Patent Description:
As electrical power distribution becomes more complex through the advent of renewable energy, distributed generation and the adoption of electric vehicles, intelligent electrical distribution and associated electrical sensing is becoming more useful and even necessary. Useful sensing may include, for example, voltage, current, and the time relationship between voltage and current at various locations within a power distribution network.

The German patent publication <CIT> relates to a voltage sensing device comprising a capacitive voltage divider for an insulated metal-encapsulated high-voltage switchgear, in which the high-voltage capacitor consists of a high-voltage electrode embedded in a resin body and a measurement electrode formed by a conductive coating on the outer surface of the resin body.

patent application <CIT> relates to a high voltage sensing capacitor comprising a molded insulator body encapsulating two electrodes partially or incompletely overlapping within the insulator body.

In the European patent application <CIT> a high voltage measurement device is explained which has a capacitive divider in a container filled with insulating gas. A measurement electrode and a low voltage electrode are formed as rings.

A further German patent publication, <CIT>, illustrates a voltage divider assembly for measuring high and medium voltages in which a supply electrode and a sensor electrode are arranged on an outer surface of a tubular dielectric containing a high-voltage electrode in its interior.

Yet another European patent application, published as <CIT>, refers to a terminal connection device for a power cable in which, in one aspect, a printed circuit board element is placed over an electrically isolated piece of conductive or semiconductive material which may be operable to form an electrode of a sensing capacitor.

In general, this disclosure is directed to a voltage sensor that can be connected to a power line, cable, or cable accessories. In particular, the invention is defined by the voltage sensor according to claim <NUM>.

In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as "top," "bottom," "front," "back," "leading," "forward," "trailing," etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

The present disclosure describes a voltage sensor that can be used, for example, to measure the voltage of a power line, such as an overhead power line, at a particular location, such as a capacitor bank, switch or protective device, such as an overhead switch (manual or actuated by a motor, solenoid, etc.), a sectionalizer or recloser, or a voltage regulation transformer, etc. In one aspect, the voltage sensor utilizes an integrated, high accuracy capacitive voltage sensor. The voltage sensor can have a compact design and can be coupled to an existing power line (conductor or cable) in a straightforward manner. The voltage sensor described herein can provide a compact mechanism for providing real time, high accuracy voltage characteristics of a power cable or location in an electrical grid. The output of the voltage sensor can be a waveform that is directly proportional to the voltage of the power line. The division ratio of the actual line voltage to the output voltage can be tailored to any desired voltage. In some embodiments, the division ratio can be between <NUM>:<NUM> and <NUM>,<NUM>,<NUM>:<NUM>; in other preferred embodiments, the division ratio can be approximately <NUM>,<NUM>:<NUM>, where for example an actual line voltage of approximately <NUM>,<NUM> Volts would result in an output voltage of approximately <NUM> Volt. The voltage sensor supplies a voltage level that can in some embodiments be easily converted to a digital value for interaction with computational devices, microcontrollers, communication devices, etc. The voltage sensor can thus provide a utility, solar farm, wind farm, ship, industrial plant, or any individual or company that uses medium or high voltage equipment with an easy access to obtain a real time voltage reading of a live power line, as well as the ability to create a smart node at many different grid locations.

<FIG> shows a first aspect of the invention, voltage sensor <NUM>.

Voltage sensor <NUM> includes a conductor (also referred to as an inner conductor) <NUM>, which may be a solid or stranded metal axial conductor such as an aluminum or copper alloy conductor. Inner conductor <NUM> includes a first end <NUM>, which can include a first connection interface <NUM> and a second end <NUM>. The second end <NUM> has no connection. In one aspect, the second end is shaped to allow for optimal stress control in a minimal space with ease, to substantially reduce the probability of partial discharge or electrical failure. In one aspect, second end <NUM> includes a rounded surface <NUM>, such as a fully rounded surface (i.e., having no or almost no sharp edges). This rounded surface shape reduces electric field stress concentration. In one example configuration, such as shown in <FIG>, the rounded surface <NUM> has a bulbous shape. Alternatively, depending on the size of conductor <NUM>, if conductor <NUM> is of large enough diameter, a bulbous end can be omitted. Instead, in some embodiments, a full radius (semi-hemisphere) can be formed from the end <NUM> of the conductor. This semi-hemispherical shape would also remove any sharp edges that can lead to electric stress concentrations. In a further alternative aspect, the second end <NUM> of the voltage sensor <NUM> can be covered with a molded semiconducting rubber or semiconducting plastic material. In this alternative aspect, the semiconducting molding can be used to cover a rounded surface or a sharp surface.

The first connection interface <NUM> can include a lug, which is shown in <FIG>. Alternatively, the connection interface can comprise a separable connector, a splice, a modular connector, or other connection interfaces.

The connection interface can have a circular cross section configured to mate to a male end of conductor <NUM>. In alternative aspects, the first end of the conductor <NUM> can be formed as a male or hybrid type connector.

As shown in <FIG>, connection interface <NUM> comprises a lug. The structure of <FIG> allows for straightforward mechanical fastening and electrical conduction (or path) from an overhead power cable or line. For example, one method of attaching the voltage sensor <NUM> to an overhead line is to use a conventional overhead primary tap (such as a BHF/AHF two hole hot line pad connector available from Hubbell Power Systems, USA) and bolt that connector to connection interface/lug <NUM>. Alternatively, a conventional stem connector can be used. As such, voltage sensor <NUM> can be installed at any point along a power cable, line or in a cable accessory.

Moreover, voltage sensor <NUM> is configured to control the electrical field created by medium or high voltage within a power line or cable, such as an overhead power line or cable, wherein the power line or cable operates at voltages in excess of <NUM>,<NUM> Volts. As shown in <FIG>, a high K layer <NUM> can be employed to control the electric field. Alternatively, voltage sensor <NUM> can include geometric stress control (not shown).

Optionally, in some aspects, inner conductor <NUM> may be radially surrounded by conductor shield layer <NUM>. Conductor shield layer <NUM> comprises a conductive or semi-conductive material that is configured to smooth out any conductor surface inconsistencies that could create high electric field stress concentrations, especially when sensing the voltage of a medium or high voltage line or cable, which could cause a reduction in accuracy or possible sensor failure. In one aspect, the outer surface of the conductor shield layer <NUM> is smooth. As will be described in further detail below, the inner conductor <NUM> and optional inner shield layer <NUM> provide one electrode of a capacitor for the sensor section. The other electrode of the capacitor is formed by the isolated section <NUM> of insulation shield layer <NUM>, and insulation layer(s) <NUM> serves as the dielectric of the capacitor.

Voltage sensor <NUM> further includes insulation layer <NUM>, which concentrically surrounds conductor shield layer <NUM>. The insulation layer <NUM> can be formed from a conventional dielectric material, such as elastomeric silicone, ethylene propylene diene monomer rubber (EPDM), hybrids or combinations thereof. Alternatively, insulation layer <NUM> can comprise more than <NUM> layer of insulation material, such as first and second insulation layers (not shown), with each layer being formed from a different or same insulation material. The optional semi-conductive or conductive shield layer <NUM> functions to eliminate or reduce the potential for voids between conductor <NUM> and insulation layer(s) <NUM> that might allow leakage leading to degradation of insulation layer(s) <NUM>. Shield layer <NUM> may also relieve electrical stresses caused by any roughness on the surface of the inner conductor <NUM> due to, for example, manufacturing processes such as casting.

In an alternative aspect, conductive layer <NUM> can have a highly smooth outer surface. As such, an adhesive or other bonding material can be interposed between the conductive layer <NUM> and the insulation layer <NUM>, with the shield layer <NUM> being omitted. The adhesive or other bonding material can be applied to the outer surface of conductor <NUM> and can bond the insulation layer <NUM> to the conductive layer <NUM>.

In addition, an insulation shield layer <NUM> is provided and concentrically surrounds insulation layer <NUM>. The insulation shield layer <NUM> comprises a conductive or semiconductive material formed as a layer adjacent to and concentrically surrounding insulation layer <NUM>. As described below, for purposes of the sensing section <NUM>, this insulation layer <NUM> also forms the insulation layer of a capacitor, which also comprises the inner conductor <NUM> and/or conductor shield layer <NUM> and isolated section <NUM> of insulation shield layer <NUM>. Isolated section of insulation shield layer <NUM> is isolated from the ground potential of the remainder of insulation shield layer <NUM>.

In the embodiment of <FIG>, voltage sensor <NUM> further comprises a tubular sleeve <NUM> that extends over at least a portion of the conductor/inner shield/insulation/shield structure and the sensor section <NUM>. In one aspect, tubular sleeve <NUM> comprises a suitable cold-shrinkable material, such as a highly elastic rubber material that has a low permanent set, such as EPDM, elastomeric silicone, electrical grade resin, or a hybrid thereof. Insulation layer <NUM> and tubular sleeve can be made of the same or different types of materials. The semi-conductive and insulating materials may have differing degrees of conductivity and insulation based on the inherent properties of the materials used or based on additives added to the materials. Tubular sleeve <NUM> may also be made from a suitable heat-shrinkable material. Alternatively, the tubular sleeve <NUM> may be an overmolded or push-on layer. A ground reference wire <NUM> can also be provided. Optionally, in the illustrated embodiment, tubular sleeve <NUM> includes skirts <NUM> which serve to reduce leakage current and which is particularly useful for outdoor applications. In some embodiments, tubular sleeve <NUM> can also cover rounded end <NUM>.

In addition, a sealing compound <NUM> can be provided to create an environmental seal and prevent moisture from migrating into the area between the insulation layer <NUM> and the connection interface/lug <NUM>.

As shown in <FIG>, and in greater detail in <FIG>, voltage sensor <NUM> includes a sensor section <NUM> disposed between the first and second ends of conductor <NUM>. In one aspect, the sensing section includes a voltage sensor, such as an impedance voltage divider that utilizes complex impedance based voltage division, or a capacitive voltage sensing device, having an electrically isolated capacitive voltage sensor. More generally, in at least one aspect, where the sensing section includes an impedance voltage divider, a first impedance and a second impedance are connected in series. The input voltage is applied across the series impedances and the output voltage is the voltage across the second impedance. The first and second impedances may be composed of any combination of elements such as resistors, inductors and capacitors. In at least one aspect, the sensing section includes a multi-component AC circuit, wherein the response can be complex and can have imaginary components. In another aspect, the sensor section includes at least one temperature compensation component, such as, e.g., a thermistor. The temperature sensor (e.g., thermistor) can be located within (or outside of) the sensing section <NUM>. While one specific embodiment is described below, the sensing section can also be configured in a manner similar to the voltage sensors described in International Publ. <CIT> and <CIT>, each incorporated by reference herein in their entirety. Moreover, in a further alternative aspect, the voltage sensor <NUM> can further include one or more additional sensors.

As shown in <FIG>, the sensing section <NUM> includes an electrically isolated section <NUM> of conductive or semiconductive material (insulation shield) layer <NUM> in contact with an outer surface of insulation layer <NUM>. The electrically isolated section <NUM> of conductive or semiconductive material (insulation shield) layer <NUM> forms an electrode of a sensing capacitor of a capacitive voltage divider or sensor. The electrically isolated section thus can be capacitively coupled to the conductor <NUM> and electrically isolated from ground potential. In addition, insulation layer <NUM> is operable to form a dielectric of the sensing capacitor of the capacitive voltage divider or sensor.

In some examples, the electrically isolated section <NUM> may be in an annular ring configuration and be electrically isolated from conductive or semiconductive shielding layer <NUM> by non-conductive axial sections 111a and 111b. Non-conductive axial sections 111a, 111b may comprise non-conductive material or a void.

In such examples, conductive or semiconductive shielding layer <NUM> may be discontinuous at two longitudinal positions to form electrically isolated section <NUM> in the annular ring configuration. In such examples, electrically isolated section <NUM> may be formed out of a common material and manufacturing process, such that electrically isolated section <NUM> and shield layer <NUM> have a common thickness.

In other examples, electrically isolated section <NUM> may be formed from a different material than shield layer <NUM> and/or have a different configuration such as a rectangular or round shape formed by a flexible material affixed to insulation layer <NUM>. Electrically isolated section <NUM> may, for example, comprise an electrically conductive metal or an electrically conductive polymer. As one example, electrically isolated section <NUM> may comprise a layer of copper. In some examples, voltage sensor <NUM> may include an adhesive that affixes electrically isolated section <NUM> to insulation layer <NUM>. In some examples, electrically isolated section <NUM> may further include a conforming rubber insulation or high dielectric constant tape or a self-fusing insulation or high K material <NUM>, such as a rubber mastic material, to prevent moisture from migrating into the sensor section <NUM>. In some aspects, strips of insulating or high dielectric constant material cover gaps 111a, 111b to separate isolated section <NUM> from any other conductive or semiconductive material or elements, except from the PCB <NUM>, and to prevent the presence of air in gaps 111a, <NUM>1b, which air could cause a partial electrical discharge and a failure of the voltage sensor. The insulating or high dielectric constant material may be any suitable material such as a combination of mastic, which will more easily fill gaps 111a, 111b, and PVC tape placed over the mastic. In some examples, the electrically isolated section <NUM> may include a heat shrinkable or cold shrinkable material.

In some aspects, inner and outer conductive or semiconductive shield layers <NUM>, <NUM> and insulating layer <NUM> of voltage sensor <NUM> may be made from any materials suitable for shrinkable sleeve applications. Most suitable are materials such as a highly elastic rubber material that has a low permanent set, such as ethylene propylene diene monomer (EPDM), elastomeric silicone, or a hybrid thereof, that may include conventional additives to make the layers appropriately conductive, semiconductive or insulating, as needed. The conductive or semiconductive shield layers and the insulation layer may be made of the same or different types of materials, depending on the types of additives which may be incorporated in the individual layers. The inner and outer conductive or semiconductive shield layers and the insulation layer may have differing degrees of conductivity and insulation based on the inherent properties of the materials used or based on additives added to the materials.

As mentioned above, in some aspects, the sensor section <NUM> is configured as a capacitive voltage sensor, which is operable to sense a voltage on inner conductor <NUM>, which is also representative of the voltage on the power line (not shown) by way of the connection with the connection interface <NUM>. Electrically isolated section <NUM> is operable to form an electrode of the sensing capacitor of the capacitive voltage sensor and may, for example, have two opposed major surfaces, e.g. first and second major surfaces. The first major surface may be in mechanical contact with insulation layer <NUM>. The second major surface may be in mechanical contact with a capacitive element, such as a capacitor, circuitry, or a printed circuit board (PCB) <NUM>. In many aspects, the capacitive element, such as PCB <NUM>, has a pre-defined capacitance value.

As mentioned previously, the output of the voltage sensor can be a waveform that is directly proportional to the voltage of the power line. The division ratio of the actual line voltage to the output voltage can be tailored to any desired voltage. In some embodiments, the division ratio can be between <NUM>:<NUM> and <NUM>,<NUM>,<NUM>:<NUM>; in other aspects, the division ratio can be approximately <NUM>,<NUM>:<NUM>, where for example an actual line voltage of approximately <NUM>,<NUM> Volts would result in an output voltage of approximately <NUM> Volt. The voltage sensor <NUM> supplies a voltage level that can in some embodiments be easily converted to a digital value for interaction with computational devices, microcontrollers, communication devices, etc..

The capacitive voltage sensor further includes capacitive element (here PCB <NUM>), which is in electrical contact with electrically isolated section <NUM>. The PCB <NUM> is located directly over the electrically isolated section <NUM> to arrange for the electrical contact with the isolated section <NUM>, which in turn is arranged on insulation layer <NUM>. PCB <NUM> further includes at least one additional capacitor or other capacitive element to form a capacitive voltage divider for determining the voltage of inner conductor <NUM> by way of the detected voltage of electrically isolated section <NUM>. The capacitor(s) of PCB <NUM> may be electrically connected to electrically isolated section <NUM>. The capacitive element may be operable as a secondary capacitor in a capacitive voltage divider. The capacitive voltage divider may comprise the sensing capacitor, which includes electrically isolated section <NUM>, and the secondary capacitor.

In some aspects, PCB <NUM> may be flexible such that PCB <NUM> may be bent to conform around electrically isolated section <NUM>. PCB <NUM> may establish electrical contact to electrically isolated section <NUM> in several locations. This construction avoids the disadvantages of having electrical contact only in one location on electrically isolated section <NUM>, such as, problems resulting from a bad electrical contact in the one location, if that one contact is, e.g., incomplete, corroded, or damaged, which might preclude a voltage reading. In addition providing multiple points of contact may avoids problems arising from the fact that electrons travelling from a rim of electrically isolated section <NUM> to a single contact location experience the electrical resistance of electrically isolated section <NUM> over a longer path. This, in turn, may lead to a voltage drop and eventually to a lower, i.e. less accurate, voltage being measured on PCB <NUM>.

In some examples, PCB <NUM> may be mechanically attached to electrically isolated section <NUM>. In other examples, PCB <NUM> may alternatively be in a pressure contact with electrically isolated section <NUM>. PCB <NUM> may comprise a double-sided PCB, i.e. PCB <NUM> can have opposed first and second major sides. Alternatively the PCB <NUM> can be located remotely from the isolated section <NUM>, where the PCB <NUM> can be electrically coupled to the isolated section <NUM>.

For example, as further illustrated in <FIG>, PCB <NUM> can comprise a multilayer structure, with a first layer 120a comprising a conductive metal, e.g. gold, silver, or copper; a second layer 120b comprising a flexible insulation material; a third layer or conductive trace 120c to connect to jumper wires <NUM>; a fourth layer 120d comprising an outer insulation layer; and an outer conductive shield layer 120e comprising a conductive or semiconductive layer which shields PCB <NUM>.

In one example, the first layer 120a can comprise a copper layer that may be gold-plated for enhanced electrical contact and/or for protection against environmental influences, e.g. against corrosion. In different examples, first PCB layer 120a comprises a conductive region that provides a continuous surface contact area or a patterned, i.e. interrupted, non-continuous, surface contact area for contact with electrically isolated section <NUM>. All parts of the patterned surface contact area may be electrically connected with each other. A patterned surface contact area may require less conductive material for manufacturing it, while having only a negligible influence on reliability of the electrical contact and resistive losses.

PCB <NUM> may comprise a flexible portion. A patterned surface contact area may also enhance the mechanical flexibility of PCB <NUM>, thus reducing the risk of layer cracking and/or flaking, when PCB <NUM> is bent. In a specific example, the first PCB layer 120a comprises a patterned gold-plated copper layer. A pattern of the surface contact area may, for example, be a grid with a square-shaped or a diamond-shaped pattern.

The PCB <NUM> may further comprise a second layer 120b comprising a flexible insulating material, such as a conventional, flexible insulation material.

A flexible portion of PCB <NUM> and in particular a flexible PCB may allow PCB <NUM> to conform better to electrically isolated section <NUM>. This, in turn, enhances the electrical contact between PCB <NUM> and electrically isolated section <NUM> and thereby makes the contact more reliable, reduces resistive losses, and facilitates higher accuracy of the voltage sensor.

A conductive trace 120c connects with jumper wires <NUM>, which are connected to ground on either side of the isolated section <NUM> by conductive tape/adhesive <NUM> disposed on shield layer <NUM>. The conductive tape/adhesive <NUM> provides adequate surface area. The outer shield layer 120e can comprise a conductive or semiconductive material and is grounded to conductive tape/adhesive <NUM>, as shown in <FIG>.

Although not shown, PCB <NUM> may further include a plurality of ratio adjustment capacitors.

PCB <NUM> may generate a signal that is indicative of the voltage of inner conductor <NUM>. Sensor signal wire <NUM> can be connected to PCB <NUM> for transmitting the sensor voltage signal from PCB <NUM>. In some examples, electrical measurement circuitry may be incorporated into the PCB <NUM>; in other examples, PCB <NUM> may include electrical measurement circuitry. Sensor signal wire <NUM> they may be connected to, for example, a remote terminal unit that processes voltage data from the sensor section <NUM>, or an integrator, a measuring device, a control device, or other suitable types of devices.

A ground reference wire <NUM> may be used to bring ground onto PCB <NUM> for connecting electrical ground to the electrical measurement circuitry. In one aspect, ground reference wire <NUM> is connected to a conductive trace of PCB <NUM>, such as conductive trace 120c shown in <FIG>. This configuration brings a bridging connection between the insulation shield layers on either side of isolated section <NUM>. The electric measurement circuitry may be operational to determine the voltage of inner conductor <NUM> versus ground.

In some examples, PCB <NUM> may be adapted to support additional sensing such as temperature, humidity, magnetic field, etc..

In an alternative aspect, PCB <NUM> can be directly disposed on insulation layer <NUM>, such that the isolated section <NUM> of the shielding layer <NUM> can be eliminated. In a further alternative aspect, PCB <NUM> can be disposed directly on insulation layer <NUM> at a position beyond an end of the shielding layer <NUM>.

In one aspect, the sensor section <NUM> further includes a sensor insulation layer <NUM> that is disposed adjacent to the isolated section <NUM>. In another aspect, the sensor insulation layer <NUM> can be adjacent to the PCB <NUM> and on the opposing side of PCB <NUM> relative to electrically isolated section <NUM>. The sensor insulation layer <NUM> helps to prevent the PCB <NUM> from shorting out.

In a further aspect, the sensor section <NUM> further includes a sensor (outer) shielding layer <NUM> that is disposed adjacent to sensor insulation layer <NUM> on the opposing side of sensor insulation layer <NUM> relative to PCB <NUM>. Outer sensor shield layer <NUM> may be formed from a conductive or semiconductive material and may be electrically connected to shield layer <NUM>, e.g., at ground potential. Outer sensor shield layer <NUM> provides electric field shielding to contain the electric field from the isolated section <NUM>/outer electrode and from external electric fields. Outer sensor shield layer <NUM> and insulation shield layer <NUM> may function to substantially encapsulate the capacitive voltage sensor, including the electrically isolated section <NUM>, PCB <NUM> and sensor insulation layer <NUM>. In some examples, outer sensor shield layer <NUM> and insulation shield layer <NUM> may be formed as a unitary feature. In addition, as shown in <FIG>, tubular sleeve <NUM> extends over at least a portion of the sensor section <NUM>.

The precise dimensional control facilitated by the design and configuration of voltage sensor <NUM> allows for precise voltage measurements by the capacitive voltage sensor of the sensor section <NUM>. For example, capacitance is directly related to the geometry of two conductive electrodes and the insulation forming the capacitor. With respect to the capacitive voltage sensor, the sensing capacitor is formed from inner conductor <NUM>/inner shield layer <NUM>, insulation layer <NUM> and electrically isolated section <NUM>.

In some examples, voltage sensor <NUM> may be formed using overmolded construction. For example inner shield layer <NUM> may be overmolded on inner conductor <NUM>. Similarly, insulation layer <NUM> may be an overmolded insulation layer overmolded on inner shield layer <NUM> or overmolded directly on inner conductor <NUM> if inner shield layer <NUM> is not included in the voltage sensor device <NUM>. Likewise, shield layer <NUM> may be an overmolded outer conductive or semiconductive layer overmolded on insulation layer <NUM>. As such, in some aspects, the construction can comprise a multilayer body that can be formed as a contiguous overmolded body that comprises the insulation layer <NUM>, shield layer <NUM>, the isolated section <NUM>, and optionally the inner shield layer <NUM>.

In another aspect, the voltage ratio of the sensing section <NUM> can be adjusted by varying the length of the isolated section <NUM> or, in an alternative aspect, by varying the length of the PCB <NUM> that replaces isolated section <NUM>. RTV, grease, mastic, or other insulating or high dielectric constant materials can be applied to eliminate air gaps/voids between the PCB <NUM> and the cable insulation <NUM> and/or to eliminate corona discharges.

The voltage sensor described herein can be utilized in a variety of applications. For overhead applications, the voltage sensor can be deployed on any section of the power grid having a voltage, such as with standard medium or high voltage cable, bus bars, capacitor banks, connectors, lugs, jumpers, any component used in a power grid, switches, and switch gear. In other applications, the voltage sensor can be used in underground equipment applications such as pad mounted transclosures, pad mounted primary metering cabinets, and many live front pad mounted or vault-type live front applications. The voltage sensor can also be used in switch gear applications, where the gear is considered deadfront underground equipment.

Claim 1:
A voltage sensor (<NUM>), comprising:
a conductor (<NUM>) having a first end (<NUM>) and a second end (<NUM>), the first end including a first connection interface (<NUM>) and the second end having no connection, and
a sensor section (<NUM>) including at least one sensor disposed over the conductor, the sensor sensing at least a voltage or a sample of the voltage of the conductor;
wherein the sensor section includes a capacitive voltage sensor having an inner shield layer (<NUM>) in contact with the conductor (<NUM>), an insulation layer (<NUM>) disposed over the inner shield layer, and an electrically isolated outer shield layer (<NUM>) disposed over the insulation layer, the outer shield layer comprising an electrically isolated section (<NUM>) of conductive or semiconductive material,
characterized in that the sensor section includes a printed circuit board (<NUM>) as a capacitive element, which is in electrical contact with the electrically isolated section (<NUM>) of conductive or semiconductive material,
wherein the printed circuit board (<NUM>) is located directly over the electrically isolated section (<NUM>) to arrange for the electrical contact with the isolated section (<NUM>), which in turn is arranged on insulation layer (<NUM>).