Electrical circuit and arrangement

Abstract

The present invention relates to an electrical circuit (100) comprising: an electrical power source (102); at least one electrical load (104); and at least one cable (110) coupled between the electrical power source (102) and the electrical load (104) for electrically connecting the power source (102) to the load (104), wherein the cable (110) comprises an electrical conductor (112) disposed within an electrically insulating casing (114), wherein the electrically insulating casing (114) is configured to be fully or partially attached to a structure (200), and wherein the electrical conductor (112) is slidably disposed along the length of the cable (110) within the electrically insulating casing (114) to compensate for a mechanical movement of the structure (200) and / or a change in length of the electrical conductor (112). The invention also relates to an arrangement comprising such an electrical circuit.

Description

[0001] 11 -03-2025

[0002] ELECTRICAL CIRCUIT AND ARRANGEMENT

[0003] The present invention relates to an electrical circuit. The invention also relates to an arrangement comprising such an electrical circuit.

[0004] Background

[0005] Wind turbines are used to extract energy from wind power. Wind energy is a renewable energy source and is part of the energy transition from fossil-based energy sources to renewable energy sources in order to achieve set climate goals.

[0006] A common type of wind turbine is the type that has horizontal-axis wind turbines comprising three blades which are also referred to as wings. Icing of blades or wings can occur under certain meteorological conditions where the combination of temperature, humidity and wind are considered to be the most important parameters. Ice formation on blades leads to reduced efficiency at the wind turbine and also constitutes a safety risk in the event of so-called ice throw.

[0007] To reduce the risk of ice formation, de-icing systems are most often used which can be arranged to heat the blades and thereby reduce ice formation on the blades. Deicing systems can also be of the type comprising heat-emitting panels which are powered by electric current.

[0008] Summary

[0009] An objective of the present invention is to provide a circuit which has advantages over prior art.

[0010] A further objective of the present invention is to provide a robust electrical circuit in which the risk of cable breakage is reduced or minimised.

[0011] The above object is achieved with an electrical circuit comprising: an electrical power source; at least one electrical load; and at least one cable coupled between the electrical power source and the electrical load for electrically connecting the power source to the load, the cable comprising an

[0012] RECORD COPY TRANSLATION Rule 12.4 11 -03-2025 electrical conductor arranged inside an electrically insulating casing, the electrically insulating casing being configured to be fully or partially attached to a structure, and the electrical conductor being slidably arranged along the length of the cable inside the electrically insulating casing to compensate for a mechanical movement of the structure and / or a change in length of the electrical conductor.

[0013] A structure refers to a physical structure and can be understood as a physical construction or a physical object, which means that the surface of a structure is also a physical surface of the structure, construction or object. The electrically insulating casing is configured to be fully or partially attached to the structure or a surface of the structure.

[0014] As previously mentioned, de-icing systems for wind turbines can be of the type that include heat-emitting panels mounted on blades which are powered by electrical current. This means that a power source provides power to the heat-emitting panels via electrical cables. Mechanical movement of the blades occurs continuously as the blades are subjected to very large forces. This is especially true for modern wind turbines where the blades can be 50 m or longer. Cables attached to the blade structure and connected to the heat-emitting panels break due to the mechanical movement of the blade structure. Replacing broken cables is both time-consuming and very expensive. In addition, cable breakage means downtime of wind turbines.

[0015] The present circuit thus provides a solution in which cable breakage due to mechanical movement of the structure is substantially reduced or minimized compared to conventional solutions. Furthermore, cable breakage due to thermal movement of the electrical conductor itself is prevented or reduced as the conductive material in the conductor is exposed to large temperature variations due to heat generation attributable to current flow. If a cable breakage nevertheless occurs, the electrical conductor can be easily replaced.

[0016] According to an embodiment of the circuit, the length of the cable is greater than 10 m, or greater than 20 m, or greater than 25 m, or greater than 30 m, or greater than 40, or greater than 45 m. 11 -03-2025

[0017] According to an embodiment of the circuit, the cable comprises an electrically insulating layer arranged between the electrical conductor and the electrically insulating sheath.

[0018] This further improves the electrical insulation of the cable, which is important in certain applications.

[0019] According to one embodiment of the circuit, the electrically insulating layer is a lacquer.

[0020] This allows the electrical conductor to move more easily in the electrically insulating casing and further improves the electrical insulation. The lacquer can be applied to the electrical conductor during the manufacture of the electrical conductor.

[0021] According to one embodiment of the circuit, the electrical conductor is made / formed of a non-braided metal such as a single solid metal wire, or a plurality of braided metal wires.

[0022] This simplifies the assembly of the electrical conductor in the electrically insulating casing.

[0023] According to one embodiment of the circuit, the electrical conductor is formed of a plurality of braided metal wires.

[0024] This allows the electrical conductor to be manufactured at a lower cost.

[0025] According to one embodiment of the circuit, the electrical conductor is made of copper, aluminium or steel alloy. The diameter of the electrical conductor can be kept small as copper has very good conductivity. Aluminium and steel alloys have lower conductivity than copper but have material properties that make them have better strength in certain applications.

[0026] According to one embodiment of the circuit, the circuit comprises a plurality of cables together forming a band of cables arranged next to each other. The plurality of cables 11 -03-2025 may be arranged parallel to each other. The plurality of cables may form a common band cable in which they abut each other.

[0027] According to one embodiment of the circuit, the electrically insulating casing is liquid- tight.

[0028] Thus, the electrical conductor can be prevented from corroding.

[0029] According to one embodiment of the circuit, the electrical circuit comprises first fastening means for fastening the electrically insulating casing to the surface of the structure, and / or second fastening means for fastening the load to the structure.

[0030] According to one embodiment of the circuit, it comprises at least one second cable, wherein the second cable comprises a second electrical conductor arranged inside a second electrically insulating casing, wherein the second electrical conductor is non- slidably arranged along the longitudinal extension of the second cable inside the second electrically insulating casing, and wherein the second cable electrically connects the cable to the electrical power source and / or the electrical load. The second cable can also interconnect two different cables.

[0031] According to one embodiment of the circuit, the second cable has a length that exceeds a shortest cable path between two electrical connection points for electrically connecting the cable to the electrical power source and / or the electrical load.

[0032] Thus, the connection between the power source and the load can be given greater freedom of movement.

[0033] According to one embodiment of the circuit, the length of the second cable is dependent on the shortest cable path between the two electrical connection points and the change in length of the electrical conductor.

[0034] Thus, the appropriate excess length for the second cable can be calculated. 11 -03-2025

[0035] According to one embodiment of the circuit, the load comprises at least one electrical heating panel arranged to heat a surface of the structure. The load may also be a sensor configured to provide sensor data.

[0036] According to one embodiment of the circuit, the heating panel comprises at least one conductive mesh connected to the electrical conductor, and wherein the conductive mesh is housed between two electrically insulating layers.

[0037] According to one embodiment of the circuit, the load comprises two or more electric heating panels, wherein the two or more electric heating panels are electrically interconnected by means of a cable.

[0038] The two or more electric heating panels may be connected to the power source by means of a band cable according to embodiments of the invention, i.e. a band cable comprising a plurality of cables according to the invention. Each cable in the band cable connects a heating panel to the power source.

[0039] According to one embodiment of the circuit, the circuit comprises at least one extender electrically connected to the cable, wherein the extender comprises a conductive conductor of variable length.

[0040] Thus, the total length of the electrical connection between the power source and the load can be varied.

[0041] According to one embodiment of the circuit, the conductive conductor is arranged in an electrically insulating casing or does not have an electrically insulating casing.

[0042] According to an embodiment of the circuit, the extender is arranged: between an output of the power source and the cable, and / or between an input of the load and the cable, and / or between a first part of the cable and a second part of the cable.

[0043] Thus, the extender can be placed at critical locations in the circuit. 11 -03-2025

[0044] According to an embodiment of the circuit, the electrical power source is configured to supply a pulsed current. Pulsed current can mean that the current is supplied to the load in pulses, i.e. in an ON state when power is supplied to the load and an OFF state when no power is supplied to the load. The time period of the ON state and the OFF state will determine the supplied power and can be adapted to different power needs of the load. The pulsed current can be direct current or alternating current depending on the application.

[0045] According to an embodiment of the circuit, the electrical power source is an alternating current source.

[0046] According to an embodiment of the circuit, the alternating current source has at least two phases.

[0047] According to one embodiment of the circuit, the circuit comprises a control device configured to control an amount of current supplied to the load. Therefore, the control device may be in communication with the electrical power source and control the electrical power source.

[0048] According to one embodiment of the circuit, the control device is configured to control the amount of current supplied to the load based on at least one resistance measurement of the electrical conductor.

[0049] The above object is also achieved by an arrangement or system comprising: an electrical circuit according to any one of the preceding claims; a structure; wherein the electrically insulating casing is fully or partially attached to the structure.

[0050] According to one embodiment of the arrangement, the cable is fully or partially arranged inside the structure and / or fully or partially integrated with the structure.

[0051] According to one embodiment of the arrangement, the structure is one of: a blade of a wind turbine, a dam gate in a hydroelectric power plant, and a stretcher. 11 -03-2025

[0052] Further advantages and embodiments of the invention will become apparent from the following detailed description.

[0053] Brief description of the figures

[0054] The following figures are intended to show embodiments of the invention in which: Figure 1 shows an electrical circuit according to embodiments of the invention; Figures 2 and 3 show a cable according to embodiments of the invention;

[0055] Figure 4 shows an electrical circuit according to further embodiments of the invention;

[0056] Figures 5 to 7 show an electrical circuit where the load is a heating panel and / or a sensor according to embodiments of the invention; and

[0057] Fig. 8 shows an electrical circuit according to further embodiments of the invention.

[0058] Detailed Description of the Invention

[0059] Figure 1 shows an electrical circuit 100 according to embodiments of the invention and Figure 2 shows a cable 1 10 to be included in such a circuit 100 where the outer casing is partially removed in a side view. According to the invention, the electrical circuit 100 comprises an electrical power source 102, at least one electrical load 104, and at least one cable 1 10 coupled between the electrical power source 102 and the electrical load 104 for electrically connecting the power source 102 to the load 104. Thus, the power source can deliver an electrical current to the load 104.

[0060] With reference to Figure 2, the cable 1 10 comprises an electrical conductor 1 12 arranged inside an electrically insulating casing 1 14. The electrically insulating casing 1 14 is configured to be fully or partially attached to a structure 200 and thereby be fully or partially attached to the structure 200. The electrical conductor 1 12 is slidably arranged along the length of the cable 1 10 inside the electrically insulating casing 1 14 to compensate for a mechanical movement of the structure 200 and / or a change in length of the electrical conductor 112. Thus, the electrical conductor 1 12 can move completely freely inside the insulating casing 1 14. According to an embodiment of the invention, the electrical conductor 1 12 has an outer diameter d1 that is smaller than an inner diameter d2 of the electrically insulating casing 1 14. The change in length of the electrical conductor 1 12 is illustrated by the horizontal double-headed arrow in the 11 -03-2025 figure. Also, other reasons may occur which means that the electrical conductor 1 12 has to move inside the electrically insulating casing 1 14 to avoid cable breakage.

[0061] A mechanical movement of the structure causes the cable 1 10 to be exposed to large forces in its longitudinal extension which causes cable breakage when the cable 1 10 is fully or partially attached to e.g. a surface 202 of the structure 200 and thus moves with the movement / change of the structure. For example, the tip of a blade of a wind turbine may move several meters from a starting position during operation. The change in length of the electrical conductor 1 12 itself is usually due to the electrical conductor 1 12 being exposed to large temperature changes and / or temperature differences. In exemplary applications, such as in heating panels, the temperature variation is very large because the power supplied must be very high, which means that the length of the conductive conductor can change significantly in a short time. For example, the length expansion may be 1.7 mm per meter of cable at a temperature difference of 100QC, and 2.0 mm per meter of cable at a temperature difference of 130QC. These large temperature differences arise when the cable 1 10 is fixed to the structure 200. During operation of the heating panels, the temperature difference may be up to 60QC at -40QC outside temperature and 20QC at the heating panels.

[0062] Furthermore, the length of the cable 1 10 is usually large in many applications. The length of the cable 1 10 needs to be adapted to different applications and lengths of the cable 1 10 are according to embodiments of the invention larger than 10 m, or larger than 20 m, or larger than 25 m, or larger than 30 m, or larger than 40 m or larger than 50 m.

[0063] According to embodiments of the invention, the electrical conductor 1 12 is formed of a non-braided metal. This means that the electrical conductor 112 in such cases is manufactured and formed of a solid conductive material such as a solid metal which makes the electrical conductor 1 12 rigid for easier mounting inside the electrically insulating casing 114. A suitable material choice is copper as the conductor, which is why the electrical conductor 1 12 is a solid copper conductor according to embodiments of the invention. Since copper has very good conductivity, the diameter of the electrical conductor 1 12 can be kept low, which is important in many applications where it is not desired that the cable arrangement should build up too much height or width on the 11 -03-2025 surface 202 where the cable arrangement is attached / attached. Other suitable materials are aluminium and steel alloys which have lower conductivity but other properties such as better strength and stiffness.

[0064] In embodiments of the invention, the electrical conductor 1 12 can instead be formed from a plurality of braided metal wires. Each braided metal wire can be enclosed by an insulating casing. The plurality of braided metal wires can be assembled closely adjacent to each other to form an electrical conductor 1 12.

[0065] According to further embodiments of the invention, the electrically insulating casing 1 14 is liquid-tight and has a very high electrical insulating capacity. For this purpose, the casing 1 14 may be made of a braided electrically insulating material encapsulated in a thermoplastic or other material having properties similar to those of a thermoplastic.

[0066] Figure 3 shows a cable in cross-section according to one embodiment of the invention. In this embodiment, the cable 1 10 includes an electrically insulating layer 1 16 disposed between the electrical conductor 1 12 and the electrically insulating casing the insulation further, which means that several cables 1 10 can be placed close together without electrical interference between the cables. This is particularly important when the currents carried in the cables 1 10 are high. A useful application is when two or more cables 1 10 are arranged close together in a band of parallel arranged cables 1 10. Thus, embodiments of the invention relate to bands comprising two or more cables 1 10, wherein the band of cables 1 10 is connected between the power source 102 and one or more loads 104. These band cables may comprise more than 6 cables 1 10, or more than 12 cables 110, or more than 24 cables 1 10 according to embodiments of the invention.

[0067] The electrically insulating layer 1 16 is, according to embodiments of the invention, a lacquer. This allows the electrical conductor 112 to slide better in the casing 1 14, which also facilitates the manufacture of the cable 1 10. Furthermore, the lacquer further improves the electrical insulation performance for reduced electrical interference, which is important when a plurality of cables 1 10 together form a band cable. This is 11 -03-2025 especially true when two or more phases of an alternating current are conducted in a band cable.

[0068] Figure 4 shows an electrical circuit 100 according to further embodiments of the invention, where the circuit 100 includes at least one extender 140 electrically connected to the cable 1 10. The extender 140 includes a conductive conductor 142 of variable length, i.e. the length of the conductive conductor 142 can be varied depending on various parameters. Since the extender 140 includes a conductive conductor 142 of variable length, the length of the electrical connection between the power source 102 and the load 104 can be varied to compensate for the length variation of the cable 1 10. This further reduces the risk of cable breakage.

[0069] The conductive conductor 142 of the extender 140 is arranged in an electrically insulating casing or in other cases completely lacks an electrically insulating casing depending on the application. The latter case could refer to a reel on which a part of the conductive conductor 142 without casing is wrapped around an insulator and the length of the part of the conductive conductor 142 that is wrapped depends on various parameters such as, for example, maximum length extension of the electrical conductor 1 12, minimum length extension of the electrical conductor 1 12, mechanical change of the structure, temperature changes at the structure, etc.

[0070] As shown in Figure 4, the extender 140 is arranged between an output of the power source 102 and the cable 1 10, and / or between an input of the load 104 and the cable 1 10, and / or between a first part of the cable 1 10 and a second part of the cable 1 10. These locations of the extender have been identified as important as at these locations such extension may be needed to avoid cable breakage.

[0071] An alternative or complement to an extender is shown in Figure 8 where the electrical circuit 100 includes at least one additional cable which may be named a second cable 150 which means that the cable 1 10 previously mentioned with a slidably arranged inner electrical conductor 1 12 may be named a first cable. The second cable 150 may be a conventional electrical cable electrically connected to the first cable 1 10, for example via a clamping sleeve 174 which electrically connects them together. The clamping sleeve 174 is conductive and configured to move with the movement of the 11 -03-2025 inner electrical conductor 1 12. Thus, the electrical circuit 100 includes at least one second cable 150 according to embodiments of the invention.

[0072] The second cable 150 includes a second electrical conductor 152 arranged inside a second electrically insulating casing 154, and the second electrical conductor 152 is non-slidably arranged along the longitudinal extension of the second cable 150 inside the second electrically insulating casing 154. The second cable 150 electrically connects the first cable 110 to the electrical power source 102 and / or the electrical load 104 and / or two different first cables 1 10. Figure 8 shows the case where the second cable 150 electrically connects the first cable 1 10 to the power source via a junction box 172 and a flat-cable. The other end of the first cable 1 10 is fixedly connected to the load 120, which in this example is a heating panel. Furthermore, a so-called HUB is shown through which the power from the power source can be conducted to the junction box via the flat-cable. Said HUB may comprise a control device 130 and a communication unit with which the control device can communicate with other control devices, databases, servers and control power sources 102, loads 104, and other parts of the present arrangement.

[0073] According to embodiments of the invention, the second cable 150 has a length that exceeds a shortest cable path between two electrical connection points 162, 164 for electrically connecting the first cable 1 10 to the electrical power source 102 and / or the electrical load 104, i.e. the second cable 150 is longer than the physical length between the two electrical connection points 162, 164. This implies that the length of the second cable 150 is dependent on the shortest cable path between the two electrical connection points 162, 164 and the change in length of the first electrical conductor 1 12. The excess length of the second cable is thus also dependent on the shortest cable path between the two electrical connection points 162, 164 and the change in length of the first electrical conductor 1 12. For example, the second cable may have a length of 1 .5 m if the shortest cable path is 1 m. The excess length of the second cable 150 is illustrated in Figure 8 in which the second cable 150 is wavy, which allows for a margin of movement that can compensate for the movement of the first electrical conductor 1 12 without cable breakage. It is also understood that instead of a clamping sleeve 174, a sliding contact (not shown) may be used for electrical contact between the first cable 1 10 and the second cable 150. The first conductor 112 is then attached 11 -03-2025 to the sliding contact such that the sliding contact follows the movement of the first conductor 112.

[0074] As previously mentioned, the circuit 100 may include a control device 130 configured to be in communication with the electrical power source 102 and further configured to control an amount of electrical current supplied to the load 104. According to an embodiment of the invention, the control device 130 is configured to control the amount of current supplied to the load 104 based on at least one resistance measurement of the electrical conductor 1 12. The dashed arrow into the control device 130 in Figure 4 illustrates input data and information such as sensor data for resistance and / or direct resistance values. The solid double-headed arrow in Figure 4 illustrates how the control device 130 can control the power source 102 with, for example, a control interface and that the power source 102 can include means for feedback of data and information to the control device 130 which can be used by the control device 130 in a control algorithm for controlling the power source 102.

[0075] According to embodiments of the invention, the electrical power source 102 is configured to supply a pulsed current to the loads such as heating panels. The pulsed current may be a current having an ON state or an OFF state. The power source 102 may be a DC power source or an AC power source depending on the application. In the case where the electrical power source 102 is an AC power source, the AC power source may supply at least two different phases. This is particularly relevant in applications involving a band cable connecting a plurality of heating panels to the power source 102. In these heating panel applications, high currents are needed for the heating panels to generate sufficient heat, which means that the current may be greater than 5 Ampere, or greater than 10 Ampere, or greater than 15 Ampere, or greater than 20 Ampere according to embodiments of the invention.

[0076] Figures 5 to 7 show an electrical circuit 100 where the load 104 is a heating panel for heating a surface and / or a sensor for providing sensor data about the surface 202, the structure 200 and / or a nearby environment for the sensor.

[0077] Figure 5 shows how a load 104 is attached to a surface 202 of a structure 200. In this example, the structure 200 is a blade of a wind turbine. Thus, the circuit 100 includes 11 -03-2025 second attachment means 154 for attaching the load 104 to the surface 202 of the structure 200 according to embodiments of the invention. Furthermore, the circuit 100 according to embodiments of the invention includes first attachment means 152 for attaching the electrically insulating casing 1 14 to the surface 202 of the structure 200. Examples of first 152 and second 154 attachment means are adhesives and joints of various types (e.g. screw joints, bolt joints, etc.) with, for example, holders for the cable 1 10 or the load 104. The first attachment means may be curing the cable 1 10 to the structure 200. This may be done by heating an adhesive in a solid form applied at the cable 1 10 and the structure 200. An example of a suitable adhesive is epoxy adhesive or other adhesive with similar properties. Also milled grooves in the structure or arranged on the surface 202 of the structure 200 into which the cable is pressed could constitute first fastening means for the cable 1 10. Also fastening means such as hooks, rings, etc. can constitute suitable fastening means.

[0078] Figure 6 shows when the load 104 includes two or more electrical heating panels or sensors 120, 120'. The two or more electrical loads 120, 120' are electrically interconnected / connected by means of an intermediate cable 1 10' between the loads with the characteristics described above. In these contexts, it may be appropriate that one or more band cables with a plurality of cables 1 10 extends from the power source 102 to at least the nearest load 104 as shown in Figure 6. The first band cable from the power source to the nearest heating panel 120, referred to as the first heating panel, comprises 3 or more cables 1 10 and the second band cable arranged between the second heating panel 120' and the third heating panel 120" comprises 2 or more cables 1 10.

[0079] Figure 7 shows that a heating panel 120 may comprise at least one conductive network 122 connected to the electrical conductor 1 12 of the cable 1 10. The conductive network 122 is housed between two electrically insulating layers. For example, the cable 110 may be directly connected to the conductive network 122 via metal connection means such as bimetal with suitable temperature response which means automatic activation and deactivation of the heating panel 120.

[0080] The invention also relates to an arrangement / system 300 comprising an electrical circuit 100 according to embodiments of the invention. Furthermore, the arrangement 11 -03-2025

[0081] 300 includes a structure 200 having a surface 202 and an electrically insulating casing 1 14 of the cable 110 which is fully or partially attached to the structure 200 or to the surface 202 of the structure 200.

[0082] According to embodiments of the invention, the cable 1 10 is fully or partially arranged inside the structure 200 and / or is fully or partially integrated with the structure 200. In these cases, the surface refers to an inner surface of the structure 200. The inner surface could be located on the inside of a blade of a wind turbine or in another suitable hollow structure.

[0083] The structure 200 can be any of a blade of a wind turbine, a dam in a hydroelectric power plant, a stretcher or other suitable physical structure where the circuit and thus the cable 1 10 are subjected to movement and / or material expansion and / or material contraction.

[0084] Finally, it is understood that the present invention is not limited to the embodiments described above but includes and relates to all embodiments within the scope of the independent patent claim.

Claims

11 -03-2025CLAIMS1. An electrical circuit (100) comprising: an electrical power source (102); at least one electrical load (104); and at least one cable (1 10) coupled between the electrical power source (102) and the electrical load (104) for electrically connecting the power source (102) to the load (104), wherein the cable (1 10) comprises an electrical conductor (112) arranged inside an electrically insulating casing (1 14), wherein the electrically insulating casing (1 14) is configured to be fully or partially attached to a structure (200), and wherein the electrical conductor (1 12) is slidably arranged along the length of the cable (110) inside the electrically insulating casing (1 14) to compensate for a mechanical movement of the structure (200) and / or a change in length of the electrical conductor (1 12).

2. An electrical circuit (100) according to claim 1 , wherein the cable (1 10) comprises an electrically insulating layer (1 16) arranged between the electrical conductor (1 12) and the electrically insulating casing (1 14).

3. An electrical circuit (100) according to claim 1 or 2, wherein the electrically insulating layer (1 16) is a lacquer.

4. An electrical circuit (100) according to any one of claims 1 to 3, wherein the electrical conductor (1 12) is made of a non-braided metal such as a single solid metal wire, or a plurality of braided metal wires.

5. An electrical circuit (100) according to any one of the preceding claims, wherein the electrical conductor (1 12) is made of copper, aluminium or steel alloy.

6. An electrical circuit (100) according to any one of the preceding claims, wherein the electrically insulating casing (114) is liquid-tight.

7. An electrical circuit (100) according to any one of the preceding claims, wherein the electrical circuit (100) comprises:11 -03-2025 first fastening means for fastening the electrically insulating casing (1 14) to the structure (200), and / or second fastening means for fastening the load (104) to the structure (200).

8. An electrical circuit (100) according to any one of the preceding claims, wherein the electrical circuit (100) comprises at least one second cable (150), wherein the second cable (150) comprises a second electrical conductor (152) arranged inside a second electrically insulating casing (154), wherein the second electrical conductor (152) is non-slidably arranged along the longitudinal extension of the second cable (150) inside the second electrically insulating casing (154), and wherein the second cable (150) electrically connects the cable (1 10) to the electrical power source (102) and / or the electrical load (104).

9. An electrical circuit (100) according to claim 8, wherein the second cable (150) has a length that exceeds a shortest cable path between two electrical connection points (162, 164) for electrically connecting the cable (110) to the electrical power source (102) and / or the electrical load (104).

10. An electrical circuit (100) according to claim 9, wherein the length of the second cable (150) is dependent on the shortest cable path between the two electrical connection points (162, 164) and the change in length of the electrical conductor (1 12).1 1. An electrical circuit (100) according to any one of the preceding claims, wherein the electrical circuit (100) comprises a plurality of cables (1 10) arranged adjacent to each other.

12. An electrical circuit (100) according to claim 1 1 , wherein the plurality of cables (1 10) are arranged in parallel with each other.

13. An electrical circuit (100) according to claim 1 1 or 12, wherein the plurality of cables (1 10) form a common band cable.11 -03-202514. An electrical circuit (100) according to any one of the preceding claims, wherein the load (104) comprises at least one electrical heating panel (120) arranged to heat a surface (202) of the structure (200).

15. An electrical circuit (100) according to any one of the preceding claims, wherein the electrical power source (102) is configured to supply a pulsed current ( / ).

16. An electrical circuit (100) according to any one of the preceding claims, wherein the electrical power source (102) is an alternating current source.

17. An electrical circuit (100) according to claim 16, wherein the alternating current source has at least two phases.

18. An electrical circuit (100) according to any preceding claim, further comprising: a control device (130) configured to control an amount of current supplied to the load (104).

19. An electrical circuit (100) according to claim 18, wherein the control device (130) is configured to control the amount of current supplied to the load (104) based on at least one resistance measurement of the electrical conductor (1 12).

20. An arrangement (300) comprising: an electrical circuit (100) according to any preceding claim; and a structure (200); wherein the electrically insulating casing (1 14) is fully or partially attached to the structure (200).

21. Arrangement (100) according to claim 20, wherein the structure (200) is one of: a blade of a wind turbine, a dam gate in a hydroelectric power plant, or a stretcher.

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