker 100, illustrated in FIG. 1. The main contacts 312, 314 include fixed terminals 312A, 314A and moving terminals 312B, 314B, respectively, as shown in FIG. 3. Also, the resistor contact 316 of the improved circuit breaker 300 is functionally similar to the resistor contacts 122, 124 of the high voltage circuit breaker 100, illustrated in FIG. 1. The resistor contact 316 includes a fixed contact 316A and a moving contact 316B, as illustrated in FIG. 3. All three moving contacts 312B, 314B, 316B are connected to the mechanical links 310 of the breaker tank 308, as shown in FIG. 3.

[0029] During normal flow of current through the improved circuit breaker 300, the fixed contacts 312A, 314A of the main contacts 312, 314 are connected to the moving contacts 312B, 314B, respectively, and the fixed contact 316A of the resistor contact 316 is not connected with the moving contact 316B. In other words, during normal flow of current, the main contacts 312, 314 of the interrupter units 302, 304 remain in a closed state and the resistor contact 316 of the closing resistor unit 306 remains in an open state. In case of a fault or maintenance requirement, the improved circuit breaker 300 is needed to be in breaker open condition so that the flow of current through the improved circuit breaker 300 may be restricted. In order to achieve the breaker open condition, all the contacts, (e.g., the main contacts 312, 314 and the resistor contact 316), of the improved circuit breaker are set to be in an open state, as illustrated in FIG. 3. After completion of the maintenance and/or rectification of the fault, it is needed to resume a flow of current through the improved circuit breaker 300. To resume the flow of current, it is required that the improved breaker 300 attains its normal condition under which the main contacts 312, 314 of the interrupter units 302, 304 of the improved circuit breaker 300 should be closed and the resistor contact 316 of the closing resistor unit 306 of the improved circuit breaker 300 should be open. A step-by-step circuit level functionality of the improved circuit breaker 300 from the breaker open condition to the normal condition is explained in following figures.

[0030] FIG. 4 illustrates a circuit 400 of the improved circuit breaker 300 during breaker open condition. The main contacts 312, 314 and the resistor contact 316 of the improved circuit breaker 300 are illustrated as switches 312, 314, 316 of the circuit 400 in FIG. 4. The circuit 400 of the improved circuit breaker 300 also includes resistors R5, R6 representing the resistance offered by the closing resistor unit 306 of the improved circuit breaker 300, illustrated in FIG. 3. In one embodiment, a resistance value offered by the resistors R5, R6 is equivalent to the resistance value offered by the resistors R1, R2, R3, R4 of the circuit 200 of the high voltage circuit breaker 100 shown in FIG. 2. During the breaker open condition, all the contacts 312, 314, 316 are open; hence no flow of current between the incoming terminal 318 and the outgoing terminal 320 of the improved circuit breaker 300, as illustrated in FIG. 4.

[0031] To resume the flow of current through the improved circuit breaker 300, at least one contact out of the outgoing main contact 314 and the resistor contact 316 should be in a closed state along with the incoming main contact 312. If the main contacts 312, 314 get back to the closed state directly, it will lead to over-voltage due to switching transients that may negatively affect the electrical system. To avoid the over-voltage, the resistor contact 316 should attain a closed state along with the incoming main contact 312, as illustrated in FIG. 5. When the incoming main contact 312 is closed along with the resistor contact 316 and the outgoing main contact is open, as shown in FIG. 5, then the improved circuit breaker 300 is considered to be in a closing resistor closed condition. Once the incoming main contact 312 and the resistor contact 316 are in a closed state along with the outgoing main contact 314 in an open state, the current will start flowing between the incoming terminal 318 and the outgoing terminal 320 through the resistors R5, R6, the resistor contact 316 and the incoming main contact 312, as illustrated in FIG. 5. The over-voltage due to switching transients is avoided because of the damping effect provided by the resistors R5, R6.

[0032] After a pre-defined time delay, the outgoing main contact 314 also attains a closed state along with the incoming main contact 312 and the resistor contact 316, as illustrated in FIG. 6. The pre-defined time delay is defined on the basis of an amount of current flowing through the improved circuit breaker 300, the resistance value offered by the resistors R5, R6 and other system parameters. Various methods for calculating the pre-defined time delay based on the electrical system parameters including, but not limited to, current and resistance value, are disclosed in the state of the art. In one embodiment, the pre-defined time delay is 10 milliseconds. When all the contacts, (e.g., the incoming main contact 312, the outgoing main contact 314, and the resistor contact 316), are in a closed state, then the improved circuit breaker 300 attains a breaker closed condition, as illustrated in FIG. 6. In one embodiment, the breaker closed condition, illustrated in FIG. 6, is a normal condition of operation for the improved circuit breaker 300. In an embodiment, all the contacts, (e.g., the incoming main contact 312, the outgoing main contact 314, and the resistor contact 316), are closed during the normal operation of the improved circuit breaker 300 and as the interrupter unit 304 offers negligible resistance in comparison to the closing resistor unit 306; hence, almost all the current will flow through the interrupter units 302, 304 instead of the closing resistor unit 306.

[0033] After the improved circuit breaker 300 attains the breaker closed condition, then the current start flowing from both the contacts, that are the outgoing main contact 314 and the resistor contact 316, as the two contacts are connected in parallel. However, a significant current will flow through the outgoing main contact 314 in comparison to the resistor contact 316 because the interrupter unit 304 offers negligible resistance in comparison to the closing resistor unit 306. The closing resistor unit 306 offers a substantial resistance to the flow of current in comparison of the interrupter unit 304 even then some current may flow through the closing resistor unit 306. If the current start flowing through the closing resistor unit 306, (e.g., if the current start flowing through the resistor contact 316 and the resistors R5, R6, as illustrated in preceding figures), then the current will negatively affect the efficiency of the improved circuit breaker 300. In other words, the flow of current through the resistors R5, R6 will lead to loss of power that degrades the efficiency of the improved circuit breaker 300. Hence, to avoid the power loss, the resistor contact 316 should return to an open state after closing of the outgoing main contact 314, as illustrated in FIG. 7. The circuit 400, shown in FIG. 7, illustrates the state of the main contacts 312, 314, (e.g., in a closed state), and the resistor contact 316, (e.g., in an open state), for the improved circuit breaker under the normal condition of operation, e.g., when the current is flowing through a minimum resistance path of the improved circuit breaker 300. The normal condition of the circuit 400 of the improved circuit breaker 300 may also be known as closing resistor open condition.

[0034] FIG. 2 depicts an exemplary embodiment. In the embodiment, the resistor closing unit 306 is connected in parallel with the incoming interrupter unit 302. In another exemplary embodiment, the improved circuit breaker 300 includes one or more than one interrupter units 302, 304. In the exemplary embodiment, the closing resistor unit 306 is connected in parallel with at least one of the one or more than more interrupter units 302, 304.

[0035] The resistors R5, R6 illustrated in FIG. 4 to FIG. 7 are merely for explanation purpose. In other embodiments, however, a combination of active and/or passive electrical devices and/or components may be used instead of or in combination with the resistors R5, R6.

[0036] An improved circuit breaker 300 is disclosed for which less amount of manufacturing materials are required in comparison to the circuit breaker know in the state of the art. Additionally, the improved circuit breaker 300 is light in weight; hence easy to keep the improved circuit breaker 300 at an elevated height without any mechanical stability problems. In the improved circuit breaker 300, the use of only one closing resistor unit 306 reduces significantly the complexity of the breaker tank 308 and also reduces the complexity of the improved circuit breaker 300. Due to less complexity of the improved circuit breaker 300, in comparison to the circuit breakers known in the state of the art, it becomes possible to assemble the improved circuit breaker 300 quickly. Further, due to less complex design and light weight, the improved circuit breaker 300 is significantly less susceptible to seismic load failure risk in comparison of the circuit breakers known in the state of the art. Furthermore, due to significant reduction in the closing resistor units in the improved circuit breaker 300, in comparison to the circuit breakers known in the state of the art, the mechanical energy required for operating the contacts of the improved circuit breaker 300 is significantly less than the mechanical energy required for operating the contacts of the circuit breaker known in the state of the art.

[0037] From the foregoing description, it is evident that the present disclosure provides a light weight, less complex, and efficient improved circuit breaker.

[0038] While the present disclosure has been described in detail with reference to certain embodiments, it should be appreciated that the present disclosure is not limited to those embodiments. In view of the present disclosure, many modifications and variations would present themselves, to those of skill in the art without departing from the scope of various embodiments, as described herein. The scope of the present disclosure is, therefore, indicated by the following claims rather than by the foregoing description. All changes, modifications, and variations coming within the meaning and range of equivalency of the claims are to be considered within their scope.