System for determining the quantity of carbon dioxide emissions resulting from the heating of an electrical conductor in an electrical cable by Joule heating

Abstract

The invention relates to a system for determining (100) the quantity of carbon dioxide emissions resulting from the heating of an electrical conductor in an electrical cable by Joule effect, said system comprising: - an electrical cable (10) comprising at least one electrical conductor (12) and at least one layer of material surrounding said at least one conductor, - a measuring unit (110) associated with the electrical cable, said measuring unit comprising at least one temperature sensor (20) and a device for measuring the electrical intensity Icond (112) of an electric current flowing in the electrical conductor, - a computing unit (120) configured to communicate information with the measuring unit, the computing unit being configured to determine the conductor temperature Θcond by means of said at least one temperature sensor,said calculation unit being further configured to determine the quantity of carbon dioxide emissions resulting from the heating of the electrical conductor by Joule effect as a function of the conductor temperature Θcond and the electrical current Icond in the electrical conductor. Figure for the abbreviation: Figure 1,

Description

Title of the invention: System for determining the quantity of carbon dioxide emissions resulting from the heating of an electrical conductor in an electrical cable by Joule effect technical field

[0001] The present invention relates to a system for determining the quantity of carbon dioxide emissions resulting from the heating of an electrical conductor of an electrical cable by Joule effect.

[0002] More specifically, the invention relates to a non-invasive determination system. Technological background

[0003] In an electrical distribution network, the electrical conductor of an electrical cable heats up due to the Joule effect when a current flows along the conductor. With this temperature increase, the resistance of the electrical conductor increases, resulting in an increase in power loss.

[0004] This annual power loss has a direct impact on the quantity of carbon dioxide (CO2) emissions.

[0005] To date, there are no integrated or reportable solutions for determining these carbon dioxide emissions resulting from the heating of an electrical conductor of an electrical cable by Joule effect.

[0006] There is therefore a need for a system for determining the quantity of carbon dioxide emissions resulting from the heating of an electrical conductor of an electrical cable by Joule effect, directly integrated on an electrical cable or reportable on it. Summary of the invention

[0007] To this end, the invention proposes a system for determining the quantity of carbon dioxide emissions resulting from the heating of an electrical conductor in an electrical cable by Joule heating, said determination system comprising: - an electrical cable comprising at least one electrical conductor and at least one layer of material surrounding said at least one conductor, - a unit of measurement associated with the electrical cable, said unit of measurement comprising at least one temperature sensor and a device for measuring the electrical intensity of an electric current flowing in the electrical conductor, - a computing unit configured to communicate information with the measuring unit, the computing unit being configured to determine the temperature of conductor 0cond by means of said at least one temperature sensor, said computing unit being further configured to determine a quantity of carbon dioxide emissions resulting from heating of the electrical conductor by joule effect as a function of the temperature of conductor 0cond and the electrical current Icond in the electrical conductor.

[0008] The integration of a measurement unit and a calculation unit configured to determine the conductor temperature 0cond and the electrical intensity Icond within the same determination system makes it possible to determine the quantity of CO2 emissions induced by heating of the electrical conductor.

[0009] According to one embodiment of the determination system, the calculation unit is configured to determine an electrical resistance Rc of the electrical conductor as a function of the conductor temperature 0cond.

[0010] This electrical resistance Rc is determined in particular as follows: R c = R o x (l + a 20 x (© (w;J -20))

[0011] According to one embodiment of the determination system, the calculation unit is configured to determine a power loss POL as a function of the electrical current Icond in the electrical conductor and the electrical resistance Rc of the electrical conductor, the calculation unit being configured to determine the amount of carbon dioxide emissions as a function of said power loss POL.

[0012] This power loss POL is determined in particular as follows: PoL = Rc x

[0013] According to one embodiment of the determination system, it further comprises a measuring box mounted on the electrical cable, said measuring box comprising at least one of said at least a temperature sensor and the electrical current measuring device Icond.

[0014] According to one embodiment of the determination system, the measuring housing further includes the calculation unit.

[0015] According to one embodiment of the determination system, the measuring box is configured to be removably mounted on the electrical cable.

[0016] According to one embodiment of the determination system, the measuring box includes a device for attaching to the electrical cable.

[0017] According to one embodiment of the determination system, said at least one temperature sensor is disposed on an external surface of said at least one layer of material to measure a peripheral temperature 0bi at the level of the external surface of said at least one layer of material, the calculation unit being configured to determine the conductor temperature 0cond as a function of the peripheral temperature 0b i.

[0018] The use of one or more external temperature sensors on the electrical cable allows for a non-invasive and non-destructive determination of the conductor temperature.

[0019] According to one embodiment of the determination system, it further comprises: - an additional layer of material arranged around said at least one layer of material and covering said at least one temperature sensor, - at least one additional temperature sensor disposed on an external surface of said additional material layer to measure an additional peripheral temperature 0b2 at the level of the external surface of said at least one additional material layer.

[0020] According to one embodiment of the determination system, the calculation unit is configured to determine the conductor temperature 0cond as a function of the peripheral temperature 0bi and the additional peripheral temperature 0b2.

[0021] Said at least one layer of material of the electrical cable has a layer thermal resistance Th

[0022] The calculation unit may include a conductor temperature determination unit 0cond. Thus, the determination unit is configured to determine the conductor temperature 0cond as a function of the measured peripheral temperature 0b[, the layer thermal resistance T iet the heat flux Wc generated by the circulation of an electric current in the electric conductor.

[0023] The determination of the conductor temperature 0cond is done here by means of a physical model using the measured peripheral temperature 0bi, the thermal resistance of the layer Tiet and the heat flux Wc generated by the circulation of an electric current in the electrical conductor.

[0024] The use of this physical model makes it possible to do away with the use of an internal temperature of the electrical cable, i.e. measured via a component placed near the conductor, or more generally inside the external sheath of the electrical cable.

[0025] The physical model used allows the temperature of conductor 0condau to be estimated by means of the measured peripheral temperature 0bi, the thermal resistance of layer T^t the heat flux Wc generated by the circulation of an electric current in the electric conductor.

[0026] According to one embodiment of the determination system, the determination unit is configured to determine the conductor temperature 0cond on the basis of the following equation: 0cond = ©bl + W^Tj

[0027] The determining unit can be placed near the electrical cable or at distance from it.

[0028] According to one embodiment of the determination system, said at least one layer of material comprises an outer sheath forming said outer surface, said at least one temperature sensor being disposed on said outer sheath.

[0029] According to one embodiment of the determination system, it further comprises a device for measuring the electric intensity Icond of an electric current flowing in said at least one electric conductor, the determination unit being configured to determine said conductor temperature 0cond further as a function of this electric intensity Icond.

[0030] According to one embodiment of the determination system, the measuring device is a non-invasive device, in particular of the type of a Rogowski coil.

[0031] According to one embodiment of the determination system, the temperature of conductor 0cond is determined as follows: 0cond = 0b 1 + Rc*Icond2*Ti Rc being the electrical resistance of the conductor

[0032] According to one embodiment of the determination system, the latter further comprising: - an additional layer of material disposed around said at least one layer of material and covering said at least one temperature sensor, said additional layer of material having an additional thermal resistance Tb - at least one additional temperature sensor disposed on an external surface of said additional layer of material to measure an additional peripheral temperature 0b2 at the level of the external surface of said at least one additional layer of material.

[0033] According to one embodiment of the determination system, said additional layer of material extends around said at least one layer of material only over a portion of the length of the electrical cable.

[0034] According to one embodiment of the determination system, the determination unit is configured to determine the conductor temperature 0cond on the basis of the following equation: a _ n । OWW vy 0bi is the peripheral temperature measured by the said at Uamd ~ Ubl + T. X 1 1 b minus a temperature sensor, 0b2 is the additional peripheral temperature measured by said at least one additional temperature sensor, Tb being the additional thermal resistance of the additional layer of material, Ti being the thermal resistance of said at least one layer of material.

[0035] According to one embodiment of the determination system, the determination unit is configured to determine the conductor temperature 0cond further as a function of a heating Wd arising from a dielectric loss in said at least one layer of material.

[0036] According to one embodiment of the determination system, the determination unit is configured to determine the conductor temperature 0cond on the basis of the following equation: gi = g^ + T yX ( Wc - -y- j Wd being heating from a dielectric loss in said at least one layer of material.

[0037] According to one embodiment of the determination system, the determination unit is configured to determine the conductor temperature 0cond on the basis of the following equation: g — g^ -p 7'1 xj Wd being warming from a loss di electrical in said at least one layer of material.

[0038] According to one embodiment of the determination system, said at least one additional layer of material and said at least one additional temperature sensor are carried by the measuring housing.

[0039] This measuring unit is preferably removable from the electrical cable so as to allow for a point and localized measurement on the electrical cable. This unit is, for example, a measuring accessory.

[0040] The measuring box preferably has a dimension along the longitudinal axis of the electric cable so that it extends only over a portion of the length of the electric cable. Brief description of the figures

[0041] The following description, with reference to the accompanying drawings, given by way of non-limiting examples, will clearly explain what the invention consists of and how it can be implemented. In the accompanying figures:

[0042] [Fig-1] Fig. 1 represents a perspective view of a determination system including an electrical cable, a unit of measurement, a unit of calculation for determining a quantity of carbon dioxide emissions resulting from the heating of an electrical conductor of the electrical cable;

[0043] [Fig.2] Fig.2 represents a perspective view of an embodiment of the determination system of Fig.1 comprising a measuring box mounted on the electrical cable, the measuring box including in particular the measuring unit;

[0044] [Fig.3] The [Fig.3] represents a cross-sectional view of the electrical cable according to a first configuration comprising an electrical conductor and at least one layer of material;

[0045] [Fig.4] Fig.4 represents a cross-sectional view of the electrical cable of Fig.3 comprising a plurality of sensors on an external surface of said at least one layer of material;

[0046] [Fig.5] The [Fig.5] represents a diagram of a first model of the electric cable, according to a first method of determination including a determination of the electric intensity of the electric current flowing in the electric conductor;

[0047] [Fig.6] Fig.6 represents a cross-sectional view of the electrical cable of Fig.3 according to a second determination method in which the determination system comprises an additional layer of material around the electrical cable and a plurality of additional sensors arranged on an external surface of this additional layer of material;

[0048] [Fig.7] The [Fig.7] represents a diagram of a second model of the electric cable according to the second method of determination;

[0049] [Fig.8] The [Fig.8] represents a third model of the electrical cable in which the dielectric losses in said at least one layer of material are taken into account, according to the first method of determination;

[0050] [Fig.9] The [Fig.9] represents a fourth model of the electrical cable in which the dielectric losses in said at least one layer of material are taken into account, according to the second method of determination;

[0051] [Fig. 10] The [Fig. 10] represents a cross-sectional view of the electrical cable according to a second configuration comprising an electrical conductor, one or more layers of material surrounding the electrical conductor and a screen surrounding said layers of material;

[0052] [Fig. 11] The [Fig. 11] a fifth model of the electrical cable in which the dielectric losses in said at least one layer of material are taken into account as well as the dielectric losses in the screen;

[0053] [Fig. 12] The [Fig. 12] a sixth model of the electrical cable to determine the conductor temperature 0cond independently of the surrounding environment; Description of embodiment(s)

[0054] For the sake of clarity, the same references designating the same elements according to the state of the art and according to the invention are used for all figures.

[0055] The concept of the invention is described more fully below with reference to the accompanying drawings, in which embodiments of the concept of the invention are shown. In the drawings, the size and relative sizes of the elements may be exaggerated for clarity. Similar numbers refer to similar elements in all the drawings. However, this concept of the invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are proposed so as to make this description complete and communicate the scope of the concept of the invention to men skilled in the art.

[0056] A reference throughout the specification to "an embodiment" means that a particular feature, structure, or characteristic described in relation to an embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrase "in an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Moreover, the term "including" does not exclude other elements or steps.

[0057] A system for determining the quantity of carbon dioxide emissions resulting from the heating of an electrical conductor of an electrical cable by Joule effect is illustrated in [Fig.1].

[0058] This determination system 100 comprises an electrical cable 10 including at least one electrical conductor 12 and at least one layer of material surrounding said at least one conductor. This layer of material is, for example, an insulating layer.

[0059] The electrical cable 10 extends along a longitudinal axis A.

[0060] This determination system 100 includes a measuring unit 110 associated with the electrical cable 10. The measuring unit includes at least one temperature sensor 20 and a measuring device 112 for the electrical intensity Icond of an electric current flowing in the electrical conductor 12.

[0061] The measuring device 112 is preferably a non-invasive device, in particular of the type of a Rogowski coil.

[0062] The determination system 100 further includes a calculation unit 120 configured to communicate information with the measurement unit 110.

[0063] The computing unit 120 is configured to determine the temperature of conductor 0 cond by means of said at least one temperature sensor.

[0064] Preferably, said at least one temperature sensor 20 is disposed outside the electrical cable, i.e. on an external surface of this electrical cable 10. In this configuration, the conductor temperature 0cond is determined by means of a physical model described below in connection with Figures 4 to 12.

[0065] In a variant compatible with the invention, said at least one temperature sensor may be disposed inside the electrical cable 10. In this variant, the temperature of conductor 0cond is measured directly in the vicinity of the electrical conductor 12.

[0066] The calculation unit 120 is further configured to determine a quantity of carbon dioxide emissions resulting from heating of the conductor electric by joule effect as a function of the conductor temperature 0cond and the electric current Icond in the electric conductor.

[0067] With reference to [Fig.2], the determination system 100 may include a measuring housing 130 in which are housed one or more of said at least a temperature sensor 20 and the measuring device 112.

[0068] The entire measuring unit 110 is preferably carried by the measuring housing 130.

[0069] The calculation unit 120 is configured to communicate with the measuring unit 110. The calculation unit 120 can be separated from the measuring box 130 as illustrated in [Fig.2] or integrated into this measuring box 130.

[0070] This measuring box 130 is for example mounted in a removable manner in relation to the electrical cable 10 in order to carry out a point and localized measurement on the electrical cable 10. This measuring box 130 is for example a portable measuring accessory.

[0071] The measuring box 130 has a dimension along the longitudinal axis A such that it extends only over a portion of the length of the electrical cable 10. The measuring box 130 preferably extends around the electrical cable 10, i.e. around the longitudinal axis A.

[0072] The measuring housing 130 may also include an additional structure described below, in particular in relation to figures 6 and 10.

[0073] For the determination of CO2 emissions, the calculation unit 120 is configured to determine an electrical resistance Rc of the electrical conductor as a function of the conductor temperature 0cond.

[0074] This electrical resistance Rc is determined in particular as follows: (j+a^x (0cW-2O)) Ro being the DC resistance of the conductor at 20°C, in Ohms, Ys being the unitless skin effect factor, Yp being the unitless proximity effect factor, a20 being the electrical resistivity coefficient, in K 1 (i.e. per kelvin).

[0075] The calculation unit 120 is then configured to determine a power loss P OL as a function of the electrical current Icond measured in the electrical conductor and the electrical resistance Rc of the electrical conductor determined.

[0076] This POL power loss is determined in particular as follows: PoL^Rcxllmî

[0077] The computing unit 120 is configured to then determine the annual power losses induced by heating of the electrical conductor 10. The quantity of carbon dioxide emissions is then determined as a function of these annual power losses.

[0078] To determine the quantity of CO2 emissions as a function of these annual power losses, it is possible to use a scaling factor multiplied by the annual power losses.

[0079] In general, the quantity of CO2 emissions as a function of these annual power losses can be determined using a relationship defined by a distribution system operator.

[0080] With reference to [Fig.3], an electrical cable 10 comprises an electrical conductor 12, a first layer of material 14 around the electrical conductor 12 and a second layer of material 16 around the first layer of material 14.

[0081] The electrical conductor 12 extends along a longitudinal axis A.

[0082] The first 14 and second 16 layers of material extend along the longitudinal axis A, around the electrical conductor 12.

[0083] The first layer of material 14 is, for example, a layer formed of an electrically insulating material. The first layer of material 14 can therefore be considered as an insulating layer.

[0084] The second layer of material 16 here forms an outer layer of the electrical cable 10. The second layer of material 16 forms an outer surface 18 of the electrical cable 10.

[0085] The second layer of material 16 is, for example, an outer sheath.

[0086] More generally, the electrical cable 10 may include one or more layers of material surrounding the electrical conductor 12. The electrical cable 10 may in particular include one or more of the following: a screen, a semiconducting layer, an insulating layer, an outer sheath.

[0087] In a preferred configuration, the electrical cable 10 comprises, around the conductor, in order of arrangement from the center to the periphery: a semiconducting layer, an insulating layer, a screen, and an outer sheath. This configuration corresponds, for example, to an electrical cable configured for a medium-voltage network (between 1 and 52 kV).

[0088] According to one embodiment, the determination system 100 is preferably non-invasive and / or non-destructive. In other words, neither said at least one temperature sensor 20 nor the measuring device 112 is disposed inside the electrical cable.

[0089] In this embodiment, the calculation unit 120 includes a determination unit 22 configured to determine the conductor temperature 0cond by means of a physical model using in particular a peripheral temperature 0bi measured by said at least one temperature sensor 20 disposed on an external surface of the electrical cable 10.

[0090] The determination of this conductor temperature 0condau means of this model The physical aspects are described below in relation to figures 4 to 12.

[0091] As illustrated in [Fig.4], the determination system 100 comprises said at least one temperature sensor 20 and one determination unit 22.

[0092] The unit of determination 22 belongs to the calculation unit 120.

[0093] The determination system 100 can include a plurality of temperature sensors 20 distributed around the longitudinal axis A in the same plane transverse to this longitudinal axis A. In the example of [Fig.4], the determination system 100 includes 9 temperature sensors 20.

[0094] The temperature sensor(s) 20 are configured to measure a peripheral temperature 0M. In this configuration where the temperature sensors 20 are arranged at the external surface 18 of the electrical cable, the peripheral temperature 0bi corresponds to the surface temperature of the electrical cable 10.

[0095] The temperature sensor(s) 20 are connected to the determining unit 22 so as to communicate the peripheral temperature 0bi to this determining unit 22.

[0096] Preferably, the temperature sensors 20 are equidistributed around the longitudinal axis A. The determination system 100 may provide one or more temperature sensors 20 further distributed along the longitudinal axis A so as to measure the peripheral temperature 0b[at different locations along the electrical cable 10.

[0097] This unit of determination 22 is configured to determine the temperature of conductor 0cond, i.e. the temperature of the electrical conductor 12.

[0098] This determination is carried out in a non-invasive and non-destructive manner. Thus, no component is inserted under the material layers or near the electrical conductor 12 to determine its conductor temperature 0cond. Furthermore, no material layer of the electrical cable 10 is damaged or pierced to perform this determination. No third-party component, such as an optical fiber or a sensor, is integrated into the manufacture of the electrical cable 10 within any of the material layers or between these material layers.

[0099] This makes it possible to determine the conductor temperature on an existing electrical cable, for example already installed in situ, without having to damage it or insert any measuring tool into it.

[0100] It is assumed here that the addition of measuring components or additional layers of material is not invasive or destructive.

[0101] The determination unit 22 uses a physical model allowing the conductor temperature 0cond to be determined as a function of the peripheral temperature 0bi measured by the temperature sensor(s) 20.

[0102] With reference to [Fig. 5], the diffusion of heat through the electrical cable 10 is represented in diagram form to illustrate the physical model used by the determination unit 22.

[0103] This physical model is based on the fact that the diffusion of heat through the layers of an electrical cable follows a behavior close to that of the circulation of a current within an electrical circuit having an electrical resistance.

[0104] Thus, the physical model establishes a relationship between the thermal resistance Tl of said at least one layer of material. The thermal resistance Ti can correspond to the thermal resistance of one or more of the material layers. In the example of [Fig. 4], the thermal resistance Ti represents the thermal resistance of the entirety of the first 14 and second 16 material layers. For this physical model, the first 14 and second 16 material layers therefore form a single layer of material having a layer thermal resistance, called Ti

[0105] The passage of current inside the conductor generates heating inducing a heat flux Wc.

[0106] In this physical model, the voltage difference AU across an electrical resistance is approximated by a temperature difference A0 between the internal and external surfaces of said at least one layer of material (i.e. across the terminals of this layer of material).

[0107] In the application of the electrical cable 10, the temperatures across the thermal resistance Tl are, on the one hand, the conductor temperature 0cond and, on the other hand, the peripheral temperature 0M. Thus, the temperature difference A0 is expressed as follows: A0 = 0cond - 0M

[0108] According to this physical model, a mathematical relationship is established between heat flux Wc, thermal resistance Tl, and the temperature difference A0 across this thermal resistance. This relationship is as follows: A0 = Tj*Wc with A0 being the temperature difference A0 between the internal and external surfaces of the layer of said at least one layer of material, Ti being the thermal resistance of said at least one layer of material, Wc being the heat flux generated by heating the conductor.

[0109] The conductor temperature 0cond can therefore be expressed as follows: 0eond = ©bl + WC*T! with 0cond being the conductor temperature, ©bi being the peripheral temperature.

[0110] The thermal resistance Ti of said at least one layer of material is determined as follows: T _ 2k_infi « 7*_Lûavec DJ pT being the thermal conductivity of said at least one layer of material, dc being the internal diameter of said at least one layer of material, ti being the thickness of said at least one layer of material.

[0111] The physical model includes two modes of determining the temperature of conductor 0cond.

[0112] In the first determination mode, the determination system 100 includes a device for measuring the electric intensity Icond of an electric current flowing in said at least one electrical conductor 12.

[0113] The measuring device is a non-invasive device, in particular of the type of a Rogowski coil.

[0114] In the second determination mode, the determination system 100 includes at least one additional layer 24 of material and at least one additional temperature sensor 26.

[0115] This second method of determination makes it possible to do away with the use of the electrical intensity Icond of the current flowing in the conductor.

[0116] Said at least one additional layer of material 24 is arranged around said at least one layer of material. The additional layer(s) of material 24 cover said at least one temperature sensor 22, as seen in [Fig. 6].

[0117] These two methods of determination can be used for determining the temperature of conductor 0cond according to different models of an electrical cable 10. These different models can involve different assumptions (e.g. taking into account or not dielectric losses) or different configurations of the electrical cable 10.

[0118] The determination unit 22 is configured to implement the first and / or second determination modes. The determination unit 22 is configured to determine the conductor temperature 0cond according to one or more models, including one or more of the models presented below.

[0119] Unshielded electrical cable without consideration of dielectric losses

[0120] The determination unit 22 is configured to determine the conductor temperature 0cond according to a first and a second modeling respectively illustrated in figures 5 and 7.

[0121] More specifically, the determination unit 22 is configured for the conductor temperature 0cond according to the first model using the first determination mode. The determination unit 22 is configured for the conductor temperature 0cond according to the second model using the second determination mode. termination.

[0122] In the first and second modeling, the dielectric losses in said at least one layer of material are not taken into account or are considered to be minimal.

[0123] In these first and second models, the electrical cable 10 is unscreened.

[0124] The first model applies to an electrical cable 10 comprising an electrical conductor 12 and one or more layers of material surrounding the electrical conductor 12. One or more temperature sensors 20 are disposed on the external surface 18 of said at least one layer of material.

[0125] The electrical cable 10 according to [Fig.4] is an example compatible with this first modeling.

[0126] As indicated above, the conductor temperature 0cond can be expressed as follows: 0COnd= ©bl + WC*T! with 0cond being the conductor temperature, ©By the peripheral temperature, Ti being the thermal resistance of said at least one layer of material, Wc being the heat flux generated by heating the conductor.

[0127] According to the first method of determination, the heat flux Wc due to heating of the electrical conductor 12 is expressed as follows: W = R * 1 a2 ' ' c xvc -tcond Rc being the electrical resistance of the electrical conductor, Icond being the intensity of the current flowing along the electrical conductor.

[0128] The conductor temperature 0cond according to the first method of determination, i.e. a function of the current in the electric conductor, is therefore expressed as follows: ®cond= ®bl + Rc*Icond2*T 1

[0129] As previously seen, the electrical resistance Rc of the electrical conductor is expressed as follows: ^ = S o x (l + a,„x (0,^-20)) x (1 + v + y„)^ Ro being the DC resistance of the conductor at 20°C, in Ohms, Ys being the unitless skin effect factor, Yp being the unitless proximity effect factor, a20 being the electrical resistivity coefficient, in K 1 (i.e. per kelvin). The parameters Ro, Ys, Ypet a20 are values ​​related to the structure and nature of the electrical conductor.

[0130] The conductor temperature 0cond can thus be expressed as follows: 0brI^T^( l-20x«2ü) cm,d ।

[0131] According to the second determination method, i.e. without the intensity of conductor Icond, the determination unit 100 comprises an additional structure illustrated in [Fig. 6]. Thus, the determination system 100 comprises at least one additional layer 24 of material and at least one additional temperature sensor 26.

[0132] Said at least one additional layer of material 24 has an additional thermal resistance Tb.

[0133] Said at least one additional layer of material 24 is for example at least one electrically insulating layer.

[0134] The material of said at least one additional layer of material 24 preferably has a thermal resistance between 0.001 m².K / W and 0.1 m².K / W. Within this thermal resistance range, said at least one layer of material 24 prevents overheating of the conductor while allowing a temperature difference large enough to be measured.

[0135] Said at least one additional temperature sensor 26 allows for the measurement of an additional peripheral temperature 0b2 at the level of the external surface 28 of said at least one additional layer of material 24.

[0136] The determination system 100 can include a plurality of additional temperature sensors 26 distributed around the longitudinal axis A in the same plane transverse to the longitudinal axis A. In the example of [Fig.6], the determination system 100 includes 9 additional temperature sensors 26.

[0137] The additional temperature sensor(s) 26 are connected to the determining unit 22 so as to communicate the additional peripheral temperature 0b2 to this determining unit 22.

[0138] Preferably, the additional temperature sensors 26 are equally distributed around the longitudinal axis A. The determination system 100 may provide one or more additional temperature sensors 26 further distributed along the longitudinal axis A so as to measure the additional peripheral temperature 0b2 at different locations along the electrical cable 10.

[0139] Preferably, the number and / or angular position and / or longitudinal position of the temperature sensors 20 are respectively identical to the number and / or angular position and / or longitudinal position of the additional temperature sensors 26.

[0140] The electrical cable 10 equipped with said at least one additional layer of material 24 and said at least one additional temperature sensor 26 is modeled by a second model in [Fig. 7]. Said at least one additional layer of material 24 is considered as a resistor of value Tb in series with the resistance value Ti corresponding to said at least one layer of material.

[0141] According to this second method of determination, the heat flux Wc is expressed as follows: We = i2M

[0142] The conductor temperature can thus be expressed as follows: “Ubl + Tb X 1 1

[0143] The determination of the temperature of conductor 0cond can thus be determined without requiring the value of the intensity of the current flowing in the electrical conductor 12. This determination is made possible by the addition of an additional layer and an additional sensor.

[0144] Unshielded electrical cable with consideration of dielectric losses

[0145] The determination unit 22 is configured to determine the conductor temperature 0cond according to a third and a fourth modeling respectively illustrated in figures 8 and 9.

[0146] More specifically, the determination unit 22 is configured to determine the conductor temperature 0cond according to the third model using the first determination mode. The determination unit 22 is configured for the conductor temperature 0cond according to the fourth model using the second determination mode.

[0147] In the third and fourth models, the dielectric losses in said at least one layer of material are taken into account.

[0148] In these third and fourth models, the electrical cable 10 is unscreened.

[0149] In these third and fourth models, the dielectric losses in said at least one layer of material are considered as a loss heat flux Wd at the resistance level of value Ti corresponding to said at least one layer of material. This loss heat flux Wd is visible in Figures 8 and 9.

[0150] The third model applies to an electrical cable 10 comprising an electrical conductor 12 and one or more layers of material surrounding the electrical conductor 12. One or more temperature sensors 20 are disposed on the external surface 18 of said at least one layer of material.

[0151] The electrical cable 10 according to [Fig.4] is an example compatible with this third modeling.

[0152] According to the first method of determination, the conductor temperature 0cond can be expressed as follows as a function of the electric current Icond: e„,^=ebl+T^ (wc-^)

[0153] This conductor temperature 0cond can also be expressed as follows by decomposing Rc as described above: a 1-20*^^ cond “ W^or,

[0154] According to the second determination method, i.e. without the intensity of conductor Icond, the determination unit 100 comprises an additional structure as illustrated in [Fig. 6]. Thus, the determination system 100 comprises at least one additional layer 24 of material and at least one additional temperature sensor 26.

[0155] The electrical cable 10 equipped with said at least one additional layer of material 24 and said at least one additional temperature sensor 26 is modeled by a fourth model on the [Fig.9].

[0156] Said at least one additional layer of material 24 is considered as a resistance of value Tb in series with the resistance of value Ti corresponding to said at least one layer of material.

[0157] According to this second method of determination, the temperature of conductor 0cond is expressed as follows:

[0158] The preceding equation is obtained by considering the following equations:<Ud=¾l + r,> <(w'<+■îT)e, 6b, = ab.+Tbx(w,l+wc)

[0159] The loss heat flux Wd is determined as a function of the voltage applied to the electrical conductor 12, the frequency of the voltage applied to the electrical conductor 12 and the dielectric characteristics of said at least one layer of material.

[0160] Electrical cable with screen and consideration of dielectric losses

[0161] The determination unit 22 is further configured to determine the conductor temperature 0cond in an electrical cable configuration 10 comprising a screen 17.

[0162] As illustrated in [Fig. 10], the electrical cable 10 comprises an electrical conductor 12, one or more layers of material surrounding the electrical conductor 12 and a screen 17 surrounding said layers of material.

[0163] Said material layers are for example a dielectric layer 30 surrounding the electrical conductor 12 and an insulating layer 32 disposed between the dielectric layer 30 and the screen 17.

[0164] The electrical cable 10 also includes an outer layer 34, for example a outer sheath, defining an external surface 38 of the outer layer 34. The outer layer 34 may comprise a plurality of material layers.

[0165] The outer layer 34 has a thermal resistance T3.

[0166] One or more temperature sensors 20 are arranged on the external surface 38 of the external layer 34.

[0167] Losses in the screen 17 are modeled by a screen heat flux Ws. These losses are due to heating by Joule effect in the screen 17.

[0168] Determining the heat flux of the screen Ws requires an invasive measurement on the electrical cable 10. To avoid expressing the conductor temperature 0cond as a function of the heat flux Ws, it is proposed here to combine the first and second methods of determination described above. In other words, it is planned here to express the conductor temperature 0cond as a function of the current Icond of the voltage flowing in the electrical conductor 12 and to use an additional structure comprising at least one additional layer of material 24 and at least one additional temperature sensor 26, as shown in [Fig. 10].

[0169] Said at least one additional layer of material 24 has a thermal resistance Tb.

[0170] A fifth model is illustrated in [Fig.1 1] taking into account the screen losses (heat flux Ws) as well as the dielectric losses in said at least one layer (heat flux Wd) and comprising three resistances in series to model the thermal resistances of said at least one layer of material (TJ, of the outer sheath 34 (T3) and of said at least one additional layer of material 24 (Tb).

[0171] In this fifth model, the conductor temperature 0cond is expressed as follows: t-20xa2l)) 0b [being the peripheral temperature Qcmd = measured by said at least one temperature sensor 20, 0b2 being the additional peripheral temperature measured by said at least one additional temperature sensor 26, A0 being the temperature difference 0br 0b2, Ti being the thermal resistance of said at least one layer of material, Tb being the thermal resistance of said at least one additional layer of material 24, T3 being the thermal resistance of the outer layer 34, Ro being the DC resistance of the conductor at 20°C, in Ohms, Ys being the unitless skin effect factor, Yp being the unitless proximity effect factor, a20 being the electrical resistivity coefficient, in K 1 (i.e. per kelvin).

[0172] The determination unit 22 is thus capable of determining the conductor temperature 0cond independently of the screen heat flux Ws.

[0173] This expression for the conductor temperature 0cond is obtained by considering that: 0C(W = + Wd ) T3 + ( Wc + ) T xn ( Wc + W, + Wd ) = ^d^r = T ©surfing the peripheral temperature at the level of the external surface of the electrical cable 10, and n being the number of electrical conductors 12.

[0174] As detailed previously, the thermal resistance Ti is determined as follows: T i + 1 2X:~ \ d, /

[0175] The thermal resistance T3 of the outer layer 34 is determined as follows: 7>^Ml + 2*> vec t3 being the thickness of the outer layer 34, Da being the internal diameter of the outer layer 34.

[0176] According to a sixth model illustrated in [Fig.12], the unit of determination is also configured to determine the temperature of conductor 0condde independently of the surrounding environment, in particular the temperature of this surrounding environment.

[0177] This sixth model applies to the same electrical cable configuration 10 as the fifth model. In other words, the sixth model applies to an electrical cable of the type shown in [Fig. 10] with an additional structure and a screen 17.

[0178] Depending on the surrounding environment, heat will be more or less well dissipated from the electrical cable 10. The surrounding environment is modeled by a layer of material with a certain thermal resistance T5 and a temperature 0a corresponding to the ambient temperature of the surrounding environment.

[0179] The conductor temperature 0cond can be expressed as follows: econd = ea + ( + IL(. + Wd + te )T3+n( Wc + Wd + ) Th + n ( Wc + W(l + W y ) T5

[0180] The temperature difference 0br 0b2 on either side of the additional layer of material 24 allows the conductor temperature 0cond to be expressed as follows: = 6m + ( + TF ) T, + n( Wc + Wd + W, ) Tf1 el,le,a = n(.wc+wll+wdTb

[0181] The conductor temperature 0cond can thus be determined by the determination unit 22 independently of the surrounding environment.

Claims

Demands

1. A system for determining (100) the quantity of carbon dioxide emissions resulting from the heating of an electrical conductor in an electrical cable by Joule heating, said system comprising: - an electrical cable (10) comprising at least one electrical conductor (12) and at least one layer of material (14, 16, 17, 30, 32, 34) surrounding said at least one conductor, - a measuring unit (110) associated with the electrical cable, said measuring unit comprising at least one temperature sensor (20) and a device for measuring the electrical intensity Icond (112) of an electric current flowing in the electrical conductor, - a computing unit (120) configured to communicate information with the measuring unit, the computing unit being configured to determine the conductor temperature 0cond by means of said at least one temperature sensor,said calculation unit being further configured to determine a quantity of carbon dioxide emissions resulting from heating of the electrical conductor by Joule effect as a function of the conductor temperature 0cond and the electrical current Icond in the electrical conductor.

2. A determination system (100) according to claim 1, wherein the calculation unit is configured to determine an electrical resistance Rc of the electrical conductor as a function of the conductor temperature

3. '-'cond. Determination system (100) according to claim 2, wherein the calculation unit is configured to determine a power loss P OL as a function of the electrical current Icond in the electrical conductor and the electrical resistance Rc of the electrical conductor, the calculation unit being configured to determine the amount of carbon dioxide emissions as a function of said power loss POL.

4. A determination system (100) according to any one of the preceding claims, further comprising a measuring box mounted on the electrical cable, said measuring box comprising at least one of said at least one temperature sensor and the electrical current measuring device Icond.

5. Determination system (100) according to claim 4, wherein the measuring housing further comprises the calculation unit.

6. Determination system (100) according to claim 4 or 5, wherein the measuring housing is configured to be removably mounted on the electrical cable.

7. Determination system (100) according to claim 6, wherein the measuring housing includes a device for attaching to the electrical cable.

8. A determination system (100) according to any one of the preceding claims, wherein said at least one temperature sensor is disposed on an external surface of said at least one layer of material to measure a peripheral temperature 0M at the level of the external surface of said at least one layer of material, the computing unit being configured to determine the conductor temperature 0cond as a function of the peripheral temperature 0M.

9. A determination system (100) according to claim 8, further comprising: - an additional layer of material disposed around said at least one layer of material and covering said at least one temperature sensor, - at least one additional temperature sensor disposed on an external surface of said additional layer of material to measure an additional peripheral temperature 0b2 at the level of the external surface of said at least one additional layer of material.

10. A determination system (100) according to the preceding claim, wherein the calculation unit is configured to determine the conductor temperature 0cond as a function of the peripheral temperature 0Met and the additional peripheral temperature 0b2.