IES65613B2 - An electrical substation - Google Patents

Abstract

A prefabricated electrical substation (1) comprises a switch cabinet (2) with an associated transformer housing (3) mounted back to back. The switch cabinet (2) has a number of compartments, namely a switch compartment (20) housing switchgear, a metering compartment (24) housing electrical supply metering equipment and a meter box (28). A transformer (32) is mounted on a back wall of the switch cabinet (2), the transformer having cooling radiators (34). Mounted at a rear of the transformer (32) is a low voltage cable box (35) housing low voltage connectors (36) of the transformer (32).

Description

An electrical substation This invention relates to an electrical substation.

Industrial consumers which require an electricity supply greater than about 300kVA must provide their own transformer and switchgear. It is generally necessary for the user therefore to provide a block house within which to install the transformer and switchgear. This is both inconvenient and relatively expensive for the industrial consumer.

The present invention is directed towards overcoming this problem.

According to the invention, there is provided a prefabricated electrical substation, comprising a switch cabinet having a base with upstanding sidewalls on the base and a rear wall upstanding on the base and extending between the sidewalls, a roof mounted on and extending between the sidewalls and between the rear wall and a front of the cabinet, the front of the cabinet being closed by one or more doors, a switch compartment within the cabinet having electrical switchgear mounted therein, a transformer housing attached to the switch cabinet and communicating with the switch compartment, an electrical transformer mounted within the transformer housing and connected to the switch gear in the switch compartment.

In one embodiment of the invention there is provided a prefabricated electrical substation, comprising a switch cabinet having a base with upstanding sidewalls on the base and a rear wall upstanding on the base and extending between the sidewalls, a roof mounted on and extending between the sidewalls and between the rear wall and a front of the cabinet, the front of the cabinet being $65613 - 2 closed by one or more doors, a switch compartment within the cabinet having electrical switchgear mounted therein, i a metering compartment within the cabinet having electrical supply metering equipment mounted therein, a « transformer housing attached to the switch cabinet and communicating with the switch compartment, an electrical transformer mounted within the transformer housing and connected to the switchgear in the switch compartment.

In another embodiment of the invention, the metering equipment is connected intermediate the switchgear and the transformer.

In an alternative arrangement, the metering equipment is connected downstream of the transformer.

In a further embodiment, a low voltage cable box is provided on the transformer for housing low voltage connectors of the transformer.

In another embodiment, a meter box is provided within the metering compartment for reception of electricity meters associated with the electrical supply metering equipment.

In a further embodiment, the switchgear is mounted on a movable support within the switch compartment, the switchgear being movable between a retracted stored position within the switch compartment and an extended position projecting outwardly of a front of the cabinet. a Preferably, the movable support comprises a switch carriage and associated slide rails mounted within the switch compartment.

Ideally, lifting means is provided for the substation. Conveniently, the lifting means comprises lifting lugs on an exterior of the cabinet.

In another embodiment, a face plate is mounted at an outside face of the rear wall of the switch compartment for attachment of the transformer to the switch compartment.

In a further embodiment of the invention, the switch cabinet has a number of compartments comprising the switch compartment, a disconnect cubicle and an instrument transformer cubicle.

Preferably, a pair of doors are provided on the switch cabinet, namely a first door mounted across an inlet to the switch compartment and a second door mounted across inlets to the disconnect cubicle and the instrument transformer cubicle.

In a preferred embodiment, a pair of access panels are provided, one of the access panels being removably mounted across the inlet to the disconnect cubicle and the other access panel being removably mounted across an inlet to the instrument transformer cubicle.

In another embodiment, loadbreak bushings are provided in the disconnect cubicle to allow a user to isolate/earth associated instrument transformers housed in the instrument transformer cubicle.

In some cases, an isolation switch is mounted in the disconnect cubicle to allow earthing of the high tension bushings of the transformer.

The invention will be more clearly understood by the following description of an embodiment thereof, given by way of example only, with reference to the accompanying drawings, in which:Fig. 1 is a front elevational view of an electrical substation according to the invention; Fig. 2 is a plan view of the substation with a roof of the substation removed; Fig. 3 is a side elevational view of the substation; Fig. 4 is a front elevational view of the substation in an open position; Fig. 5 is a side elevational view of a switch cabinet portion of the substation; Fig. 6 is sectional plan view of the switch cabinet; Fig. 7 is an enlarged sectional plan view of the switch cabinet; and Fig. 8 and 9 are views similar to Figs. 1 and 2 respectively of another substation.

Referring to the drawings, and initially to Figs. 1 to 7 thereof, there is illustrated an electrical substation according to the invention and indicated generally by the reference numeral 1. The substation 1 comprises a switch cabinet 2 and an associated transformer housing 3 mounted back to back.

The switch cabinet 2 has a rectangular base 5 with upstanding sidewalls 6 at each end of the base 5. A rear wall 7 is upstanding on the base 5 and extends between the sidewalls 6. A pair of hinged doors 9, 10 are mounted at a front edge of each sidewall 6 to close a front of the cabinet 2. A sloped roof 14 is mounted on and extends between the sidewalls 6 and between the rear wall 7 and a front of the cabinet 2. A rain run-off lip 15 projects outwardly at the front of the cabinet 2 over the doors 9, 10. Mounted adjacent an upper end of each sidewall 6 is a lifting lug 17.

Within the cabinet 2, a switch compartment 20 is provided having an electrical switchgear 21 mounted therein. In this case, the switchgear 21 comprises three medium voltage switches (20kV) for connection to a mains supply.

A metering compartment 24 within the cabinet 2 houses electrical supply metering equipment 25. The metering equipment 25 comprises a number of medium voltage instrument transformers 26 and associated utilities electricity meters (not shown) mounted within a meter box 28.

Connectors 29 for connecting the power supply to a transformer mounted within the transformer housing 3 are provided on the rear wall 7.

A face plate 30 is mounted on an exterior of the rear wall 7 for attachment of a transformer 32 which is mounted within the transformer housing 3. The transformer 32 has oil cooling radiators 34. Mounted at a rear of the transformer 32 is a low voltage cable box 35 housing low voltage connectors 36 of the transformer 32 to which outgoing low voltage cables can be attached. Lifting lugs 38 are provided at each side of the transformer 32. In this case, the transformer 32 steps down power supply from 20kV/10kV to 410/237V.

It will be appreciated that while in the embodiment described above supply metering is carried out on the medium voltage supply upstream of the distribution transformer, in some cases low voltage metering of the supply can be carried out downstream of the transformer 32.

The switchgear may be fixed within the cabinet or alternatively it may be mounted on a carriage for movement into and out of the cabinet to facilitate maintenance.

Referring now to Figs. 8 and 9, there is shown another electrical substation 40. Parts similar to those described with reference to Figs. 1 to 7 are assigned the same reference numerals. In this case, the cabinet 2 has three compartments, namely a switch compartment 20 as previously described, a disconnect cubicle 41 and a instrument transformer cubicle 42. Each of the disconnect cubicle 41 and instrument transformer cubicle 42 are closed by independent access panels 43,44 mounted behind the door 9. The disconnect cubicle 41 contains loadbreak bushings, elbows, parking stands etc. to allow a user to isolate/earth associated current transformers (not shown) and voltage transformers (not shown), which are housed in the transformer cubicle 42, from possible power back-feeds which could come from the consumer's electrical network. Optionally, the disconnect cubicle 41 may also contain a disconnect or isolation switch, which in addition to allowing isolation of the current transformers and voltage transformers would allow the user to earth the high tension bushings of the transformer.

It will be appreciated that with this substation 40, electricity meters will be mounted within a consumer's premises while the instrument transformers remain in the substation 40.

It will be appreciated that the invention advantageously provides a prefabricated substation with all necessary electrical equipment supplied within its own housing which can be delivered on site and connected between a mains electricity supply and an industrial consumer. The industrial consumer has a capital cost saving in that it is not necessary to provide a building to house the equipment.

The invention is not limited to the embodiment hereinbefore described which may be varied in both construction and detail.

Claims (5)

1. A prefabricated electrical substation, comprising a switch cabinet having a base with upstanding sidewalls on the base and a rear wall upstanding on the base and extending between the sidewalls, a roof mounted on and extending between the sidewalls and between the rear wall and a front of the cabinet, the front of the cabinet being closed by one or more doors, a switch compartment within the cabinet having electrical switchgear mounted therein, a transformer housing attached to the switch cabinet and communicating with the switch compartment, an electrical transformer mounted within the transformer housing and connected to the switch gear in the switch compartment.

2. A prefabricated electrical substation, comprising a switch cabinet having a base with upstanding sidewalls on the base and a rear wall upstanding on the base and extending between the sidewalls, a roof mounted on and extending between the sidewalls and between the rear wall and a front of the cabinet, the front of the cabinet being closed by one or more doors, a switch compartment within the cabinet having electrical switchgear mounted therein, a metering compartment within the cabinet having electrical supply metering equipment mounted therein, a transformer housing attached to the switch cabinet and communicating with the switch compartment, an electrical transformer mounted within the transformer housing and connected to the switchgear in the switch compartment.

3. An electrical substation as claimed in claim 1 or 2, wherein the metering equipment is connected intermediate the switchgear and the transformer, or wherein the metering equipment is connected downstream of the transformer, and preferably the switchgear is mounted on a movable support within the switch compartment, the switchgear being movable between a retracted stored position within the switch compartment and an extended position projecting outwardly of a front of the cabinet, and preferably the movable support comprises a switch carriage and associated slide rails mounted within the switch compartment.

4. An electrical substation as claimed in any preceding claim wherein the switch cabinet has a number of compartments comprising the switch compartment, a disconnect cubicle and an instrument transformer cubicle, and preferably a pair of doors are provided on the switch cabinet, namely a first door mounted across an inlet to the switch compartment, and a second door mounted across inlets to the disconnect cubicle and the instrument transformer cubicle, and preferably a pair of access panels are provided, one of the access panels being removably mounted across an inlet to the disconnect cubicle and the other access panel being removably mounted across an inlet to the instrument transformer cubicle, and preferably loadbreak bushings are provided in the disconnect cubicle to allow a user to isolate/earth associated instrument transformers housed in the instrument transformer cubicle.

5. A prefabricated electrical substation substantially as hereinbefore described with reference to the accompanying drawings.