Claims:1. An electromagnetic trip actuating device for a circuit breaker, wherein said trip actuating device comprising:
a multi-polar fixed frame (6), wherein said fixed frame jointly provide a flux path to a permanent magnet’s (7) flux;
a moving pin (16);
a multi-directional winding (5) generating a flux in relation with said winding energization and said winding direction;
a multi-polar moving plunger (4);
a control system configured to control fault detection and logical trip excitation in said circuit breaker; and
an air gap controlling chip (26)
wherein, said device capable of operating in different modes selected from high sensitive mode or heavy duty mode or measurement sensor mode or trip event monitor mode or any combinations thereof.

2. The device as claimed in claim 1, wherein said multi-polar moving plunger (4) is of two types: a free moving plunger, and a locked plunger.

3. The device as claimed in claim 2, wherein in said free moving plunger said multi-pole moving plunger (4) and said moving pin (16) have a clearance in between allowing them to move freely with a common axis.

4. The device as claimed in claim 2, wherein in said locked plunger said multi-pole moving plunger (4) is locked along with said moving pin (16) through a tight fit or welding means.

5. The device as claimed in claim 1, wherein a number of multi-polar moving plunger (4) is increased from one to multiple plungers (19 a & b).
6. The device as claimed in claim 1, wherein operating modes of said device are selected from said high sensitive mode and said heavy duty mode which are user tunable.

7. The device as claimed in claim 1, wherein in said high sensitive application mode said trip actuator trip at relatively low input voltages.

8. The device as claimed in claim 1, wherein in said heavy duty mode said electromagnetic trip actuator maintain hold position at high levels of shock and vibration.

9. The device as claimed in claim 1, wherein said control system comprise sensors for real-time sensing of current flowing through said circuit breaker, a microprocessor based control unit, trip actuator, circuit breaker mechanism and circuit breaker contact system.

10. The device as claimed in claim 1, wherein said air gap controlling chip adapted to reduce a reluctance of path to an extent it shifts the device from one operating mode to the other.
, Description:TECHNICAL FIELD OF THE INVENTION

[001] The present subject matter described herein, in general, relates to a trip actuating device of circuit breakers. More particularly, the invention relates to a customizable multipurpose magnetic trip actuating device for use in circuit breakers.

BACKGROUND OF THE INVENTION

[002] The current technology demands different trip actuators for various faults in the circuit breaker. This not only complicates the space available inside the circuit breaker but also leads to a demanding design control over too many components and assemblies considering the sensitivities and seriousness involved in the failure of such systems to act in case of a fault condition.

[003] For existing patents related to the various uses of trip actuator in the various fields, reference is made to US 6,763,789 B1, entitled “Electromagnetic actuator with permanent magnet”. The prior art discloses a system and method for increasing force density of a valve actuator particularly suited for use in actuation of intake and/or exhaust valves of an internal combustion engine include at least one electromagnet having a coil wound about a core, and an armature fixed to an armature shaft extending axially through the coil and the core, and axially movable relative thereto. The actuator includes a flux generator, such as at least one permanent magnet positioned between the coil and the armature, oriented so that magnetic flux of the generator travels in a direction opposite to magnetic flux produced by the coil through the core during coil energization to reduce saturation of the core, but in the same direction as the magnetic flux produced by the coil through the armature, to increase an attractive force between the armature and the electromagnet, resulting in an actuator with an increased force density.
[004] Reference is made to US6791442B1, entitled “Magnetic latching solenoid”. This prior art document discloses a device utilizing a permanent magnet latching assembly incorporating high-energy, permanent magnets of rare earth or other relatively fragile permanent magnet materials, and to provide a mechanical structure that protects such materials from damaging impact when subjected to motion of a solenoid plunger. The proposed invention mentions the isolation of permanent magnet from any mechanical impact and use of rare earth materials.
[005] Reference is further made to US 5,614,878, entitled “Two pole remote controlled circuit breaker”. This prior art discloses a two pole remote controlled circuit breaker, in which the solenoid is provided with two coil windings. The first coil winding is a low resistance high current (approximately 3 amp) winding which produces a strong magnetic force to pull plunger from its rest (extended) position to its activated (retracted) position where the plunger is withdrawn into the body of the solenoid. The second coil winding is a high resistance winding which, when connected in series with the low resistance winding, results in reduced power consumption for maintaining contacts in an open position. The switching from the low resistance high current winding to the high resistance winding connected in series with the low resistance winding is accomplished by a solenoid switch which is activated/deactivated by a switch lever.
[006] Reference is made to US 7,633,728, entitled “Arc fault circuit interrupter and method of parallel arc fault detection”. This prior art document discloses that a processor is structured to provide for detecting arc fault conditions.
[007] Reference is even made to US7570140B2, entitled “Magnetic trip mechanism including a plunger member engaging a support structure, and circuit breaker including the same”. This prior art discloses a circuit breaker including separable contacts, an operating mechanism structured to open and close the separable contacts, and a magnetic trip mechanism cooperating with the operating mechanism to trip open the separable contacts. The magnetic trip mechanism includes a support structure including a slotted support portion therein, and a plunger assembly. The plunger assembly includes a movable core resting in the support portion of the support structure, and a plunger member including a first portion cooperating with the operating mechanism, a second portion coupled to the movable core, and a third portion engaging the support structure.
[008] Reference is made to US 4,691,182, entitled “Circuit breaker with adjustable magnetic trip unit”. The prior art discloses a circuit breaker structure having an adjustable magnetic trip unit characterized by an insulating housing containing a circuit breaker mechanism having separable contacts and containing a trip unit comprising a magnetic device responsive to overload current conditions for separating the contacts, the magnetic device having an armature and a calibrating screw for calibrating an air gap between the armature and an associated magnet, the trip unit also including a cam for varying the tension of the spring and the cam having spaced indexing indentations and an associated ball in the frame for rolling engagement with the cam surface and for seating in any indentation to provide positive settings of the spring tension.
[009] Reference is further made to US 5,206,618, entitled “Magnetic latch”. This prior art document discloses a magnetic latch includes a coil, a frame receiving magnetic flux from the coil when energized, a latching member mounted in the frame and rotatably movable between first and second positions with the latching member providing a magnetic flux bridge between flux carrying means of the frame by contacting the flux carrying means with the latching member is in a first position, a magnet providing magnetic flux carried by the flux carrying means and a portion of the latching member for magnetically retaining the latching member is a first position with the coil is de-energized and a spring biasing the latching member towards a second position with force sufficient to overcome magnetic retention of the latching member at the first position when the coil is providing magnetic flux to the flux carrying members of the frame in the direction opposite of that of flux provided by the magnet.
[0010] In the above referenced prior art, due to mechanical impact on the magnet, the material loses its property and the device tends to malfunction and also due to insufficient shielding, the external field interference disturbs the performance of the device by demagnetizing the magnet. Thus, there is a need to overcome the problems cited above. Therefore, the present invention is providing an improved magnetic actuating device which is eliminating mechanical impact on the magnet, reducing interference problems, and reduction of leakage flux.
[0011] Further reference is made to 495MUM2010, entitled “An Improved Trip Actuating Device for use in Circuit Breakers”. This document relates to an improved trip actuating device for use in circuit breakers. The tripping device comprising plurality of fixed core members, moving core is located substantially coaxial to said fixed core members, magnet means placed in between said fixed core members such that appropriate air gap is maintained in the space between the fixed cores and magnet means. The magnet means is establishing plural flux paths comprising first flux path and second flux path whereby said moving core being attracted towards said core members by flux content in the said first flux path. plurality of identical coils wounded around said core members and connected serially to each other; wherein pair of adjacent identical coils being positioned with one coil facing toward top direction and another coil adjacent to former being located in a tilted direction such that the current in both the coils flows in opposite directions so as to establish flux opposing the flux prevailing in the said flux paths produced by the magnet means thereby reducing the resultant flux flowing through the moving core adapted to delatch the said moving core from the fixed core members. Although, this prior art provides the improved magnetic actuating device with less energy consumption for flux reduction and increased trip force produced as the output of the device, but do not provide which can eliminate the dependency on multiple tripping devices to trip the circuit breaker in the event of various fault conditions.
[0012] Accordingly, there is a dire need for a multi-purpose permanent magnet trip actuators for circuit breakers which can be substituted for other different types of the trip actuators such as under voltage release, shunt release, remote operations, and communication module based interactions; and can perform all the different trip signals to the circuit breaker.

SUMMARY OF THE INVENTION

[0013] 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.

[0014] An objective of the present invention is to provide a multipurpose magnetic trip actuating device for use in circuit breakers to remove the dependency on multiple tripping devices to trip the circuit breaker in the event of various fault conditions.

[0015] Another objective of the present invention is to reduce the space occupied by various tripping devices in the circuit breaker assembly and also reduce the need of trip actuating features spread across the mechanism of the circuit breaker.

[0016] Yet another objective of the present invention is to provide multiple modes of operation with a single device configuration such as High sensitive mode, Heavy duty mode, Measurement sensor mode and Trip Event Monitor Mode.

[0017] Another objective of the present invention is to provide a trip actuator having mechanical tolerance compensation feature and enabling multiple mechanical system integrate with the trip device at ease.

[0018] Still another objective of the present invention is to provide a control system that controls the complete fault detection and logical trip excitation.

[0019] Accordingly, in one implementation, the present invention discloses an electromagnetic trip actuating device for a circuit breaker, wherein said trip actuating device comprising:
a multi-polar fixed frame, wherein said fixed frame jointly provide a flux path to a permanent magnet’s flux;
a moving pin;
a multi-directional winding generating a flux in relation with said winding energization and said winding direction;
a multi-polar moving plunger;
a control system configured to control fault detection and logical trip excitation in said circuit breaker; and
an air gap controlling chip;
wherein, said device capable of operating in different modes selected from high sensitive mode or heavy duty mode or measurement sensor mode or trip event monitor mode or any combinations thereof.

[0020] 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

[0021] 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:

[0022] Figure 1 shows the general arrangement of Trip Actuator, according to one implementation of the present invention.

[0023] Figure 2 shows the Reluctance path in the Trip Actuator, according to one implementation of the present invention.

[0024] Figure 3 shows flux directions with respect to the energization, according to one implementation of the present invention.

[0025] Figure 4 shows Free Moving Multi-Polar Moving Plunger, according to one implementation of the present invention.

[0026] Figure 5 shows Locked Moving Multi-Polar Moving Plunger, according to one implementation of the present invention.

[0027] Figure 6 shows the schematic diagram of the trip actuator in Measurement sensor mode, according to one implementation of the present invention.

[0028] Figure 7 shows the schematic diagram of the trip actuator in multi trip mode, according to one implementation of the present invention.

[0029] Figure 8 shows the Flux path in the multi – trip mode, according to one implementation of the present invention.

[0030] Figure 9 shows the reverse energization mode, according to one implementation of the present invention.

[0031] Figure 10 shows calibration of output force using the trip level & force controller, according to one implementation of the present invention.

[0032] Figure 11 shows mechanical assembly tolerance compensation mode, according to one implementation of the present invention.

[0033] Figure 12 shows mode selection using air gap controlling chips, according to one implementation of the present invention.

[0034] Figure 13 shows fault detection sequence of the electronic control unit, according to one implementation of the present invention.

[0035] Figure 14 shows measurement sensor mode sequence of the electronic control unit, according to one implementation of the present invention

[0036] 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

[0037] 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.

[0038] 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.

[0039] 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.

[0040] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] In one implementation, the present invention discloses a multipurpose trip actuation device for use in circuit breakers that can be substituted for other different types of the trip actuators such as under voltage release, shunt release, remote operations and communication module based interactions. All the different trip signals to the circuit breaker are carried by only this new tripping actuation means. This single tripping device achieves the following activities in the circuit breakers:
1. Electromagnetic trip actuator comprising a rare earth permanent magnet consuming no energy during normal operation of the circuit breaker.
2. Electromagnetic trip actuator that has two operating modes, high sensitive mode and heavy duty mode based on the application of the circuit breaker that is user selectable.
3. Electromagnetic trip actuator that can trip at relatively low input voltages in the high sensitive application mode.
4. Electromagnetic trip actuator that can maintain its hold position at high levels of shock and vibration in its heavy duty mode.
5. Electromagnetic trip actuator that can trip one or more mechanical system at the same time in the event of fault.
6. The trip actuator that can multiply as a sensor based on the rate of change of magnetic flux density in the working magnetic circuit.
7. Electromagnetic trip actuator that can double as surface uniformity measurement sensor with no operating energy expenditure.
8. Electromagnetic trip actuator that can accommodate mechanical assembly tolerances with the feature of free multi-polar moving plunger configuration.
9. Electromagnetic trip actuator that can auto-reset upon reverse excitation of multi-polar coil from the electronic control means.

[0045] In one implementation, the tripping device as disclosed in the present invention has the following components in its assembly, multi-polar fixed frames (6), multi-polar moving plunger (4), moving pin (16), bobbin with multi-directional winding (5), rare earth magnet (7), loading springs (2), orientation springs (3), insulated support member (24), air gap controlling chips (26), circuit connector (25) and trip level & force controller (1). The components of work are shown in the figure 1. The multi-polar fixed frames (6) jointly provide a flux path to the permanent magnet’s (7) flux. The flux is split into two different parts based on the reluctance ratio of the device. The reluctance path is shown in the figure 2.
[0046] Figure 3 shows the multi-polar coil (5) generating the flux in relation with the coil energization and winding direction. The reluctance in the path is user controllable based on the requirement of the force or the available trip energy.
[0047] In one implementation, the device can be made to operate at two different modes based on the application: 1) High sensitive application mode; 2) For heavy duty application mode, as shown in figure-12. The device on its high sensitive mode will have the magnetic circuit configuration modified for operating under low input voltage or operating voltage and still be able to deliver high force required for actuating a bigger mechanism. In this case user / configurator / technician who have the thorough knowledge about the device can logically place the air gap controlling chip (26) close to the bottom air gap location. The device on its heavy duty mode will have the magnetic circuit configuration modified for equipment operating under heavily shaky environment such rolling stocks, etc., will operate at a higher operating voltage. In this mode, the device will have higher holding force in order to avoid tripping due to shock and vibration and at the same time will operate to give that tripping force in the event of trip voltage appearing in the input terminals. In this case user / configurator / technician who have the thorough knowledge about the device can logically place the air gap controlling chip (26) close to the magnet’s location. The air gap controlling chip (26) is a carefully selected magnetic material that when placed in a strategic location in a magnetic path, will reduce the reluctance of the path to such an extent that it shifts the device from one operating mode to the other. The material of the air gap controlling chip (26) varies over the application of the device.
[0048] In one implementation, the device with following two types of multi-polar moving plunger (4) allows the device to perform two completely different activities: 1. Free moving plunger (multi-pole moving plunger (4) and the moving pin (16) have a clearance in between allowing them to move freely with a common axis shown in figure-4; 2. Locked plunger (multi-pole moving plunger (4) is locked along with the moving pin (16) through tight fit or welding means) shown in figure-5. The free moving plunger as shown in figure-4 will help the device to adjust to the mechanical tolerances associated with the various assembly components of the circuit breaker and operate without any problems in trip actuation. This will also reduce the critical design considerations required in other sub-system designs leading to cost and lead time reduction of design development, efforts on integration of various sub-assemblies and manufacturing. The locked plunger as shown in figure-5 helps in using the device in the continuous sense mode for various measurement or trigger based on actuation applications.
[0049] In one implementation, the continuous sense mode is based on the sensor voltages connected generated towards the input side of the device through mechanical movements. i.e., whenever there is a movement in the multi-polar moving plunger (4), there is a change in magnetic flux density inside the magnetic circuits of the device. This change in the magnetic flux density is captured and delivered as the sensor (trip actuator) output voltage. In this applications, the device works in the passive mode. There is no supply requirement to the device as the device operates based on rate of change of magnetic flux density in the system. This can be used for continuous sense applications such as profile follower and the like. The sample arrangement is shown in the figure 6. The device in its continuous sense mode also captures sudden actuation of it through external forces and can give the feedback to the control system controlling the circuit breaker. This is a trip event monitor mode.
[0050] In one implementation, the device also has a multi-tripping option as shown in figure 7 with an addition of multiple moving plunger (4) to it. i.e., keeping the multi-polar frames (6) as such as in the original arrangement as shown in the figure 1, the number of multi-polar moving plunger (4) is increased from one to multiple plungers (19 a & b). The tripping will happen based on the tripping voltage applied in the input terminals (25) and the spring associated with the corresponding moving plunger. The energization of the device will start to oppose the main flux flowing in the main path as shown in the figure 3. The opposed flux will have to take alternate paths as available in the new configuration of the device as shown in the figure 4. Since in this configuration, there are N+1 (where N = number of multi-polar moving plungers) flux paths in total. In this case, the main path is split into two parts in the new configuration. i.e., one through the multi-polar moving plunger-1 (19 a) and the other through the multi-polar moving plunger-2 (19 b). The flux path in this configuration is shown in figure 8.
[0051] In one implementation, the opposed flux will take N different paths based on the amount of voltage applied across the input terminals (25). The path-1 will be through magnet (7) ? multi-polar fixed frames (6) ? multi-polar moving plunger-1 (19 a) and the path-N will be through magnet (7) ? multi-polar fixed frames (6) ? multi-polar moving plunger-N (19). As the voltage continues to increase, the flux through the plunger (19 a & b) reduces continuously leading to reduction in the holding force acting on the plunger. Based on the volume of the plunger (19 a & b) and the mating surface between the multi-polar fixed frames (6) and the multi-polar moving plunger (19 a & b), the sequence of tripping will happen. This tripping sequence mainly depends on the number of multi-polar moving plungers (19a, b, … n), their volume, their mating surface, their material and the spring that is loading them. This way enables the use of single tripping device to operate multiple mechanical systems through multi-voltage inputs controlled by an microcontroller or microprocessor based algorithm.
[0052] Based on the fault it detects, the voltage given to the same device can be at different levels. Accordingly, one or more plungers (19 a & b) can trip under a critically lower timeline from the point of detection of fault in the system. This will in-turn enable mechanical systems to evolve for multiple stages of operation removing the limitation of mechanical system from the conventional ON-OFF-TRIP-RESET positions.
[0053] Figure 10 shows calibration of output force using the trip level & force controller. Figure 11 shows mechanical assembly tolerance compensation mode. The trip actuator can reset on its own when the excitation of the coil is changed in the electronic control unit. Flux directions shown in the figure 3 & 9. Sequence of electronic control unit are shown in figure 13 & 14. The MCCBs will trip on actuation from this device which in-turn will receive the trip command from the electronic circuit based control system after it senses the fault current in the circuit breakers. The control system involve sensors for real-time sensing of current flowing through the circuit breaker, a microprocessor based control unit, trip actuator, circuit breaker mechanism and circuit breaker contact system.
[0054] Some of the noteworthy features of the present invention are as follows:
• Arrangement of components in the assembly.
• Multiple modes of operation with a single device configuration – High sensitive mode, Heavy duty mode, Measurement sensor mode & Trip Event Monitor Mode.
• Mechanical tolerance compensation feature using Free Moving Multi-Polar Moving Plunger (4).
• Trip actuator multiplying as a measurement sensor for rate of change of magnetic field using its coil.
• Trip actuator enabling multiple mechanical system tripping at the same time by having multiple multi-polar moving plungers (19 a & b).
• Manual mode selection using air gap controlling chips (26) and plunger configurations (4).
• Use of trip actuator as a measurement sensor or trip event monitor.
• Control system that controls the complete fault detection and logical trip excitation.

[0055] Although a multipurpose trip actuation device for use in circuit breakers have been described in language specific to structural features, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific methods or devices described herein. Rather, the specific features are disclosed as examples of implementations of the multipurpose trip actuation device for use in circuit breakers.