DESC:TECHNICAL FIELD OF THE INVENTION

The present subject matter described herein, in general relates to a circuit breaker or switchgears, and more particularly, to an air insulated medium voltage switchgears.

BACKGROUND AND PRIOR ART

In the electric power system, switchgears are the combinations of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done and to clear faults downstream. From the beginning of the development, medium voltage switchgear encompasses wide range of applications, which calls for various forms of designs. These designs are sometimes complex and hence costlier; also the complexity of the design may result in performance life of the equipment.

Today’s fast growing world is becoming dense with every passing day. This is making availability of space as a vital factor for switchgear designers demanding for lower foot print and reliable switchgear designs. Together with the above factors customers today are more aware and educated of the safety hazards associated with switchgear and hence demands for complete mechanical interlocks and features to ensure thorough safety for the operating personnel. In the present scenario single tier or two tier switchgears are used for power distribution system. The present invention describes the medium voltage switchgear in multi-tier configurations, thereby providing flexibility for the station designing and commissioning body.

Thus, almost all the aforesaid requirements are attainted by the multi-tier switchgear arrangement. The present invention provides a simpler but effective design of a multi-tier switchgear arrangement. A very compact foot print, higher reliability and safety are the basic feature of the invention.

OBJECTS OF THE INVENTION

A basic object of the invention is to overcome the disadvantages/ drawback of the known art.

Another object of the present invention is to provide an air insulated ultra-compact multi-tier medium voltage switchgear arrangement.

Yet another object of the present invention is to provide a well designed multi-tier medium voltage switchgear arrangement which allows efficient usage of valuable floor space without undue compromise on cabling space and space for control and protection devices is disclosed.

Yet another object of the present invention is to provide a segregation of switchgear into tiers facilitates maintenance in a specific tier. Thus maintenance can be carried out with less added complexity.

Yet another object of the present invention is to provide an ease in manufacturability of components and assembly in less time.

Yet another object of the present invention is to provide an optimized arrangement in terms of material used resulting into cost effective as well as eco-friendly product.

Yet another object of the present invention is to provide a rigid structure with light weight resulting into ease of transportation and installation.

Yet another object of the present invention is to provide a flexible/adjustable arrangement for various variants offered.

Yet another object of the present invention is to provide a complete isolation and ingress protection to the switchgears.

Yet another object of the present invention is to provide an arrangement using air as an insulating medium.

SUMMARY OF THE INVENTION

This summary is provided to introduce concepts related an air insulated ultra-compact multi-tier medium voltage switchgear arrangement. This summary is not intended to identify essential features of the subject matter nor is it intended for use in determining or limiting the scope of the subject matter.

In an aspect of the present invention, there is provided a multi-tier circuit breaker arrangement comprising multiple circuit breakers is disclosed. The multi-tier circuit breaker arrangement is CHARACTERIZED IN THAT each circuit breaker, from said multiple circuit breakers, forming a single tier comprises an encapsulated pole module of said at least two circuit breaker assembled at an equal distance from each other, a mechanism to drive said encapsulated pole modules, wherein said mechanism is fixed on a common housing with said encapsulated pole module actuating said at least one circuit breaker from said multiple circuit breakers, thereby electrically connects and disconnects said at least one circuit breaker, and a unique rack in and rack out mechanism thereby giving a withdraw able feature. The single tier formed from said each circuit breaker from said multiple circuit breakers are stacked on top of each other to form multi-tier circuit breaker arrangement.

BRIEF DESCRIPTION OF THE 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 1 illustrates a single-tier circuit breaker is shown, in accordance with an embodiment of the present subject matter.

Figure 2 illustrates a multi-tier switchgear arrangement is shown, in accordance with an embodiment of the present subject matter.

Figure 3 illustrates a multi-tier switchgear arrangement is shown, in accordance with an embodiment of the present subject matter.

Figure 4 illustrates a multi-tier switchgear arrangement is shown, in accordance with an embodiment of the present subject matter.

DETAILED DESCRIPTION OF THE INVENTION

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 terms and words used in the following description are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention.

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

By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.

In one embodiment, an air insulated ultra-compact multi-tier medium voltage switchgear arrangement is provided.

In one embodiment, the present invention relates to a unique multi-tier arrangement of a medium voltage circuit breaker. Each circuit breaker consists of an encapsulated pole module assembled at an equal distance from each other, mechanism to drive the pole modules and a unique rack in and rack out mechanism thereby giving a withdraw able feature to it. Pole module accommodates a pair of coaxially arranged electrical contacts. Encapsulation allows maintaining the desired insulation level between the poles and also the switchgear body, thereby reducing the overall dimension. Mechanism is fixed on a common housing with the pole module actuating the circuit breaker, thereby electrically connects and disconnects the circuit breaker. Racking mechanism gives a horizontal draw out and horizontal isolation.

After having arrived at a compact arrangement of a circuit breaker which forms a single tier, this arrangement is stacked on top of each other to form a multi-tier medium voltage switchgear arrangement. The entire multi-tier arrangement is housed in a metal enclosure meeting almost all the demanding enclosure specifications and defining the outer geometrical dimension of the switchgear.

Various components used in the present multi tier switch gear as disclosed in present invention is given below:
1: Isolating contact incoming.
2: Isolating contact outgoing.
3: Encapsulated pole module
4: Actuating and racking mechanism.
5: Single-tier circuit breaker
6: Cable chamber
7: Multi-tier switchgear.
8: Multi-tier switchgear.

In an embodiment of the invention, a multi-tier voltage switchgear arrangement is provided. The arrangement comprises various components which provide a rigid structure with light weight resulting into ease of transportation and installation. The multi tier switchgear (8) arrangement having an isolating contact incoming (1), an isolating contact outgoing (2), an encapsulated pole module (3), an actuating and racking mechanism (4), a single-tier circuit breaker (5), a cable chamber (6) and a multi-tier switchgear panel (7) shown in figure 1 and figure 4.

In an embodiment of the invention, the switchgear arrangement comprises incoming and outgoing isolating contacts (1, 2). The incoming and outgoing isolating contacts (1, 2) allow engagement and withdrawal of the circuit breaker. These isolating contacts function like an off load isolator i.e. these contacts can carry the rated STC for given duration. The incoming and outgoing isolating contacts are designed to offer least contact resistance, self-alignment while circuit breaker racking in.

In an embodiment, an encapsulated pole module (3) is provided in the multi tier switchgear arrangement. The pole module (3) accommodates a pair of coaxially arranged electrical contacts. Encapsulation allows maintaining the desired insulation level between the poles and also the switchgear body, thereby reducing the overall dimension. The pole module (3) provides mechanical support to the power path of the breaker. The pole module (3) is designed for easy assembly and replacement of electrical contacts. The encapsulated pole module (3) insulates the power path of breaker from earthed body of breaker and surroundings. The material used for the encapsulated pole module can be epoxy, sheet molded compound (SMC), bulk molded compound (BMC).

In an embodiment, an actuating and racking mechanism (4) is provided in said arrangement. The actuating and racking mechanism (4) stores and discharges the energy to open and close the electrical contacts. Lesser number of parts ensures a higher MTBF (Mean Time between Failures). The mechanism is operative electrically and manually both. The actuating and racking mechanism can be of following type: spring charged mechanism, solenoid operated mechanism, solenoid operated and magnetically latched (magnetic actuator), hydraulic mechanism, pneumatic mechanism.

In an embodiment, the arrangement comprises a single-tier circuit breaker (5). The circuit breaker (5) mainly consists of fixed contacts and moving contacts. In normal "ON" condition of the circuit breaker (5), these two contacts are physically connected to each other due to applied mechanical pressure on the moving contacts. There is an arrangement in the circuit breaker (5) for storing potential energy in the operating mechanism which is realized if switching signal given to the breaker (5). The potential energy can be stored in the circuit breaker (5) by different ways like by deforming metal spring, by compressed air, or by hydraulic pressure. But whatever the source of potential energy, it must be released during operation. Release of potential energy makes sliding of the moving contact at extremely fast manner. All circuit breakers have operating coils (tripping coils and close coils), whenever these coils are energized by switching pulse the plunger inside them displaced. This operating coil plunger is typically attached to the operating mechanism of circuit breaker; as a result the mechanically stored potential energy in the circuit breaker mechanism is released in form of kinetic energy, which makes the moving contact to move as these moving contacts are mechanically attached through a gear lever arrangement with the operating mechanism. After a cycle of operation of circuit breaker the total stored energy is released and hence the potential energy again stored in the operating mechanism of circuit breaker by means of spring charging motor or air compressor or by any other means.

In an embodiment, a cable chamber (6) is provided within said arrangement. The function is to house the outgoing/incoming connection of the switchgear.

In an embodiment, a multi-tier switchgear panel (7) is provided in said arrangement shown in figure 4. The function is to cover and house the circuit breaker (5) to protect the operator from moving parts of the mechanism and to provide a good aesthetic look. The switchgear panel is made up of metal and is held together or assembled in place with different methods like bolting, welding and the like.

In one embodiment of the present invention, a multi-tier circuit breaker arrangement comprising multiple circuit breakers is disclosed. The multi-tier circuit breaker arrangement is CHARACTERIZED IN THAT each circuit breaker, from said multiple circuit breakers, forming a single tier comprises an encapsulated pole module of said at least two circuit breaker assembled at an equal distance from each other, a mechanism to drive said encapsulated pole modules, wherein said mechanism is fixed on a common housing with said encapsulated pole module actuating said at least one circuit breaker from said multiple circuit breakers, thereby electrically connects and disconnects said at least one circuit breaker, and a unique rack in and rack out mechanism thereby giving a withdraw able feature. The single tier formed from said each circuit breaker from said multiple circuit breakers are stacked on top of each other to form multi-tier circuit breaker arrangement.

In one embodiment, said encapsulated pole module accommodates a pair of coaxially arranged electrical contacts.

In one embodiment, said racking mechanism gives a horizontal draw out and horizontal isolation.

In one embodiment, said multi-tier circuit breaker arrangement is housed in a metal enclosure with specifications and defining an outer geometrical dimension of said multi-tier circuit breaker.

In an embodiment, present invention provides a minimum horizontal space occupied per tier, thereby achieving lower foot print.

In an embodiment of the invention, flexibility is provided in height for the various variants offered.

In an embodiment of the invention, a combination of multi-tier arrangement can be joined together to form a switchboard.

Yet in other embodiment of the invention, an access to various parts is not compromised. Yet in other embodiment of the invention, ultra-compact dimensions without use of any insulating gas or liquid are disclosed in the proposed invention.

Still in other embodiment of the invention, a sizable carbon foot prints reduction by eliminating gas/any other insulating medium and material.

Operation/working of the invention:

The multi-tier medium voltage switchgear arrangement has been designed for reliability with minimal maintenance with each tier having independent operation. The motor wound stored energy spring mechanism has been designed with a minimum number of high quality components in line with this concept. The mechanism and drive is placed in the outer compartment of the cubicle, and the three pole assemblies are positioned in the circuit breaker compartment. The circuit breaker compartment is air insulated, and segregated by sheet metal from the mechanism compartment. Both mechanism and pole assembly modules are connected via drive linkages to contact wipe springs and drive rods supported by insulators fixed to the vacuum interrupter moving terminals.

1. Closing of Interrupter Contacts:

The discharging of the mechanism closing spring rotates the main shaft to push the interrupter contacts to the contact touch point via the pre-stressed contact spring and the drive rods. The coupling rods stop moving at this point but the mechanism continues to further compress the contact spring opening up the wipe or snatch gap until the mechanism latches and the circuit breaker pole is then considered closed. This closing movement also charges the pre-loaded opening springs.

2. Opening of the interrupter contacts:

The displacement of the mechanism trip latch allows the opening springs and the contact springs to rotate the main shaft until the wipe or snatch gaps are zero. This is the point of contact separation and from this point the momentum and the continuing action of the opening springs alone pull the drive rods and thus the interrupter contacts to the fully open position.

3. Circuit breaker operating mechanism:

The mechanism is of the stored energy, motor wound or manually charged spring operated type. It is suitable for auto-reclosing duties. Basically it comprises a closing spring charging system and a spring charged latch, a closing cam, the close / trip latch which are displaced to trip the closed circuit breaker, and the drive to the poles in the form of the main shaft. In addition there are the spring release solenoid, the trip solenoid, the auxiliary switches and manual operation On-Off push buttons.

Although an air insulated ultra-compact multi-tier medium voltage switchgear arrangement has been described in language specific to structural features and/or methods, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific features or methods or devices described. Rather, the specific features are disclosed as examples of an air insulated ultra-compact multi-tier medium voltage switchgear arrangement.
,CLAIMS:1. A multi-tier circuit breaker arrangement comprising multiple circuit breakers CHARACTERIZED IN THAT:
each circuit breaker, from said multiple circuit breakers, forming a single tier comprises:
an encapsulated pole module;
a mechanism to drive said encapsulated pole modules, wherein said mechanism is fixed on a common housing with said encapsulated pole module actuating said at least one circuit breaker from said multiple circuit breakers, thereby electrically connects and disconnects said at least one circuit breaker; and
a unique rack in and rack out mechanism thereby giving a withdraw able feature; and
each single tier formed from said each circuit breaker from said multiple circuit breakers are stacked on top of each other to form multi-tier circuit breaker arrangement.

2. The multi-tier circuit breaker arrangement as claimed in claim 2, wherein said encapsulated pole module accommodates a pair of coaxially arranged electrical contacts.

3. The multi-tier circuit breaker arrangement as claimed in claims 2 and 3, wherein said racking mechanism gives a horizontal draw out and horizontal isolation.

4. The multi-tier circuit breaker arrangement as claimed in claims 2 to 4 is housed in a metal enclosure with specifications and defining an outer geometrical dimension of said multi-tier circuit breaker.

5. The multi-tier circuit breaker arrangement as claimed in claims 2 to 5, wherein said encapsulated pole modules of each circuit breaker from said multiple circuit breakers are assembled at an equal distance from each other.