DESC:FIELD OF THE INVENTION

[001] The present invention relates generally to electrical substations which are part of electrical transmission and distribution systems, and more particularly to a compact secondary distribution substation.

BACKGROUND OF THE INVENTION

[002] Power is generated by different means such as hydro, thermal or atomic at power plants. Depending on the availability of resources these plants are constructed at different places. The location of power plants is usually far from the places where the actual consumption of power takes place. So it is necessary to transmit electrical power produced from power generating plants to their load centers. Long and high voltage transmission networks are used for this purpose.

[003] Power is generated comparatively at low voltage. It is economical to transmit power at high voltage. Distribution of electrical power is done at lower voltage as specified by the utilities for the consumers. For maintaining these voltage levels and for providing greater stability a number of transformation and switching stations have to be created in between generating power station and end consumers. These transformation and switching stations are generally known as electrical substations.

[004] An electrical substation is a subsidiary station of an electricity generation, transmission and distribution system where voltage is transformed from high to low or the reverse using transformers. Electric power may flow through several substations from power generating plant to the end consumer, and undergoes changes in voltage at several steps.

[005] It is uneconomical to directly connect electricity consumers to the main transmission network, unless they use large amounts of power, so the distribution substation reduces voltage to a level suitable for local distribution. Distribution substations are situated where the primary distribution voltages are stepped down to supply voltages for feeding the actual consumers through a distribution network.

[006] The most common type of substation is the “exterior” or “outdoor” substation, in which the primary electrical equipment such as transformers, circuit breakers and other associated equipment are installed in open air on an outdoor site. Outdoor substations typically employ conventional ambient-air-insulated equipment, including high-voltage circuit breakers and transformers. These are comparatively inexpensive, and the electrical equipment is usually readily accessible for purposes of maintenance, repair and replacement. However this type of substation has the disadvantages that it generally requires a large surface area, and that it is aesthetically unattractive. Another disadvantage of the outdoor substation type is that, the electrical equipment is subject to climatic and weather conditions, which may be harsh and include wide temperature ranges, rain, lighting, and possibly icing conditions, which may require a great deal of frequent maintenance.

[007] The space requirements of outdoor substations, and their non-appealing aesthetic appearance, disqualify them for many urban applications such as shopping malls, a high rise apartments, a factory etc.

[008] For urban applications where the space and other conditions required by conventional outdoor substations are not available, compact substations are now been developed and widely used.

[009] The compact substation is a global solution with three main components viz a MV switchgear, a transformer and a LT distribution panel connected directly with busbars in a metallic enclosure. The compact substation also includes standard components such as circuit breakers, switches, incoming cables and other components as used in conventional substation systems.

[0010] Currently available compact substations are compact as compared to the outdoor substations; however the foot print area occupied by the compact substation is always an area of research and needs to be reduced. Since compact substations find application for use in buildings, malls and similar places, the floor space occupied by the substation can become burdensome to a building space planner or building owner.

[0011] Another problem faced with prior art compact substations is that, the occurrence of fault in one component propagates and damages all other components in the substation. Since the present day compact substations are in the form of a box with the MV switchgear, transformer and LT Panel kept at different locations within the box type enclosure; any arc created due to fault in any component (say switchgear) will propagate to other components thereby damaging the whole compact substation. Even in case the transformer is only damaged, the whole of compact substation has to be picked from its location and replaced with other functioning compact substation. When there is failure of any component of the equipment, utilities needs to send complete compact substation for repairing which involves wastage of time and money.There is no provision with presently available compact substations to pick and replace any one single component only.

[0012] Since the transformer is kept in closed enclosures, the heat produced by the working of the transformer heats up the whole compact substation and other components thereby putting them to risk of damage by heating. The heat needs to be continuously dissipated in order to prevet any failure by using forced or natural cooling methods. Currently available cooling solutions are not efficient and there is a need of better ways of installation of transformer and designs of cooling solutions.

[0013] Since the compact substations are customized as per the voltage rating and available foot print area in a location, the present day compact substation do not provide the flexibility to increase rating capacity of the substation based on any future demands.

[0014] The LT panel component comprising bus bars, contributes significantly large amount to the overall size of the compact substation. This increases the footprint area required and adds to the cost for the utility companies. The conventional design of LT Panel costs more, due to requirements of long run of busbars as well as higher size of enclosure. With respect to safety, designs of panels are not sufficient to handle faults and it is also poses danger to the operators if touched accidently.

[0015] In view of the above mentioned limitations inherent in the available compact distribution substations, there exists a need for an improved compact substation which overcomes the disadvantages of the prior art and which can be manufactured in a cost effective, reliable, secure and environmental friendly manner.

[0016] The present invention fulfils this need and provides further advantages as described.

SUMMARY OF THE INVENTION

[0017] In view of the foregoing disadvantages inherent in the prior arts, the general purpose of the present invention is to provide an improved combination of convenience and utility, to include the advantages of the prior art, and to overcome the drawbacks inherent therein.

[0018] A primary objective of the present invention is to provide an electrical substation compact in size which is simple and cost effective.

[0019] In one aspect, the present invention provides an electrical substation that comprises a LV compartment including a LT panel, a MV compartment and a transformer compartment including a transformer, such that the LV compartment, the MV compartment and the transformer compartment are mounted on a common cable trench plinth and are adapted to be detachably joined with each other to form the electrical substation.

[0020] In another aspect of the present invention, each of the LV compartment, MV compartment and transformer compartment, comprises a base frame with a C-channel for joining one compartment with another compartment, a rectangular framed structure mounted on the base frame, a plurality of sheets adapted to be detachably connected with the framed structure to form a front, a back and two side walls of the compartment, a removable roof, a cable opening for the incoming cables in the base frame and a lifting arrangement enabling lifting of any of the LT panel compartment, the MV compartment or the transformer compartment.

[0021] In yet another aspect of the present invention, the front wall of the MV compartment is a hinged door and the MV compartment further includes one pressure relief flap on the removable roof to release pressure created during arcing in the MV compartment and a perforated sheet in the base frame for providing air flow passage.

[0022] In another aspect of the present invention, the front wall of the LV compartment is a hinged door including a transparent window providing visibility to inside components of the LV compartment and one side wall of the two side walls of the LV compartment includes a hylem insulating plate.
[0023] In one aspect of the present invention, the LV compartment further includes a busbar connecting chamber for containing a plurality of connections of busbars of the transformer and busbars of the LT panel.

[0024] In another aspect of the present invention, the plurality of connections are located in top portion of the busbar connecting chamber, such that the connection from the transformer to the LT panel is made from top of the LT panel.

[0025] In a further aspect of the present invention, the busbar joining chamber comprises a first wall towards the LT panel side, a second wall towards the transformer compartment side, a hylem insulating plate containing holes to allow busbars to pass through them and keep multiple busbars insulated from each other and a plurality of air vents and louvers adapted to dissipate hot air to outside environment.

[0026] In another aspect of the present invention, the LT panel comprises a plurality of MCCBs placed in a rack formation, such that each of the plurality of MCCBs is placed over an insulating hylem plate, a ACB placed on top of the plurality of MCCBs, a plurality of main busbars aligned vertically, the main busbars electrically connected to the ACB from top, a plurality of tapping busbars aligned horizontally having a first end and a second end, such that the tapping busbars are electrically connected with the main busbars from the first end and to one of the plurality of MCCBs from the second end, a plurality of insulated support members for connecting and arranging the main busbars and the tapping busbars in an enclosure of the LT panel, a pressure release flap on a roof of the LT panel for releasing air pressure created by accidental arcing and an insulated back cover to separate live connections from the enclosure of the LT panel.

[0027] In yet another aspect of the present invention, the transformer compartment comprises a plurality of louvers on three of the four walls, a door as the front wall with a transparent window to view inside the transformer compartment, an insulating back cover to avoid direct exposure to live portions of transformer and a body ground connector in the base frame, such that the body ground connector electrically ground the transformer.

[0028] In a further aspect of the present invention, the LV compartment, the MV compartment and the transformer compartment are joined with each other using nuts and bolts making the electrical substation a retrofit arrangement, such that one of the compartment may be detached from the substation when required.

[0029] These together with other aspects of the invention, along with the various features of novelty that characterize the invention, are pointed out with particularity in the description annexed hereto and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The advantages and features of the present invention will become better understood with reference to the following more detailed description taken in conjunction with the accompanying drawings in which:

[0031] FIG.1 illustrates a schematic diagram of an electrical substation, according to one embodiment of the present invention;

[0032] FIG. 2 illustrates a schematic diagram of a Medium Voltage compartment, according to one embodiment of the present invention;

[0033] FIG. 3 illustrates a schematic diagram of a Low Voltage compartment, according to one embodiment of the present invention;

[0034] FIG. 4 illustrates another view of the electrical substation showing the busbar connecting chamber, according to one embodiment of the present invention;

[0035] FIG. 5 illustrates a schematic diagram of the busbar arrangement in the LT panel, according to one embodiment of the present invention; and

[0036] FIG. 6 illustrates a schematic diagram of a transformer compartment, according to one embodiment of the present invention.

[0037] Like reference numerals refer to like parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE DRAWINGS

[0038] In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details.

[0039] As used herein, the term ‘plurality’ refers to the presence of more than one of the referenced item and the terms ‘a’, ‘an’, and ‘at least’ do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

[0040] Reference herein to “one embodiment” or “another embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Further, the diagrams representing one or more embodiments of the invention do not inherently indicate any particular order nor imply any limitations in the invention.

[0041] Referring to FIG. 1, that illustrates a schematic diagram of an electrical substation 10, according to one embodiment of the present invention. The electrical substation 10 comprises a Low Voltage (LV) compartment 12 including a LT panel, a Medium Voltage (MV) compartment 14 and a transformer compartment 16 including a transformer, such that the LV compartment 12, the MV compartment 14 and the transformer compartment 16 are mounted on a common cable trench plinth and are adapted to be detachably joined with each other to form the electrical substation 10.

[0042] These compartments 12, 14 and 16 are separate boxes which are joined together at their walls and on a common cable trench to form the electrical substation 10 of desired electrical and mechanical capacity. In one embodiment of the present invention, the MV compartment 14 includes at least one of a MV RMU or a HT Breaker as per the requirements of the customer. The compartments may also include additional instruments and devices as per the state of the art for the functioning of the electrical substation 10.

[0043] Referring to FIG. 2 that illustrates a schematic view of the MV compartment 14, according to one embodiment of the present invention. In one embodiment of the present invention, each of the LV compartment 12, the MV compartment 14 and the transformer compartment 16 comprises a base frame 20 with a C-channel for joining one compartment with another compartment, a rectangular framed structure 22 mounted on the base frame 20, a plurality of sheets 24 adapted to be detachably connected with the framed structure 22 to form a front 24F, a back 24B and two side walls 24S of the compartment, a removable roof 26, a cable opening 28 for the incoming cables in the base frame and a lifting arrangement 30 enabling lifting of the compartment. It is to be noted that the different elements of the MV compartment 14 are shown in FIG. 2, however most of the elements are similar in the LV compartment 12 and the transformer compartment 16 with some changes.

[0044] The plurality of sheets 24 which forms the walls of the compartments are preferably made of metal sheets which are slided into the rectangular frame 22 on its sides and bolted to keep them in place. Other fastening means such as rivets may also be used to fasten the sheets 24 with the framed structure 22 to form the compartment. There are two side walls 24S, one front wall 24F and a back wall 24B.

[0045] In one embodiment of the present invention, the front wall 24F of the MV compartment 14 is a hinged door which provides access to inside the MV components such as RMU for maintenance or repair or replacement. In one embodiment of the present invention, the door arrangement is vertical opening, such that it can be opened and fixed in position to form a shade for linemen to work during rainy conditions and summer weather. The MV compartment 14 further includes at least one pressure relief flap 32 on the removable roof 26 to release pressure created during arcing in the MV compartment and a perforated sheet (not shown) in the base frame 20 for providing air flow passage.

[0046] All the sheets 24 are made of metal with stiffener cladded to provide strength. The sheets 24 may be made with mild steel, cast steel, aluminium alloy, FRP or any material which provides the required strength and machining capability for the structure. The sheets 24 are further provided with gaskets for tight fit and to prevent leakage thereby giving Ingress Protection to the whole compartment.

[0047] The base frame 20 further includes a lifting arrangement 30 in the form of a hook, so that the compartment may be attached by belts to a crane, such that the compartment can be lifted and replaced without disturbing other compartments. The base frame 20 is mounted on the walls of the cable trench at the installation location. The base frame 20, sheets 24, rectangular framed structure 22 are so designed and provided with arrangements such that they allow connection with other similar compartments in a side by side manner.

[0048] All the compartments have separate bottom base frame 20 with channels and they are joined together with the help of bolts. Design of bottom C Channels is such that, all compartments can be easily joined with the help of bolts at the time of manufacturing and at site. There is a cable opening 28 provided in one of the four sheets 24 of the compartments for the incoming cables. The cable opening 28 also includes a door with a gasket to seal the cables for any leakage through the cable opening 28.

[0049] The removable roof 26 of the compartment is also attached to the rectangular framed structure 22 using nuts and bolts. In one embodiment, the nut part of the fasteners is riveted on the roof 26 such that only bolts needs to be tightened and there is no need to hold nuts and no issue of nuts falling down during installations.

[0050] As seen in FIG. 2, the roof 26 plate further includes pressure relief flaps 32 in closed position. In case of any fault or arc generation in the MV compartment 14, a large amount of pressure is produced, and this may cause damage to the closed enclosure and components inside it. Therefor the generated pressure needs to be dropped immediately by releasing it to the outside environment. The pressure relief flap 32 is like a hinged door on the roof of the MV compartment 14, which is configured to remain close in the absence of an arc fault and open on the occurrence of the arc fault in the compartment.

[0051] When a fault occurs, the pressure thus created opens the flap 32 upwards to let the plasma from the arc fault vent from the compartment to outside environment, thereby decreasing the pressure inside the compartment to its normal operating pressure. The pressure relief flaps 32 are shown in open position in FIG.1. On release of pressure, the flap 32 then drops regaining its normal position due to its own weight.

[0052] Now referring to FIG. 3, that illustrates a schematic diagram of the LV compartment 12, according to one embodiment of the present invention. LV compartment 12 includes LT panel 34(shown in FIG. 5), which consists of Protection & Measuring devices with busbars as a connecting media for the protections devices. All these arrangements are in one enclosure and due to that its overall size becomes larger for the applications in electrical substation 10. The design of LT panel 34,as disclosed in the present invention occupies less space, making the LT panel 34 smaller in size and volume thereby making the electrical substation 10 compact as compared to compact electrical substation available in the market.

[0053] As seen in FIG. 3, the LV compartment 12 is similar to the MV compartment 14, with some changed features. The removable roof 26 does not have pressure relief arrangement because LV compartment 12 does not have components which may cause serious arcing. In one embodiment of the present invention, the front wall 24F of the LV compartment 12 is a hinged door including a transparent window 36 providing visibility to inside components of the LV compartment 12 and one side wall of the two side walls of the LV compartment includes a hylem insulating plate 38.

[0054] The LV compartment 12 includes, the LT panel 34 and all the vital readings are displayed on the display which can be seen from outside of the compartment via the transparent window 36. The window 36 also helps in visually inspecting any fault from outside without opening the LV compartment 12. The side sheet 24S further includes an insulating plate 38 made of hylem configured to provide support and insulation to busbar connection between transformer and the LT panel. The hylem insulating plate 38 is in a form of a sheet with a plurality of holes of the shape of the busbar, to keep different busbars electrically separated from each other and also provide mechanical support for mounting the busbars.

[0055] In one embodiment of the present invention, the LV compartment 12 further includes a busbar connecting chamber 40 for containing a plurality of connections of a plurality of busbars of the transformer and a plurality of busbars of the LT panel. The transformer in the transformer compartment 16 is connected with the LT panel 34 of the LV compartment 12 by busbars. In one embodiment of the present invention, the plurality of connections are located in top portion of the busbar connecting chamber 40, such that the connection from the transformer to the LT panel is made from top of the LT panel.

[0056] Referring to FIG. 4, which illustrates another view of the electrical substation 10 showing the busbar connecting chamber 40, according to one embodiment of the present invention. The busbar connecting chamber 40 is like a small compartment as a part of LV compartment 12, such that one of its wall is towards the transformer chamber and another parallel wall towards the LT panel 34.

[0057] In one embodiment of the present invention, the busbar connecting chamber 40 is located between the LT panel and the transformer compartment 16 and comprises a first wall towards the LT panel side, a second wall towards the transformer compartment 16 side, a hylem insulating plate containing holes to allow busbars to pass through them and keep multiple busbars insulated from each other and a plurality of air vents and louvers adapted to dissipate hot air to outside environment.

[0058] The busbar connecting chamber 40 provides a separate space where all the busbar connections are present. Since the busbar joints are one of the major heat generating areas in the substation, keeping it as separate compartment reduces heat transfer rate to other components of the substation 10. The busbar connecting chamber 40 is also provided with air vents and louvers for dissipation of heat by natural air convection.

[0059] Referring to FIG. 5, that illustrates a schematic diagram of the busbar arrangement in the LT panel 34, according to one embodiment of the present invention. In one embodiment of the present invention, the LT panel 34 comprises a plurality of (Module Case Circuit Breaker) MCCBs placed in a rack formation, such that each of the plurality of MCCBs is placed over an insulating hylem plate, a (Air Circuit Breaker) ACB placed on top of the plurality of MCCBs, a plurality of main busbars 44 aligned vertically, the main busbars 44 electrically connected to the ACB from top, a plurality of tapping busbars 46 aligned horizontally having a first end and a second end, such that the tapping busbars 46 are electrically connected with the main busbars 44 from the first end and to one of the plurality of MCCBs from the second end, a plurality of insulated support members 48 for connecting and arranging the main busbars 44 and the tapping busbars 46 in an enclosure of the LT panel 34, a pressure release flap on a roof of the LT panel for releasing air pressure created by accidental arcing and an insulated back cover to separate live connections from the enclosure of the LT panel.

[0060] Insulated hylem sheets are also provided between two MCCB rows. The busbar arrangement of the present invention has two sets of busbars: main vertical busbars 44 and horizontal tapping busbars 46. The vertical busbar is also interchangeably referred as ‘Main Busbar’ and the horizontal busbar as ‘Tapping Busbar’ hereafter in the description. The busbars maybe made of Copper or Aluminium. The busbars are arranged in vertical and horizontal configuration by using various insulated support members 48 which form the structure for the busbar fixing in the LT panel 34. The use of long vertical busbars eliminates the need of joining small busbars as in conventional LT panel designs. The main busbars 44 are connected to small tapping busbars 46 by minimum number of nuts and bolts. The reduced joints and long busbars, thus provide less contact resistance and reduces potential hot spot areas thereby increasing the overall efficiency of the LT panel.

[0061] The busbars are arranged in steps to increase distance between two adjacent busbars thereby allowing better air circulation within the LT panel and this also reduces electromagnetic forces during short circuit conditions. The step arrangement provides ease of installation in tapping of the cables with minimum bending. Busbars fixed with two sides supports front and back side which gives additional strength during short circuit faults. With respect to safety and reductions in chances of phase to ground faults, one insulated sheet provided on the back cover of panel.

[0062] To make the substation compact besides vertical busbars, the ACBs (Air Circuit Breakers) are placed on the top of MCCBs (Module Case Circuit Breaker). Incoming connections are provided on the top of the panel whereas in conventional design of LT panel incoming connections are at bottom of panel.

[0063] Separate door arrangements are provided for the outgoing cable connections from MCCBs, due to which the installation becomes easy and safe. To increase safety of operator insulated sheet is provided to separate MCCBs compartments.

[0064] At the time of circuit breaker operations in fault conditions, high pressure along with fumes is exhausted from its contact chamber through arc chutes at top. To release pressure, a flap opening arrangement is provided which also protect enclosure side walls.

[0065] Referring to FIG. 6, that illustrates a schematic diagram of a transformer compartment 16, according to one embodiment of the present invention. The transformer compartment 16 is similar in structure to other compartments with some additional features. In one embodiment of the present invention, the transformer compartment 16 comprises a plurality of louvers 50 on three of the four walls, a door 24F as the front wall with a transparent window 52 to view inside the transformer compartment, an insulating back cover to avoid direct exposure to live portions of transformer and a body ground connector 54 in the base frame 20, such that the body ground connector 54 electrically grounds the transformer.

[0066] In one embodiment of the present invention, the sheets 24 used in the transformer compartment 16 may be made into two or three parts as shown in FIG. 6 to have more ease of installation. As per the number of parts of sheets 24, corresponding changes are done in the rectangular framed structure 22 to accommodate different sheets.

[0067] Since the transformer is the component in the electrical substation 10 which gets heated very much during its operation, it is necessary to dissipate the generated heat to the surrounding. Louvers 50 are provided to assist natural convection cooling of the transformer. The louvers are designed considering the rating of the substation, dimension of the enclosure, outside ambient conditions etc.

[0068] The base frame 20 of the transformer compartment 16 further includes a body ground connector 54 to electrically ground the transformer. The door 24F further includes lock and position holding arrangement. This provides access in case of repair or maintenance requirements. The front sheet 24F may further include a transparent tap changing door, which assists in visible inspection of the transformer from outside the compartment 16 and also provides access for tap changing. It also includes locking and position holding arrangement.

[0069] The louvers 50 are also provided with gaskets for tight fit and preventing any leakage. The back wall 24B also includes a hylem plate for supporting busbars and insulating busbars from each other and the enclosure. The hylem plate is connected to the back wall by bolts.

[0070] All the doors of the in the substation 10 may further include limit switches to prevent operator from the shock and also prevent to work on live status. For preventing theft from the substation, password protected electromagnetic power lock may be provided on each door which will open with the specific password only. All the louvers in the substation 10 are designed in such a way that, it will prevent fixing of any posters on it which can stop the flow of air from the substation for ventilation.

[0071] In one embodiment of the present invention, rollers may be are provided at the bottom of different compartments, RMU, LT Panel and transformer which makes it easy for removal and installation of faulty parts as well as during range extensions.

[0072] In one embodiment of the present invention, the LV compartment 12, the MV compartment 14 and the transformer compartment 16 are joined with each other using nuts and bolts making the electrical substation 10 a retrofit arrangement, such that one of the compartment may be detached from the substation when required.

[0073] Different compartments are made such that they can be connected with each other using nuts and bolts without many complications. Compartments of substation 12, 14 and 16 may also be connected with each other with the help of nut bolts as well as rivets. There are hybrid combinations used as per requirements to provide strengths and ease of assembly.

[0074] This allows the electrical substation 10 to have retrofit design, such that when there is a fault in it and some components are damaged, there is no need to send whole substation for the repairing at manufacturing plant and only that compartment may be detached and picked using the lifting hooks to transport and sent for repair. Meanwhile another replacement of the same compartment may be used during the repair period.

[0075] Also if there is need to increase the rated capacity of the present electrical substation 10 to cater increased demand of power, in that case only some of the components in the substation needs to be changed. Furthermore the capacity can be enhanced at the site only and there is no need to send whole substation to the factory.

[0076] Although a particular exemplary embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized to those skilled in the art that variations or modifications of the disclosed invention, including the rearrangement in the configurations of the parts, changes in steps and their sequences may be possible. Accordingly, the invention is intended to embrace all such alternatives, modifications and variations as may fall within the spirit and scope of the present invention.

[0077] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching.

[0078] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
,CLAIMS:WE CLAIM:

1. An electrical substation, comprising:
- a LV compartment including a LT panel;
- a MV compartment; and
- a transformer compartment including a transformer, such that the LV compartment, the MV compartment and the transformer compartment are mounted on a common cable trench plinth and are adapted to be detachably joined with each other to form the electrical substation.

2. The electrical substation according to claim 1, wherein the MV compartment includes at least one of a MV RMU and a HT Breaker.

3. The electrical substation according to claim 1, wherein each of the LV compartment, the MV compartment and the transformer compartment, comprises:
- a base frame with a C-channel for joining one compartment with another compartment;
- a rectangular framed structure mounted on the base frame;
- a plurality of sheets adapted to be detachably connected with the framed structure to form a front, a back and two side walls of the compartment;
- a removable roof;
- a cable opening for the incoming cables in the base frame; and
- a lifting arrangement enabling lifting of any of the LT panel compartment, the MV compartment or the transformer compartment.

4. The electrical substation according to claim 3, wherein the front wall of the MV compartment is a hinged door and the MV compartment further includes:
- at least one pressure relief flap on the removable roof to release pressure created during arcing in the MV compartment; and
- a perforated sheet in the base frame for providing air flow passage.

5. The electrical substation according to claim 3, wherein the front wall of the LV compartment is a hinged door including a transparent window providing visibility to inside components of the LV compartment and one side wall of the two side walls of the LV compartment includes a hylem insulating plate.

6. The electrical substation according to claim 3, wherein the LV compartment further includes a busbar connecting chamber for containing a plurality of connections of a plurality of busbars of the transformer and a plurality of busbars of the LT panel.

7. The electrical substation according to claim 6, wherein the plurality of connections are located in top portion of the busbar connecting chamber, such that the connection from the transformer to the LT panel is made from top of the LT panel.

8. The electrical substation according to claim 6, wherein the busbar connecting chamber is located between the LT panel and the transformer compartment, the busbar joining chamber comprises:
- a first wall towards the LT panel side;
- a second wall towards the transformer compartment side;
- a hylem insulating plate containing holes to allow busbars to pass through them and keep multiple busbars insulated from each other; and
- a plurality of air vents and louvers adapted to dissipate hot air to outside environment.

9. The electrical substation according to claim 1, wherein the LT panel comprises:
- a plurality of MCCBs placed in a rack formation, such that each of the plurality of MCCBs is placed over an insulating hylem plate;
- a ACB placed on top of the plurality of MCCBs;
- a plurality of main busbars aligned vertically, the main busbars electrically connected to the ACB from top;
- a plurality of tapping busbars aligned horizontally having a first end and a second end, such that the tapping busbars are electrically connected with the main busbars from the first end and to one of the plurality of MCCBs from the second end;
- a plurality of insulated support members for connecting and arranging the main busbars and the tapping busbars in an enclosure of the LT panel;
- a pressure release flap on a roof of the LT panel for releasing air pressure created by accidental arcing; and
- an insulated back cover to separate live connections from the enclosure of the LT panel.

10. The electrical substation according to claim 1, wherein the transformer compartment comprises:
- a plurality of louvers on three of the four walls;
- a door as the front wall with a transparent window to view inside the transformer compartment;
- an insulating back cover to avoid direct exposure to live portions of transformer; and
- a body ground connector in the base frame, such that the body ground connector electrically ground the transformer.

11. The electrical substation according to claim 1, wherein the LV compartment, the MV compartment and the transformer compartment are joined with each other using nuts and bolts making the electrical substation a retrofit arrangement, such that one of the compartment may be detached from the substation when required.