GB2335546A

GB2335546A - Power supply system using a high voltage inductive coupling arrangement

Info

Publication number: GB2335546A
Application number: GB9805252A
Authority: GB
Inventors: Ian Leonard Gallon; David James Painter
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-08-14
Filing date: 1998-03-12
Publication date: 1999-09-22
Anticipated expiration: 2018-03-12
Also published as: GB2335546B; GB9805252D0; GB9717126D0

Abstract

A method or means of obtaining an electrical power source comprises using an inductor arrangement 6, 7, 11 to inductively couple with a high voltage electrical supply arrangement. The inductor arrangement may comprise a magnetic core 6 with a flux duct 13, a winding 7 and a winding bobbin 11. The inductor arrangement may be located in a weather-proof box 9, which is positioned adjacent to one or more high voltage supply lines, which may also enclose power conversion means 15, 16, 17. The power source may be used to supply illumination or telecommunication or other devices which are required in locations near to high voltage supply systems.

Description

1 2335546 S UPPLY SYSTEMS POWER

Field of the Invention

This invention relates to power supply systems and has been designed in connection with telecommunications systems, but is not limited thereto.

Mobile telephones are linked to a central control via local antennas. There is a finite number of channels per cell and, with increasing demand, the cell size is reduced. This increases the requirement for masts on which to mount the antennas and the provision of power supplies for the antennas and associated transmitters.

The demand for mobile telephones is particularly high in areas of high population density. There is a shortage of suitable locations for masts in such high population density areas. It can be 2 difficult to obtain planning permission for erecting a new mast and this thus creates further expense.

It is accordingly an object of the present invention to provide means for overcoming the problem outlined above.

Other objects of the invention will be apparent from the following specific description with reference to the accompanying drawings.

Summary of the Invention

According to a first aspect of the present invention there is provided a method of providing a low voltage electrical power supply which includes mounting an inductor adjacent a high voltage electrical supply line in such manner that, in combination with the high voltage supply line, the inductor constitutes a loose coupled transformer.

According to a second aspect of the present invention there is provided a method of enabling telecommunication systems which includes mounting telecommunication devices, e.g. antennas, on pylons for high voltage electrical supply lines, mounting inductors on the pylons adjacent the supply lines in such manner that, in combination with the supply lines, the inductors constitute loose coupled transformers and connecting the inductors to the telecommunication devices.

3 The inductors are preferably connected to the communication system via power conversion units.

According to a third aspect of the present invention there is provided an inductor contained within a weatherproof enclosure and designed in such manner that it can be positioned in the leakage magnetic field of a high power supply or apparatus in such manner that, together, the inductor and the high power supply or apparatus function as a loose coupled transformer.

Brief Description of the Drawings

Figure 1 illustrates the principles of the invention, Figure 2 shows one form of inductor, Figure 3 shows a second form of inductor, Figure 4 shows one possible method of mounting the inductors shown in Figures 2 and 3, and Figure 5 is a schematic illustration of a communication sub- station.

Description of the Preferred Embodiments

As shown in Figure 1, a high current 1 flowing in a power supply line of the national grid will generate strong magnetic fields

4 at distances of several metres from the grid conductor, which can be regarded as the primary of a transformer. A secondary for the transformer is formed from a coil L placed in this magnetic field but without any physical connection between the coil L and the power supply line. The coupling of the primary to the secondary is thus very much weaker than for conventional transformers. Nevertheless, a significant current i is caused to flow through the load R connected across the ends of the secondary coil L. This current i can be used for a variety of purposes, for example, for lighting a lamp 5 as indicated in Figure 4 or for providing the power for a converter and transmitter unit 20 connected to an antenna 21 of a mobile telephone communication system.

The available power is proportional to,a) the current in the supply line squared, b) the inverse square of the distance of the secondary from the primary, and c) the cube of the core length, and is a function of.- a) the volume of the core of the secondary, b) the permeability of the core, and c) the core geometry.

In one particular arrangement, as shown in Figure 2, the inductor or secondary comprises a number of insulated windings 7 wound on a laminated core 6 and a coil former 11. The inductor core 6 is extended and expanded to form a flux duct 13. A voltage selection block 8 and a capacitor 14 are mounted on a non- conductive support 10 that is fixed to the coil former 11 and the whole assembly is mounted within a plastic weather-proof box 9 by bolts (not shown). The inductor is connected in parallel (low impedance) or in series (high impedance) with the capacitor 14 which is so selected as to form a resonant circuit. The use of a voltage selection block 8 enables the user to tap selected windings to enable the provision of an appropriate voltage to a device connected to a customer specified socket mounted on the outside of the weather-proof box 9.

The inductor shown in Figure 3 comprises the same components as described above in relation to Figure 2 together with an AC/DC converter 17 which is connected to the voltage selection pack and to a rechargeable battery pack 16 which, in turn, is connected to a DC/AC converter 15. The socket 12 is connected to the DC/AC converter 15, the arrangement shown in Figure 3 being intended to provide a constant power output to whatever device is connected to the socket 12.

In situations where high voltage supply lines extend across the countryside but no low wattage supplies are readily available, the devices shown in Figures 2 and 3 can be used to provide such low wattage supply. With one prototype and with the inductor core in a simulator equivalent to 10 kA at 2 m. from a single conductor, a measured power output of 74 watts has been obtained. The use of three-phase conductors would double the field strength so that the power available would then be multiplied 4 times if the inductor core were at the same distance. Alternatively, the distance of the

6 inductor core from the high voltage supplied could be doubled to obtain the same power output. Arbitrary power outputs can be obtained by appropriate scaling of the design.

Figure 4 shows the mounting of a box 3 (corresponding to the box 9) on a support bracket 2 attached to a high voltage transformer 1. The inductor within the box 3 will act as a loose coupled secondary coil to provide an output along line 4 to the indicator lamp 5. The invention thus provides simple and effective means for illuminating the pylons of the national grid in any areas in which these are located, for example, at all close to airport flight paths.

In the further arrangement shown in Figure 5, a box 22 containing an inductor core assembly, as described above in relation to Figure 2 or Figure 3, is mounted on a pylon 23. The box 22 is connected to the power conversion and transmission unit 20 which is connected to the fibre optic link 24 and to the antenna 21. A sub-station for powering the antenna system is thus provided without any need for additional mains supply lines.

7

Claims

Claims:-

1. A method of providing a low voltage electrical power supply which includes mounting an inductor adjacent a high voltage electrical supply line in such manner that, in combination with the high voltage supply line, the inductor constitutes a loose coupled transformer.

2. A method as claimed in Claim 1, in which a capacitor is connected to the inductor so that the inductor and capacitor form a resonant circuit.

3. A method as claimed in Claim 1 substantially as hereinbefore described with reference to the accompanying drawings.

4. A method of enabling telecommunications systems which includes mounting telecommunications devices on pylons for high voltage supply lines, mounting inductors on the pylons adjacent the supply lines in such manner that, in combination with the supply lines, the inductors constitute loose coupled transformers and connecting the inductors to the telecommunications devices.

5. A method as claimed in Claim 4, in which the telecommunications devices are antennas.

8

6. A method as claimed in Claim 4 or Claim 5, in which the inductors are connected to the communication system via power conversion units.

7. A method as claimed in Claim 4 substantially as hereinbefore described with reference to the accompanying drawings.

8. An inductor contained within a weatherproof enclosure and designed in such manner that it can be positioned in the leakage magnetic field of a high power supply or apparatus in such manner that, together, the inductor and the high power supply or apparatus function as a loose coupled transformer.

9. An inductor as claimed in Claim 8, connected to a capacitor in such manner that the inductor and capacitor form a resonant circuit.

10. An inductor as claimed in Claim 8, constructed and arranged to operate substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

c Amendments to the claims have been filed as follows 1. A method of providing a low voltage electrical power supply which includes mounting an inductor on a pylon for a high voltage electrical supply line in such manner that the inductor is adjacent but spaced from the high voltage electrical supply line so that, in combination with the high voltage supply line, the inductor constitutes a loose coupled transformer.

4. A method of enabling telecommunications systems which includes mounting telecommunications devices on pylons for high voltage supply lines, mounting inductors, on the pylons adjacent but spaced from the supply lines in such manner that, in combination with the supply lines, the inductors constitute loose coupled transformers, and connecting the inductors to the telecommunications devices.

:. 0 6. A method as claimed in Claim 4 or Claim 5, in which the inductors are connected to the communication system via power conversion units.