FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. Title of the invention. - BUS BAR SYSTEM FOR EFFECTIVE CURRENT DISTRIBUTION IN POWER DISTRIBUTION APPLICATIONS
2. Applicant(s)
(a) NAME: LARSEN & TOUBRO LIMITED
(b) NATIONALITY: An Indian Company.
(c) ADDRESS: L & T House, Ballard Estate, Mumbai 400 001,
State of Maharashtra, India
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed:

TECHNICAL FIELD OF THE INVENTION
This invention relates generally to electrical power distribution system and more particularly to a Bus bar system for effective current distribution in power distribution applications.
BACKGROUND AND THE PRIOR ART
Bus bars are massive conductors carrying heavy electrical current. These are used to carry and distribute the current in the Switching and Control equipment such as Switchgears, Circuit breakers (ACBs, MCCBs) fuse switches, contactors, and other control circuits. All these equipments are housed as a package in an enclosure commonly known as switchboard or/ Switchgear assembly or/ panelboard or/ distribution board. Busbars play a vital role in the transport and distribution of electrical power. The optimum use of Expensive/ valuable raw material of bus bars could be achieved by allocating the material in areas where current density is at its highest.
Bus bars, which carry and distribute the current in the equipment housed in switchboard, are placed in the top area at back of the switchboard assembly. These acts as a heat sink to the equipment fitted in switchboard as long as temperature of bus bars is lesser than the temperature of components fitted in switchboard. Thus temperature rise of bus bar becomes another critical aspect in selection of right bus bars.
The alternating magnetic flux created by an alternating current interacts with the conductor, generating a back emf that tends to reduce the current in the conductor. The center portions of the conductor are affected by the greatest number of lines of force, the number of line linkages decreases as the edges are approached. The electromotive force produced in this way by self-inductance varies both in magnitude and phase through the cross-section of the conductor, being larger in

the center and smaller towards the outside. The current therefore tends to crowd into those parts of the conductor in which the opposing emf is a minimum; that is, into the skin of a circular conductor or the edges of a flat strip, producing what is known as 'skin' or 'edge' effect. The resulting non-uniform current density has the effect of increasing the apparent resistance of the conductor and gives rise to increased losses.
When conductors are placed closer in low voltage equipments a further distortion of current density results due to interaction with the magnetic field of other conductors. The way as an emf may be induced in a conductor by its own magnetic flux, so may the magnetic flux of one conductor produce an emf in any other conductor sufficiently near for the effect to be significant. This effect, known as the 'proximity effect' (or 'shape effect'), tends usually to increase the apparent AC resistance. In some cases, however, proximity effect may tend to neutralize the skin effect and produce a better distribution of current as in the case of strip conductors arranged with their flat sides towards one another or grouped in interleaved manner.
US 6517363 discloses an improved electrical bus system maximizes the distance that electrical current must travel between adjacent buses before a short can occur by placing the buses at the top portion of upside down U-shaped channels within the insulator, and connecting the adjacent U-shaped channels at their bottom ends. The buses are exposed at each end of a bus section, with a joint insulator frictionally secured between the bus insulator and housing to provide insulation for these exposed bus ends. Adjacent bus sections are electrically connected using a snap-on connector extending across the adjacent bus sections. If a neutral bus is included, for example, in a three-phase system, the neutral bus is located directly between a pair of live buses. Because the potential between a live bus and a neutral bus is one-half the potential between two live buses, the live buses may be positioned closer to the neutral bus than another live bus.

US 6888066 discloses a channel bus splice assembly and method for use in switchgear equipment having channel bus bars joined together at a bus joint. The channel bus splice assembly comprises switchgear or switchboard equipment having channel bus bars joined together at a bus joint, there is provided a channel bus splice assembly. The channel bus splice assembly comprises an inner splice plate defining a plurality of through bores. A sliding clamp plate is configured to reciprocally move within the inner splice plate. The sliding clamp plate defines a plurality of access ports. A pair of nut plates is coupled to the sliding clamp plate and having threaded orifices corresponding to selected through bores in the inner splice plate. An outer splice plate having a plurality of through bores corresponding to the threaded orifices in the nut plates.
US 6506068 discloses a kit for a bus bar system for connecting bus bars with connectors of an electric installation device, which avoids the production of special connecting rails, depending on the position of the connecting planes of the bus bars and the connectors of the installation device.
US 6381122 discloses a bus bar system having several bus bars spaced apart from each other in a first connecting plane and of an essentially square cross section and having T-shaped connecting grooves cut into all outsides for a connection with electrical installation devices having flat connectors in a second connecting plane, which is arranged perpendicular to the first connecting plane. With specially embodied connecting and insulating elements, it is possible to displace the connecting planes of the bus bars and of the flat connectors of the installations device parallel and perpendicular with respect to each other without it being necessary to perform elaborate matching assembly work at the site.
US 5101080 disclose a bus bar provided for current distribution systems such as bus bar trunking systems, switchgear and the like. The busbar has a C-shaped cross section and walls which are not uniform in thickness. The walls which lie closest to one another in adjacently mounted busbars have a thickness which is

greater than the thickness of the walls which lie parallel to the mounting surface onto which the busbars are mounted.
US 5847321 discloses a busbar device with an insulating support block with two assemblable fixing parts bounding internal housings to receive multipole current conductors, each housing being formed by a semi-open recess. The bottoms of the recesses are located in distinct planes extending in a parallel manner along the longitudinal direction of the profiled sections, and separated from one another by a predetermined transverse pitch, and the profiled sections of the current conductors are staggered at regular intervals in the extension direction of the assembly interface of the fixing parts to form a stepped structure.
The present inventors have found that a bus bar system having a uniquely profiled cross-section of bars provides effective current distribution. The special section will allow flexibility in assembly and coupling to other conductive or insulating components. Further providing modular geometry in the bus bar system will allow advantageous economics of scale. The optimization of expensive conducting material is required to achieve an economic benefit. Further the construction of the bus bar system of the present invention provides robust bus bar system required to withstand higher short circuit fault level.
OBJECTS OF THE INVENTION
A basic object of the present invention is to overcome the disadvantages/drawbacks of the known art.
Other object of the present invention is to provide a bus bar system having a uniquely profiled cross-section of bars providing effective current distribution.
Other object of the present invention is to provide flexibility in assembling and coupling to other conductive or insulating components.

These and other advantages of the present invention will become readily apparent from the following detailed description read in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
There is provided a current distribution system.
According to one embodiment of the present invention, there is provided a Bus bar system for effective current distribution in power distribution applications wherein said bus bar system having substantially E shaped cross section comprising a plurality of bars providing effective current distribution, said bars connected through plurality of connectors made with prefabricated parts; said system having a substantially hollow center portion providing thermal balance.
Yet other embodiment of the present invention provides a fastener coupling said bus bar to said connectors, said fastener having substantially T shape.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig. 1 illustrates a trimetric view of shape of the bus bar according to the invention
Fig. 2 illustrates a plan view of the bar of Fig. 1
Fig. 3 illustrates a trimetric view of a second shape of the bus bar according to the invention.
Fig. 4 illustrates a plan view of the bar of Fig. 3

Fig. 5 illustrates a trimetric view of a third shape of the bus bar according to the invention
Fig. 6 illustrates a plan view of the bar of Fig. 5
Fig. 7 illustrates a trimetric view of a fourth shape of the bus bar according to the invention
Fig. 8 illustrates a plan view of the bar of Fig. 7
Fig. 9 illustrates a view of a bus bar coupled with a specially modified T-shaped
fastener/bolt.
Fig. 10 illustrates a view of Switchboard using the said invented bus bar.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The following drawings are illustrative of particular examples for enabling methods of the present invention, are descriptive of some of the methods, and are not intended to limit the scope of the invention. The drawings are not to scale (unless so stated) and are intended for use in conjunction with the explanations in the following detailed description.
Reference is first invited to Fig 1 and 2 where the E shaped cross section is shown. It also shows hollow center portion, fastener and open fringes.
Fig. 3 and 4 shows the other shape of the bus bar and respective plan of the same.
Fig. 5 and 6 shows different shape of bus bar and plan of the same.
Fig. 7 and 8 shows other shape of the bus bar and plan for the same.

Fig. 9 shows a view of a bus bar coupled with a specially modified T-shaped
fastener/bolt.
Fig. 10 shows a view of Switchboard using the said invented bus bar.
The invented system is thus a Bus bar system for effective current distribution in power distribution applications.
DETAILED DESCRIPTION OF THE INVENTION
Accordingly in the present invention describes a bus bar structure/section having a modular geometry. The basic shape can be easily adopted for nominal current of different amperages, for example from 400A till 4000A or others. Connection between the said bus bar and the flat connectors of a device is made with prefabricated parts. The prefabricated connectors are used for joining 2 such profiled bars in different planes also.
The design is made for effective current distribution after analyzing the prominent "skin" & "proximity" effects. The present invention results in optimization of the amount of expensive conducting material used in production to achieve an economic benefit.
As a result of the more uniform current distribution, the current carrying capacity of the material used, such as copper, copper alloys, aluminum, aluminum alloys, can be substantially improved. More rigidity to withstand electro-dynamic stresses produced by the flow of current during normal as well as adverse conditions like short circuit.
The bus bar system is provided with E-shaped cross-section (1) portion which allows effective air circulation. The hollow center portion defined by the E shape of the bus bar conductor helps in thermal balance and hence effective heat

distribution resulting in usage of reduced cross-section. When the bus bar system is installed vertically, the better ventilation is achieved as a result of "chimney effect" produced by hollow (circular or semi-circular) center section as well as open flanges of E-shaped cross-section. When the bus bar system is installed horizontally, the better ventilation is achieved by forced ventilation through the space created by hollow (circular or semi-circular) center section (3) as well as open flanges (5) of E-shaped cross-section.
A special modified T-Shaped Anti-rotation fastener (bolt) is used to join such bus bar with the other connecting element.
In the present invention, Bus bar structure/section has a modular geometry. The basic shape can be easily extended across all the different amperages. Connection between the said bus bar and the flat connectors of a device is made with prefabricated parts. The prefabricated connectors are used for joining two such profiled bars in different planes also. The design is made for effective current distribution after analyzing the prominent "skin" & "proximity" effects. Present invention results in optimization of the amount of expensive conducting material used in production, so as to achieve an economic benefit.
As a result of the more uniform current distribution, the current carrying capacity of the material used, such as copper, copper alloys, aluminum, aluminum alloys, can be substantially improved. More rigidity to withstand electro-dynamic stresses produced by the flow of current during normal as well as adverse conditions like short circuit. E-shaped cross-section (1) portion allows effective air circulation. Hollow center portion helps in thermal balance and hence effective heat distribution resulting in usage of reduced cross-section. When the bus bar system is installed vertically, the better ventilation is achieved as a result of "chimney effect" produced by hollow center section as well as open flanges of E-shaped cross-section. When the bus bar system is installed horizontally, the better

ventilation is achieved by forced ventilation through the space created by hollow center section as well as open flanges of E-shaped cross-section.
Although the embodiments herein are described with various specific embodiments, it will be obvious for a person skilled in the art to practice the embodiments herein with modifications. However, all such modifications are deemed to be within the scope of the claims.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the embodiments described herein and all the statements of the scope of the embodiments which as a matter of language might be said to fall there between.

WE CLAIM:
1. A Bus bar system for effective current distribution in power distribution
applications wherein said bus bar system having substantially E shaped
cross sections (1) comprising:
a plurality of bars (2) providing effective current distribution, said bars connected through plurality of connectors made with prefabricated parts; said system having a substantially hollow center portion (3) providing thermal balance;
a fastener (4) coupling said bus bar to said connectors, said fastener having substantially T shape.
2. System as claimed in claim 1 having substantially modular geometry adapted to carry nominal current of different amperages.
3. System as claimed in claim 1 wherein said cross section (1) having open flanges (5) allowing effective air circulation.
4. System as claimed in claim 1 wherein said hollow center portion (3) is substantially circular or semicircular.
5. System as claimed in claim 1 wherein said fastener (4) is substantially an anti rotation fastener (4).
6. System as claimed in claim 1 adapted to get installed vertically or horizontally providing effective current distribution.

7. A Bus bar system for effective current distribution in power distribution
applications as herein described and illustrated with reference to accompanying drawings.