WO2014118488A1

WO2014118488A1 - Electric power generation arrangments and components thereof

Info

Publication number: WO2014118488A1
Application number: PCT/GB2013/050245
Authority: WO
Inventors: James Todd; Mark Mcallister
Original assignee: Caterpillar (Ni) Limited
Priority date: 2013-02-03
Filing date: 2013-02-03
Publication date: 2014-08-07
Also published as: CN105027395B; CN105027395A

Abstract

This disclosure is directed towards a power transmission cable and a control tower for use with an electric power generation (EPG) arrangement. The power transmission cable (13) comprises at least one electrically conductive cable layer (30) having a bend partway along its length to define first and second sections. The control tower (12) comprises a frame having a pair of opposing horizontal walls (20), a pair of opposing vertical walls (21), and a vertical back plate (22) attached to the horizontal walls (20) and the vertical walls (21). Mounting means (25) are located on the vertical back plate (22), on which is mounted at least one circuit breaker (23) having electrical terminals (24). The electrical terminals (24) are located adjacent an aperture (27) in the vertical back plate (22). An EPG arrangement (10) may comprise a generator (11) having electrical terminals and a control tower (12). The electrical terminals of the generator (11) and the at least one circuit breaker (23) of the control tower (12) are connected by power transmission cables (13).

Description

ELECTRIC POWER GENERATION ARRANGMENTS AND COMPONENTS THEREOF

Technical Field This disclosure is directed towards a power

transmission cable and a control tower for use with an electric power generation (EPG) arrangement.

Background

EPG arrangements, such as generator sets for example (also known as gensets), may comprise combination of an engine and a generator. Both components may be mounted together to form a single machine. An EPG arrangement may be used to provide electricity at various locations, such as construction sites or emergency response sites. Generally, an EPG arrangement may be used to provide electricity for telecommunications towers, apartments, office buildings, hotels and hospitals. An EPG arrangement may be a small person-portable device or a larger device that may be mounted on a skid or a trailer, depending on the

requirements and location and the amount of power that is needed for a particular use. Often, an EPG arrangement may be housed within an enclosure, such as a removable shroud or cover.

EPG arrangements typically include a generator that is electrically connected to a circuit breaker housed in a control tower. The control tower may be mounted adjacent to, or in the vicinity of, the generator, with power

transmission cabling arrangements between the control tower and the generator. Variations in the mounting location of the control tower in relation to the generator in known EPG arrangements has, in the past, lead to the need for long transmission cabling arrangements; such arrangements may be costly and bulky.

In some cases, the circuit breaker has been mounted on the generator housing itself to avoid problems of providing cabling from the generator to the circuit breaker. However, this arrangement is believed to be undesirable for EPG arrangements using acoustic, noise-attenuating enclosures. The arrangement may be considered to be undesirable because airflow in such enclosures can be critical and control circuit panels, which are desirably accessible from outside of the enclosure must generally be placed nearby the circuit breaker. As the circuit breaker is usually located inside the enclosure, this limits flexibility for airflow paths.

EP-A-1544981 discloses an EPG arrangement which solves the power transmission cabling problem in one manner through the use of rotary cabling guide mounted on the generator, which guides the power transmission cables between the generator and the control tower.

There is a need to further improve EPG arrangements, and in particular the components of EPG arrangements such as the power transmission cables and the control tower.

Summary

The disclosure therefore provides a power transmission cable for use with an electrical power generation (EPG) arrangement, the power transmission cable comprising at least one electrically conductive cable layer having a bend partway along its length to define first and second

sections . The disclosure further provides a method of assembling a power transmission cable, comprising the steps of:

superposing in order of increasing length a plurality of electrically conductive cable layers having different lengths ;

securing the cable layers together with an electrically conductive cuff at each end; and

providing the cable layers with a bend partway along their lengths, the bend defining first and second sections. The disclosure further provides a control tower for use with an EPG arrangement, the control tower comprising:

a frame having a pair of opposing horizontal walls, a pair of opposing vertical walls, and a vertical back plate attached to the horizontal walls and the vertical walls; mounting means located on the vertical back plate; and at least one circuit breaker having electrical

terminals, the at least one circuit breaker being mounted on the mounting means;

wherein the electrical terminals are located adjacent an aperture in the vertical back plate.

The disclosure further provides an EPG arrangement comprising a generator having electrical terminals and a control tower according to any one of claims 21 to 24, wherein the electrical terminals of the generator and the at least one circuit breaker of the control tower are connected by power transmission cables according to any one of claims 1 to 16.

By way of example only, embodiments of an EPG

arrangement, a power transmission cable and a control tower are now described with reference to, and as show in, the accompanying drawings .

Brief Description of the Drawings

Figure 1 is a perspective view of one exemplary embodiment of an EPG arrangement including a plurality of power transmission cables and a control tower; Figure 2 is a side elevation of the EPG arrangement of

Figure 1 ;

Figure 3 is a perspective view of the control tower of Figure 1 ;

Figure 4 is a front elevation of the control tower of Figures 1 and 3 ;

Figure 5 is a perspective view of one of the power transmission cables of Figure 1 ;

Figure 6 is a further perspective view of the power transmission cable of Figure 4, including an insulation sleeve ;

Figure 7 is a perspective view of a cable duct for use with the EPG arrangement of Figure 1 and Figure 2; and Figure 8 shows a perspective view of a terminal box for use with the EPG arrangement . Detailed Description

Figures 1 and 2 illustrate one exemplary embodiment of an EPG arrangement 10. The EPG arrangement 10 may generally comprise a generator 11, a control tower 12 positioned adjacent to the generator 11, and a plurality of power transmission cables 13 connected between the generator 11 and the control tower 12. The generator 11 and the control tower 12 may be mounted on or in a conventional base or frame (not shown) .

The term 'generator' may include a conventional

dynamoelectric alternator having a rotating armature or rotor and a fixed stator, a hydrogen or other fuel cell, a solar power cell, or any other device for producing

electrical power. In embodiments using a conventional dynamoelectric alternator, such as illustrated in the figures, the alternator may be driven by any suitable motive source, such as a spark-ignited or compression-ignited reciprocating piston engine or a diesel or natural gas powered turbine engine for example.

The control tower is shown in more detail in Figure 3. The control tower 12 may have a frame-like structure. One suitable structure may comprise a pair of opposing

horizontal walls 20, a pair of opposing vertical walls 21, and a vertical back plate 22 attached to the horizontal walls 20 and vertical walls 21. One or more circuit breakers 23, having terminals 24, may be mounted in the control tower 12 by any suitable means, such as a mounting bracket 25. The mounting bracket 25 may be attached to, or form part of, the back plate 22. The control tower 12 may provide a rigid mounting enclosure for a range of sizes of circuit breaker, for example 630A-1600A. The back plate 22 may include an aperture 27 through which the power transmission cables 13 may pass into the control tower 12. In the embodiment shown in the figures, one power transmission cable 13 is connected to each terminal 24 of the circuit breaker (s) 23, and a further power transmission cable 13 is connected to a neutral connection (not shown) in the control tower 12.

However, the number of power transmission cables 13 may vary according to requirements of the EPG arrangement.

Alternatively, the power transmission cables 13 may connect to power terminal strips, such as copper strips, which may be mounted in the control tower (not shown) . In this case, the circuit breaker (s) 23 may be mounted remotely and electrically connected to the power terminal strips in the control tower 12.

The mounting position of the circuit breaker (s) 23 in the control tower 12 may be at a predetermined distance from the generator 11, which may be determined by the dimensions of the power transmission cables 13. Similarly, and

consequently, the mounting location of the control tower 12 on the frame (not shown) may also be determined by the dimensions of the power transmission cables 13. The control tower 12 may be secured to the frame (not shown) using any suitable fastening means, such as bolts. The control tower 12 may further include earthing points. The earthing points may be in the form of a copper bar 28, which may mounted inside the control tower via electrically conductive

fastening means 26. The fastening means 26, which may be bolts, may pass through apertures in the wall of the control tower 12. The portions of the fastening means 26 which are external to the control tower 12 may be earthed. The control tower 12 may be provided with a suitable face-cover or door (not shown) . The control tower 12 may be made of any

suitable material, such as mild steel. The circuit breaker 23 may be a conventional 3-pole circuit breaker (plus earth or ground) , but a 4-pole or other circuit breaker could be used. The control tower 12 may further include one or more conventional control

circuits (not shown) and/or one or more conventional status monitors (not shown) . Any control circuits may include, for example, printed circuit boards, relays, switches, fuses, and additional circuit breakers 23. Any status monitors may include conventional digital or analogue displays or gauges. The control tower 12 may also include optional connection points (not shown) for users to provide current to auxiliary devices .

The generator 11 may have phase copper terminals (not shown) which may be aligned along a rear face of the

generator 11.

Each power transmission cable 13 may comprise

conventional power transmission cabling as commonly used in diesel generator sets, copper braids as shown in detail in Figures 4 and 5, or any other suitable electrical

transmission medium. Each power transmission cable 13 may comprise at least one cable layer 30. The power transmission cable 13 may be multi-layered and comprise three to seven cable layers 30. The number of cable layers 30 may be dependent on the current rating and the thickness of each cable layer 30. Each cable layer 30 may be substantially flat, with the cable layers 30 secured one above each other. Each cable layer 30 may be formed from a single element, or from a plurality of strands. In the latter case the strands may be braided (as shown in Figure 4) . The cable layers 30 may be made from copper cabling. Aluminium cabling may be used as an alternative to copper.

Each power transmission cable 13, as shown in Figures 4 and 5, may be substantially L-shaped, having a pair of substantially straight lengths joined together at a bend. The bend may define an angle of approximately 90°. The angle of the bend may be selected according to the relative heights and angles of the terminals between which each power transmission cable connects. The L-shape has an inner side 31 and an outer side 32. The bend of the L-shapemay be of any suitable radius. The radius may be determined by the intended use and location of the power transmission cable 13. In an alternative embodiment, the power transmission cable 13 may have a different shape. For example, the power transmission cable 13 may be flat or may have a curved shape. Where there is a plurality of cable layers 30, each cable layer 30 may be of a different length so as to enable the shape of the power transmission cable 13 to be formed. The cable layers 30 may increase in length from the inner side 31 to the outer side 32. The bend of the L-shape, or other shape, may be formed into the cable layers 30 by suitable tooling.

First ends and second ends of the cable layers 30 may be secured together respectively by means of an electrically conductive cuff 33. The cuff 33 may be metallic. The sets of ends of the cable layers 30 may each be fed through a cylindrical tube, which may then be compressed by clamping, forging, or another suitable deformation method to form the cuffs 33. This may be done from all four sides, which may result in a generally rectangular cuff 33. Two or more fastening means 34, such as screws, may be used to prevent relative movement (such as rotational or translational movement) between the cable layers 30 and the cuffs 33. The cuffs 33 may be suitable for direct connection to the generator 11 and to the terminals 24 of the circuit breaker 23.

An insulating sleeve 35 may be provided around the cable layers 30. The insulating sleeve 35 may be moulded or otherwise formed into the shape of the power transmission cable 13. The insulating sleeve 35 may provide rigidity to the shaped power transmission cable 13. The insulating sleeve 35 may be made of a high temperature resistant material, such as high temperature resistant PVC . An example of suitable high temperature resistant PVC is material code C3609 Version 2 from Runfold Plastics Ltd. This material has a maximum service temperature of 110°C and a tensile

strength of 15MNm². The insulating material may be heat shrunk PVC. The cable layers 30 may be fed through the sleeve 35 after the sleeve 35 has been moulded. The sleeve 35 may be loosely fit around the cable layers 30. The sleeve 35 may not be attached to the cable layers 30. Alternatively it may be attached to the cuffs 33 at either end of the power transmission cable 13. The sleeve 35 may therefore 'float' on the cable layers 30. This 'floating connection' may allow air to flow between the sleeve 35 and the cable layers 30. A layer of insulating material 36 may be provided at each end of the power transmission cable 13, substantially inwardly adjacent to the cuffs 33. The layers of insulating material 36 may at least partially underlie or overlie the cuffs 33. The layers of insulating material 36 may prevent any of the cable layers 30 from being exposed by the floating

insulating sleeve 35.

The power transmission cable 13 may be manufactured according to one of more methods including various steps. One method includes the steps of superposing in order of increasing length a plurality of electrically conductive cable layers 30 having different lengths, providing each of the first and second ends of the cable layers 30 with a cuff 30 for securing the cable layers 30 together, and forming the cable layers 30 into a substantially L-shape. Those steps may be carried out in that order, or they may be carried out in another order. Similarly, the steps of providing insulating layers 36 and the sleeve 35 may carried out at varying points in the forming process. A terminal box 50 may be mounted externally on the generator 11. The terminal box 50 may house terminals (not shown) for connection of the power transmission cables 13. The terminal box 50 may include a cable configuration section (not shown) . The terminal box 50 may include a current transformer (not shown), which may be electrically mounted to the generator 11. The terminal box 50 may have an opening 51, which may be aligned with the aperture 27 in the back plate 22 of the control tower 12. The opening 51 may be provided with a silicone gasket 52. The silicon gasket 52 may be located within and/or around the opening 51. The current transformer (not shown) may be a three- phase moulded case block current transformer. The current transformer may have internal staggered rectangular wound cores. The current transformer may be purpose designed to fit over the generator 11 terminals away from the braids. The current transformer may have a single connection to feed current measurements back to a control panel.

A cable duct 40 may be provided between the generator 11 and the control tower 12, to enclose the power

transmission cables 13 passing therebetween. More

specifically, a cable duct 40 may be provided between the opening 51, in the terminal box 50 mounted on the generator 11, and the control tower 12. The cable duct 40 may comprise a generally rectangular tubular portion 41. The tubular portion 41 may have curved corners 42. The tubular portion 41 may have an outwardly extending flange 43 at one end, which may provide a mounting face. The cable duct 40 may be made of any suitable material, for example fabricated steel. Alternatively, the cable duct 40 may be made of plastic, though it should be noted that the use of plastic for such applications is prohibited in certain territories. The shape and size of the cable duct 40 may vary according to the space available on the generator 11 and control tower 12 and also the size and number of power transmission cables 13 to be enclosed. As such, the cable duct 40 may be rectangular, square, triangular, or even irregularly shaped.

The tubular portion 41 of the cable duct 40 may be passed through the aperture 27 in the back plate 22 of the control tower 12, such that the tubular portion 41 extends outwardly from the control tower 12 and the flange 43 of the cable duct 40 locates against the inside surface of the back plate 22. Alternatively, the cable duct 40 may be arranged such that the flange 43 locates against the outside face of the control tower such that the tubular portion 41 overlies the aperture 27. The flange 43 may secured to the back plate 22 by any suitable fastening means, such as bolts. The free end 44 of the cable duct 40 may pass through the opening 51 in the terminal box 50 connected to the generator 11. The silicone gasket 52 of the opening 51 in the terminal box 50 may provide an at least partial seal between the terminal box and the cable duct 40. The silicone gasket 52 may be generally annular, so as to define an outer portion by which it may be attached to the terminal box 50 and an inner portion arranged sealingly to receive the free end 44 of the cable duct 40. This 'floating' connection between the cable duct 40 and the terminal box 50 may reduce the vibration transferred from the generator 11 to the circuit breaker 23 in the control tower 12. The curved corners 42 of the cable duct 40 may reduce the wear on the silicone gasket. Industrial Applicability The EPG arrangement described, with its various components, may be used to provide a power generation arrangement that is easily assembled, and may be used when grid power is not available. The control tower 12 may be aligned with the rear face of the generator 11. This may allow for a more direct route for the power transmission cables 13 between the generator 11 and the circuit breaker 23, and therefore shorter power transmission cables 13 and a common length of connections on all phases. The power transmission cables 13 are electrically connected between the electrical terminals (not shown) on the generator 11 and the electrical terminals 24 on the circuit breaker 23. The relative location of the control tower 12, and in particular of the circuit breaker (s) 23 within the control tower 12, with the generator 11 may be determined by the power

transmission cables 13.

Claims

CLAIMS :

1. A power transmission cable for use with an electrical power generation (EPG) arrangement, the power transmission cable comprising at least one electrically conductive cable layer having a bend partway along its length to define first and second sections.

2. A power transmission cable according to claim 1, wherein the bend defines an angle of approximately 90°.

3. A power transmission cable according to claim 1 or claim 2, wherein the at least one cable layer comprises braided cable.

4. A power transmission cable according to any one of the preceding claims, comprising a plurality of cable layers of different lengths.

5. A power transmission cable according to claim 4, wherein the cable layers of different lengths are ordered according to increasing length to form the shape of the cable when the ends are substantially aligned.

6. A power transmission cable according to any one of the preceding claims, wherein the at least one cable layer is made from copper.

7. A power transmission cable according to any one of the preceding claims, further comprising two electrically conductive cuffs secured at opposed ends of the power transmission cable.

8. A power transmission cable according to any one of the preceding claims, further comprising a layer of insulating material towards each end of the power transmission cable.

9. A power transmission cable according to claim 8 as dependant on claim 7, wherein each layer of insulating material is inwardly adjacent to each respective cuff.

10. A power transmission cable according to any one of claims 7 to 9, as dependent on claim 6, wherein each layer of insulating material at least partially underlies each respective cuff.

11. A power transmission cable according to any one of claims 8 to 10, wherein the layer of insulating material is made from heat shrunk PVC .

12. A power transmission cable according to any one of the preceding claims, further comprising a sleeve encasing the one or plurality of cable layer (s) .

13. A power transmission cable according to claim 12, wherein the sleeve adopts a shape corresponding to the shape defined by the one or plurality of cable layers.

14. A power transmission cable according to claim 12 or claim 13, wherein the sleeve is made from a high temperature resistant material.

15. A power transmission cable according to any one of claims 12 to 14, wherein the sleeve is a loose-fit with the cable layer ( s ) .

16. A power transmission cable according to any one of claims 12 to 15, wherein the sleeve floats on the cable layer ( s ) .

17. A method of assembling a power transmission cable, comprising the steps of:

providing the cable layers with a bend partway along their lengths, the bend defining first and second sections.

18. A method of assembling a power transmission cable according to claim 17, wherein the step of securing the layers together with a cuff at each end comprises the steps of feeding each end through a substantially cylindrical tube and compressing the tube on all four sides to form a generally rectangular cuff.

19. A method of assembling a power transmission cable according to claim 17 or claim 18, further comprising the step of providing an insulating layer towards each end of the superposed cable layers.

20. A method of assembling a power transmission cable according to any one of claims 17 to 19, further comprising - li the step of feeding the cable layers through a sleeve having the same shape as the power transmission cable.

21. A control tower for use with an EPG arrangement, the control tower comprising:

22. A control tower according to claim 21, further

comprising a cable duct mounted to the back plate.

23. A control tower according to claim 22, wherein the cable duct comprises an outwardly extending flange at one end of the tubular portion.

24. A control tower according to claim 22 or claim 23, wherein the cable duct extends outwardly through the

aperture in the vertical back plate of the control tower.

25. An EPG arrangement comprising a generator having electrical terminals and a control tower according to any one of claims 21 to 24, wherein the electrical terminals of the generator and the at least one circuit breaker of the control tower are connected by power transmission cables according to any one of claims 1 to 16.

26. An EPG arrangement according to claim 25, wherein the power transmission cables are guided by the cable duct between the generator and the control tower.