FIELD OF THE INVENTION
The present invention generally relates to a three phase common enclosure type
gas insulated switchgear, particularly to a three phase common enclosure type
gas insulated bus bar module. The invention relates to an improved three phase
Gas insulated multi-port bus bar module to inter connect the modules of three
phase electrical power systems.
BACKGROUND OF THE INVENTION
A three phase gas insulated bus bar module is used to interconnect three phase
electric power systems. The bus bar module lacks capability to make inter-
connection between different three phase gas insulated modules. The gas
insulated bus bar module normally consists of a metallic chamber filled with SF6
gas and is provided with need-based number of ports and are located at a pre-
defined angle. This configuration leads to a complex procedure / tools to
manufacture a bus bar system. The angular orientation of the ports is required
for mounting of the terminal bushings at an angle, which otherwise would not
provide safe working clearances for the rated and test voltages. Further, angled
conductors corresponding to said orientation of the terminal bushings are
essentia, for efficient current transfer. End terminals and shields are provided
to make the high voltage electric field to become more and more uniform. In the
commercially used electric power systems, it is often required to integrate a new
gas insulated electric system with the exisung air insulated electric system In
such circumstances, there is a need of an improved system which shall
interconnect those two electric systems.

Pat. No. RU 2523429, describes an arrangement in which the bus bars are
arranged in a row which significantly increases enclosure dimensions with the
system voltage. In conventional arrangements, the bus of one phase of a three-
pole bus bar is made with bends and curves around the bends of the adjacent
phases. Hence electrostatic field levels are quite high. Fig. 1 shows conventional
bus bar arrangements. Following are some of the drawbacks with these
arrangements:
1. If the bus bar arrangement is in a row, the dimensions of the enclosure
are quite high. Compactness of equipment is limited.
2. If the bus bar arrangement is in a row, there is a resultant magnetic field
on the grounded enclosure which may result to eddy currents for some
type of enclosure materials.
3. In the conventional right angled arrangement, current transfer takes place
through complex machined terminals, bends etc.
4. In the conventional right angled arrangement, uniform electrostatic field
levels between the phases are quite difficult to achieve because of the
presence of HT crossings across bus bar phases.
In some of the conventional bus bar arrangements for example pat. No. DE
3137783, and US 7485807, each bus bar is supported by an insulated spacer.
Further, integration of the bus bars to other modules of GIS involves complex
machining of the components. Hence, the present invention aims to address the
above problems.

OBJECTS OF THE INVENTION:
It is therefore an object of the invention to propose an improved three phase
Gas insulated multi-port bus bar module to inter connect the modules of three
phase electrical power systems, in which the bus bars are located at the vertices
of an equilateral triangle configuration or a right angled configuration.
Another object of the invention is to propose an improved three phase Gas
insulated multi-port bus bar module to inter connect the modules of three phase
electrical power systems, in which each phase conductor is positioned at each
vertex of an equilateral triangle or right angle with flexible rotary angled
conductors to extend the current transfer of the phase conductors or the bus
bar.
A still another object of the invention is to propose an improved three phase Gas
insulated multi-port bus bar module to inter connect the modules of three phase
electrical power systems in which each phase conductor is positioned at a pre-
defined angle which becomes an unique adaptable module for testing of different
modules of GIS equipment.
Yet another object of the invention is to propose an improved three phase Gas
insulated multi-port bus bar module to inter connect the modules of three phase
electrical power systems in which each phase conductor is positioned at each
vertex of an equilateral triangle or right angle or at a pre-defined angle which
forms a Hybrid module to provide integration to other insulating media for
example, gas or liquid or solid or combination of them.

A further object of the invention is to propose each phase conductor is
positioned such that terminal connections in other insulation media can be
maintained with phase-phase and phase-ground electric isolation.
A still further object of the invention is to propose an improved three phase Gas
insulated multi-port bus bar module to inter connect the modules of three phase
electrical power systems which is enabled to provide transposition from one bus
bar to another using a profiled HT integrator.
Yet further object of the invention is to propose an improved three phase Gas
insulated multi-port bus bar module to inter connect the modules of three phase
electrical power systems which is enabled to provide current transfer from a bus
bar to a support insulator using HT integrator.
Another object of the invention is to propose an improved three phase Gas
insulated multi-port bus bar module to inter connect the modules of three phase
electrical power systems which is provided with means for plugging in other GIS
three phase or single phase modules.
A still another object of the invention is to propose an improved three phase Gas
insulated multi-port bus bar module to inter connect the modules of three phase
electrical power systems which reduces complexity of manufacturing of a
compact bus bar assembly.
Yet another object of the invention is to propose an improved three phase Gas
insulated multi-port bus bar module to inter connect the modules of three phase
electrical power systems which reduce assembly time of a compact bus bar
assembly.

SUMMARY OF THE INVENTION
Accordingly, there is provided an improved three phase Gas insulated multi-
port bus bar module to inter connect the modules of three phase electrical
power systems in which "conductors (bus bars)" with "termination shields" are
placed in a metal enclosure in equilateral triangle configuration or right angled
configuration or any other angled configuration comprising "angled terminals"
and "straight conductors" to extend the current transfer from the bus bars in a
radial direction through a "current transfer bridge" with "current transfer bridge
shield" via at least one "metallic port"; A "HT integrator transfers the current
from the "current transfer bridge" to other insulation media such as gas or
liquid or solid or combination of them. The HT Integrator also transfers current
from the support insulator to the bus bar and from one bus bar to another bus
bar for transposition.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The invention is described with the help of Figures 1 to 7, where:
Figure 1: Conventional Bus bar arrangements
Figure 2: Angled terminals and straight conductor for extending current
transfer in all three phases according to the invention.
Figure 3: Current transfer bridge with current transfer bridge shields and HT
integrator for current transfer arrangement according to the invention.
Figure 4: An HT Integrator for transposition of bus bars according to the
invention.
Figure 5: An HT integrator for transposition of bus bars in right angled
configuration of a compact bus bar arrangement according to the invention.
Figure 6: A Support insulator with three high voltage ports according to the
invention.
Figure 7: Invented three phase Bus bar module according to the invention.

DETAILED DESCRIPTION OF THE INVENTION
As shown in figure 1, a compact gas insulated bus bar comprises three bus bars
[01] in single grounded metallic enclosure [02]. Three Bus bars [01] are made of
high electrical conductivity material to enable efficient current flow with minimal
power loss and is insulated from the grounded metallic enclosure [02] with
designed SF6 gas density. A support insulator [03] is made of SF6 gas compatible
filled epoxy material. The support insulator [03] holds each of the bus bars [01]
through a socket/HT Integrator [04] in such a configuration where each bus bar
[01] is placed at the vertices of an equilateral triangle or right angled or a pre-
defined angle in a grounded metallic enclosure [02] filled with SF6 gas at
designed density. The socket / HT integrator [04] is made of high electrical
conductivity material makes the electrical connection between the support
insulator [03] and the bus bars [01]. Each of the bus bar [01] is ended with a
termination shield [05], which controls the electric stress between the bus bars
[01] and bus bars to the grounded enclosure [02].
The grounded metallic enclosure [02] which encloses the bus bars [01] consists
of a plurality of angularly disposed ports [06] and a straight port [07]. These
ports are used to commensurate to other insulating media like gas or liquid or
solid or combination of them. The angularly disposed ports [06] on metallic
enclosure [02] are made radially at a designed angle to keep electrical isolation
between phase-phase and phase-ground of insulated terminal connections. The
angled terminal [08] and a straight conductor/terminal [09] transfers current
from the bus bar [01] to high voltage terminal of other insulation media or gas
insulated module through a current transfer bridge [10]. Figure 2 shows the
angled terminal [08] and straight terminal [09] proposed for three phase gas
insulated bus bar assembly. Each of a plurality of current transfer bridges [10] is

integrated with two sets of similar current transfer bridge shields [11] and
designed in such a way that the radial electric filed between the current transfer
bridge shields [10] and the metallic enclosure [02] is almost uniform. Figure 3
shows the current transfer bridge and current transfer bridge shields. An HT
integrator [12] extends the current transfer from one bus bar [01] to other bus
bar [01] of right angled configuration or any other pre-defined angled
configuration for transposition purpose. Figure 4 shows the HT integrator (12)
for transposition of the bus bars. The angled terminals [08], straight terminal
[09], current transfer bridge [10], current transfer bridge shields [11] and HT
integrator [12] are made of high electrical conductivity material to maintain
efficient current transfer with minimal power losses. Figure 5 shows the invented
HT integrator [12] for transposition of bus bars [01] in right angled configuration
of a compact bus bar arrangement. The straight terminal [09] extends the
electrical connection orthogonally from the bus bar [01] to other insulation media
whereas the angled terminals [08] extend the electrical connection radially at a
designed angle from bus bars [01] to other insulation media. The angled
terminals [08] are profiled at a designed angle equal to the angle of the angular
ports [06] on the metallic enclosure [02] to keep the uniform electric stresses
around the angled terminals [08], between the bus bars [01] and between the
bus bar [01] and the grounded metallic enclosure [02]. The angled terminal
[08] / straight terminal [09] provide the flexibility in design; these terminals shall
rotate radially at any desired angle based on the requirement.
The epoxy support insulator [03] consists of three parts. First one is an HT insert
[13] with an integrated shield [14]. Second one is a low tension (LT) insert or
metallic studs. The third one is a casted epoxy body [15]. The three phase
support insulator (refer Figure 6) has cylindrical profile and can be fastened to
the tubular grounded enclosure [02]. The HT integrated shield [14] has a

cylindrical / spherical profile and its profile / radius depend on the operating
voltage for which the insulator [03] is used. The HT integrated shield [14] is
fastened electrically to high voltage (HV) conductor / bus bar [01] through an HT
integrator [16]. The HT integrator provides low contact resistance current
transfer from the HT insert [13] to the bus bar [01]. As desired, electrostatic
field level at tri-junction point (junction of gas, metal and epoxy insulation) is
much less than that E-field level on the HT conductor. An electrostatic field shield
[17] connected to the HT integrator [16] limits highest electric field levels well
below permissible levels. Figure 6 also shows the HT integrator [16] with shied
[17] disclosed herein. The gas gap *g' between the HT integrator [16] and the
epoxy body [15] shall be high enough to limit the surface stress on epoxy body.
This helps in improving voltage withstanding capabilities of the insulator and
provide operate margins. For terminating ends of the high voltage conductor /
bus bar [01], a plurality of spherical shields [05] are proposed. Figure 7 shows
the bus bar arrangement according to the invention.

WE CLAIM :
1. An improved three phase Gas insulated multi-port bus bar module to inter
connect the modules of three phase electrical power systems comprising at
least three bus bars [01] terminated with shields [05], and HT integrators
[04] disposed in equilateral triangle or right angled or any other angled
configuration with uniform electric stress distributed between phase-phase
and phase-ground; a three phase support insulator [03] to hold the three
phase bus bar module; a plurality of angled terminals [08] and/or straight
terminals [09] with at least one current transfer bridge [10], at least one set
of current transfer bridge shields [11] and at least one HT integrator [12]
which allow current transfer from the bus bars [01] to an insulating medium
which can be gas or liquid or solid or combination of them, wherein all the
three phases of the bus bar module located a single in metallic chamber
consisting of multiple angularly dispensed ports [06] or straight ports [07] for
extending the terminal connection from bus bars [01] at a desired angle
radially to the bus bars [01].
2. The bus bar module as claimed in claim 1 or 2 wherein the angled terminals
[08] / straight terminal [09] provides flexible rotary extension from the bus
bars [01] at any angle in radial direction.
3. The bus bar as claimed in claim 1 comprising a profiled angled conductor [08]
disposed between bus bar module and the HT integrators [12] which are
connected to other insulation media.

4. The bus bar as claimed in claim 1, wherein the at least one current transfer
bridge [10] with two sets of shields [11] is positioned on either side to
integrate HT integrators [12] to the angled conductors [08] for effective
current transfer.
5. The bus bar as claimed in claim 1, wherein a three-in-one insulator [03] with
three ports configured at a pre-defined angle is provided.
6. The bus bar as claimed in claim 5, wherein the insulator (03) comprises an
HT insert (13) with an integrated shield (14), a low tension insert (LT), and a
casted epoxy body (15).
7. The bus bar as claimed in claim 6, wherein gas gap 'g' from the HT insert
(13) to the epoxy body [15] controls the electric field across the insulator and
improves withstand-able voltage.