Method for balancing the phases of a polyphase electric current supply, and system for its implementation

Abstract

Method for balancing the phases of a polyphase electric current supply, and system for its implementation Method for generating at least one item of information relating to the balancing of the phases of a supply inlet (P), comprising: a. at least for each electrical outlet (Di) and preferably for the supply inlet (P) also, the measurement (E1) of the intensities of the different phases using a measuring device (30), in particular a measuring device arranged around the corresponding conductor(s) (34), this measurement being carried out, in particular continuously, over a predefined duration, the measurements being transmitted to a processing system (40), b.the generation (E2) by the processing system (40), from said measurements, of at least one item of information providing information on the balancing of the phases of the supply inlet and / or providing information on at least one permutation to be carried out between two phases of at least one departure (Di), this permutation leading to an improvement in the balancing of the phases of the supply inlet (P). Figure for the abstract: Fig. 1.

Description

Title of the invention: Method for balancing the phases of a polyphase electric current supply, and system for its implementation Technical field

[0001] The present invention relates to the distribution of electrical energy from polyphase networks. Prior art

[0002] The transmission of electricity, particularly low and medium voltage, to end consumers (particularly residential, tertiary or small industrial customers) is generally carried out with polyphase alternating currents, generally three-phase.

[0003] It is desirable that the phases are balanced, that is to say that the currents which flow through them have substantially the same amplitude, in order to optimize the transport of electrical energy.

[0004] A known technique for balancing a three-phase installation generally consists of successively measuring, by means of a Rogowski winding or a Hall effect sensor, the current intensity in each of the phase conductors, also called "phases". This technique is time-consuming and generally provides imprecise results because it is punctual and not simultaneous for all phases.

[0005] Applications EP4083746 and GB2566680 describe methods for balancing phases within computing centers.

[0006] It is known from publications WO2015066048 and US9728971 to control the balance of an installation via the analysis of the energy needs of the latter and the capacities of the power source.

[0007] EP3748373 describes a method for diagnosing an electrical network including a plurality of nodes, each node being equipped with a local device capable of measuring at least one property of the electrical energy passing through the node.

[0008] FR2971897 discloses a method for balancing loads on an electrical network polyphase, based on measurements made on single-phase loads and the use of an inverter.

[0009] US7898104 and US9865410 describe phase balancing methods based on measurements on single-phase conductors and on the use of switches.

[0010] Furthermore, from application EP 2 776 853, a device is known for measuring currents in the conductors of a sheathed cable (i.e. with its sheath) of a network polyphase. Statement of the invention

[0011] There is a need for a solution to improve the phase balancing of electricity distribution circuits, in a way that is simple to implement and relatively precise. Summary of the invention

[0012] The invention aims to meet this need and achieves it, according to one of its aspects, by proposing a method for generating at least one item of information relating to the balancing of the phases of a polyphase electrical current supply inlet of an installation comprising at least two single-phase or polyphase electrical outlets connected in parallel to said inlet and serving user equipment, the method comprising:

[0013] a. at least for each of said electrical outlets and preferably for the power supply inlet as well, the measurement of the current(s), or other physical quantities linked to these, of the different phase(s) using a measuring device, in particular a measuring device arranged around the corresponding conductor(s), this measurement being carried out, in particular continuously, over a predefined duration, the measurements being transmitted to a processing system,

[0014] b. the generation by the processing system, from said measurements, of at least one item of information providing information on the balancing of the phases of the power supply inlet and / or providing information on at least one permutation to be carried out between two phases of at least one of said feeders, this permutation leading to an improvement in the balancing of the phases of the power supply inlet.

[0015] The measurement can be carried out, in particular continuously, over a sufficient duration determined by the user depending on the application, of at least one hour.

[0016] The invention can allow, if desired, continuous and simultaneous monitoring of the intensity of the electric current in the different phases of several polyphase or single-phase electrical feeders, thanks to the use of a set of measuring devices, which can transmit information to a processing system, for example a centralized receiver and / or an internet server, in particular via IoT type communication, all of the measuring devices then forming a network of connected measuring devices.

[0017] The user equipment may be located in residential, office or industrial buildings. For example, each phase of a feeder supplies a single-phase meter of a dwelling within a collective housing complex.

[0018] The processing system which produces the information providing information on the balancing of the phases and / or the recommendation on one or more permutations to be carried out, can be present locally at the level of the connections of the installation, or remotely, in particular in the form of an internet server, which can transmit the information to the operator responsible for carrying out the permutation by means of notifications for example.

[0019] The invention thus makes it possible to have a network of connected measuring devices making it possible to know the distribution of the currents in the different departures in order to determine the minimum imbalance which can be obtained by switching certain phases of the electrical departures.

[0020] This can help improve the balance between the phases, and thus reduce Joule losses and environmental impact. Measurement of intensities

[0021] Each of said outlets may comprise a multi-conductor cable, the measuring device associated with this outlet then being advantageously placed around the corresponding multi-conductor cable. This installation may be carried out on the cables with their sheath, without having to remove the sheath or disconnect the cables, if the measuring device comprises two parts which are movable relative to each other and which can be closed on the cable.

[0022] This can make it possible to measure the current intensity in all the conductors of each outlet in a single operation and to quickly obtain extremely precise results, without needing to access each conductor individually, for example by removing the sheath from the cables. The measurement can be carried out statically, that is to say without relative movement of the sensors of the measuring device with respect to the cable during the measurement.

[0023] The measurements of the current intensities, or other related quantities, in all the conductors of all the feeders, can be carried out in parallel by the various associated measuring devices, which can transmit the result of the measurements carried out continuously or periodically to the aforementioned processing system.

[0024] Each measuring device may comprise one or more sensors arranged around the corresponding cable, being for example substantially equally distributed angularly around the latter. In particular, each measuring device may comprise magnetic field sensors each adapted to measure at least one component of the magnetic field produced by the current flowing in the conductors of the cable around which the measuring device is placed, in particular the tangential component and the radial component.

[0025] Step a) of the above method can thus comprise, in an exemplary embodiment: (i) for each of said phases of each of said feeders, determining the angle between said phase and the nearest magnetic field sensor, said angle being defined relative to the center of the cable and by assimilating the conductors and the sensors at points, and (ii) the calculation of the intensities of the electric current flowing in said phases of said electrical feeders, these intensities being linked 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 measured for the same cable, I is the matrix of said intensities of the currents in this cable, M is a matrix comprising a plurality of proportionality coefficients depending on said angles between said phases and said magnetic field sensors of this cable and k is a predetermined coefficient.

[0026] Step a) of the method defined above can thus consist of simultaneously measuring, for each of the conductors of each of the feeders, the tangential component and the radial component of the magnetic field produced by the current flowing in said conductor, by means of the plurality of magnetic field sensors. This makes it possible to minimize the error on the intensity values ​​obtained, that is to say to further increase the precision of these values.

[0027] The calculation of the intensities in step (ii) involves calculating the inverse M 1 of the matrix M, so as to deduce the values ​​of the intensities of the currents I = (pO / 2ir).M *.B, where pO is an equivalent magnetic permeability which takes into account the presence of insulating materials in the cable.

[0028] As mentioned above, the installation of the aforementioned measuring devices around multi-conductor cables does not require removing their sheath, when present, and can be carried out simply and without causing damage, marks or deformation to the cables. Taking into account the angular offset between sensors and conductors contributes to the accuracy of the intensity values ​​obtained.

[0029] Each measuring device may comprise an electronic system configured for example to carry out the calculations of steps (i) and (ii), and to transmit the result of the measurement, directly or indirectly, to the processing system responsible for delivering the information relating to the balancing of the phases as well as a possible recommendation aimed at improving it, if necessary.

[0030] The method according to the invention may comprise supplying electrical energy to the measuring devices and / or all or part of the processing system by inductive coupling with at least one electrical conductor of a feeder. This may make the measuring device energy-autonomous. This supply may be carried out by any energy recovery means, for example using at least one winding subjected to the magnetic field present in the vicinity of at least one electrical conductor, this winding being for example arranged between two phase conductors, or by any other energy recovery means, or even via a direct electrical connection or by a cell or battery.

[0031] In a variant, the measurement of the intensity of the electric current in a conductor is carried out continuously by means of a measuring device comprising a measuring module comprising several sensors each having different current measuring ranges and / or a multi-caliber sensor having different measuring calibers, for example from 0 to 100 A and from 0 to 1000 A. The sensors may be Rogowski sensors, Hall effect sensors or current transformers. The measuring module thus provides different analog signals for measuring the current flowing in the conductor, and which have different measurement accuracies. The measuring module may further comprise a multiplexer for successively selecting the analog measurement signals from the sensor(s), and an analog-to-digital converter for generating a digital signal corresponding to the analog measurement signal selected by the multiplexer.

[0032] The measuring device may further comprise a microcontroller for analyzing each digital signal so as to determine the optimal analog measurement signal which has the maximum measurement accuracy. The optimal analog measurement signal preferably corresponds to the unsaturated digital signal having the largest deviation A between the maximum and minimum values ​​of the corresponding digital signal, over a predetermined measurement time interval.

[0033] The measuring device may comprise a radiofrequency communication module for transmitting the optimal analog measurement signal and / or the corresponding digital signal to the processing system.

[0034] The measuring device may comprise several measuring modules for measuring the current intensity in different conductors, the magnetic sensor(s) of each measuring module being configured to be arranged around one of the conductors. Processing of measurements

[0035] Step b) of the method defined above may include the transmission of the measurements, and / or data linked to the measurements, to the processing system via a wireless link, in particular radio frequency, and more generally via any communication network, for example of the IoT type.

[0036] The processing system may comprise one or more processors, and more generally any electronic and / or computer equipment, local or remote, for example an internet server communicating with the network of measuring devices via an IoT type communication network, and / or a laptop, tablet or smartphone communicating with the measuring devices and / or a gateway connected to them by Bluetooth, Wifi or another means of wireless or wired communication.

[0037] The processing system can analyze the collected measurements and calculate all the connection combinations of the different phases of the departures in order to minimize the difference between the intensities of the arrival phases II, 12 and 13 respecting Kirchhoff's laws.

[0038] As indicated above, the method may comprise the generation by the processing system, from said measurements, of at least one item of information providing information on a permutation to be carried out between two phases of at least one feeder, this permutation leading to improved balancing of the phases of the supply inlet.

[0039] The generation of said information may be followed by at least one permutation of two phases of at least one departure from the installation. This permutation may be carried out manually by an operator authorized to intervene on the installation. The latter may receive the recommendation on the permutation(s) to be carried out by any means, for example by receiving a notification on a portable terminal such as a tablet or a smartphone, or by display on a screen of a dedicated device.

[0040] The balance of the phases of the supply arrival can be considered to be achieved when the phases have substantially the same intensity, to within a predefined tolerance. When the intensities are likely to vary over time, the information delivered by the processing system can include a recommendation on one or more permutations to be carried out to minimize an average imbalance of the phases over a given period of time and / or to minimize the difference between maximum intensities of the phases during a given period of time.

[0041] Once the permutations have been carried out, steps a) and b) can be restarted after a predefined period of time, in order to carry out a possible new rebalancing by one or more new permutations, to take into account, for example, changes in equipment or consumption habits.

[0042] The information generated in step b) may in particular be determined by the application by the processing system of any suitable optimization model, such as a linear programming model or a mixed integer programming model. Arrival and departures

[0043] The arrival may comprise three electrical phases, as well as a neutral if necessary. Thus, the intensities measured by the measuring devices may be those flowing through the conductors of each of these phases as well as the neutral.

[0044] Each of the departures may comprise a number of phases less than or equal to the number of phases of the arrival.

[0045] Depending on the applications, the voltages between phases may be greater than or equal to 1000V or less than 1000V, for example of the order of 400V. The voltages between the phases and the neutral may be of the order of 240V, and the frequency of 50 or 60 Hz for example. Measuring devices

[0046] The measuring devices may be arranged to transmit via a wireless link, directly or indirectly, the result of the measurements to the processing system.

[0047] Each measuring device can be arranged to be mounted around a multi-conductor cable of a corresponding outlet, and comprise magnetic field sensors each adapted to measure at least one component of the magnetic field produced by the current flowing in the conductors of the cable around which the measuring device is placed, in particular the tangential component and the radial component.

[0048] The measuring device may comprise a housing containing the magnetic field sensors. This may facilitate the installation of the sensors of the measuring device around the cable, since it is then not necessary to install each sensor individually, all of the sensors being mounted in a single operation around all of the conductors of the feeder.

[0049] The housing may include electromagnetic shielding making it possible in particular to prevent the penetration of electromagnetic disturbances due for example to the permanent Earth magnetic field and to possible sources of electromagnetic field located near the cable and the measuring device.

[0050] The housing may have a section formed of two half-rings, suitable for positioning the measuring device around the cable, in particular with its sheath. This configuration allows in particular rapid installation of the measuring device around the cable, which is therefore housed in the center of the circular opening formed by the meeting of the two half-rings.

[0051] Each measuring device may comprise an electronic system arranged to recover the measurements made by the sensors of said measuring device and / or communicate these measurements and / or data from these measurements to the processing system.

[0052] Each electronic system may comprise two cards respectively housed in the first and second half-rings of the housing and the two cards are preferably in mutual mechanical contact. Thus, the maintenance in position of the electronic system relative to the housing is even better.

[0053] The electronic system may comprise a transmitter for transmitting the results of the measurements via a wireless link.

[0054] The sensors are for example arranged on the printed circuits of the cards, for example in an angularly equidistributed manner around the axis of the opening of the device intended to be crossed by the multi-conductor cable.

[0055] The measuring devices may also be other, for example as mentioned above, comprising inductive sensors of different calibers.

[0056] Network of measuring devices and system for phase balancing

[0057] The invention also relates, independently or in combination with what above, a network of measuring devices, in particular as defined above, each placed around the conductors of a respective polyphase or single-phase feeder, and preferably of the feeder as well, in order to measure the intensities, or other physical quantities linked to them, in the different conductors of this feeder traversed by currents, and transmit the values ​​of the intensity measurements, directly or indirectly, to a common processing system, for example an internet server, in particular by an IoT type link, to allow this processing system to calculate the currents in each of the phases of a power feeder to which the feeders are connected in parallel.

[0058] The measuring devices may transmit the result of the measurements via a wireless link, as detailed above. This transmission may be carried out automatically, continuously or at regular time intervals, for example, or in response to a query from a server, as a variant, or otherwise.

[0059] The invention also relates to a system for balancing the phases of a polyphase electrical current supply inlet of an installation comprising at least two polyphase or single-phase electrical outlets connected in parallel to said inlet and serving user equipment, comprising: a. A set of measuring devices each configured for measuring the current(s), or other physical quantities linked to them, of the different phase(s) of a corresponding electrical outlet, and preferably of the inlet as well, and b. A processing system arranged to generate, from said measurements, at least one item of information providing information on the balancing of the phases of the power supply inlet and / or providing information on at least one permutation to be carried out between two phases of at least one feeder, this permutation leading to improved balancing of the phases of the power supply inlet.

[0060] As indicated above, each measuring device can be arranged to be mounted around a multi-conductor cable of a corresponding outlet, and comprise magnetic field sensors each adapted to statically measure at least one component of the magnetic field produced by the current flowing in the conductors of the cable around which the measuring device is placed, in particular the tangential component and the radial component.

[0061] The measurement can be carried out over a predefined period, chosen according to the application. Brief description of the drawings

[0062] [Fig. 1] is a schematic and partial representation of an example of an installation intended to be equipped with a set of sensors of a system for balancing the phases, in accordance with the present invention,

[0063] [Fig.2] is a schematic and partial representation of an example of a system for balancing phases in accordance with the invention,

[0064] [Fig.3] schematically and partially represents an example of a measuring device,

[0065] [Fig.4] schematically and partially illustrates steps of an example method in accordance with the invention, and

[0066] [Fig.5] illustrates different parameters used when measuring intensities. Detailed description

[0067] The installation 1 illustrated in [Fig.l] comprises a multi-phase P arrival, with for example three phases and a neutral, for example the three-phase 400V 50Hz network. The intensities (true effective values) of the currents of each of the phases are noted Ib I2 and I3 respectively.

[0068] The arrival is carried out for example by means of a sheathed cable comprising all the phase conductors and the neutral, or a bundle of cables each with a single conductor, for example twisted together.

[0069] The installation 1 may comprise one or more branch cabinets or a technical room, allowing connection to the incoming power supply of multi-phase outgoing feeders, directly or via electrical equipment such as contactors, circuit breakers, circuit breakers, fuses, meters or others, not shown.

[0070] The departures can be made using sheathed multi-conductor cables, towards the consumer equipment.

[0071] The installation 1 may comprise n electrical outlets Di, for i from 1 to n, each comprising for example, as illustrated, three phases whose respective intensities are noted Ou, O2ji and O3ji and ONji for the neutral.

[0072] According to the invention, a set of measuring devices 30, shown schematically in [Fig.l], is used to measure the currents in each of the feeders.

[0073] These measuring devices 30 are part of a system 2 for balancing the phases, shown in [Fig.2].

[0074] Each measuring device 30 is placed around the conductors of a corresponding departure.

[0075] Each measuring device may comprise, as illustrated in [Fig.3], a plurality of magnetic field sensors 36 arranged around the cable 32 corresponding to the corresponding electrical outlet Di, at at least one location of said cable, to measure at least the current flowing in the conductors 34 of this cable 32 corresponding to the different phases.

[0076] A processing system 40 is present to generate, from the current measurements made by the measuring devices 30, at least one item of information providing information on the balancing of the phases of the incoming line P and / or providing information on at least one permutation to be carried out between two phases of at least one outgoing line, this permutation leading to an improvement in the balancing of the phases of the incoming line P.

[0077] The processing system 40 transmits for example this information to a user terminal 50 such as a dedicated device, a laptop, a tablet or a smartphone.

[0078] The measuring device 30 comprises an electronic system 38 adapted to receive the values ​​of the components of the magnetic field measured by the plurality of sensors 36.

[0079] As illustrated, the measuring device advantageously comprises a housing 31 containing the plurality of magnetic field sensors 36. Such a housing is however optional, the sensors 36 being able to be placed around the cable 32 without being contained in any enclosure.

[0080] Preferably, as illustrated, 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 (with its sheath).

[0081] The two half-rings 311 and 312 can be connected to each other by means of a hinge-type joint, or can be secured to each other, for example, by means of screws or nuts or other fixing means, preferably removable.

[0082] The electronic system 38 can be located either in the housing or at a distance from it.

[0083] Optionally, the housing 31 includes electromagnetic shielding preventing disturbance of the sensors 36 by possible sources of surrounding electromagnetic waves as well as by the Earth's permanent magnetic field. This shielding can be made, for example, of a specific steel.

[0084] Whether such shielding is present or not, the measuring 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 additional sensor(s) 37 may be arranged inside and / or outside the housing 31, or even directly around the cable 32 when there is no housing.

[0085] The installation of the various measuring devices 30 and the operation of the system 2 according to the invention can be carried out according to the method illustrated in [Fig.4].

[0086] In this figure, block E1 groups together steps leading to the measurement, in particular continuously and / or simultaneously, of the intensities or other physical quantities linked to these, of the different phases of each electrical departure using respective measuring devices 30.

[0087] Block E2 groups together steps aimed at the generation by the processing system 40, from said measurements, of at least one item of information providing information on the balancing of the phases of the power supply arrival and / or providing information on at least one permutation to be carried out between two phases of at least one departure, this permutation leading to an improvement in the balancing of the phases of the power supply arrival.

[0088] The method may comprise a first sub-step El 1 consisting of placing the magnetic field sensors 36 around each cable 32 corresponding to an electrical outlet. Step El 1 may consist of fixing at least one measuring device 30 as described previously on each cable, for example by closing the two half-rings on it. A measuring device may also be placed around the incoming cable.

[0089] Once the measuring devices 30 are in place, it is possible to measure, in a second sub-step El2, for each conductor 34 of each cable 32, at least one component of the magnetic field produced by the current flowing in this conductor. These measurements are carried out in parallel on the conductors by means of the plurality of magnetic field sensors 36.

[0090] In a particular embodiment, the plurality of magnetic field sensors 36 can measure for each conductor only the tangential component or only the radial component of the magnetic field. Alternatively, for greater accuracy, the plurality of magnetic field sensors measure for each conductor both the tangential component and the radial component of the magnetic field.

[0091] In a non-limiting example of the invention, it is possible, during a third sub-step E13, for each conductor 34 of each cable 32, to determine the angle a between this conductor and the magnetic field sensor 36 of the plurality of magnetic field sensors of said nearest cable, as illustrated in [Fig.5], described later. The angle a is defined relative to the center of the section of the corresponding cable and by assimilating the conductors and the sensors to points. Indeed, for simplicity, it is assumed that each conductor has an infinitely small section and that the magnetic field captured by each sensor is located at a point corresponding to the location of the sensor.

[0092] Finally, we can calculate in a sub-step E14 the intensities of the currents circulating in each conductor of each of the cables. The calculations of steps E13 and E14 can be carried out by the electronic systems 38 of the measuring devices 30 of each cable.

[0093] 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 of the same cable by all the sensors around this cable, I is the matrix of the intensities of the currents circulating in all the conductors of this cable, M is a matrix comprising a plurality of proportionality coefficients depending on the angles between the conductors and the magnetic field sensors of this cable and k is a predetermined coefficient. It follows from this formula that I = (po / 2ir).M *.B, where M 1 is the inverse matrix of M and po is an equivalent magnetic permeability which takes into account the presence of insulating materials in the cable.

[0094] We can first calculate the magnetic field produced by the current using the Biot-Savart law, then invert all the local measurements of the components of the magnetic field by determining an inverse matrix, in order to obtain the current intensities coming from the N current sources.

[0095] In [Fig.5], a cable of circular section is shown 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 T. Only the magnetic field sensor closest to the conductor C1 has been shown, and is symbolized by the point A. The radius of the circle T is designated by r, the distance between the conductor C1 and the sensor A is designated by db the straight line segment connecting the sensor A and the center of the circle T is designated by d'b 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 [3. The magnetic field picked up by the sensor A is represented by the vector B1, which is orthogonal to the straight line segment connecting the conductor C1 and the point A.

[0096] For a cable comprising N conductors each producing a magnetic field B; , i = 1, ..., N, the component BA of the magnetic field at point A coming from the N conductors is defined as follows:

[0097] [Math.l] BA = = E ' ।Bim • coscos( Arcsinl ■■■■■■■■y-- ) ) • / ■ / 1 i lin y ad; \ y. / y un

[0098] where:

[0099] Bim is the component of the magnetic field coming from the ith conductor captured by the mth sensor;

[0100] the angles a; and [3; are defined for the ith conductor in a similar way to the angles a and [3 defined above, respectively;

[0101] di denotes the distance between the ith conductor and the nearest sensor;

[0102] po is an equivalent magnetic permeability which takes into account the presence of insulating materials in the cable;

[0103] r is as defined above the radius of the circle T; and

[0104] Iim is the value of the intensity of the current flowing in the ith conductor and deduced of the magnetic field measurement carried out by the mth sensor.

[0105] 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:

[0106] [Math.2]

[0107] where h, i = 1, ..., 5 denotes the intensity of the current flowing in the ith conductor and BA, Bb, Bc, Bd and Be denote the components of the magnetic field respectively measured by the five sensors. The equivalent magnetic permeability pO is a macroscopic permeability, which makes the calculation simpler than if we considered the local magnetic permeability.

[0108] In a particular embodiment, the angle a between a conductor and the nearest magnetic field sensor is determined so as to maximize the following function F:

[0109] [Math.3]

[0110] where h denotes the intensity of the current flowing in the ith conductor.

[0111] 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.

[0112] The intensities can also be determined differently, in particular by means of different sensors, without departing from the scope of the present invention.

[0113] Once the intensities have been determined, the results can be communicated in a first sub-step E21 by each measuring device 30 to the processing system. 40, which is for example common to all measuring devices 30.

[0114] In a sub-step E22, the intensities Ib, I2, I3 of each phase of the electrical inlet, as well as of the neutral IN, can be calculated by summing the intensities measured for the same phase in all n feeders, as illustrated in [Fig.l], so as to be able to calculate the imbalance between them. If necessary, the intensity values ​​measured in the inlet cable can be used to check that the measurements correspond with the calculation. The intensity values ​​measured on the inlet can also be used to determine the values ​​of the intensities of one or more feeders not equipped with measuring devices, using Kirchhoff's laws.

[0115] During a third step E23, information relating to the balancing of the phases of the electrical supply can be determined.

[0116] This information may consist of a quantity representative of the phase imbalance, for example observed over a given period of time.

[0117] The processing system 40 can execute an optimization program making it possible to determine one or more permutations of the phases of the departures making it possible to minimize the observed imbalance.

[0118] For example, for an installation comprising three three-phase electrical outlets D1, D2 and D3, it is assumed that the following average effective intensities are measured over a given period representative of consumption habits, for example a period of a few days to a few months, for each of the phases:

[0119] [Tab 1] Dl D2 D3 P 01,i / Il 10 A 10 A 10 A 30 A 02,i / 12 20 A 30 A 20 A 70 A 03,i / 13 30 A 20 A 30 A 80 A

[0120] We see that the arrival P is unbalanced, the intensities of the three phases II, 12 and 13 having a significant difference.

[0121] In order to improve the balancing of the phases of the arrival P, the optimization program executed by the processing system 40 can determine that the permutation of the phases 01,1 and 03,1 of the departure D1 as well as the phases 01,3 and 0,2,3 of the departure D3 leads to reducing the imbalance, as illustrated in table 2 below.

[0122] [Tab 2] Dl D2 D3 P 01,i / Il 30 A 10 A 20 A 60 A 02,i / 12 20 A 30 A 10 A 60 A 03,i / 13 10 A 20 A 30 A 60 A

[0123] It is visible in Table 2 that the arrival P becomes more balanced, the averaged effective intensities of the three phases II, 12 and 13 being equal to each other.

[0124] A recommendation can then be generated and distributed to an operator responsible, in step E3, for applying the recommendation by manually intervening on the installation to swap the conductors of the different departures.

[0125] The recommendation may in particular identify the departures and the conductors to be swapped, for example by designating identifiers for these cables and conductors.

[0126] Of course, the invention is not limited to the examples which have just been described.

[0127] It is possible in particular to have an installation with cascade connections, so that an initial multi-phase inlet using a multi-conductor cable supplies at least one intermediate stage of feeders, each of these feeders from the intermediate stage being carried out using a multi-conductor cable which in turn supplies a final stage of feeders; in such a case, the measuring devices can be installed on the final multi-phase feeders, to aim for the balance of the initial inlet.

Claims

Claims

1. Method for generating at least one item of information relating to the balancing of the phases of a polyphase electric current supply inlet (P) of an installation (1) comprising at least two single-phase or polyphase electrical outlets (Di) connected in parallel to said inlet and serving user equipment, the method comprising: a. at least for each of said electrical outlets (Di) and preferably for the power supply inlet (P) also, the measurement (El) of the current(s), or other physical quantities linked thereto, of the different phase(s) using a measuring device (30), in particular a measuring device arranged around the corresponding conductor(s) (34), this measurement being carried out, in particular continuously, over a predefined duration, the measurements being transmitted to a processing system (40), b.the generation (E2) by the processing system (40), from said measurements, of at least one item of information providing information on the balancing of the phases of the power supply arrival and / or providing information on at least one permutation to be carried out between two phases of at least one of said departures (Di), this permutation leading to improving the balancing of the phases of the power supply arrival (P).

2. Method according to claim 1, the measurements of the current intensities, or other related quantities, in all the conductors (34) of all the departures (Di), being carried out in parallel by the different associated measuring devices (30), which transmit in particular the result of the measurements carried out continuously or periodically to the processing system (40).

3. Method according to one of the preceding claims, each of the departures (Di) comprising a multi-conductor cable (32), the measuring device associated with this departure being placed around the corresponding multi-conductor cable.

4. Method according to the preceding claim, each measuring device (30) comprising magnetic field sensors (36), static during the measurement, and each adapted to measure at least one component of the magnetic field produced by the current flowing in the conductors of the cable (32) around which the measuring device is placed, in particular the tangential component and the radial component, step (a) comprising: (i) for each of said phases of each of said feeders, determining the angle between said phase and the nearest magnetic field sensor, said angle being defined relative to the center of said cable and by treating the conductors and sensors as points, and (ii) calculating the intensities of the electric current flowing in said phases of said electrical feeders, these intensities being linked to the components of the magnetic field measured by the relationship B = kMI where B is the matrix of said components of the magnetic field measured in the same cable, I is the matrix of said intensities of the currents flowing in the conductors of this cable, M is a matrix comprising a plurality of proportionality coefficients depending on said angles between said phases and said magnetic field sensors of the cable and k is a predetermined coefficient, the calculation of the intensities in step (ii) involving the calculation of the inverse Ml of the matrix M, so as to deduce therefrom the values ​​of the intensities of the currents I = (pO / 2ir).Ml.B, where pO is an equivalent magnetic permeability which takes into account the presence of insulating materials in the cable.

5. Method according to one of claims 1 and 2, the measurement of the intensity of the electric current in a conductor being carried out continuously by means of a measuring device comprising a measuring module comprising several sensors each having different intensity measurement ranges and / or a multi-caliber sensor having different measurement calibers.

6. Method according to any one of the preceding claims, each of the departures (Di) having a number of phases less than or equal to that of the arrival.

7. Method according to any one of the preceding claims, comprising supplying electrical energy to the measuring devices (30) by inductive coupling with at least one electrical conductor (34) of a feeder.

8. Method according to any one of the preceding claims, the arrival (P) comprising three electrical phases, as well as, where appropriate, a neutral.

9. Method according to any one of the preceding claims, step (b) comprising the transmission of the measurements, and / or data linked to the measurements, to the processing system (40) by a wireless link, in particular radiofrequency.

10. Method according to any one of the preceding claims, comprising the generation by the processing system (40), from said measurements, of at least one item of information providing information on a permutation to be carried out between two phases of at least one feeder (Di), this permutation leading to improved balancing of the phases of the supply inlet (P).

11. Method according to the preceding claim, the generation of said information being followed by at least one permutation of two phases of at least one departure from the installation.

12. Method according to the preceding claim, in which once the permutation(s) have been carried out, steps a) and b) are restarted after a predefined period of time, in order to carry out a possible new rebalancing by one or more new permutations, in particular to take into account changes in equipment or consumption habits.

13. Network of measuring devices (30), in particular for implementing the method according to any one of the preceding claims, each placed around the conductors (34) of a respective polyphase or single-phase feeder (Di), and preferably on the feeder as well, in order to measure the intensities, or other physical quantities linked to them, in the different conductors of this feeder traversed by currents, and transmit the values ​​of the intensity measurements, directly or indirectly, to a common processing system (40), to allow this processing system to calculate the currents (Il; 12; 13) in each of the phases of a power supply feeder (P) to which the feeders are connected in parallel.

14. System (2) for balancing the phases of a polyphase electrical power supply inlet (P) of an installation (1) comprising at least two polyphase or single-phase electrical outlets (Di) connected in parallel to said inlet (P) and serving user equipment, comprising: a. A set of measuring devices (30) each configured for measuring the current(s), or other physical quantities linked thereto, of the different phase(s) of a corresponding electrical outlet and preferably of the inlet as well, and b. A processing system (40) arranged to generate, from said measurements, at least one item of information providing information on the balancing of the phases of the power supply inlet (P) and / or providing information on at least a permutation to be carried out between two phases of at least one departure, this permutation leading to improved balancing of the phases of the supply arrival.

15. System according to the preceding claim, the measuring devices (30) being arranged to transmit via a wireless link, directly or indirectly, the result of the measurements to the processing system (40).

16. System according to claim 14 or 15, each measuring device (30) being arranged to be mounted around a multi-conductor cable (32) of a corresponding outlet (Di), and comprising magnetic field sensors (36) each adapted to statically measure at least one component of the magnetic field produced by the current flowing in the conductors (34) of the cable (32) around which the measuring device (30) is placed, in particular the tangential component and the radial component.

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