Method and device for diagnosing an electrical network and associated installation method

Abstract

The invention relates to a method for diagnosing energy consumption of an electrical network supplying electrical energy to a plurality of items of equipment and comprising at least one single- or multi-conductor electrical cable supplying these items of equipment, which comprises the following steps not requiring any halting of the operations performed by the electrical network: identifying (10) at least one item of equipment to be monitored; locating (12) at least one point of the network where the consumption is to be measured; selecting (14) at least one cable to be monitored; positioning (16), in at least one location of the cable to be monitored, at least one device for measuring the intensity of the current simultaneously determining the intensity of the current flowing in all the conductors of the cable to be monitored and determining the energy consumption, per conductor, of the cable; parameterising (18) the measurement device; and returning (20) a network consumption diagnosis.

Description

Description Title of the invention: METHOD AND DEVICE FOR DIAGNOSING AN ELECTRICAL NETWORK AND ASSOCIATED INSTALLATION METHOD

[0001] The present invention relates to a method and device for non-intrusive diagnosis of the energy consumption of an electrical network, as well as to an associated method for installing this diagnostic device in this network.

[0002] The methods and device according to the present invention are based on the simultaneous measurement of the intensity of the instantaneous current in each phase of a single-phase or polyphase electric cable, with alternating or direct current, by means of magnetic field sensors.

[0003] The invention belongs to the field of electrical cables intended for the transport of energy and / or the transmission of data. It finds application in particular in the field of optimizing energy distribution in buildings.

[0004] When an electrical network, for example a low-voltage network, requires an energy consumption diagnosis, there are two cable configurations in the network: single-phase or single-conductor cables and polyphase or multi-conductor cables.

[0005] Currently, to measure the instantaneous current intensity in each conductor of a cable, whether single- or multi-conductor, most often, the current intensity in the conductor(s) of the cable is measured successively using a measuring device such as a clamp-on current meter. In the case of a multi-conductor cable, such a device does not allow the intensity for each phase of the cable to be known at a given time.

[0006] Furthermore, these operations are time-consuming and generally provide imprecise results. Furthermore, while they are suitable for one-off measurements, in practice they do not allow for long-term monitoring or diagnosis of an electrical network.

[0007] A commonly implemented solution to be able to monitor the energy consumption of an electrical network in a sustainable manner consists of integrating a connected metering device into the electrical panel or cabinet of the electrical network in question, which generally monitors the current intensity, the power used and the energy consumption.

[0008] However, these connected metering devices require a mandatory suspension of operations carried out by the electricity network, since it is necessary to disconnect and then reconnect the cables when installing the metering device.

[0009] Additionally, upon exiting diagnostic mode, a further suspension of operations is required to rewire the electrical network identically to its original configuration.

[0010] In the state of the art, there is therefore no known solution for diagnosing the energy consumption of an electrical network comprising single- and multi-conductor cables without having to suspend the operations carried out by this network.

[0011] The present invention aims to remedy the aforementioned drawbacks of the prior art.

[0012] For this purpose, the present invention proposes a method for diagnosing the energy consumption of an electrical network, this network supplying electrical energy to a plurality of devices and comprising at least one electrical cable supplying the plurality of devices, this cable comprising one or more conductors, the method being remarkable in that it comprises the following steps requiring no stopping of the operations carried out by the electrical network: a step of entering a diagnostic mode, comprising the following steps: - an identification step, consisting of identifying, among the plurality of devices, at least one device to be monitored; - a location step, consisting of locating at least one point in the network where energy consumption is measured, at least from the identification of at least one piece of equipment to be monitored in the identification step; - a step of selecting at least one cable to be monitored from among the at least one electrical cable of the network, from the location of the at least one point of the network at the location step; - a positioning step, consisting of positioning, in at least one location around the at least one cable to be monitored, at least one current intensity measuring device simultaneously determining the intensity of the current flowing in all the conductors of the at least one cable to be monitored and determining the energy consumption, per conductor, of the at least one cable to be monitored; - a configuration step, consisting of configuring the at least one measuring device; - a restitution step, consisting of providing a diagnosis of energy consumption of the electrical network, comprising information on the intensity of the current flowing in each of the conductors of the at least one cable to be monitored and on the energy consumption, per conductor, of the at least one cable to be monitored, this information on the intensity of the current flowing in each of the conductors of the at least one cable to be monitored and on the energy consumption, per conductor, of the at least one cable to be monitored being obtained from the measurements carried out by the at least one measuring device once configured in the configuration step.

[0013] Thus, the invention makes it possible, thanks to the use of suitable measuring devices placed in the electrical network and thanks to the measurement of the current intensity in all the conductors of the cable to be monitored, in a single operation and without the need to remove the sheath of the cable, to obtain a diagnosis of the energy consumption of an electrical network in real time, in a non-intrusive manner and without requiring any suspension of the operations carried out by the network.

[0014] The invention offers numerous applications, such as the identification of unbalanced current distributions which sometimes reveal a faulty power supply, the anticipation of cable failures when a conductor reaches an excessive temperature or even the reduction of electrical energy consumption in the installation supplied by the electrical network diagnosed using the present invention.

[0015] In a particular embodiment, the identification step consists of identifying, among the plurality of devices, those which have an average energy consumption greater than a predetermined threshold and / or which are used most intensively according to a predefined intensive use criterion.

[0016] This helps identify locations on the power grid where failures and / or maintenance needs are most likely to occur.

[0017] In a particular embodiment, the location step consists of locating the at least one point of the network from available information concerning the configuration of the network and from the location of the at least one piece of equipment to be monitored identified in the identification step.

[0018] This allows the diagnosis to be focused on the points of the network that need to be monitored in particular because they present the highest probability of failure and / or high frequency of maintenance.

[0019] In a particular embodiment, the selection step consists of selecting at least one cable passing through the at least one point of the network which was determined in the location step.

[0020] This allows for optimal selection of locations on electrical cables where it is relevant to monitor current flow and energy consumption, in order to provide the most accurate and useful consumption diagnosis possible.

[0021] In a particular embodiment, the method further comprises, between the selection and positioning steps, a determination step, consisting of determining whether the at least one cable to be monitored is single-conductor or multi-conductor.

[0022] This allows the use of the measuring device(s) most suited to the type of cable to be monitored.

[0023] In a particular embodiment, the configuration step consists of configuring the at least one measuring device via a visualization platform.

[0024] This visualization platform allows the user to configure the measuring devices quickly, simply and ergonomically.

[0025] In this embodiment, the restitution step may include an immediate visualization step, as soon as the at least one measuring device is configured, of the intensity and consumption, in graphic form, via this visualization platform.

[0026] This allows the user to easily, quickly and ergonomically view diagnostic data.

[0027] In a particular embodiment, the at least one device for measuring the current intensity comprises a plurality of magnetic field sensors and a processing means adapted to receive values ​​of at least one component of the magnetic field induced by the current flowing in the conductors of the cable to be monitored and the diagnostic method comprises, between the parameterization and restitution steps, steps consisting of: placing the plurality of magnetic field sensors around the cable, at at least one location of the cable; simultaneously measuring, for each of the conductors, the at least one component of the magnetic field produced by the current flowing in the conductor, by means of the plurality of magnetic field sensors;for each of the conductors, determining, by means of the processing means, the angle between the conductor and the nearest magnetic field sensor of the plurality of magnetic field sensors, this angle being defined relative to the center of the cable and by assimilating the conductors and the sensors to points; and the intensities of the currents in the conductors being related to the components of the magnetic field measured by the relation B = kMI where B is the matrix of the components of the magnetic field, I is the matrix of the intensities of the currents, M is a matrix comprising a plurality of proportionality coefficients depending on the angles between the conductors and the magnetic field sensors and k is a predetermined coefficient, calculating the inverse M; -1 of the matrix M, so as to deduce the values ​​of the current intensities I = (PO / 2TT).M' 1.B, WHERE po is an equivalent magnetic permeability which takes into account the presence of insulating materials in the cable.

[0028] Thus, the measuring devices implemented in the present diagnostic method make it possible to obtain, simultaneously for all the phases of a cable and in real time, the intensity of the current flowing therein, in an easy, rapid and non-intrusive manner, therefore without damaging, marking, deforming or requiring modification of the cable to be monitored. In addition, given that the position of the magnetic field sensors relative to the conductors of the cable is unknown, taking into account the angular offset between sensors and conductors makes it possible to increase the accuracy of the intensity values ​​obtained. Furthermore, this makes it possible to ensure adequate measurement of the intensities of the currents in the conductors of the cable to be monitored in the event that these conductors are twisted in such a way that they are likely to influence the sensitivity of the intensity measurement.

[0029] In the aforementioned embodiment where the at least one current intensity measuring device comprises a plurality of magnetic field sensors, the measuring step may consist of simultaneously measuring, for each of the conductors of the cable to be monitored, the tangential component and the radial component of the magnetic field produced by the current flowing in the conductor, by means of the plurality of magnetic field sensors.

[0030] This makes it possible to minimize the error in the intensity values ​​obtained, i.e. to further increase the precision of these values.

[0031] In a particular embodiment, the diagnostic method further comprises the following step requiring no stopping of the operations carried out by the electrical network: a step of exiting the diagnostic mode, consisting of removing the at least one measuring device from the at least one cable to be monitored.

[0032] Alternatively, rather than removing the measuring devices from the network to be diagnosed, they can be left in the network, around the cables to be monitored, but turned off or disabled.

[0033] This avoids having to replace them if you subsequently wish to carry out a new diagnosis of the same network, i.e. containing the same cables and electrical equipment.

[0034] For the same purpose as that indicated above, the present invention also proposes a device for diagnosing the energy consumption of an electrical network, the network supplying electrical energy to a plurality of devices and comprising at least one electrical cable supplying the plurality of devices, the cable comprising one or more conductors, this diagnostic device being remarkable in that its implementation does not require any stopping of the operations carried out by the electrical network and in that it comprises at least one device for measuring the intensity of the current adapted to simultaneously determine the intensity of the current flowing in all the conductors of a cable to be monitored among the at least one electrical cable and adapted to determine the energy consumption, per conductor, of the at least one cable to be monitored,the at least one measuring device being suitable for implementing the steps of a diagnostic method as briefly described above.,

[0035] Since the advantages of the diagnostic device are similar to those of the diagnostic method, they are not all repeated here.

[0036] In a particular embodiment of the diagnostic device, the latter further comprises a visualization platform adapted to serve as a human-machine interface making it possible to configure the at least one measuring device.

[0037] In this embodiment, the visualization platform may further be adapted to display the aforementioned intensity and consumption.

[0038] In a particular embodiment of the diagnostic device, the at least one device for measuring the current intensity comprises a plurality of magnetic field sensors and a processing means adapted to receive values ​​of at least one component of the magnetic field induced by the current flowing in the conductors of the cable to be monitored and to carry out steps of a diagnostic method as described briefly above.

[0039] In a particular embodiment of the diagnostic device, the at least one measuring device further comprises a housing containing the plurality of magnetic field sensors.

[0040] This makes it easier to install the measuring device around the cable to be monitored, as it is not necessary to install each sensor individually.

[0041] In this embodiment, the housing may optionally be surrounded by electromagnetic shielding.

[0042] This prevents the penetration of electromagnetic disturbances due, for example, to the Earth's permanent magnetic field and possible sources of electromagnetic fields located near the cable to be monitored and the sensors.

[0043] According to a particular characteristic, the housing may have a section formed of two half-rings, suitable for positioning at least one measuring device around the cable to be monitored.

[0044] This configuration allows rapid installation of the measuring device around the cable to be monitored, which is therefore housed in the center of the circular opening formed by the meeting of the two half-rings.

[0045] According to a particular characteristic, the diagnostic device may further comprise at least one additional magnetic field sensor adapted to measure the Earth's magnetic field.

[0046] This allows the value of the Earth's magnetic field to be taken into account, which can then be subtracted when processing the magnetic field values ​​collected by the sensors.

[0047] According to a particular characteristic, the at least one additional sensor can be arranged inside the housing and / or outside the housing.

[0048] Still with the same aim as that indicated above, the present invention also proposes a method of installing, in an electrical network, a diagnostic device as described briefly above, this installation method being remarkable in that it comprises a step consisting of positioning, in at least one location around the at least one cable to be monitored, the at least one measuring device in order to execute steps of a diagnostic method as described briefly above.

[0049] Since other special features and advantages of the diagnostic device, as well as the special features and advantages of the installation method are similar to those of the diagnostic method, they are not repeated here. Brief description of the drawings

[0050] Other aspects and advantages of the invention will appear on reading the detailed description below of particular embodiments, given as non-limiting examples, with reference to the appended drawings, in which:

[0051] [Fig. 1] is a flowchart illustrating steps of a method, in accordance with the invention, for diagnosing the energy consumption of an electrical network, in a particular embodiment.

[0052] [Fig. 2] is a geometric representation illustrating different parameters used in a diagnostic method according to the present invention, in a non-limiting example where an electrical cable to be monitored comprises five conductors.

[0053] [Fig. 3] is a schematic representation of a measuring device implemented in the present invention, in a particular embodiment.

[0054] [Fig. 4] is a partial schematic representation of an electrical cable to be monitored according to a diagnostic method in accordance with the present invention, around which several measuring devices implemented in the present invention have been positioned, in a particular embodiment.

[0055] [Fig. 5] is a flowchart illustrating the implementation of a measuring device in a diagnostic method according to the present invention, in a particular embodiment.

[0056] [Fig. 6] is a flowchart illustrating another step of a method, in accordance with the invention, for diagnosing the energy consumption of an electrical network, in a particular embodiment.

[0057] [Fig. 7] is a flowchart illustrating yet another step of a method, in accordance with the invention, for diagnosing the energy consumption of an electrical network, in a particular embodiment.

[0058] [Fig. 8] is a schematic representation of a diagnostic device according to the present invention, in a particular embodiment. Description of embodiment(s)

[0059] In the present invention, an electrical network is considered, which supplies electrical energy to a plurality of devices. The electrical network comprises at least one electrical cable, all of the electrical cables in the network supplying the plurality of electrical devices. The cables may be single-phase (single-conductor) or polyphase (multi-conductor) and may carry alternating or direct current.

[0060] A method according to the present invention for diagnosing the energy consumption of an electrical network comprises steps which do not require any shutdown of the operations carried out by the electrical network.

[0061] As shown in Figure 1, the diagnostic method includes a step of entering a diagnostic mode.

[0062] This step itself includes steps described below.

[0063] An identification step 10 consists of identifying, among the plurality of devices, at least one device to be monitored.

[0064] This step 10 may, for example, consist of identifying, among all the equipment supplied by the network, those which have an average energy consumption greater than a predetermined threshold.

[0065] By way of non-limiting examples of equipment, mention may be made of a motor, a compressor, or an extruder. For example, the extruder may be considered to have a high energy consumption if its average energy consumption is greater than 1 kWh, this threshold value being given for illustrative purposes and being in no way limiting. In this regard, the present invention is particularly suitable for measuring and monitoring high currents. However, it is on high currents that the most significant savings can be made.

[0066] In addition to or instead of high-energy consuming equipment, step 10 may involve identifying those that are used most intensively, within the meaning of a predefined intensive use criterion. As a non-limiting example, a compressor consuming several hundred amperes per phase may be considered to be subject to intensive use.

[0067] Then a location step 12 consists of locating at least one point in the network where energy consumption is to be measured. This step is carried out in particular based on the identification of the equipment(s) to be monitored carried out in identification step 10.

[0068] For example, location step 12 may consist of collecting information that is available, for example concerning the network configuration and may also use information giving the location of the equipment(s) to be monitored identified in identification step 10.

[0069] Location step 12 may also be based on information possibly obtained elsewhere on the equipment or on other information concerning sensitive points of the network already known before launching the diagnosis, i.e. the places in the network deemed to require specific monitoring.

[0070] As shown in Figure 1, following location step 12, the diagnostic method according to the invention comprises a step 14 of selecting at least one cable to be monitored from among all the electrical cables in the network.

[0071] This selection step 14 is carried out from the location of the point(s) of the network where the energy consumption is to be measured, carried out in location step 12.

[0072] Selection step 14 may, for example, consist, for each point of the network which was determined in location step 12, in selecting at least one cable which passes through this point of the network.

[0073] Then, the diagnostic method may optionally, but not necessarily, include a step 15 of determining the type of cable to be monitored. This determination step 15 is illustrated in Figure 7 and consists of determining, for each cable to be monitored selected in the selection step 14, whether it is a single-conductor or multi-conductor cable. This determination is for example carried out by reading information appearing on the cable and possibly also on the electrical diagram of the installation.

[0074] Determination step 15 is performed after selection step 14 and before a positioning step 16, which, as shown in Figures 1 and 7, consists of positioning, in one or more locations around each cable to be monitored, one or more devices 30 for measuring the current intensity.

[0075] The measuring device 30 is described in detail further on in connection with FIG. 3. It is capable of simultaneously determining the intensity of the current flowing in all the conductors of the cable to be monitored and of determining the energy consumption, per conductor, of the cable to be monitored.

[0076] The diagnostic method according to the invention further comprises a parameterization step 18, which consists of parameterizing each measuring device 30. The parameterization step 18 of the measuring device(s) 30 can be carried out after the positioning step 16 of these measuring devices 30, but can also be carried out before the positioning step 16, provided that information on the cable to be monitored by this measuring device 30 which is useful for the parameterization is available for a measuring device 30.

[0077] As a non-limiting example, this configuration can be carried out on screen, via a visualization platform 82, described later in connection with figure 8.

[0078] The diagnostic method according to the invention further comprises a restitution step 20 which consists of providing, at the end of the steps described previously, a diagnosis of energy consumption of the electrical network.

[0079] The diagnosis thus returned includes information on the intensity of the current flowing in each of the conductors of the cable(s) to be monitored and on the energy consumption, per conductor, of these cables. This information may, for example, take the form of a value in kWh which may be updated at a given frequency, this frequency being able, for example, to be chosen by the user. Thus, the present invention has the advantage of offering a return of the diagnosis including measurement of the current, power and consumption, at a frequency, for example, defined by the user according to his needs, or according to the needs of the equipment(s) monitored.

[0080] This information is obtained from the measurements made by the measuring device(s) 30 once they have been configured in configuration step 18.

[0081] The restitution step 20 may for example include an immediate visualization step, after configuration of the measuring device(s) 30, of the intensity and consumption, in graphic form, via the visualization platform 82.

[0082] Figure 6 illustrates another step that can be included in the diagnostic method according to the invention, in a particular embodiment. This is a step of exiting the diagnostic mode. In accordance with the invention, it does not require any suspension of the operations of the electrical network. In the particular embodiment illustrated, the step of exiting the diagnostic mode comprises a step 60 consisting of removing the measuring device(s) 30 from the cable(s) 32 to be monitored.

[0083] Alternatively, rather than removing the measuring devices 30 from the network to be diagnosed as soon as the diagnosis is complete, they can be left in the network, around the cables 32 to be monitored, but switched off, put on standby or deactivated in another way.

[0084] In the particular embodiment illustrated in FIG. 3, the device 30 for measuring the intensity of the electric current comprises a plurality of magnetic field sensors 36.

[0085] In the non-limiting example of Figure 3, a cable 32 to be monitored is illustrated. This cable 32 comprises five conductors 34 and the measuring device 30 comprises two sets of five sensors 36 each (one set of sensors 36 is shown in solid lines and the other in dashed lines). This example is in no way limiting, the diagnostic method according to the invention being applicable regardless of the number of conductors of the cables to be monitored and using a number of sensors chosen according to the electrical network to be diagnosed.

[0086] The measuring device 30 further comprises a processing means 38 adapted to receive values ​​of at least one component of the magnetic field induced by the current flowing in the conductors of the cable 32 to be monitored, measured by the plurality of magnetic field sensors 36.

[0087] Thus, the diagnostic method according to the invention comprises, between the step 18 of configuration and step 20 of restitution, steps detailed below.

[0088] As mentioned above, the 32 cable to be monitored is a single-phase or polyphase electrical cable, with alternating or direct current. N denotes the number of conductors in the cable. These conductors are not necessarily identical.

[0089] The invention is based on the local measurement of at least one component of the magnetic field emitted by the current sources, which are here the N conductors, by means of magnetic field sensors.

[0090] In short, given that the cable 32 to be monitored has one or more current densities coming from its N conductors (N = 1 when the cable 32 is single-phase), we can first calculate the magnetic field produced by the current using the Biot-Savart law, then invert all the local measurements of the magnetic field components by determining an inverse matrix, in order to obtain the current intensities coming from the N current sources.

[0091] Thus, as shown in the flowchart of Figure 5, the current intensity in the N conductors is simultaneously measured by carrying out a first step E1 which corresponds to the positioning step 16 described above, consisting of placing a plurality of magnetic field sensors around the cable, at at least one location on the cable.

[0092] Step E1 may for example consist of fixing around the cable one or more measuring devices 30 in accordance with the invention containing the plurality of sensors.

[0093] Then a step E2 consists of simultaneously measuring, for each of the N conductors of the cable, at least one component of the magnetic field produced by the current flowing in this conductor.

[0094] These simultaneous measurements are carried out by means of the plurality of magnetic field sensors.

[0095] In a particular embodiment, the plurality of magnetic field sensors can measure for each conductor only the tangential component or only the radial component of the magnetic field.

[0096] Alternatively, for greater accuracy, the plurality of magnetic field sensors may measure for each conductor both the tangential component and the radial component of the magnetic field.

[0097] Then, during a step E3, for each of the conductors, the angle a is determined between this conductor and the nearest magnetic field sensor of the plurality of magnetic field sensors. The angle a is defined relative to the center of the cable section and by treating the conductors and the sensors as points. Indeed, for simplicity, it is assumed that each conductor has an infinitely small section and that the magnetic field picked up by each sensor is located at a point corresponding to the location of the sensor.

[0098] Figure 2 schematically illustrates, by way of non-limiting example, a cable of circular section comprising five conductors regularly distributed inside the cable, which are assimilated to five points C1 to C5 equidistant from each other on the circumference of a circle Te. Only the magnetic field sensor closest to the conductor C1 has been represented and is symbolized by the point A. The radius of the circle Te is designated by r, the distance between the conductor C1 and the sensor A is designated by di, the straight line segment connecting the sensor A and the center of the circle Te is designated by d'i, the angle at point A between the straight line segment d'i and the straight line segment connecting the conductor C1 and the point A is designated by p. The magnetic field captured by the sensor A is represented by the vector Bi, which is orthogonal to the straight line segment connecting the conductor C1 and the point A.

[0099] For a cable comprising N conductors each producing a magnetic field Bi, i = 1, ..., N, the component BA of the magnetic field at point A coming from the N conductors is defined as follows:

[0100] [Math. 1]

[0102] Or : Bim is the component of the magnetic field coming from the i ème driver captured by the rn ième sensor; the angles Oi and i are defined for the i ème conductor similarly to the angles a and P defined above, respectively; di denotes the distance between the i ème conductor and the nearest sensor; o is an equivalent magnetic permeability which takes into account the presence of insulating materials in the cable; r is as defined above the radius of the circle Te; and lim is the value of the intensity of the current flowing in the i ème conductor and deduced from the magnetic field measurement carried out by the m ième sensor.

[0103] The number of magnetic field sensors is at least equal to the total number N of conductors in the cable.

[0104] Thus, the intensities of the currents in the conductors are linked to the components of the magnetic field measured, by the relation B = kMI where B is the matrix of the components of the magnetic field measured in all the conductors by all the sensors, I is the matrix of the intensities of the currents circulating in all the conductors, M is a matrix comprising a plurality of proportionality coefficients depending on the angles between the conductors and the magnetic field sensors and k is a predetermined coefficient.

[0105] It follows that I = (PO / 2TT).M' 1 .B, WHERE M -1 is the inverse matrix of M.

[0106] Thus, as shown in Figure 5, following step E3 of determining the angle a between each conductor and the nearest sensor, a step E4 is carried out consisting of calculating the inverse matrix M -1 , so as to deduce the values ​​of the intensities I of the currents in all the conductors of the cable.

[0107] As a non-limiting example, for N = 5 conductors and five magnetic field sensors placed respectively at points A, B, C, D and E, the analytical expression allowing the intensities of the currents in the conductors to be deduced is as follows:

[0108] [Math. 2]

[0110] where h, i = 1, ..., 5 denotes the intensity of the current flowing in the i ème conductor and BA, BB, BC, BD and BE denote the magnetic field components respectively measured by the five sensors.

[0111] The equivalent magnetic permeability po is a macroscopic permeability, which makes the calculation simpler than if we considered the local magnetic permeability.

[0112] In a particular embodiment, the angle α between this conductor and the nearest magnetic field sensor of the plurality of magnetic field sensors is determined so as to maximize the following function F:

[0113] [Math. 3]

[0115] where h denotes the intensity of the current flowing in the i ème driver.

[0116] There are various known mathematical convergence methods for maximizing F, such as the Levenberg-Marquardt algorithm (also called the LM algorithm) or the Nelder-Mead method.

[0117] The processing means 38 is adapted to apply the steps E3 of angle determination and E4 of inverse matrix calculation, to deduce therefrom the intensity of the current flowing in each of the conductors 34.

[0118] The processing means 38 can be located either in the measuring device 30 or at a distance from it, a means of communication then being intended to transmit from the sensors 36 to the processing means 38 the values ​​of the measured components of the magnetic field. When located remotely from the measuring device 30, the processing means 38 may be located in a laptop or other portable computer, a tablet, a smartphone or other mobile means of communication, or even be located in the cloud.

[0119] In the particular embodiment illustrated, the measuring device 30 further comprises a housing 31 containing the plurality of magnetic field sensors 36. Such a housing is optional, the sensors 36 being able to be placed around the cable without being contained in any enclosure.

[0120] In the particular embodiment illustrated in Figure 3, the housing 31 has a section formed by two half-rings 311 and 312, adapted to the positioning of the measuring device 30 around the cable 32, the two half-rings 311 and 312 defining by their assembly an opening in which the cable 32 passes. In the particular embodiment illustrated, the cable 32 has a circular section and the opening formed by the two half-rings 311 and 312 is also circular and of diameter slightly greater than that of the section of the cable.

[0121] Once the measuring device 30 is placed around the cable 32, the two half-rings 311 and 312 can be connected to each other, for example, by means of a hinge-type joint, or can be secured to each other, for example, by means of screws or nuts or other preferably removable fixing means.

[0122] Also optionally, the housing 31 can be surrounded by electromagnetic shielding preventing the sensors from being disturbed by any surrounding sources of electromagnetic waves as well as by the Earth's permanent magnetic field. This shielding can be made, for example, of a specific steel.

[0123] Whether such shielding is present or not, the device 30 may further be equipped with one or more additional magnetic field sensors 37 adapted to measure in particular the Earth's magnetic field, in order to subtract the value thereof when processing the values ​​of the components of the magnetic field measured by the magnetic field sensors 36. The one or more additional sensors 37 can be arranged inside and / or outside the housing 31, or even directly around the cable to be monitored when there is no housing.

[0124] Thus, an electrical cable arrangement within a network undergoing diagnosis according to a diagnostic method according to the present invention comprises the cable 32 and at least one measuring device 30 placed around the cable 32.

[0125] As shown in the particular embodiment of FIG. 4, the electrical cable arrangement may comprise, around the same cable 32 to be monitored, a plurality of measuring devices 30, placed around the cable 32 at predetermined intervals from each other.

[0126] The processing means 38 may be unique and common to all of the measuring devices 30. Alternatively, a processing means 38 may be provided for each measuring device 30 and communication means adapted to communication between the various processing means 38 may possibly be provided.

[0127] In the particular embodiment illustrated, the measuring devices 30 are all identical, each comprise two sets of five magnetic field sensors 36 each (one set of sensors 36 is shown in solid lines and the other in dashed lines) and are arranged at regular intervals along the cable 32.

[0128] Such a configuration makes it possible to guarantee high-quality measurement of current intensities even in the case where the conductors 34 are twisted, for example due to manufacturing conditions and / or specific constraints, which could influence the sensitivity of the measurement of magnetic fields.

[0129] The number of measuring devices 30 to be placed around the cable 32 to be monitored and the distance between each measuring device 30 on this cable 32 are of course to be defined according to the type of cable 32 considered.

[0130] Figure 8 illustrates a particular embodiment of a device 80 for diagnosing the energy consumption of an electrical network, in accordance with the present invention, the network supplying electrical energy to a plurality of equipment and comprising at least one electrical cable supplying the plurality of equipment, this cable comprising one or more electrical conductors, as described above in connection with the diagnostic method.

[0131] The diagnostic device 80 is suitable for implementing the diagnostic method described in detail above.

[0132] The implementation of the diagnostic device 80 therefore does not require any shutdown of the operations carried out by the electrical network.

[0133] As shown in Figure 8, the diagnostic device 80 comprises at least one measuring device 30. As described above in connection with the diagnostic method, the measuring device(s) 30 are adapted to measure the intensity of the current flowing in all the conductors of a cable to be monitored among the cable(s) of the network and are adapted to determine the energy consumption, per conductor, of the cable(s) to be monitored.

[0134] In the particular embodiment of figure 8, the measuring device 30 comprises at least one magnetic field sensor 36 and at least one processing means 38 as described above.

[0135] In the particular embodiment of figure 8, the diagnostic device 80 further comprises a visualization platform 82, adapted to serve as a human-machine interface and allowing for example the configuration of the measurement device(s) 30.

[0136] Optionally, the visualization platform 82 can further be adapted to display the current intensity measured in each conductor of each cable to be monitored and the energy consumption per conductor.

[0137] Like the processing means 38, the visualization platform 82 can be located in a laptop or other computer, a tablet, a smartphone or other mobile means of communication, or even be located in the cloud.

[0138] The diagnostic device 80 according to the invention can be installed in the electrical network to be diagnosed by implementing the installation method according to the invention, which comprises the positioning step 16 described previously, consisting of positioning, in at least one location around the or cables to be monitored, the measuring device(s) 30 in order to carry out steps of the diagnostic method detailed previously.

[0139] The invention can be applied to many types of cables, such as cables used in buildings, which are designed for voltages generally less than 1000 V, and distribution cables, which are designed for voltages generally equal to or greater than 1000 V.

Claims

Claims

1. Method for diagnosing the energy consumption of an electrical network, said network supplying electrical energy to a plurality of devices and comprising at least one electrical cable supplying said plurality of devices, said cable comprising one or more conductors, said method being characterized in that it comprises the following steps requiring no stopping of the operations carried out by said electrical network: a step of entering a diagnostic mode, comprising the following steps: - an identification step (10), consisting of identifying, among said plurality of equipment, at least one equipment to be monitored; - a location step (12), consisting of locating at least one point of said network where to measure the energy consumption, at least from the identification of said at least one piece of equipment to be monitored in the identification step (10); - a step (14) of selecting at least one cable to be monitored from among said at least one electrical cable of said network, from the location of said at least one point of the network in the location step (12); - a positioning step (16), consisting of positioning, in at least one location around said at least one cable to be monitored, at least one device (30) for measuring the current intensity simultaneously determining the intensity of the current flowing in all the conductors of said at least one cable to be monitored and determining the energy consumption, per conductor, of said at least one cable to be monitored; - a parameterization step (18), consisting of parameterizing said at least one measuring device (30); - a restitution step (20), consisting of providing a diagnosis of energy consumption of said electrical network, comprising information on the intensity of the current flowing in each of the conductors of said at least one cable to be monitored and on the energy consumption, per conductor, of said at least one cable to be monitored, said information on the intensity of the current flowing in each of the conductors of said at least a cable to be monitored and on the energy consumption, per conductor, of said at least one cable to be monitored being obtained from the measurements carried out by said at least one measuring device (30) once configured in the configuration step (18).

2. Diagnostic method according to claim 1, characterized in that the identification step (10) consists of identifying, among said plurality of devices, those which have an average energy consumption greater than a predetermined threshold and / or which are used most intensively according to a predefined intensive use criterion.

3. Diagnostic method according to claim 1 or 2, characterized in that the location step (12) consists of locating said at least one point of said network from available information concerning the configuration of said network and from the location of said at least one piece of equipment to be monitored identified in the identification step (10).

4. Diagnostic method according to any one of the preceding claims, characterized in that the selection step (14) consists of selecting at least one cable passing through said at least one point of said network which was determined in the location step (12).

5. Diagnostic method according to any one of the preceding claims, characterized in that it further comprises, between the selection (14) and positioning (16) steps, a determination step (15), consisting of determining whether said at least one cable to be monitored is single-conductor or multi-conductor.

6. Diagnostic method according to any one of the preceding claims, characterized in that the parameterization step (18) consists of parameterizing said at least one measuring device (30) via a visualization platform (82).

7. Diagnostic method according to the preceding claim, characterized in that the restitution step (20) comprises a step of immediate visualization, after configuration (18) of said at least one measuring device (30), of said intensity and of said consumption, in graphic form, by means of said visualization platform (82).

8. Diagnostic method according to any one of the preceding claims, characterized in that said at least one device (30) for measuring the current intensity comprises a plurality of magnetic field sensors (36) and a processing means (38) adapted to receive values ​​of at least one component of the magnetic field induced by the current flowing in the conductors of said cable to be monitored and in that said diagnostic method comprises, between said parameterization (18) and restitution (20) steps, steps consisting of: placing (E1) said plurality of magnetic field sensors around said cable, at at least one location of said cable; measuring (E2) simultaneously, for each of said conductors, said at least one component of the magnetic field produced by the current flowing in said conductor, by means of said plurality of magnetic field sensors;for each of said conductors, determining (E3), by means of said processing means (38), the angle between said conductor and the nearest magnetic field sensor of said plurality of magnetic field sensors, said angle being defined with respect to the center of said cable and by assimilating said conductors and said sensors to points; and the intensities of the currents in said conductors being related to the components of the magnetic field measured by the relation B = kMI where B is the matrix of said components of the magnetic field, I is the matrix of said intensities of the currents, M is a matrix comprising a plurality of coefficients of proportionality depending on said angles between said conductors and said magnetic field sensors and k is a predetermined coefficient, calculating (E4) the inverse M; -1 of the matrix M, so as to deduce the values ​​of the said current intensities I = (O / 2TT).M -1.B, WHERE po is an equivalent magnetic permeability which takes into account the presence of insulating materials in said cable.

9. Diagnostic method according to the preceding claim, characterized in that the measuring step (E2) consists of simultaneously measuring, for each of said conductors, the tangential component and the radial component of the magnetic field produced by the current flowing in said conductor, by means of said plurality of magnetic field sensors.

10. Diagnostic method according to any one of the preceding claims, characterized in that it further comprises the following step requiring no stopping of the operations carried out by said electrical network: a step of exiting said diagnostic mode, consisting of removing (60) said at least one cable to be monitored from said at least one measuring device (30).

11. Device (80) for diagnosing the energy consumption of an electrical network, said network supplying electrical energy to a plurality of devices and comprising at least one electrical cable supplying said plurality of devices, said cable comprising one or more conductors, said device being characterized in that its implementation does not require any stopping of the operations carried out by said electrical network and in that it comprises at least one device (30) for measuring the intensity of the current adapted to simultaneously determine the intensity of the current flowing in all the conductors of a cable to be monitored among said at least one electrical cable and adapted to determine the energy consumption, per conductor, of said at least one cable to be monitored, said at least one measuring device (30) being adapted to implementing the steps of a diagnostic method according to any one of the preceding claims.

12. Diagnostic device (80) according to the preceding claim, characterized in that it further comprises a display platform (82) adapted to serve as a human-machine interface making it possible to configure said at least one measuring device (30).

13. Diagnostic device (80) according to the preceding claim, characterized in that said viewing platform (82) is further adapted to display said intensity and said consumption.

14. Diagnostic device (80) according to any one of claims 11 to 13, characterized in that said at least one device (30) for measuring the intensity of the current comprises a plurality of magnetic field sensors (36) and a processing means (38) adapted to receive values ​​of at least one component of the magnetic field induced by the current flowing in the conductors of said cable to be monitored and to carry out steps of a diagnostic method according to claim 8 or 9.

15. Diagnostic device (80) according to any one of claims 11 to 14, characterized in that said at least one measuring device (30) further comprises a housing (31) containing said plurality of magnetic field sensors (36).

16. Diagnostic device (80) according to the preceding claim, characterized in that said housing (31) is surrounded by electromagnetic shielding.

17. Diagnostic device (80) according to claim 15 or 16, characterized in that said housing (31) has a section formed of two half-rings (311, 312), adapted to the positioning of said at least one measuring device (30) around said cable (32).

18. Diagnostic device (80) according to any one of claims 15 to 17, characterized in that it further comprises at least one additional magnetic field sensor (37) adapted to measure the Earth's magnetic field.

19. Diagnostic device (80) according to the preceding claim, characterized in that said at least one additional sensor (37) is arranged inside said housing and / or outside said housing (31).

20. Method for installing a diagnostic device (80) according to any one of claims 11 to 19 in an electrical network, characterized in that it comprises a step consisting of positioning, in at least one location around said at least one cable to be monitored, said at least one measuring device (30) in order to execute steps of a diagnostic method according to any one of claims 1 to 10.

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