Junction box

Abstract

An electrical T-junction box is provided for taking a spur off an electrical transmission- and-return line arrangement. The junction box has a cable entry / exit port for each of a transmission line, a return line, and a spur, and an electrically conducting connector that can electrically connect the two conductors in a capacitive transmission / return line. Each connector has fastening means for each conductor in each line. The connector has an electrical joint which is electrically connected to the spur, so forming a T-junction, and the spur can be connected as a capacitive spur.

Description

[0001] JUNCTION BOX

[0002] Introduction

[0003] The present invention relates to an electrical junction box (or enclosure), in particular to an electrical T-junction / T-junction box. The present invention also relates, in certain embodiments, to an electrical junction box (or enclosure) for transmission-and-return line arrangements, that may utilise capacitive power transfer, and to electrical power distribution networks comprising the same.

[0004] Background

[0005] Electrical junction boxes are known in the art. For example, CN 207021623 U describes “a cable branch T junction box”, GB 2496683 A describes “a pre-wired electrical junction box”, and US 6,677,521 B2 describes “an electrical junction box for a vehicle”.

[0006] Prior art junction boxes are relatively simple mechanical devices, designed to make a junction in an electrical wire. However, many are ill equipped to deal with complex or sophisticated electrical equipment, in particular in the field(s) of capacitive cables and capacitive power transfer, or cables for specific purposes such as in relation to typical (wireless) electric vehicle charging (systems), or transmission of power from low to high voltage or low to high frequency or in the form of alternating current. The present invention seeks to mitigate, or at least ameliorate, some of these problems and / or drawbacks with prior art junction boxes.

[0007] Summary of the Invention

[0008] The invention provides a junction box for use with a transmission-and-return line arrangement, particularly for use with a transmission-and-return line arrangement comprising a capacitive transmission line and / or a capacitive return line. The invention also provides an electrical circuit comprising a transmission-and-return line arrangement, the junction box, and a spur, as well as use of the junction box in an electric circuit and a method of connecting a transmission-and-return line arrangement to a junction box to form an electric circuit. The invention is advantageous because it can enable an electric circuit to be established in which power is transmitted via capacitive power transfer to at least two distinct loads, preferably multiple loads, in parallel. Use of the junction box can enable an additional load to be integrated into the electric circuit than would otherwise be possible.

[0009] Detailed Description of the Invention

[0010] According to the present invention, there is provided an electrical junction box (or enclosure). This is suitable for making, taking, or connecting a spur (or branch, or tie, or lead, or take-off; these terms are used interchangeably) from an electrical cable, which is usually a transmission-and-return line arrangement (or system or apparatus). The junction box preferably encloses, or protects, a joint (or T junction) between the cable (transmission-and-return line arrangement) and the spur.

[0011] Electrical circuits usually have a transmission line for supplying power from a power supply / source to a load, and a return line for returning power from the load to the supply / source. It will be appreciated that an electrical circuit must have both a transmission line and a return line to be considered a “complete” (or circular) electrical circuit, and thus for current to flow.

[0012] The cable (or transmission-and-return line arrangement / system / apparatus) may thus comprise a (electrical) transmission line and a return line. It (or a an electrical power distribution network) usually also comprises a power source / supply and / or a load (for example, a circuit and / or equipment).

[0013] Each line (or cable) may comprise one or more sub-lines, such as a plurality of (or surplus of) lines, each of which may comprise a transmission line and / or return line. Preferably, the transmission line comprises a capacitive transmission line and / or the return line comprises a capacitive return line. The, or each, line (or cable) may also comprise additional conductor(s) or groups of conductor(s).

[0014] The term “capacitive transmission line” normally means an (electrical power) transmission line comprising a first conductor (or first plurality of conductors / electrically conducting elements electrically or galvanically connected to each other) which may be galvanically connected to a power source / supply (but not to a load), and comprising a second conductor (or second plurality of conductors I electrically conducting elements galvanically connected to each other) galvanically connected to the load (but not to the power source / supply).

[0015] There may be no galvanic connections between the first and second (e.g. pluralities of) conductors. The first and second (e.g. pluralities of) conductors can be separated from each other, suitably by one or more dielectric material(s). Distributed capacitance may arise or be present along the lengths of the first and second (e.g. pluralities of) conductors, such as when the power source / supply is active, supplying power. Thus, it will be appreciated that power can be transmitted along a capacitive transmission line via capacitive power transfer.

[0016] A first conductor (at the sending end) may be connected to (a terminal of) a power source and / or a second conductor (at the receiving end) may be connected to (another terminal of) a power source / supply.

[0017] It will similarly be appreciated that the term “capacitive return line” refers to a return line comprising a first conductor (or first plurality of conductors / electrically conducting elements galvanically connected to each other) galvanically (or electrically, the terms can be interchanged throughout this specification) connected to a load (but not to a power source / supply), and comprising a second conductor (or second plurality of conductors I electrically conducting elements galvanically connected to each other) galvanically connected to the power source / supply (but not to the load).

[0018] There may be no galvanic connections between the first and second (e.g. pluralities of) conductors. The first and second (e.g. pluralities of) conductors may be separated from each other by one or more dielectric material(s). Distributed capacitance may arise along the lengths of the first and second (e.g. pluralities of) conductors when the power source / supply is active, supplying power. Thus, it will be appreciated that power is returned along a capacitive return line via capacitive power transfer. Capacitive power transfer is known and is described in, for example, WO 2010 / 026380, WO 2019 / 234449, WO 2021 / 094783, WO 2021 / 094782, WO 2020 / 120932, and WO 2024 / 110610 (hereby incorporated by reference).

[0019] The enclosure may comprise capacitive protective means (for the dielectric, such as used for capacitive coupling or any capacitive modifiers).

[0020] The capacitive cable can comprise of a surplus of “supply / power source” and “load” conductors (e.g., Mark II cables, multi-layer cables, enamel cables, etc). These surplus of conductors per capacitive terminal can be terminated into either the minimal number of connectors, i.e. , grouped into the respective connectors or use multiple connectors (busbars) to split the supply and load conductors into smaller groups for greater control / manipulation in reactive properties.

[0021] The box or enclosure may also comprise passive components such as reactive banks (e.g. resistors, capacitors and / or inductors), which can suitably be added, or removed, (from a feeder line / coil) via switch(es). The box or enclosure may comprise active components such as diodes, transistors, operational amplifiers, integrated circuits, semiconductors, and / or sensors. The box or enclosure may comprise both passive and active components.

[0022] Switch(es) can be used to connect and / or disconnect a busbars of a capacitive cable / coil per given line (connect / disconnect the two capacitive terminals), suitably enabling switching between a self-compensated (capacitive) mode to an uncompensated (non-capacitive) mode (this may require a synchronised response from the control system and other joint boxes containing switches). Certain active components may partially or fully form the switch(es) used in this switching.

[0023] As used herein, references to the “source-side” circuitry are intended to mean the electrical components of the transmission-and-return line arrangement (which can be) electrically connected between the power source / supply and the junction box (as well as the power source / supply itself). In contrast, references to the “load-side” circuitry are intended to mean the electrical components of the transmission and return line arrangement (which can be) electrically connected between the junction box and the load (as well as the load itself).

[0024] On each of the source-side and / or the load-side of the junction box, the transmission line and / or the return line of the transmission-and-return line arrangement may be integrated into the same cable or provided in separate cable(s).

[0025] It will be appreciated that the term “cable” in this context is intended to refer to one or more electrical or electronic component(s), such as a continuous (e.g. metallic) (electrically conducting) wire or (electromagnetic) coils (such as comprising capacitive conductors), suitably enclosed in the same outer sheath.

[0026] The junction box may comprise one or more entry and / or exit port(s) for the (respective) transmission line and / or the return line (of the transmission-and-return line arrangement).

[0027] Wherein the junction box is for use with a transmission-and-return line arrangement, such as on each of the source-side and the load-side, the transmission line and the return line thereof can be integrated into the same cable. The junction box may thus comprise one entry port for both the transmission and return lines and one exit port (e.g. for the spur).

[0028] The junction box may be for use with a transmission and-return line arrangement wherein, on each of the source-side and the load-side, the transmission line and the return line thereof are provided in separate cables. Here the junction box may comprise one entry port for the transmission line, one exit port for the transmission line, one entry port for the return line, and one exit port for the return line.

[0029] The spur may itself comprise a transmission line and a return line, as well as a load (distinct from the load of the load-side circuitry of the transmission-and-return line arrangement). To avoid confusion with the load-side of the transmission-and-return line arrangement, the electrical components connected as part of the spur are referred to herein as the “spur-side” circuitry. Nonetheless, it will be appreciated that the loadside circuitry and the spur-side circuitry may be substantially the same or identical (although they do not have to be). Preferably, the transmission line of the spur is a capacitive transmission line and / or the return line of the spur is a capacitive return line. Alternatively, the transmission line of the spur may be a conventional transmission line and / or the return line of the spur may be a conventional return line. It will be appreciated that whether conventional or capacitive return lines are used may depend on factors such as whether a load connected as part of the spur-side circuitry comprises conventional or capacitive components, and is thus a conventional load or a capacitive load. Examples of capacitive loads, i.e. loads equipped with circuits that utilise capacitive power transfer, are described in e.g. WO 2024 / 042136.

[0030] On the spur-side, the transmission line of the spur and the return line of the spur may be integrated into the same cable or provided in separate cables.

[0031] The junction box may comprise one or more entry and / or exit port(s) for the transmission line and / or the return line of the spur.

[0032] The junction box may befor use with a spur wherein, on the spur side, the transmission line and the return line of the spur is integrated into the same cable. Here the junction box may comprise one port which acts as both an exit port for the transmission line of the spur and an entry port for the return line of the spur.

[0033] In embodiments wherein the junction box is for use with a spur (wherein, on the spur side, the transmission line and the return line of the spur are provided in separate cables), the box may comprise one exit port for the transmission line of the spur and one entry port for the return line of the spur.

[0034] The enclosure may be, or serve as, a termination or terminal box. This may be an endjoint (to a circuit or load-off) or a start-joint (first load off or power supply).

[0035] The junction box may comprise one or more (electrical) connector(s), such as one or more conductor-to-conductor connector(s). Each connector may comprise an electrically conducting element (or a coupler). Each connector may be provided with one or more connecting (or fastening or securing) means, each suitable for connecting (or fastening or securing) a conductor thereto. In embodiments wherein the transmission line of the transmission-and-return line arrangement is a capacitive transmission line, the junction box may comprise two connectors therefor. Similarly, in embodiments wherein the return line of the transmission-and-return line arrangement is a capacitive return line, the junction box may comprise two connectors therefor. Thus, the junction box may comprise four connectors.

[0036] Preferably, there is one connector for a first (e.g. plurality of) conductor(s) (such as a first (e.g. plurality of) conductor(s) galvanically connected to the power source / supply but not to the load) of the transmission line of the transmission-and-return line arrangement and there is another connector for a second (e.g. plurality of) conductor(s) (such as a second (e.g. plurality of) conductor(s) galvanically connected to the load but not to the power source / supply) of the transmission line of the transmission-and-return line arrangement.

[0037] Preferably, there is one connector for a first (e.g. plurality of) conductor(s) (such as a first (e.g. plurality of) conductor(s) galvanically or electrically connected to the load (but not to the power source / supply) of the return line of the transmission-and-return line arrangement. There may be another connector for a second (e.g. plurality of) conductor(s) (such as a second (e.g. plurality of) conductor(s) galvanically or electrically connected to the power source / supply (but not to the load), of the return line of the transmission and return line arrangement.

[0038] Thus, preferably there are two connectors for the transmission line of the transmission- and-return line arrangement and / or two connectors for the return line of the transmission-and-return line arrangement.

[0039] The connecting (or fastening or securing) means may comprise a screw, nut, and / or bolt(s) to allow the conductor(s) to be secured to the connector.

[0040] Preferably, each connector is metal, or substantially metallic, and / or electrically or galvanically conductive. Each connector may comprise solid metal, such as a rod. Each connector may comprise one or more metals, such as copper or aluminium.

[0041] Each connector may comprise a busbar.

[0042] The connectors may be the same, or similar, height. Alternatively, the connectors may be placed or spaced apart, for example at different heights, so as to minimise interference.

[0043] Each connector may have an electrical joint (or tie, lead, or take-off) that can provide an electrical connection with, or to, the transmission line of the spur and / or the return line of the spur.

[0044] In the transmission line of the transmission-and-return line arrangement (e.g. the conductor(s) of the transmission line of the transmission-and-return line arrangement galvanically connected to the load but not to the power source / supply).

[0045] Preferably, the electrical connection with, or to, the return line of the spur is with, or to, the connector for the first (e.g. plurality of) conductor(s) of the return line of the transmission-and-return line arrangement (e.g. the conductor(s) of the return line of the transmission-and-return line arrangement galvanically connected to the load but not to the power source / supply).

[0046] Thus, suitably the spur will be electrically joined to a first connector and to a second connector, and advantageously to one connector of the transmission line of the transmission-and-return line arrangement and to one connector of the return line of the transmission-and-return line arrangement. Thus, suitably the spur will be electrically joined to equivalent connectors in both the transmission line and / or the return line, e.g. the connectors galvanically or electrically connected to the load (but not to the power source / supply) in each of the transmission line and the return line.

[0047] The invention may thus provide an enclosure for a spur from an electrical cable (transmission and return line arrangement / system / apparatus) and may thus form a T- junction. Thus, the top horizontal bar of the “T” can be thought of as the transmission- and-return line arrangement, whilst the vertical part of the “T” represents the spur. The transmission line of the transmission-and-return line arrangement may comprise a first plurality of conductors galvanically or electrically connected to the power source / supply (but not to the load). For example, there may be one conductor connected on the source side of the junction box (i.e. connected to the power source / supply and to the junction box) and / or one conductor connected on the load side of the junction box (i.e. connected to the junction box but not to the load).

[0048] The transmission line of the transmission-and-return line arrangement may comprise a second plurality of conductors, usually galvanically or electrically connected to the load (but not to the power source / supply). For example, there may be one conductor connected on the source side of the junction box (i.e. connected to the junction box but not to the power source / supply) and / or one conductor connected on the load side of the junction box (i.e. connected to the junction box and to the load).

[0049] The return line of the cable (transmission-and-return line arrangement / system / apparatus) may comprise a first plurality of conductors galvanically or electrically connected to the load (but not to the power source / supply). For example, there may be one conductor connected on the load side of the junction box (i.e. connected to the junction box and to the load) and / or one conductor connected on the source-side of the junction box (i.e. connected to the junction box but not to the power source / supply).

[0050] The return line of the cable (transmission-and-return line arrangement / system / apparatus) may comprise a second plurality of conductors galvanically connected to the power source / supply but not to the load. For example, there may be one conductor connected on the load side of the junction box (i.e. connected to the junction box but not to the load) and / or one conductor connected on the source-side of the junction box (i.e. connected to the junction box and to the power source / supply).

[0051] Thus, in each of the above-described pluralities of conductors, the conductor(s) on the source-side may be galvanically or electrically connected to the conductor(s) on the load-side via one or more (electrical) connector(s) inside the junction box. Preferably, the different conductors are colour-coded. For example, conductors connected to the power source / supply (but not to the load) may be one colour, e.g. coated in red insulation, whilst conductors connected to the load (but not to the power source / supply) may be another or different colour, e.g. coated in green insulation. It will be appreciated that other distinguishing (visual) markings may be used instead of, or in addition to, colour-coding.

[0052] The load may be any type of load. Examples of suitable loads include electrical appliances and charging points for wireless electric vehicle charging systems, in particular ground pads of wireless electric vehicle charging systems.

[0053] Suitably the transmission-and-return line arrangement comprises a capacitive transmission line and / or a capacitive return line and / or may thus be, or form, a “backbone”. The spur (e.g. via the T-junction) may thus connect the (backbone) cable to an electric vehicle charging point or element, such as a ground pad of a wireless electric vehicle charging system.

[0054] Inside the junction box, the first (e.g. plurality of) conductor(s) of the transmission line of the transmission-and-return line arrangement, i.e. the conductor(s) thereof galvanically or electrically connected to the power source / supply (but not to the load), may be separated from the second (e.g. plurality of) conductor(s) of the transmission line of the transmission-and-return line arrangement, i.e. the conductor(s) thereof galvanically or electrically connected to the load (but not to the power source / supply).

[0055] Alternatively or additionally, inside the junction box the first (e.g. plurality of) conductor(s) of the return line of the transmission-and-return line arrangement, i.e. the conductor(s) thereof galvanically connected to the load but not to the power source / supply, may be separated from the second (e.g. plurality of) conductor(s) of the return line of the transmission-and-return line arrangement, i.e. the conductor(s) thereof galvanically connected to the power source / supply but not to the load.

[0056] Alternatively, or additionally, the conductor(s) of the transmission line of the transmission-and-return line arrangement may be separated from the conductor(s) of the return line of the transmission-and-return line arrangement inside the junction box. Alternatively, or additionally, inside the junction box the conductor(s) of the transmission line of the spur may be separated from the conductor(s) of the return line of the spur.

[0057] Accordingly, each conductor may be connected to its respective connector inside the junction box. The connectors may thus secure the conductors of the transmission and- return line arrangement.

[0058] Preferably, the conductor(s) can (or do(es)) carry electricity at a high frequency, such as high frequency alternating current (“AC”). This, however, might incur errant resistance, capacitance and / or inductance. Thus, (modified or improved) insulation may be needed. Thus, preferably each conductor and / or connector is insulated. There may thus be insulation from other conductor(s) and / or other connector(s). The insulation may be air. The geometric shape and / or material of the connector(s) may need to be modified or improved to account for the errant resistance, capacitance and / or inductance, as well.

[0059] The present invention is particularly applicable to wireless power transfer, in particular wireless power transfer to and / or from electric vehicles. Electric vehicles are usually charged from the grid or from a central power supply. Such vehicles often contain an onboard charger (“OBC”), which is connected to the battery (or battery management system, “BMS”) of the electric vehicle. The (mains) power usually supplies AC, but an electric vehicle’s battery, and indeed most of its internal electrics and electronics, usually works using direct current (“DC”).

[0060] The junction box can therefore be used in an electric vehicle charging system, such as a wireless electric vehicle charging system. The transmission-and-return line arrangement may therefore represent the backbone, at one end of which the source conductor(s) thereof may be connected to mains power.

[0061] Suitably, the junction box is connected to (or connects) one or more cables which are capable of carrying, or carry, AC at a frequency of 22 kHz to 25 kHz, 75 kHz or 80 kHz up to 90 kHz or 95 kHz (especially at a frequency of about 85 kHz). It can be used in a wide frequency (bank and / or band) range and / or power (demand).

[0062] The conductor(s) therefore may be capable of carrying, or carry, AC, preferably at a high frequency.

[0063] As mentioned, the transmission line of the transmission-and-return line arrangement, the return line of the transmission-and-return line arrangement, the transmission line of the spur, and / or the return line of the spur may be capacitive transmission / return lines. Such capacitive transmission / return lines comprise one or more dielectric material(s). Examples of suitable dielectric materials include polymers such as polyvinyl chloride, (low density) polyethylene, (high density) polyethylene, ethylene propylene rubber (EPR), polyurethane, polyamide nylon (10 ruslan), (Grade 12) Nylon, polyethylene terephthalate, polypropylene, polyvinylidene chloride, tetrafluoroethylene, polytetrafluoroethylene, perfluoroalkyl polyimide, silicone rubber, and / or aluminium-based dielectric tape.

[0064] The invention also relates to an electrical T-junction box (or enclosure), for example for taking a spur off a (transmission) cable, e.g. a transmission-and-return line arrangement / system / apparatus. The enclosure may have an entry port and / or an exit port for a transmission line of the transmission and return line arrangement. This transmission-and-return line arrangement can have a spur joint (thus making a T junction). There may be one or more port(s) for entry and / or exit of a transmission line and / or a return line of a spur.

[0065] The enclosure may have an electrical connector (e.g. to form the T-junction). This may have one or more fasteners suitable for securing conductors of a transmission line and / or a return line. The connector may be adapted to form a T-junction therebetween, such as between a transmission-and-return line arrangement and a spur.

[0066] Spacing between the busbars may be dependent on several factors such as: a. Insulation coordination (between capacitive terminals, line to ground, line to line for 3-ph, etc), another term used is the creepage distance (for stable and transient operational scenarios). b. Thermal capacity and consideration inside the joint box / enclosure. c. EMF interference between the busbars. d. Reactive control (inductance linkage between lines and capacitance between capacitive terminals of the same line or between different lines). i) Resistance & Inductance: The volumetric spacing between the source / power supply & load connectors (including the dimension / shape of connector, its metallic composition, etc) per line (single-phase; transmission and return) or per phase (three- phase) can affect the resistance inductance per line / 1 -ph or 3-ph (by-product of the magnetic-field interaction). ii) Capacitance: The insulation spacer placed between the contactors can also provide capacitive support by strengthening the capacitive linkage between the two capacitive connectors per line arrangement or per phase (3-ph). The spacer dielectric / capacitive properties hence can alter the capacitance within the junction box.

[0067] The load(s) can be connected to either an output capacitive busbar, such as in the input capacitive busbar, or both, preferably while the cable / coil is in capacitive (selfcompensating) mode.

[0068] A further aspect of this invention relates to a method of introducing an electrical T junction into a cable (or transmission-and-return line arrangement). This may comprise providing a transmission line and a return line of a transmission-and-return line arrangement, and then preferably splitting, and then connecting, the transmission line and the return line, suitably to or via an electrical connector. This connector is (adapted to form) a T-junction with a spur.

[0069] Another aspect of the invention is an electrical T-junction. This may comprise a T junction inserted into a cable (transmission-and-return line arrangement). An electrical connector suitably fastens two conductors inside the T-junction. The electrical (T junction) connector can form a T-junction, and thus may connect the transmission and- return line arrangement to a spur.

[0070] Suitably the entry and / or exit ports will be located on the side of the junction box (or the enclosure).

[0071] The junction box may comprise one or more additional element(s). For example, the junction box may comprise a resistance modifier, a capacitance modifier and / or an inductance modifier. These modifiers may adjust / modify electrical parameters of the system, such as resistance (e.g. in the case of a resistance modifier), capacitive reactance (e.g. in the case of a capacitance modifier) and inductive reactance (e.g. in the case of an inductance modifier). Such additional elements may be comprised or housed within the junction box. Examples of suitable additional elements are described in e.g. WO 2024 / 246228.

[0072] The enclosure, or junction box, of the invention can be one or single phase (e.g. in the transmission and return line) or it can be 3-phase, or higher multi-phases (such as 6 phase or 9 phase). If 3-phase then this can be either a 3-phase circuit or three 1 -phase circuits. Similarly, if 6-phase then this can be either two 3-phase circuits or six 1 -phase circuits and, if 9-phase, then this can be either three 3-phase circuits or nine 1 -phase circuits.

[0073] In a 1 -phase line, either the transmission and return line can be both capacitive cables, or one cable is capacitive, and the other is conventional (via shorting the connectors and busbars at the joint box and sending / receiving end). This applies equally to 3- phase, 6-phase, and 9-phase lines (as well as higher multi-phases), i.e. both the transmission line and the return line can be capacitive or one can be capacitive and the other conventional.

[0074] Sub-sections of the capacitive and conventional cable can be connected in series. This also applies to

[0075] Electromagnetic coils;

[0076] 3-ph arrangements; and n-ph arrangements. The entry / exit of the joint box may depend on the entry direction of a feeder cable i.e. , vertical (upper / lower side) or horizontal.

[0077] Methods of spur connection may depend on whether the terminals of the “load circuit” has capacitive cable / winding or conventional cable / winding:

[0078] If the “load circuit” connected has conventional wiring (cable or electromagnetic coil) then the take-off (spur) may be from a load connector of each 1 -ph line arrangement (transmission or return) or load connector of phase in a 3-phase arrangement. Similar principle applies to the multi-phase.

[0079] If the load connected has capacitive wiring (cable or electromagnetic coil), then the take-off (spur) can be either mode for transmission & return (i.e. 1 -ph, 3-ph or multi-phase arrangement):

[0080] Series Capacitive Link: take-off or spur is from the load connectors for each line in 1 -ph (transmission & return) and / or each phase in 3-ph and higher multiphases.

[0081] Parallel Capacitive Link: take-off or spur is from both connectors (source & load) for each line (transmission & return) in 1 -ph and / or each phase in 3-ph and higher multi-phases, Provided the “load circuit” is capacitive. The load circuit must be of capacitive nature (i.e. CTS component or circuit).

[0082] The intermediate Junction Boxes can be uninterrupted (i.e., no circuit load connected to the connector via the T-junction or the Junction Box can interrupt (connect and disconnect) the load circuit connected by using switches.

[0083] The enclosure or junction box can be used as a termination or terminal box. In other words, it may be an end joint (to another section of the circuit, or for final load take off) or a start joint (first load take-off or power supply).

[0084] The enclosure or junction box can comprise capacitive protective equipment for the dielectric, which may be used for capacitive coupling.

[0085] The junction box or enclosure may comprise, or be used for, both capacitive cables, as well as electromagnetic coils (for example comprising capacitive conductors). The number of conductors (and busbars and exit-entry points) can reflect, or differ, from the cable or cable of coil cross-sectional details, but suitably they should create (or meet the minimum requirements for creating) a joint.

[0086] The enclosure or box may comprise reactive banks (such as capacitors and / or inductors). These may be added, or removed, from a feeder line or coil (for example via switches).

[0087] The box or enclosure can comprise one or more switches. These may be used to connect / disconnect some of the components. For example, the busbars of a capacitive cable or coil for a given line (such as to connect or disconnect two capacitive terminals). One or more switches may enable switching between different modes, for example between a self-compensated (e.g., capacitive) mode, such as to an uncompensated (and thus non-capacitive) mode. This may require a (e.g., synchronised) response from a control system, or other joint boxes, which also may contain switches.

[0088] The junction box enclosure may be of a size that allows its use in small-scale applications, or it may be miniaturised. It may be used for or be present in a portable circuit board (“PCB”) tracing.

[0089] In say a single phase mode or (transmission and return) line, the number of contactors, conductors or busbars can be 4 or higher. In say a 3-phase line or mode, the number of conductors, busbars or contactors can be 6 or higher.

[0090] The joint box or enclosure may be used to connect a capacitive cable or coil, for example where its capacitive terminals are connected to only the terminals of a power source / supply, or only to the terminals of a load.

[0091] Suitably the joint box of the enclosure may comprise one or more conductors, contactors, busbars, and / or entry / exit points for other (e.g., building) elements in a cable or coil, for example that require galvanic or electrical connection (for example, a cable metallic screen or armour). The galvanic or electrical connection may comprise solder or may be solderable (for example when used in PCB tracing).

[0092] The distance or spacing between the conductors, contactors or busbars may be dependent on several factors. These may be: a. insulation coordination (between capacitive terminals, line to ground, line to line for 3-phase, etc.); b. thermal capacity and / or other considerations inside the joint box; c. EMF interference, for example between the conductors, contactors and busbars; and / or d. reactive control (such as inductance linkage between lines and capacitance between capacitive terminals of the same line or between different lines).

[0093] If operating in single phase, or with a single phase line, the transmission line or cable can be connected to a return line.

[0094] The load(s) can be connected to either the output capacitive connector, conductor or busbar, in the input capacitive conductor, contactor or busbar, or both. The cable / coil may be in capacitive (or self-compensating) mode.

[0095] The invention additionally provides a junction box or enclosure, comprising:

[0096] (a) a housing;

[0097] (b) a first connector for one or more conductor(s) galvanically or electrically connected to a power source / supply (but not to a load) and (so suitably) forming part of a transmission line (cable) of a transmission-and-return line arrangement;

[0098] (c) a second connector for one or more conductor(s) galvanically or electrically connected to the load (but not to the power source / supply) and (so suitably) forming part of the transmission line (cable) of the transmission-and-return line arrangement;

[0099] (d) a third connector for one or more conductor(s) galvanically connected to the load but not to the power source / supply and (so suitably) forming part of a return line of the transmission-and-return line arrangement; and / or

[0100] (e) a fourth connector for one or more conductor(s) galvanically connected to the power source / supply but not to the load and (so suitably) forming part of the return line of the transmission-and-return line arrangement, wherein the connectors are enclosed within the housing.

[0101] The housing may comprise a lid. This is advantageous because it can enable a user / operator of the junction box to access the internal components for maintenance / repair.

[0102] Preferably, the transmission line is a capacitive transmission line and / or the return line is a capacitive return line.

[0103] Preferably, the junction box additionally comprises an entry port for the transmission line, an exit port for the transmission line, an entry port for the return line, and / or an exit port for the return line.

[0104] Preferably, the junction box additionally comprises an exit port for a transmission line of a spur and / or an entry port for a return line of the spur. The spur may comprise a load, which may be a conventional load or a capacitive load. As used herein, the term “conventional load” is intended to mean a load which is configured to utilise galvanic connections to transmit power via its wiring / cabling. In contrast, as used herein the term “capacitive load” is intended to mean a load which is configured to utilise capacitive power transfer to transmit power via its wiring / cabling. Examples of capacitive loads, e.g. electrical machines which utilise capacitive power transfer, are known in the art and are described in, for example, WO 2024 / 042136.

[0105] The transmission line of the spur may be a capacitive transmission line and / or the return line of the spur may be a capacitive return line. The transmission line of the spur may be a conventional transmission line and / or the return line of the spur may be a conventional return line. It will be appreciated that the preferred setup, i.e. which of the transmission line of the spur and the return line of the spur is / are conventional or capacitive will depend on factors such as the specific industrial application of the transmission-and-return line arrangement and whether the load of the spur is a conventional load or a capacitive load.

[0106] In embodiments wherein the spur comprises a conventional load, the transmission line of the spur may be a conventional transmission line or a series capacitive transmission line and the return line of the spur may be a conventional return line or a series capacitive return line. It will be appreciated that whether conventional or series capacitive transmission / return lines are used may depend on factors such as the type of load forming part of the spur and the specific industrial / commercial application of the transmission-and-return line arrangement.

[0107] In embodiments wherein the spur comprises a capacitive load, the transmission line of the spur may be a conventional transmission line, a series capacitive transmission line, or a parallel capacitive transmission line and the return line of the spur may be a conventional return line, a series capacitive return line, or a parallel capacitive return line. Again, it will be appreciated that whether conventional, series capacitive, or parallel capacitive transmission / return lines are used may depend on factors such as the type of load forming part of the spur and the specific industrial / commercial application of the transmission-and-return line arrangement.

[0108] In this context, the terms “conventional transmission line” and “conventional return line” are each intended to mean an electrical component which galvanically connects one of the connectors inside the housing of the junction box to a load of the spur, thereby establishing direct electrical contact therebetween.

[0109] In contrast, the terms “series capacitive transmission line” and “series return line” are each intended to mean two conductors, or two pluralities of conductors, one of which is galvanically connected to a load of the spur but not to any of the connectors inside the housing of the junction box, and the other of which is galvanically connected to one of the connectors inside the housing of the junction box but not to the load of the spur, with the two conductors (or pluralities of conductors) being galvanically / electrically separated from each other by a dielectric material which enables capacitive power transfer therebetween. Thus, a series capacitive transmission line enables power to be transmitted from a connector inside the housing of the junction box to the load of the spur via capacitive power transfer I via a capacitive coupling. Similarly, a series capacitive return line enables power to be transmitted from the load of the spur to a connector inside the housing of the junction box via capacitive power transfer / via a capacitive coupling.

[0110] The terms “parallel capacitive transmission line” and “parallel capacitive return line” are each intended to mean two conductors, or two pluralities of conductors, each galvanically connected to one of the connectors inside the housing of the junction box and to the load of the spur. In parallel capacitive transmission / return lines, the two conductors, or two pluralities of conductors, are galvanically / electrically separated from each other by a dielectric material which enables capacitive power transfer therebetween. Thus, a parallel capacitive transmission line enables power to be transmitted from a connector inside the housing of the junction box to the load of the spur via capacitive power transfer / via a capacitive coupling, and a parallel capacitive return line enables power to be transmitted from the load of the spur to a connector inside the housing of the junction box via capacitive power transfer I via a capacitive coupling. Unlike series capacitive transmission / return lines, however, parallel capacitive transmission / return lines additionally enable power to be transmitted from the connector to the load (in the case of a transmission line, or vice versa in the case of a return line) via direct galvanic / electrical connections therebetween. Thus, in these parallel lines power is transmitted via both direct galvanic / electrical connections and capacitive power transfer.

[0111] If the load of the spur is a conventional load, then preferably the transmission and return lines of the spur are each conventional or series capacitive. This is advantageous compared to using parallel transmission / return lines because using parallel transmission and return lines in conjunction with a conventional load risks establishing a short circuit. This problem is not observed if the load is a capacitive load, and thus parallel transmission / return lines can be readily used therewith.

[0112] The junction box may comprise an exit port for a transmission line of a second spur and / or an entry port for a return line of the second spur. The second spur may be similar or identical to the (first) spur described above. It will be appreciated that, in this context, one of the “(first) spur” and the “second spur” may correspond to the “load- side circuitry” referred to above and the other may correspond to the “spur-side circuitry” referred to above. Thus, these terms are used interchangeably herein.

[0113] Preferably, each connector comprises one or more connection / connecting means for connecting one or more conductor(s) to the connector. The one or more connection means may be one or more screw(s), nut(s), and / or bolt(s).

[0114] Preferably:

[0115] (i) only one of the first connector and the second connector comprises a connecting means for connecting one or more conductor(s) galvanically connected to a load of the spur and forming part of the transmission line of the spur to the respective connector, and

[0116] (ii) only one of the third connector and the fourth connector comprises a connecting means for connecting one or more conductor(s) galvanically connected to the load of the spur and forming part of the return line of the spur to the respective connector.

[0117] The invention additionally provides an electrical junction, comprising:

[0118] (a) a junction box, comprising:

[0119] (i) a housing,

[0120] (ii) a first connector,

[0121] (iii) a second connector,

[0122] (iv) a third connector, and

[0123] (v) a fourth connector, wherein the connectors are enclosed within the housing,

[0124] (b) a transmission line for supplying power from a power source to one or both of the first connector and the second connector,

[0125] (c) a return line for supplying power from one or both of the third connector and the fourth connector to the power source, and

[0126] (d) a spur, comprising:

[0127] (i) a load,

[0128] (ii) a transmission line for supplying power from one or both of the first connector and the second connector to the load of the spur, and (iii) a return line for supplying power from the load of the spur to one or both of the third connector and the fourth connector.

[0129] The transmission line of the electrical junction may be a conventional transmission line. However, preferably the transmission line of the electrical junction is a capacitive transmission line for supplying power from the power source to both the first connector and the second connector.

[0130] The return line of the electrical junction may be a conventional return line. However, preferably the return line of the electrical junction is a capacitive transmission line for supplying power from both the third connector and the fourth connector to the power source.

[0131] The load of the spur may be a conventional load or a capacitive load.

[0132] In embodiments wherein the load of the spur is a conventional load:

[0133] (i) the transmission line of the spur may be a conventional transmission line or a series capacitive transmission line,

[0134] (ii) the return line of the spur may be a conventional return line or a series capacitive return line,

[0135] (iii) the transmission line of the spur may be connected to only one of the first connector and the second connector, and

[0136] (iv) the return line of the spur may be connected to only one of the third connector and the fourth connector.

[0137] In certain embodiments wherein the load of the spur is a capacitive load:

[0138] (i) the transmission line of the spur may be a conventional transmission line or a series capacitive transmission line,

[0139] (ii) the return line of the spur may be a conventional return line or a series capacitive return line,

[0140] (iii) the transmission line of the spur may be connected to only one of the first connector and the second connector, and

[0141] (iv) the return line of the spur may be connected to only one of the third connector and the fourth connector. In other embodiments wherein the load of the spur is a capacitive load:

[0142] (i) the transmission line of the spur may be a parallel capacitive transmission line,

[0143] (ii) the return line of the spur may be a parallel capacitive return line,

[0144] (iii) the transmission line of the spur may be connected to both of the first connector and the second connector, and

[0145] (iv) the return line of the spur may be connected to both of the third connector and the fourth connector.

[0146] The junction box of the electrical junction may comprise an entry port for the transmission line of the electrical junction, an exit port for the return line of the electrical junction, an exit port for the transmission line of the spur and / or an entry port for the return line of the spur.

[0147] The electrical junction may comprise a second spur, which may be similar or identical to the (first) spur described above. The electrical junction may also comprise a third spur, which may be similar or identical to the (first and second) spur(s) described above. Entry / exit ports may be provided in the junction box of the electrical circuit in a manner analogous to that described above in relation to the (first) spur. As explained elsewhere above, in this context, one of the “(first) spur” and the “second spur” may correspond to the “load-side circuitry” referred to above and the other may correspond to the “spur-side circuitry” referred to above.

[0148] Each connector may comprise one or more connection / connecting means for connecting one or more conductor(s) to the connector. The one or more connecting means may be one or more screw(s), nut(s), and / or bolt(s).

[0149] The invention also provides use of the junction box of the invention in the electrical junction of the invention.

[0150] The invention also provides a method of transmitting power comprising:

[0151] (a) providing an electrical junction of the invention, (b) connecting both the transmission line of the electrical junction and the return line of the electrical junction to a power source, and

[0152] (c) activating the power source.

[0153] The invention additionally provides an electrical circuit comprising:

[0154] (a) a transmission-and-return line arrangement;

[0155] (b) a junction box or enclosure; and

[0156] (c) a spur.

[0157] Preferably, the circuit comprises one or more capacitive transmission line(s) and one or more capacitive return line(s). More preferably, the transmission-and-return line arrangement comprises a capacitive transmission line and / or a capacitive return line, and / or the spur comprises a capacitive transmission line and / or a capacitive return line.

[0158] In another aspect the invention relates to an electrical T-junction comprising;

[0159] (a) an electrical T-junction in a transmission-and-return line arrangement comprising an electrical connector fastened to two conductors of said arrangement;

[0160] (b) an electrical T-junction connector which is adapted to form a joint, so connecting the transmission-and-return line arrangement to a spur.

[0161] Suitably one, two or more of the transmission line(s) and / or return line(s) are, or comprise, capacitive transmission line(s) and / or capacitive return line(s). Preferably one or more of the transmission and / or return lines are capable of carrying, or carry, AC at a frequency of 22 kHz to 25 kHz, or 75 kHz or 80 kHz up to 90 kHz or 95 kHz (especially about 85 kHz).

[0162] A further aspect of the invention relates to an electrical power supply distribution network comprising a plurality of electrical T junction enclosures, or an electrical T- junction, of the invention. The T-junction can be present in a transmission and return line arrangement that is connected to the mains power and / or the spur is connected to an electric vehicle charging means, such as a ground pad.

[0163] Suitably one, two or more of the transmission line(s) and the return line(s) are, or comprise, capacitive transmission line(s) and / or capacitive return line(s).

[0164] The invention additionally provides uses of the various products described above and methods of transmitting power using the same.

[0165] Preferred features and characteristics of one aspect of the invention are equally applicable to another aspect mutatis mutandis.

[0166] Examples

[0167] The invention will now be illustrated by way of the following examples, which are not intended to be limiting, and with reference to the accompanying drawings, in which:

[0168] Fig. 1 shows a circuit diagram of a transmission-and-return line arrangement, a junction box, and a spur connected according to a first embodiment of the invention;

[0169] Fig. 2 is a photograph of a junction box according to a second embodiment of the invention;

[0170] Fig. 3 is a photograph of the junction box of Figure 2 taken from a different angle to Figure 2;

[0171] Fig. 4 is a photograph of a junction box according to a third embodiment of the invention;

[0172] Fig. 5 is a photograph of a junction box according a fourth embodiment of the invention;

[0173] Fig. 6 is a photograph of a transmission-and-return line arrangement comprising the junction box of Figure 5;

[0174] Fig. 7 is a photograph of the transmission-and-return line arrangement of Figure 6 taken from a different angle to Figure 6;

[0175] Fig. 8 is a photograph of a junction box according to a fifth embodiment of the invention which comprises a capacitance modifier;

[0176] Fig. 9 is a photograph of the junction box of Figure 8 taken from a different angle to Figure 8; Fig. 10 is a photograph of the junction box of Figures 8 and 9 showing a transmission line of a transmission-and-return line arrangement connected to the exit port therefor;

[0177] Fig. 11 is a photograph of the junction box of Figures 8 to 10 showing the transmission and return lines of the transmission-and-return line arrangement connected to their respective entry and exit ports therefor;

[0178] Fig. 12 shows a circuit diagram of a 3-phase junction box;

[0179] Fig. 13 shows a circuit diagram of an end joint wherein the junction acts as a terminal box;

[0180] Fig. 14 shows a diagram highlighting each of the capacitive terminals of 1- phase CTS Mark I cable arrangement (transmission and return) is split into two smaller terminals and these smaller terminals is individually connected to a dedicated connector / busbar (8 connectors / busbars for 4 capacitive terminals). Each of the “load circuit” terminals are parallel linked to two load connectors for either the transmission or return line.

[0181] Fig. 15 shows a diagram highlighting how each of the “applicable” capacitive terminals of 1 -phase CTS Mark II cable arrangement (per 2 transmission and 2 return) is grouped and connected to a dedicated connector / busbar (4 connectors / busbars for 8 capacitive terminals).

[0182] Fig. 16 shows a diagram highlighting how each of the “applicable” capacitive terminals of 1 -phase CTS Mark II cable arrangement (per 2 transmission and 2 return) is individually connected to a dedicated connector / busbar (8 connectors / busbars for 8 capacitive terminals). Each of the “load circuit” terminals are parallel linked to two load connectors for either the transmission or return line.

[0183] Fig. 17 shows a circuit diagram of a 1 -phase junction box with possible (not complete) locations for the distributed variable impedance balancer control system;

[0184] Fig. 18 shows a circuit diagram of a 1 -phase junction box comprising switches connected between the capacitive terminals of each 1 -phase capacitive cable arrangement (transmission & return);

[0185] Fig. 19 shows a circuit diagram of a 3-phase junction box with 3-phase load circuits. The junction box has compartments / connectors to facilitate 3-phase metallic screening and armouring;

[0186] Fig. 20 shows a circuit diagram of the transposition of 1 -phase CTS cable arrangement (transmission and return) between three 1 -phase junction boxes. The load circuits continue to be connected to the “load” connectors of the transmission and return cable;

[0187] Fig. 21 shows a circuit diagram of the connection of 1 -phase load circuits in a 1 -phase junction box to the power supply connectors of the transmission and return lines of the 1 -phase capacitive cable;

[0188] Fig. 22 shows a circuit diagram of a 1 -phase junction box with capacitive cables utilised as the transmission line and conventional cables as the return line. The load circuit terminals are connected to the return (conventional) cable connector and the “load” connector of the transmission (capacitive) cable;

[0189] Fig. 23 shows a circuit diagram of a 1 -phase junction box with capacitive cables utilised as both the transmission line and (in uncompensated mode using switches to short the capacitive terminals) as the return line. line. The load circuit terminals are connected to the “load” connector of the transmission (capacitive) and return (uncompensated mode) cable;

[0190] Fig. 24 shows a circuit diagram of a 1 -phase junction box with sub-sections of capacitive cable and conventional cable connected in series via the junction box. The load circuit terminals are connected to the “load” connectors of the transmission and return lines via the conventional cables;

[0191] Fig. 25 shows a circuit diagram of a T-junction box wherein the terminals of the capacitive load circuits are connected to the “source” and “load” connectors via capacitive cables but are in a parallel connection with the capacitive elements of the cables;

[0192] Fig. 26 shows a circuit diagram of a T-junction box wherein the terminals of the capacitive load circuits are connected to the “load” connectors via capacitive cables but are connected in series with the capacitive elements of the cables;

[0193] Fig. 27 shows a circuit diagram of a T-junction box wherein the terminals of the capacitive load circuits are connected to the “load” connectors via conventional cables;

[0194] Fig. 28 shows a circuit diagram of a junction box comprising switches connected to the terminals of the load circuit thereby allowing the load circuit to be selectively connected / disconnected from either or both terminals; and

[0195] Fig. 29 shows a circuit diagram of three junction boxes employed in a ring capacitive circuit.

[0196] Example 1 - Transmission-and-Return Line Arrangement with Junction Box and Spur Referring to Figure 1 , a power source / supply 1 is galvanically connected to a conductor 2. The conductor 2 is galvanically isolated from another conductor 3 (which is not connected to the power source / supply 1 ) by a dielectric material (not shown in Figure 1 ). Conductors 2 and 3 are integrated into the same cable (not shown in Figure 1 ) on the source-side 4.

[0197] The conductors 2 and 3 enter a junction box 5 via an entry port 6 for a transmission line of a transmission-and-return line arrangement. Inside the junction box, conductors 2 and 3 are separated from each other and respectively connected to connectors 7 and 8 via connecting means 9. Connectors 7 and 8 are metallic busbars.

[0198] On the other side of the junction box, conductors 10 and 11 are similarly connected to connectors 7 and 8, also via connecting means 9. Conductors 10 and 11 are separated from each other inside the junction box 5 but exit the junction box 5 together through an exit port 12 for the transmission line of the transmission and return line arrangement.

[0199] On the load-side 13, conductors 10 and 11 are integrated into the same cable (not shown in Figure 1 ) and are galvanically isolated from each other by a dielectric material (not shown in Figure 1 ). The conductor 11 is galvanically connected to a load 14, but the conductor 10 is not.

[0200] Conductors 2, 3, 10, and 11 , together with connectors 7 and 8, collectively make up the transmission line of the transmission-and-return line arrangement.

[0201] A conductor 15 is galvanically connected to the load 14 and is integrated into the same cable (not shown in Figure 1 ) as a conductor 16. Conductor 16 is not galvanically connected to the load 14.

[0202] The conductors 15 and 16 enter the junction box 5 via an entry port 17 for a return line of the transmission-and-return line arrangement. Inside the junction box, conductors 15 and 16 are separated from each other and respectively connected to connectors 18 and 19 via connecting means 9. Connectors 18 and 19 are metallic busbars. On the other side of the junction box, conductors 20 and 21 are similarly respectively connected to connectors 18 and 19, also via connecting means 9. Conductors 20 and 21 are separated from each other inside the junction box 5 but exit the junction box 5 together through an exit port 22 for the return line of the transmission and return line arrangement.

[0203] On the source-side 4, conductors 20 and 21 are integrated into the same cable (not shown in Figure 1 ) and are galvanically isolated from each other by a dielectric material (not shown in Figure 1 ). The conductor 21 is galvanically connected to the power source / supply 1 , but the conductor 20 is not.

[0204] Conductors 15, 16, 20, and 21 , together with connectors 18 and 19, collectively make up the return line of the transmission-and-return line arrangement.

[0205] A spur is provided comprising conductors 23, 24, 25, and 26, as well as a load 27.

[0206] On the spur-side, conductors 23 and 24 are integrated into the same cable as each other and are galvanically isolated from each other by a dielectric material (not shown in Figure 1 ). Conductors 25 and 26 are similarly integrated into the same cable as each other and are galvanically isolated from each other by a dielectric material (not shown in Figure 1 ). Conductor 23 is galvanically connected to connector 8 via a connecting means 9, whilst conductor 24 is not galvanically connected to any components inside the junction box 5. Conductors 23 and 24 are separated from each other inside the junction box 5 but exit the junction box 5 together via an exit port 28 for a transmission line of the spur.

[0207] Conductor 24 is galvanically connected to the load 27, but conductor 23 is not. Conductors 2, 3, 23, and 24, as well as connector 8, collectively make up the transmission line of the spur.

[0208] Conductor 26 is galvanically connected to connector 18 via a connecting means 9, whilst conductor 25 is not galvanically connected to any components inside the junction box 5. Conductors 25 and 26 are separated from each other inside the junction box 5 but enter the junction box 5 together via an entry port 29 for a return line of the spur.

[0209] Conductor 25 is galvanically connected to the load 27, but conductor 26 is not. Conductors 20, 21 , 25, and 26, as well as connector 18, collectively make up the return line of the spur.

[0210] Example 2 - Junction Box

[0211] Referring to Figures 2 and 3, a junction box 5 is shown.

[0212] The junction box 5 comprises a connector 7 for a first plurality of conductors of a transmission line of a transmission-and-return line arrangement galvanically connected to a power source / supply but not to a load. The junction box 5 also comprises a connector 8 for a second plurality of conductors of the transmission line of the transmission-and-return line arrangement galvanically connected to the load but not to the power source / supply.

[0213] The junction box 5 additionally comprises a connector 18 for a first plurality of conductors of a return line of the transmission-and-return line arrangement galvanically connected to the load but not to the power source / supply. The junction box 5 also comprises a connector 19 for a second plurality of conductors of the return line of the transmission-and-return line arrangement galvanically connected to the power source / supply but not to the load.

[0214] Each of the connectors 7, 8, 18, and 19 is a copper busbar.

[0215] The junction box 5 comprises six entry / exit ports. Specifically, the junction box 5 comprises an entry port 6 for a transmission line of a transmission-and-return line arrangement, an exit port 12 for the transmission line of the transmission-and-return line arrangement, an entry port 17 for a return line of the transmission-and-return line arrangement, an exit port 22 for the return line of the transmission-and-return line arrangement, an exit port 28 for a transmission line of a spur, and an entry port 29 for a return line of the spur. Connecting means 9 are provided on connectors 8 and 18 to allow conductors 22 and 26 (not shown in Figures 2 and 3), to be respectively connected thereto.

[0216] Example 3 - Junction Box

[0217] Referring to Figure 4, a junction box 5 similar to that of Example 2 is shown. However, in this junction box no connecting means are provided on connectors 8 and 18.

[0218] Also unlike Example 2, the junction box 5 of Figure 4 comprises a removable lid 30.

[0219] Example 4 - Junction Box

[0220] Referring to Figure 5, a junction box 5 similar to that of Example 3 is shown. The connectors of this junction box comprise connecting means 9 for securing conductors (not shown in Figure 5) thereto.

[0221] Example 5 - Transmission-and-Return Line Arrangement with Junction Box (No Spur) Referring to Figures 6 and 7, a power source / supply (not shown in Figures 6 and 7) is galvanically connected to a conductor 2. The conductor 2 is galvanically isolated from another conductor 3 (which is not galvanically connected to the power source / supply) by a dielectric material (not shown in Figures 6 and 7). Conductors 2 and 3 are integrated into the same cable 31 on the source-side 4.

[0222] The conductors 2 and 3 enter the junction box 5 via an entry port 6 for a transmission line of a transmission-and-return line arrangement. Inside the junction box, conductors 2 and 3 are separated from each other and respectively connected to connectors 7 and 8 via connecting means 9. Connectors 7 and 8 are copper busbars.

[0223] On the other side of the junction box, conductors 10 and 11 are similarly connected to connectors 7 and 8, also via connecting means 9. Conductors 10 and 11 are separated from each other inside the junction box 5 but exit the junction box 5 together through an exit port 12 for the transmission line of the transmission and return line arrangement.

[0224] On the load-side 13, conductors 10 and 11 are integrated into the same cable 32 and are galvanically isolated from each other by a dielectric material (not shown in Figures 6 and 7). The conductor 11 is galvanically connected to a load (not shown in Figures 6 and 7), but the conductor 10 is not.

[0225] Conductors 2, 3, 10, and 11 , together with connectors 7 and 8, collectively make up the transmission line of the transmission-and-return line arrangement.

[0226] A conductor 15 is galvanically connected to the load and is integrated into the same cable 33 as a conductor 16. Conductor 16 is not galvanically connected to the load.

[0227] The conductors 15 and 16 enter the junction box 5 via an entry port 17 for a return line of the transmission-and-return line arrangement. Inside the junction box, conductors 15 and 16 are separated from each other and respectively connected to connectors 18 and 19 via connecting means 9. Connectors 18 and 19 are copper busbars.

[0228] On the other side of the junction box, conductors 20 and 21 are similarly respectively connected to connectors 18 and 19, also via connecting means 9. Conductors 20 and 21 are separated from each other inside the junction box 5 but exit the junction box 5 together through an exit port 22 for the return line of the transmission and return line arrangement.

[0229] On the source-side 4, conductors 20 and 21 are integrated into the same cable 34 and are galvanically isolated from each other by a dielectric material (not shown in Figures 6 and 7). The conductor 21 is galvanically connected to the power source / supply, but the conductor 20 is not.

[0230] Conductors 15, 16, 20, and 21 , together with connectors 18 and 19, collectively make up the return line of the transmission-and-return line arrangement.

[0231] The conductors galvanically connected to the power source / supply are coated with red insulation, whilst the conductors galvanically connected to the load are coated with green insulation.

[0232] Example 6 - Junction Box Comprising Capacitance Modifier

[0233] Referring to Figures 8 to 11 , a junction box 5 is shown. The junction box 5 comprises a connector 7 for a first plurality of conductors of a transmission line of a transmission-and-return line arrangement galvanically connected to a power source / supply but not to a load. The junction box 5 also comprises a connector 8 for a second plurality of conductors of the transmission line of the transmission-and-return line arrangement galvanically connected to the load but not to the power source / supply.

[0234] The junction box 5 additionally comprises a connector 18 for a first plurality of conductors of a return line of the transmission-and-return line arrangement galvanically connected to the load but not to the power source / supply. The junction box 5 also comprises a connector 19 for a second plurality of conductors of the return line of the transmission-and-return line arrangement galvanically connected to the power source / supply but not to the load.

[0235] Each of the connectors 7, 8, 18, and 19 is a copper busbar.

[0236] The junction box 5 comprises six entry / exit ports. Specifically, the junction box 5 comprises an entry port 6 for a transmission line of a transmission-and-return line arrangement, an exit port 12 for the transmission line of the transmission-and-return line arrangement, an entry port 17 for a return line of the transmission-and-return line arrangement, an exit port 22 for the return line of the transmission-and-return line arrangement, an exit port 28 for a transmission line of a spur, and an entry port 29 for a return line of the spur.

[0237] Connecting means 9 are provided on connectors 8 and 18 to allow conductors (not shown in Figures 8 to 10) to be respectively connected thereto.

[0238] The junction box 5 comprises a removable lid 30.

[0239] The junction box 5 additionally comprises a capacitance modifier 35 for adjusting / modifying the capacitive reactance of the system. The capacitance modifier 35 is comprised / housed within the junction box. Referring to Figure 10, a transmission line (comprising conductors 10 and 11 ) of a transmission-and-return line arrangement is connected to the exit port 12 therefor.

[0240] Example 7 - Terminal Box

[0241] Referring to Figure 13, a 1 -phase junction box configured as an end-joint is shown. In this example, the junction box includes a single (first) spur with a conventional transmission line and return line connected to a load. It will be appreciated that the embodiment shown in Figure 14 is typically used to connect to a separate section of a circuit or to serve as the final load take-off. Suitably, this embodiment may also be used as a start-joint for an initial load take-off or for connection to the power supply.

[0242] Example 8 - 3-phase Junction Box with 3-phase Load Circuits

[0243] Referring to Figure 19, a 3-phase junction box connected to a 3-phase load circuit via a first spur is shown. The connectors of this junction box comprise connecting means for securing a 3-phase metallic screen and a 3-phase armouring, all of which are connected to ground. The junction box comprises a 3-phase load circuit galvanically connected to three connectors via a first spur comprising three conductors. As will be appreciated, embodiments of the invention suitably have connection means, connectors and entry / exit ports for other building elements in a cable / coil that require galvanic connection (e.g. cable metallic screen, armour).

[0244] Example 9 - Junction Box with Capacitive Transmission Line and Conventional Return Line

[0245] Referring to Figure 22, a 1 -phase junction box with a capacitive transmission line and a conventional return line is shown. In this example, the junction box includes three connectors: a first connector for one or more conductor(s) electrically connected to a power source / supply (but not to a load) and (so suitably) forming part of a transmission line (cable) of a transmission-and-return line arrangement; a second connector for one or more conductor(s) galvanically or electrically connected to the load (but not to the power source / supply) and (so suitably) forming part of the transmission line (cable) of the transmission-and-return line arrangement; and a third connector for one or more conductor(s) galvanically connected to the load but not to the power source / supply and (so suitably) forming the return line of the transmission-and-return line arrangement.

[0246] Additionally, the junction box includes a single (first) spur comprising a conventional transmission line and a conventional return line, which respectively connect the second and third connectors to the load.

[0247] Example 10 - Junction Box with First and Second Spurs Each Comprising Conventional Transmission and Return Lines

[0248] Referring to Figure 24, a 1 -phase junction box with sub-sections of capacitive cable and conventional cable connected in series via the junction box is shown. In this example, the junction box includes a first spur and a second spur, respectively connected to two load circuits via conventional transmission and return lines. As will be appreciated, the junction box comprises four connectors: a first connector for one or more conductor(s) galvanically or electrically connected to a power source / supply (but not to a load) and (so suitably) forming part of a transmission line (cable) of a transmission-and-return line arrangement; a second connector for one or more conductor(s) galvanically or electrically connected to the load (but not to the power source / supply) and (so suitably) forming part of the transmission line (cable) of the transmission-and-return line arrangement; a third connector for one or more conductor(s) galvanically connected to the power supply / source but not to the load and (so suitably) form ing part of a return line of the transmission-and-return line arrangement; and a fourth connector for one or more conductor(s) galvanically connected to the load but not to the power supply / source and (so suitably) forming part of the return line of the transmission-and-return line arrangement.

[0249] In this example, only the second and fourth connectors in the junction box are connected to the load circuits, with the first and third connectors having no onward connections. Example 11 - Junction Box with First and Second Spurs Comprising Parallel Capacitive Transmission and Return Lines

[0250] Referring to Figure 25, a junction-box is connected to two capacitive load circuits via a first spur and a second spur each comprising a parallel capacitive transmission line and a parallel capacitive return line. The parallel capacitive transmission / return lines each comprise two conductors each galvanically connected to one of the connectors inside the housing of the junction box and to the load of its respective spur. A capacitive relationship arises between the two conductors of each line in use and the loads are also galvanically / electrically connected to the connectors via the conductors.

[0251] Example 12 - Junction Box with First and Second Spurs Comprising Series Capacitive Transmission and Return Lines

[0252] Referring to Figure 26, a junction-box is connected to two load circuits via a first spur and a second spur each comprising a series capacitive transmission line and a series capacitive return line. For each spur, the series capacitive transmission / return lines each comprise two conductors, one of which is galvanically connected to a load of the spur but not to any of the connectors inside the housing of the junction box, and the other of which is galvanically connected to one of the connectors inside the housing of the junction box but not to the load of the spur, with the two conductors (or pluralities of conductors, as the case may be) being galvanically / electrically separated from each other by a dielectric material which enables capacitive power transfer therebetween. A capacitive relationship arises between the two conductors of each line in use.

[0253] Example 13 - Electrical Junction Comprising a Spur Having Switches

[0254] Referring to Figure 28, an electrical junction comprises inter alia a junction box and a spur. The spur comprises a conventional transmission line, a load, and a conventional return line. Each of the transmission line and the return line comprises a switch which can be actuated to determine whether the spur is connected as part of the overall electrical circuit or not. This means the junction box, with its switches, can be used to provide an additional degree of control to the electrical circuit.

[0255] Example 14 - Electrical Circuit Comprising Three Junction Boxes

[0256] Referring to Figure 29, an electrical circuit comprises a power source, a transmission line and a return line, each of which passes through three junction boxes. Each junction box comprises four connectors in the form of copper busbars enclosed within a housing. Each electrical junction comprises a spur, with each spur comprising a conventional transmission line, a load, and a conventional return line. Thus, the three junction boxes enable power to be supplied to three distinct loads in the same electrical circuit.

[0257] Parts List

[0258] 1 power source / supply

[0259] 2 source-side conductor of transmission line, galvanically connected to power source / supply

[0260] 3 source-side conductor of transmission line, galvanically connected to load

[0261] 4 source-side

[0262] 5 junction box

[0263] 6 entry port for transmission line of transmission-and-return line arrangement

[0264] 7 transmission line connector, galvanically connected to power source / supply

[0265] 8 transmission line connector, galvanically connected to load

[0266] 9 connecting means

[0267] 10 load-side conductor of transmission line, galvanically connected to power source / supply

[0268] 11 load-side conductor of transmission line, galvanically connected to load

[0269] 12 exit port for transmission line of transmission-and-return line arrangement

[0270] 13 load-side

[0271] 14 load-side load

[0272] 15 load-side conductor of return line, galvanically connected to load

[0273] 16 load-side conductor of return line, galvanically connected to power source / supply

[0274] 17 entry port for return line of transmission-and-return line arrangement

[0275] 18 return line connector, galvanically connected to load

[0276] 19 return line connector, galvanically connected to power source / supply

[0277] 20 source-side conductor of return line, galvanically connected to load

[0278] 21 source-side conductor of return line, galvanically connected to power source / supply

[0279] 22 exit port for return line of transmission-and-return line arrangement

[0280] 23 spur-side conductor of transmission line 24 spur-side conductor of transmission line, galvanically connected to load

[0281] 25 spur-side conductor of return line, galvanically connected to load

[0282] 26 spur-side conductor of return line

[0283] 27 spur-side load 28 exit port for transmission line of spur

[0284] 29 entry port for return line of spur

[0285] 30 removable lid

[0286] 31 source-side cable of transmission line

[0287] 32 load-side cable of transmission line 33 load-side cable of return line

[0288] 34 source-side cable of return line

[0289] 35 capacitance modifier.

Claims

Claims1 . An electrical (T-junction) enclosure comprising:(a) an entry port and an exit port for an electrical transmission-and-return line arrangement (or system / apparatus) which is to have a spur or joint (so as to form a T junction); and(b) an electrical (T-junction) connector comprising fasteners for securing or connecting one or more conductor(s) of the transmission-and-return line arrangement and adapted to form a T junction between the transmission- and-return line arrangement and a spur (or joint), wherein the transmission and return line arrangement (e.g. cable) and / or spur comprises a capacitive transmission and / or return line or has (preferably at least two) conductors that are in a capacitive relationship with each other.

2. An enclosure according to claim 1 , wherein the transmission-and-return line arrangement comprises a capacitive transmission line and a capacitive return line.

3. An enclosure according to claim 1 or claim 2, wherein the spur comprises a capacitive spur.

4. An enclosure according to claim 3, wherein the capacitive spur comprises two conductors that are in a capacitive relationship with each other.

5. An enclosure according to claim 1 or claim 2, wherein the spur comprises a conventional spur.

6. An enclosure according to any one of claims 1 to 5, wherein the transmission line and the return line are, respectively, a capacitive transmission line and a capacitive return line that each comprise two conductors that are in a capacitive relationship with each other.

7. An enclosure according to any one of claims 1 to 6, comprising two connectors, e.g. busbars, for the transmission line.

8. An enclosure according to claim 7, wherein only one of the transmission line connectors can be connected to the spur.

9. An enclosure according to any one of claims 1 to 8, comprising two connectors, e.g. busbars, for the return line.

10. An enclosure according to claim 9, wherein only one of the return line connectors can be connected to the spur.

11. An enclosure according to any one of claims 1 to 10, which is a junction box.

12. An enclosure according to any one of claims 1 to 11 , wherein one entry port is for entry for a first conductor of the transmission-and-return arrangement and one exit port is for exit of a second conductor of the transmission-and-return line arrangement.

13. An enclosure according to any preceding claim wherein the T-junction connector is substantially metallic, or galvanically or electrically conductive, for example a busbar or a copper or aluminium rod.

14. An enclosure according to any preceding claim wherein the fasteners comprise nut(s) and / or bolt(s) and / or are suitably for connecting the conductor(s) to the (electrical) connector.

15. An enclosure according to any preceding claim which is adapted to receive, or receives or is connected to, (preferably at least) two cables; optionally with each cable suitably having two conductors; preferably so that there is an entry port and an exit port (for each respective cable).

16. An enclosure according to any preceding claim which has four ports, such as two entry ports and two exit ports.

17. An enclosure according to any preceding claim wherein each of the transmission line and the return line has two conductors, such as a source conductor and a return conductor.

18. An enclosure according to any preceding claim wherein the T-junction to the spur is from one conductor of each of the transmission line and the return line.

19. An enclosure according to any preceding claim wherein the transmission and return line arrangement comprises two cables, preferably where one cable is a transmission line, and the other cable is a return line, suitably each having two conductors.

20. An enclosure according to any preceding claim wherein the transmission and return line arrangement is a “backbone” cable and the spur is a take-off, lead, tie or electrical spur.

21. An enclosure according to any preceding claim wherein the transmission and return line arrangement is connected to the mains power and / or the spur is connected to an electric vehicle charging means, such as a ground pad.

22. A method of introducing an electrical T-junction in a transmission-and-return line arrangement, the method comprising, in a transmission-and-return line arrangement, connecting two conductors of said arrangement to an electrical connector adapted to (or so to ) form a T-junction with a spur.

23. A method according to claim 22 wherein one, two or more of the transmission line(s) and the return line(s) are, or comprise, capacitive transmission line(s) and / or capacitive return line(s).

24. A method according to claim 22 or 23 wherein one or more of the transmission and / or return lines are capable of carrying, or carry, AC at a frequency of 75 kHz or 80 kHz up to 90 kHz or 95 kHz (especially about 85 kHz).

25. An electrical T-junction comprising;(a) an electrical T-junction in a transmission-and-return line arrangement comprising an electrical connector fastened to two conductors of said arrangement;(b) an electrical T-junction connector which is adapted to form a joint, so connecting the transmission-and-return line arrangement to a spur.

26. A junction according to claim 25 wherein one, two or more of the transmission line(s) and / or return line(s) are, or comprise, capacitive transmission line(s) and / or capacitive return line(s).

27. A junction according to claim 25 or 26 wherein one or more of the transmission and / or return lines are capable of carrying, or carry, AC at a frequency of 75 kHz or 80 kHz up to 90 kHz or 95 kHz (especially about 85 kHz).

28. A junction according to any of claims 25 to 27 wherein the electrical T-junction comprises a T junction enclosure according to any of claims 1 to 21 .

29. An electrical power supply distribution network comprising a plurality of electrical T junction enclosures either according to any of claims 1 to 21 or an electrical T-junction according to any of claims 25 to 28.

30. A network according to claim 29 wherein the T-junction is present in a transmission and return line arrangement that is connected to the mains power and / or the spur is connected to an electric vehicle charging means, such as a ground pad.31 . A network according to claim 30 wherein one, two or more of the transmission line(s) and the return line(s) are, or comprise, capacitive transmission line(s) and / or capacitive return line(s).

32. A junction box, comprising:(a) a housing;(b) a first connector for one or more conductor(s) galvanically or electrically connected to a power source / supply (but not to a load) and (so suitably)forming part of a transmission line (cable) of a transmission-and-return line arrangement;(c) a second connector for one or more conductor(s) galvanically or electrically connected to the load (but not to the power source / supply) and (so suitably) forming part of the transmission line (cable) of the transmission-and-return line arrangement;(d) a third connector for one or more conductor(s) galvanically connected to the load but not to the power source / supply and (so suitably) forming part of a return line of the transmission-and-return line arrangement; and / or(e) a fourth connector for one or more conductor(s) galvanically connected to the power source / supply but not to the load and (so suitably) forming part of the return line of the transmission-and-return line arrangement, wherein the connectors are enclosed within the housing.

33. A junction box as claimed in claim 32, wherein the transmission line is a capacitive transmission line and / or the return line is a capacitive return line.

34. A junction box as claimed in claim 32 or claim 33, wherein the junction box additionally comprises an entry port for the transmission line, an exit port for the transmission line, an entry port for the return line, and / or an exit port for the return line.

35. A junction box as claimed in any one of claims 32 to 34, wherein the junction box additionally comprises an exit port for a transmission line of a spur and / or an entry port for a return line of the spur.

36. A junction box as claimed in claim 35, wherein the spur comprises a conventional load or a capacitive load.

37. A junction box as claimed in claim 36, wherein the spur comprises a conventional load, the transmission line of the spur is a conventional transmission line or a series capacitive transmission line and the return line of the spur is a conventional return line or a series capacitive return line.

38. A junction box as claimed in claim 36, wherein the spur comprises a capacitive load, the transmission line of the spur is a conventional transmission line, a series capacitive transmission line, or a parallel capacitive transmission line and the return line of the spur is a conventional return line, a series capacitive return line, or a parallel capacitive return line.

39. A junction box as claimed in any one of claims 32 to 38, wherein the junction box comprises an exit port for a transmission line of a second spur and / or an entry port for a return line of the second spur.

40. A junction box as claimed in any one of claims 32 to 39, wherein each connector comprises one or more connection means for connecting one or more conductor(s) to the connector.41 . A junction box as claimed in any one of claims 32 to 40, wherein:(i) only one of the first connector and the second connector comprises a connecting means for connecting one or more conductor(s) galvanically connected to a load of the spur and forming part of the transmission line of the spur to the respective connector, and(ii) only one of the third connector and the fourth connector comprises a connecting means for connecting one or more conductor(s) galvanically connected to the load of the spur and forming part of the return line of the spur to the respective connector.

42. An electrical junction, comprising:(a) a junction box, comprising:(i) a housing,(ii) a first connector,(iii) a second connector,(iv) a third connector, and(v) a fourth connector, wherein the connectors are enclosed within the housing,(b) a transmission line for supplying power from a power source to one or both of the first connector and the second connector,(c) a return line for supplying power from one or both of the third connector and the fourth connector to the power source, and(d) a spur, comprising:(i) a load,(ii) a transmission line for supplying power from one or both of the first connector and the second connector to the load of the spur, and(iii) a return line for supplying power from the load of the spur to one or both of the third connector and the fourth connector.

43. An electrical junction as claimed in claim 42, wherein the transmission line of the electrical junction is a capacitive transmission line for supplying power from the power source to both the first connector and the second connector.

44. An electrical junction as claimed in claim 42 or claim 43, wherein the return line of the electrical junction is a capacitive transmission line for supplying power from both the third connector and the fourth connector to the power source.

45. An electrical junction as claimed in any one of claims 42 to 44, wherein the load of the spur is a conventional load or a capacitive load.

46. An electrical junction as claimed in claim 45, wherein the load of the spur is a conventional load, and wherein:(i) the transmission line of the spur is a conventional transmission line or a series capacitive transmission line,(ii) the return line of the spur is a conventional return line or a series capacitive return line,(iii) the transmission line of the spur is connected to only one of the first connector and the second connector, and(iv) the return line of the spur is connected to only one of the third connector and the fourth connector.

47. An electrical junction as claimed in claim 45, wherein the load of the spur is a capacitive load, and wherein:(i) the transmission line of the spur is a conventional transmission line or a series capacitive transmission line,(ii) the return line of the spur is a conventional return line or a series capacitive return line,(iii) the transmission line of the spur is connected to only one of the first connector and the second connector, and(iv) the return line of the spur is connected to only one of the third connector and the fourth connector.

48. An electrical junction as claimed in claim 45, wherein the load of the spur is a capacitive load, and wherein:(i) the transmission line of the spur is a parallel capacitive transmission line,(ii) the return line of the spur is a parallel capacitive return line,(iii) the transmission line of the spur is connected to both of the first connector and the second connector, and(iv) the return line of the spur is connected to both of the third connector and the fourth connector.

49. An electrical junction as claimed in any one of claims 42 to 48, wherein the junction box of the electrical junction comprises an entry port for the transmission line of the electrical junction, an exit port for the return line of the electrical junction, an exit port for the transmission line of the spur and / or an entry port for the return line of the spur.

50. An electrical junction as claimed in any one of claims 42 to 49, wherein the electrical junction comprises a second spur.

51. An electrical junction as claimed in any one of claims 42 to 50, wherein each connector comprises one or more connection / connecting means for connecting one or more conductor(s) to the connector.

52. Use of a junction box according to any one of claims 32 to 41 in an electrical junction according to any one of claims 42 to 51 .

53. A method of transmitting power comprising:(a) providing an electrical junction according to any one of claims 42 to 51 ,(b) connecting both the transmission line of the electrical junction and the return line of the electrical junction to a power source, and (c) activating the power source.

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