CLIAMS:1. A current sensor unit assembly comprising:
a sensor unit having
a power up coil (9);
a magnetic core (7) with a core cap (8), wherein the magnetic core (7) is wrapped inside the power up coil (8);
a sensing coil (11);
an air core (10) wherein the air core (10) is wrapped inside the sensing coil (11);
an upper enclosure (2) and
a bottom enclosure (5); and
a busbar with a single primary turn having at least one conductor passing through the sensor unit window (1) or with multiple primary turns (12) having
a substantially ‘I’ shaped conductor (13);
at least one substantially ‘U’ shaped round conductor (14); and
at least one connecting ‘C’ links (15).

2. A current sensor unit assembly according to claim 1, wherein the power up coil (9) is made up of an electrically conducting material.

3. A current sensor unit assembly according to claim 1, wherein the magnetic core (7) is made up of a ferromagnetic material.

4. A current sensor unit assembly according to claim 1, wherein the sensing coils (11) is made up of a wound coil with electrically conducting material.

5. A current sensor unit assembly according to claim 1, wherein the core cap (8), the upper enclosure (2), and the bottom enclosure (5) is made up of an insulating material.

6. A current sensor unit assembly according to claim 1, wherein the sensing coils (11) is to be placed in bottom enclosure (5).

7. A current sensor unit assembly according to claim 1, wherein the upper enclosure (2) is to be fitted with the bottom enclosure (4) using click-fits provided.
,TagSPECI:TECHNICAL FIELD
The present subject matter described herein, in general relates to a current sensor arrangement, and more particularly, to a self powered vertical type compact current sensor.

BACKGROUND
A current sensor is a piece of equipment that detects an electric current passing through the conducting material, and produces a signal relative to it. The current passing through the conducting material such as wires may be alternating current (AC) or Direct current (DC). The produced signals are in the form of a digital output or a current or an analog voltage. The produced signal may be used to display a measured current passing through the conducting material. Conventionally, there are many current sensors with different types of sensor assembly available in the market that includes but not limited to, horizontal and co-axial current sensors, horizontal and co-planar current sensors, and the like. A horizontal and co-axial construction or assembly as shown in figure 1, figure 2, and figure 3 is disclosed in the prior-art US Patent 6018239, and a horizontal and co-planar construction as shown in figure 4 is disclosed in the prior-art US Patent 7078888. The disclosed prior-art has certain limitations.

The window area obtained due to the type of construction disclosed in the prior-art is very low in the given volume (i.e., the open area to pass the busbar is less), which restricts the current sensors to be put around relatively large busbars. The window area is the space in the middle of the sensor unit left open so that the busbar of which the current has to be sensed passes through. Further, the horizontal construction conductor joining space requirement with circuit breaker would be higher. Thus, the current sensors used in circuit breakers especially in Moulded Case Circuit Breaker (MCCB) or in breakers having power up coil and sensor coils need relatively big volume of area to do the function effectively. Furthermore, when the sensors are mounted parallel to the current path, the sensing signals will be noise prone, so conditioning of signals is required.

In view of the above limitations, there is a need of a cost efficient current sensor that can overcome the drawbacks of the existing sensors known in the prior art.

SUMMARY
This summary is provided to introduce concepts related to a self powered vertical type compact current sensor. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.

The present invention provides a current sensing device assembly that is the self-powered current sensor which is of vertically mounted and co-axially separated in different planes. This construction of the current sensor facilitates optimized core area for power coil and sensing coil in the available space, which gives quality powering up and sensing signal.

In on implementation, a current sensor unit assembly is disclosed. The current sensor unit assembly comprises of a sensor unit and a busbar. The sensor unit further comprises of a power up coil, a magnetic core with a core cap, a sensing coil, an air core, an upper enclosure and a bottom enclosure. The magnetic core is wrapped inside the power up coil. The air core is wrapped inside the sensing coil. Further, the busbar may be with a single primary turn having at least one conductor passing through the sensor unit window.

In another implementation, a current sensor unit assembly is disclosed. The current sensor unit assembly comprises of a sensor unit and a busbar. The sensor unit further comprises of a power up coil, a magnetic core with a core cap, a sensing coil, an air core, an upper enclosure and a bottom enclosure. The magnetic core is wrapped inside the power up coil. The air core is wrapped inside the sensing coil. Further, the busbar may be with multiple primary turns. The busbar further comprises of an ‘I’ conductor, at least one U shaped round conductor (14), and at least one connecting ‘C’ links (15).

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer like features and components.

Figure 5 illustrates a vertically mounted compact enclosed current sensor unit 100 with busbars passing through it is shown, in accordance with an embodiment of the present subject matter.

Figure 6 illustrates a sectional view of the figure 5 is shown, in accordance with an embodiment of the present subject matter.

Figure 7 illustrates an exploded view of the figure 5 is shown, in accordance with an embodiment of the present subject matter.

Figure 8 illustrates a sectional view of power up coil (9) is shown, in accordance with an embodiment of the present subject matter.

Figure 9 illustrates a sectional view of a sensing coil (11) is shown, in accordance with an embodiment of the present subject matter.

Figure 10 illustrates a sensor unit with multiple continuous primary turns (12) are shown, in accordance with an embodiment of the present subject matter.

Figure 11 illustrates the sensor with primary turns divided into two ‘U’ shape round conductor (14) and a ‘I’ conductor (13) connected from bottom with C links (15) to have continuous winding is shown, in accordance with an embodiment of the present subject matter.

Figure 12 illustrates top view figure 11 is shown, in accordance with an embodiment of the present subject matter.

Figure 13 illustrates bottom view figure 11 is shown, in accordance with an embodiment of the present subject matter.

Figure 14 illustrates the sensor with one square shaped 'U' link (14) and one 'I' link (13) for different current rating and joined with the same construction explained in figure 11, is shown, in accordance with an embodiment of the present subject matter.

Figure 15 illustrates is the explode view of figure 11 is shown, in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION
Preferred embodiments of the present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.

The busbar in electrical systems may be a stripe or bar of brass, copper, or aluminum that is a good conductor of electricity within a distribution board, switchboard, battery bank, substation, or other apparatus. Its main purpose is not to function as a structural member, but to conduct electricity. As used herein, the “busbar” or “bussbar” or “bus bar” or “buss bar” may be used alternatively and have same meaning throughout the specification.

The present invention discloses a sensor unit which consists of a magnetic core (7) and a powering up coil (9). The sensor unit provides the power to a card or the processing engine for the entire functioning of the sensor unit which gives the full-scale deflection signal. The signal given by the power up coil is rectified and linearly regulated by the electronic card to various voltage levels required for different functions in the card which helps for further functioning of the sensor unit. The sensor unit part further comprises of a sensing coil (11) which is adapted to produce a signal.

The signal from the sensing coil (11) is integrated and then amplified in the card using operational amplifiers. The signal is further used by the micro controller (in the card) to issue trip commands, monitor the line current and to maintain the fault history when various faults due to short circuit, over current, earth leakage, single phasing etc. occurs.

The present invention discloses the current sensor that is arranged vertically and co-axially separated in different planes. The sensing and powering units are arranged in different planes one upon another, due to which, a much smaller and compact sensors is possible as compared to the one used in the prior art.

The present invention facilitates the construction of multiple primary turns resulting into the amplified secondary output for powering coil and sensing coil. This facilitates effective functioning of the sensor even at lower current ranges.

For the ease of assembly, in the present invention, the multiple numbers of primary turns is converted into ‘I’ conductor and ‘U’ shaped conductors which are joined from bottom to each other by connecting C links. The joining can be done by different type of joining processes that includes but not limited to riveting, Capacitor discharge welding, Laser welding.

In one implementation, a current sensor unit assembly is disclosed. The current sensor unit assembly comprises of a sensor unit and a busbar. The sensor unit further comprises of a power up coil (9), a magnetic core (7) with a core cap (8), a sensing coil (11), an air core (10), an upper enclosure (2) and a bottom enclosure (5). The magnetic core (7) is wrapped inside the power up coil (9). The air core (10) is wrapped inside the sensing coil (11). Further, the busbar may be with a single primary turn having at least one conductor passing through the sensor unit window.

In one example, the power up coil (9) may be made up of an electrically conducting material that includes but not limited to stainless steel, metals and other conductive materials, such as copper, silver, gold, aluminum, zinc, and the like.

In one example, the magnetic core (7) is made up of a ferromagnetic material that may include but not limited to iron, nickel, gadolinium, and the like.

In one example, the sensing coils (11) may be made up of made up of a wound coil with electrically conducting material that includes but not limited to stainless steel, metals and other conductive materials, such as copper, silver, gold, aluminum, zinc, and the like. The sensing coils (11) may be toroidal in shape.

In one example, the core cap (8), the upper enclosure (2), and the bottom enclosure (5) is made up of an insulating material. The core cap (8) made up of insulating material fitted on the top and bottom of the core to secure power coil winding to be cut out from the sharp edge of magnetic core (7).The upper enclosure and bottom enclosure provides insulation to protect against impulse breakdown between conducting material inside and outside of the sensor unit. They also provide stability the unit. The insulating material may be made from glass, porcelain or composite polymer materials, plastics, and the like.
In one example, the sensing coil (11) is placed in bottom enclosure (5), and the upper enclosure (2) is to be fitted with the bottom enclosure (4) using click-fits provided.

In one implementation, a single round shape conductor passes through the busbar window of sensor. The busbar passes through the upper conducting terminal (2) and bottom conducting terminal (5) are joined with it with different joining methods. The joining can be done by different type of joining processes as riveting, capacitor discharge welding, Laser welding, and the like.

In another implementation, a current sensor unit assembly is disclosed. The current sensor unit assembly comprises of a sensor unit and a busbar. The sensor unit further comprises of a power up coil (9), a magnetic core (7) with a core cap (8), a sensing coil (11), an air core (10), an upper enclosure (2), and a bottom enclosure (5). The magnetic core (7) is wrapped inside the power up coil (9). The air core (10) is wrapped inside the sensing coil (11). Further, the busbar may be with multiple primary turns. The busbar further comprises of an ‘I’ conductor (13), at least one U shaped round conductor (14), and at least one connecting ‘C’ links (15).

In one example, the ‘I’ conductor (13) is joined with upper conducting enclosure (2 or 3) and placed in the bus bar window (1), ‘U’ shaped conductors (14) are positioned in bus bar window (1) and connected with each other and ‘I’ conductor at bottom with connecting ‘C’ links (15). Bottom enclosure (5) is connected at the one of the end of U shape conductor (14).

In another implementation, the busbars with 3 primary turns may be present. The current sensor unit assembly may be divided into 7 parts shown in Figure15 the upper enclosure (2), the ‘I’ Conductor (13), the two U shaped round Conductors (14), the two Connecting ‘C’ Links at bottom (15), and the bottom enclosure (5).

In another implementation, the busbars with 2 primary turns may be present. The current sensor unit assembly may be divided into 5 parts shown in Figure13 the upper enclosure (2), the single conductor passing through the window (1), the U shaped rectangle conductors (15), the connecting link at bottom (14), and the bottom enclosure (5).

When any current which varies with respect to time is made to be pass through the primary busbar which passes through the sensor unit window generates time varying flux which being used by power up coil and sensing coil as explained below.

Power up coil generates power in secondary coil by concentrating time varying flux in magnetic core which being used to power up the card

Sensing coil generates voltage in secondary coil which is proportional to the time varying flux which being used by card to sense the primary current.

Referring now to figure 5, a current sensor unit assembly 100 is shown, in accordance with an embodiment of the present subject matter.

In an embodiment, the vertically mounted compact enclosed current sensor unit with bus bars at top enclosure (2), passing through the window (1) and at the bottom enclosure (5). The current sensor unit includes the window (1) through which the busbars passes from top enclosure (2) to the bottom enclosure (5). The assembly may include outer covering (3), outer covering (4) and conducting terminal (6) having wires enclosed inside it. The wires may be used to provide connections to printed circuit board assemblies (PCBA) inside the current sensor unit assembly 100.

Figure 6 illustrates a sectional view of the figure 5 is shown, in accordance with an embodiment of the present subject matter.

In an embodiment of the present invention, a sectional view of the figure 5 with Power up coil (9) wound in magnetic core (7), sensing coil (11) wound in dielectric former air core (10) enclosed in outer covering (3), and outer covering (4) is shown. The bus bars at top enclosure (2), passing through the window (1) and at the bottom enclosure (5) is also shown. The sensor unit further comprises of a power up coil (9), a magnetic core (7) with a core cap (8), a sensing coil (11), an air core (10) and the air core (10) is wrapped inside the sensing coil (11) is shown in the figure.

Figure 7 illustrates an exploded view of the figure 5 is shown, in accordance with an embodiment of the present subject matter.

In an embodiment, the bus bars at top enclosure (2), passing through the window (1) and at the bottom enclosure (5), the sensing coil (11) enclosed in outer covering (3), the outer covering (4) and a power up coil (9) is shown.

Figure 8 illustrates a sectional view of power up coil (9) is shown, in accordance with an embodiment of the present subject matter.

In an embodiment, the sectional view of power up coil (9) with magnetic core (7), core cap (8), and copper coil wound on it is shown.

Figure 9 illustrates a sectional view of a sensing coil (11) is shown, in accordance with an embodiment of the present subject matter.

In an embodiment, the sectional view of sensing coil (11) with the dielectric former air core (10) and the copper coil wound on it is shown.

Figure 10 illustrates a sensor unit with multiple continuous primary turns (12) are shown, in accordance with an embodiment of the present subject matter.

In an embodiment, the current sensor unit 100 with multiple continuous primary turns (12) is shown. This is a space and time consuming process which is done to amplify the primary current with respect to the secondary current.

Figure 11 illustrates the sensor with primary turns divided into two ‘U’ shape round conductor (14) and a ‘I’ conductor (13) connected from bottom with C links (15) to have continuous winding is shown, in accordance with an embodiment of the present subject matter.

Figure 12 illustrates top view figure 11 is shown, in accordance with an embodiment of the present subject matter. The C links (15) are shown in the figure.

Figure 13 illustrates bottom view figure 11 is shown, in accordance with an embodiment of the present subject matter.

Figure 14 illustrates the current sensor unit with one square shaped 'U' conductor (14) and one 'I' conductor (13) for different current rating and joined with the same construction explained in figure 11, is shown, in accordance with an embodiment of the present subject matter. The connecting link (16) and the bottom enclosure (5) are also shown.

Figure 15 illustrates is the explode view of figure 11 is shown, in accordance with an embodiment of the present subject matter.

In an embodiment, the busbars with 3 primary turns divided into 7 parts i.e., the upper enclosure (2), the ‘I’ Conductor (13), the two U shaped round Conductors (14), the two Connecting ‘C’ Links at bottom (15), and the bottom enclosure (5) is shown in the figure.

In one implementation, the sequence of assembly of the current sensor construction is given below:

Step 1: Magnetic core (7) is wound from ferromagnetic material sheet and core cap (8) is to be placed on top and bottom of the core.
Step 2: Power coil (9) is to be wound on magnetic core
Step 3: Sensing coil (11) with round shape is wound with a compensation winding on a plastic Former (10).
Step 4: Sensing coil is to be placed in bottom enclosure (4). Wires of the same (wire of start of winding & wire of end of winding) will be brought out towards the top side.
Step 5: Insulating material is to be placed on the sensing coil (11).
Step 6: Power Coil (9) is to be placed on the insulating material, wires of the same (wire of start of winding & wire of end of winding) to be brought out towards top side along with sensing coil wires.
Step 7: Upper enclosure (3) is to be fitted with bottom enclosure (4) using click-fits provided.
Step 8: Four wires are soldered to the PCB.
Step 9: Profiles in the upper enclosure and bottom enclosure ensures that the center conductor window comes in the center of the sensing coil (this is important because the sensing coils can pick up and replicate the same signal of the bus bar with lesser amplitude and when the bus bar is offset from the center of the sensing coil, it will lead to distortion and will affect the repeatability of the signal from coil to coil. Hence, the window which carries the bus bar is centered with respect to sensing coil.)
Step 10: Bus bar assembly:
Single primary turn assembly:
Single round shape conductor (1) passes through the bus bar window of sensor and includes upper conducting terminal (2) and bottom conducting terminal (5) are joined with it with different joining methods specified.
Multiple primary turns Assembly:
‘I’ conductor (13) is joined with upper conducting terminal (2 or 3) and placed in the bus bar window, ‘U’ shaped conductors (14) are positioned in bus bar window and connected with each other & ‘I’ conductor at bottom with connecting ‘C’ links (15). Bottom terminal (5) is connected at the one of the end of U shape Terminal.

Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, these advantages may include those provided by the following features:

One feature of the invention is that the vertically mounted and co-axially separated in different planes type of construction facilitates compact dimensions of the current sensor.

Another feature of the invention is that the due to compact dimension the multi turn primary winding is possible.

Another feature of the invention is that multi turn primary winding enhances secondary output.

Yet another feature of the invention is that the plastic core cap provides enhanced protection for the power coil winding.

Yet another feature of the invention is that multi turn primary conductor converted to single U-shaped conductor and connecting links for ease of manufacturing. This arrangement reduces the space requirement for multi turn primary conductor.

Yet another feature of the invention is that the construction facilitates optimized core area for power coil and sensing coil in the available space, which gives quality powering up and sensing signal.

Although implementations for the current sensor unit assembly have been described in language specific to structural features and/or methods, it is to be understood that the appended claims are not necessarily limited to the specific features or methods described. Rather, the specific features are disclosed as examples of implementations for current sensor unit assembly.

It is intended that the disclosure and examples above be considered as exemplary only, with a true scope and spirit of disclosed embodiments being indicated by the following claims.