Claims:1. A system comprising:
a double crank mechanism adapted to reverse the magnetic flux direction across at least one first conductor by changing the orientation of at least a magnetic material encompassing at least one secondary conductor.

2. A system comprising:
at least one secondary conductor 8 connected in series with at least one first conductor, the secondary conductor 8 are surrounded by at least one magnetic material 9;
at least one double crank mechanism operatively coupled to the magnetic material 9, and adapted to reverse the magnetic flux direction to achieve a transition between an attraction and a repulsion mode by rotating the magnetic material 9 about the secondary conductor 8.

3. The system as claimed in claim 1 and 2, wherein the magnetic materials 9 is adapted to rotate, preferably 180 degrees, over the secondary conductor 8.

4. The system as claimed in claim 1 and 2, wherein the double crank mechanism is preferably a 4-bar double crank mechanism having at least two end positions.

5. The system as claimed in claim 1 and 2, wherein the double crank mechanism comprises at least one link 4 operatively coupled to at least one main spring 3, in a latched condition, using at least a latch assembly 7.

6. The system as claimed in claim 5, wherein the main spring 3 is adapted to rotate at least one crank link 6, preferably in 180 degrees, thereby rotating a magnetic material assembly 9, 10 holding the magnetic materials 9, the crank link 6 is operatively coupled to the magnetic materials 9.

7. A system, to withstand a thermal and/or mechanical stress imposed by at least a fault current, and/or to convert compensating attraction force into a repulsion force, the system comprising:
at least one secondary conductor 8 enclosed by at least one magnetic material housing 10 having at least one magnetic material 9, the magnetic material is rotatable over the secondary conductor 8;
at least one double crank mechanism operatively coupled to the magnetic material 9, and adapted to reverse the magnetic flux direction to achieve a transition between an attraction and a repulsion mode by rotating the magnetic material 9 about the secondary conductor 8.

8. The system as claimed in claim 7, wherein the double crank mechanism comprises at least one latch assembly 7 coupled to at least one latch spring 2, at least one main spring 3, at least one link 4, and at least one crank link 6.

9. The system as claimed in claim 8, wherein the link 4 is connected to the crank link 6 using at least one connector 5.

10. The system as claimed in claim 8, wherein the main spring 3 is adapted to rotate at least one crank link 6, preferably in 180 degrees, thereby rotating a magnetic material assembly 9, 10 holding the magnetic materials 9, the crank link 6 is operatively coupled to the magnetic materials 9.
, Description:TECHNICAL FIELD

[001] The present subject matter described herein, in general, relates to switchgears and circuit breakers, and more particularly relates to a mechanism of reversing the magnetic flux direction across the conductor by changing the orientation of the magnetic material encompassing the secondary conductors using double crank mechanism in low voltage (LV) switchgear applications.

BACKGROUND

[002] A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overcurrent/overload or short circuit. Its basic function is to interrupt current flow after protective relays detect faults condition.

[003] Circuit breakers may be subjected to faults which they are not intended to clear. For instance, it needs to incorporate the design of an electrical system in which the downstream protective device nearest to the system fault clears the fault without affecting the protective devices that are upstream from it. The purpose of this discrimination is to disconnect only the faulty load or feeder from the network, while keeping as much as possible of the installation powered up. While not clearing these faults, the breaker will still need to withstand the thermal and mechanical stress imposed by the fault current.

[004] The prior-art literature such as WO1986006534A1, US3550049, US8674793, US7081596, and WO02054431A1 have tried to solve the above issues occurring in circuit breakers when subjected to faults which they are not intended to clear by providing different solutions.

SUMMARY OF THE INVENTION

[005] The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

[006] An object of the present invention is to provide a method of reversing the magnetic flux direction across the conductor by changing the orientation of the magnetic material encompassing the secondary conductors using double crank mechanism in LV switchgear applications.

[007] Accordingly, in one implementation, a system comprising a double crank mechanism adapted to reverse the magnetic flux direction across at least one first conductor by changing the orientation of at least a magnetic material encompassing at least one secondary conductor is disclosed.

[008] In one implementation, a system, to withstand a thermal and/or mechanical stress imposed by at least a fault current, and/or to convert compensating attraction force into a repulsion force, is disclosed. The system comprises at least one secondary conductor enclosed by at least one magnetic material housing having at least one magnetic material, the magnetic material is rotatable over the secondary conductor, and at least one double crank mechanism operatively coupled to the magnetic material, and adapted to reverse the magnetic flux direction to achieve a transition between an attraction and a repulsion mode by rotating the magnetic material about the secondary conductor.

[009] In contrast to the prior-art available, when a circuit breaker is subjected to faults which they are not intended to clear, the present invention provide necessary compensating force to provide short time withstand for circuit breaker. Moreover by changing the positioning of few components, the compensating force can be relieved and the direction reversed in order to isolate the electrical circuit. The present invention enables to convert compensating attraction force in to a repulsion force based on requirement.

[0010] In contrast to the prior-art available, the double crank mechanism of the present invention comprises a solenoid actuated latch assembly which includes a travel of 8.5 mm to achieve the latching and de-latching mechanism. The latch profile of the solenoid actuated latch is designed in a way to optimize this stroke length/travel of the solenoid actuator. Also, the main link of the solenoid actuated latch assembly is designed in a way such that at the point of latching we get the leverage of 1.15 to 1.55 between extreme positions. This leverage is required for reducing the required spring force needed for the high speed response of the mechanism and at the same time reduce the reaction force at Latch assembly. Further, the double crank mechanism of the present invention comprises a main spring which works between the initial preload of 8 kgs, which is required for mechanism stability, to 18 kgs at the time of latching. This is a high speed response system where in the main spring dissipates 10 Kgs of stored energy to rotate the links by 180 degrees in a time span of 4.3 ms. For even higher response time spring values of higher loads to be selected keeping in mind the structural stability of the components.

[0011] Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:

[0012] Figure 1 illustrates magnetic materials and secondary conductors (a) the positioning of magnetic materials and secondary conductors in attraction mode, and (b) the positioning of magnetic materials and secondary conductors in repulsion mode, in accordance with an embodiment of the present subject matter.

[0013] Figure 2 illustrates the double crank mechanism to rotate the magnetic material, in accordance with an embodiment of the present subject matter.

[0014] Figure 3 illustrates a position of the mechanism in attraction mode, in accordance with an embodiment of the present subject matter.

[0015] Figure 4 illustrates a position of the mechanism in repulsion mode, in accordance with an embodiment of the present subject matter.

[0016] Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0017] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary.

[0018] Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

[0019] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

[0020] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

[0021] By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

[0022] Features that are described and/or illustrated with respect to one embodiment may be used in the same way or in a similar way in one or more other embodiments and/or in combination with or instead of the features of the other embodiments.

[0023] It should be emphasized that the term “comprises/comprising” when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0024] Accordingly, a concept for reversing the force polarity for LV switchgear applications is disclosed in the present invention.

[0025] In one implementation, a double crank mechanism to change the orientation of the magnetic shield is disclosed.

[0026] In one implementation, the present invention is adapted to operate in two modes. If current is flowing in two parallel conductors in same direction, their magnetic fields interact in such a manner so as to produce a resultant attractive force. Conversely, if the current flows in opposite direction, a net repulsive force is obtained. This concept is applied to generate an attractive force when short time withstand is required and repulsive force when it is required to open the electrical contacts.

[0027] The components given in the figures are individually numbered where the numbers refer to the following:
1. Base
2. Latch spring
3. Main Spring
4. Main link
5. Connector
6. Crank links
7. Latch assembly
8. Secondary conductors
9. Magnetic material
10. Housing for magnetic material

[0028] A 2d model for attraction mode and repulsion mode is depicted in figure 1(a) and figure 1(b) respectively. The secondary conductors are connected in series with the main conductor. The magnetic material surrounds the secondary conductors as shown in figure 1(a) and figure 1(b). The dot and cross are popular sign convention denoting the current flow direction.

[0029] In attraction mode, as shown in figure 1(a), the magnetic material shields the magnetic flux produced by secondary conductor 3 where the current is flowing in opposite direction to main conductor 1 whereas the conductors having current in same direction are exposed to each other thereby resulting in net attractive force. The flux linkage between the main conductor and the magnetic materials further contributes to the attractive force.

[0030] In repulsion mode, as shown in figure 1(b), the magnetic material shields magnetic flux produced by the secondary conductor 2 where the current is flowing in same direction to main conductor 1 whereas the conductors having current in opposite direction are exposed to each other thereby resulting in net repulsive force. The flux linkage between the main conductor and the magnetic materials reduces the net repulsive force.

[0031] The transition from attraction to repulsion mode is achieved by rotating magnetic materials about the secondary conductors 8 using double crank mechanism. The magnetic materials 9 are maintained in the orientation as shown in figure 1 (a) to achieve attraction mode when we need increased electrical withstand characteristics. When the contacts need to be separated to break the electrical circuit the orientation of magnetic materials 9 is switched to the position as shown in figure 1(b). The mechanism to rotate the magnetic material in a very short span of time is depicted by figure 2. It may be a 4-bar double crank mechanism wherein two end positions are shown in figure 3 and 4. The magnetic materials 9 may be adapted to rotate 180 degrees over the secondary conductors 8 between the end positions. The main link 4 is connected using the main spring 3 which is held into a position as shown in figure 3 using latch assembly 7.

[0032] In one implementation, once a command is given to de-latch the latch assembly the stored energy in the main spring 3 causes the crank links 6 to rotate 180 degrees, subsequently rotating the magnetic material assembly 9, 10 which is rigidly connected to crank links 6 with the same amount. With the help of the double crank mechanism the attraction mode shown in figure 1(a) may be replicated by position of the links as shown in figure 3. Once the main spring 3 is discharged, the links 4, 5, 6 attain a new position as shown in figure 4 which positions the magnetic materials 9 such that it replicates the repulsion mode as depicted by figure 1(b).

[0033] Apart from what is discussed above, some other benefits and/or technical advantages of the present invention are as provided below:
i. Using the present invention either of the feature are enhanced in the switching device;
ii. In attraction mode the present invention provides compensating forces for electrical withstand;
iii. The present invention by repulsion mode provides quicker response to rising current level.
iv. The present invention provides force reversal from attractive to repulsive force using electromagnetic phenomenon.
v. The present invention provides a double crank mechanism to change the orientation of magnetic material surrounding the secondary conductors.

[0034] It may be clearly understood by a person skilled in the art that for the purpose of convenient and brief description, for a detailed working process of the foregoing system, devices, and unit, reference may be made to a corresponding process in the foregoing device/apparatus embodiments, and details are not described herein again.

[0035] In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus, and device may be implemented in other manners. For example, a plurality of units or components or mechanisms may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or other forms.

[0036] The various mechanisms described as separate parts may or may not be physically separate, and the parts displayed as mechanisms may or may not be physical units, may be located in one position, or may be distributed at various location of the device. Some or all of the units may be selected to achieve the objective of the solution of the embodiment according to actual needs.

[0037] In addition, the mechanisms in the embodiments of the present invention may be integrated into one processing unit, or each of the mechanisms may exist alone physically, or two or more mechanisms may be integrated into one mechanism.

[0038] Although a double crank mechanism to achieve conductor arrangement for selective coordination disclosed, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific features or methods or devices described. Rather, the specific features are disclosed as examples of implementations of the double crank mechanism to achieve conductor arrangement for selective coordination.