Calibration of the ROGOWSKI sensor

Abstract

A method for field calibration of a Rogowski sensor to be calibrated (CC), comprising the following steps: - positioning the sensor to be calibrated on a reference phase (PhB), or positioning a reference sensor on a phase to be calibrated; - after the positioning step, obtaining calibration current measurements produced by the sensor to be calibrated (CC), reference current measurements produced by the reference sensor (CB) and reference voltage measurements on the phase on which the reference sensor to be calibrated is positioned; - using the calibration current measurements, the reference current measurements and the reference voltage measurements to generate calibration parameters of the sensor to be calibrated.

Description

Technical Field

[0001] The invention relates to the field of polyphase electricity meters connected to Rogowski sensors. Background Art

[0002] Certain electricity meters, especially those used in industrial applications, measure power and energy distributed via very high current levels, often up to 2000 A. These meters are typically three-phase meters.

[0003] The current sensors used are therefore conventionally Rogowski sensors. In these sensors, the coil support is non-ferromagnetic and provides very good linearity, since there is no magnetic saturation. These sensors are therefore very good candidates for use in high voltage and high current applications.

[0004] Rogowski sensors are usually installed at a certain distance from the meter (sometimes more than 10 meters). Each sensor is therefore positioned on a phase of the distribution network (ie the Rogowski ring surrounds the conductor forming this phase) and is connected to the meter by an electric line.

[0005] The calibration of the sensor can be done at the factory before the meter is delivered to the customer. Each sensor is thus individually matched to the meter and the calibration parameters are stored in the meter.

[0006] This calibration in the factory makes it possible to use non-pre-calibrated Rogowski sensors (without guaranteed tolerances) and without requiring a specific accuracy. Thus, the same performance is obtained as with a more "inherently" efficient Rogowski sensor. However, when a Rogowski sensor has to be replaced in the field (e.g. after a failure), it is necessary to obtain with the new sensor a measurement accuracy equal to that of the other sensors connected to the instrument. However, the test benches used in the factory cannot be used to perform a new calibration.

[0007] Therefore, the use of pre-calibrated Rogowski sensors has been considered.

[0008] Certain Rogowski sensors of the prior art therefore comprise a processing circuit which stores calibration parameters measured in the factory. The processing circuit comprises, for example, a microcontroller and a memory located in a housing which is itself integrated in the electrical wiring. Thus, when the sensor is positioned on a phase and connected to a meter in the field, the meter in this case reads the calibration parameters of the sensor and uses them to measure the current circulating on this phase.

[0009] However, such sensors are very expensive relative to non-pre-calibrated Rogowski sensors. Furthermore, this solution is less flexible since it requires the use of a rather specific type of sensor. Summary of the invention

[0010] The invention aims at calibrating on-site, simply and cheaply new Rogoswki sensors intended to be connected to polyphase electricity meters.

[0011] To achieve this object, a method is proposed for the on-site calibration of a Rogowski sensor to be calibrated, which sensor is intended to be connected to a polyphase meter in operation by being positioned on the phase to be calibrated, the method comprising the following first steps:

[0012] Positioning the Rogowski sensor to be calibrated on the first reference phase, positioning the first calibrated reference Rogowski sensor on the first reference phase, or positioning the first reference Rogowski sensor on the phase to be calibrated;

[0013] After the positioning step, acquiring a first calibration current measurement produced by the Rogowski sensor to be calibrated, a first reference current measurement produced by the first reference Rogowski sensor, and a first reference voltage measurement on a first positioning phase, wherein the Rogowski sensor to be calibrated and the first reference Rogowski sensor are positioned on the first positioning phase;

[0014] - Using the first calibration current measurement, the first reference current measurement and the first reference voltage measurement to generate first calibration parameters of the Rogowski sensor to be calibrated.

[0015] The calibration method according to the invention therefore makes it possible to calibrate new Rogowski sensors on site simply, quickly, cheaply and without requiring any special equipment.

[0016] The calibration parameters are defined on site and therefore a newly installed Rogowski sensor does not need to have its own calibration parameters integrated beforehand. It is therefore possible to install any commercial and non-precalibrated Rogowski sensor on site and connect it to the instrument.

[0017] The calibration method according to the invention therefore makes it possible to reduce the costs of the Rogowski sensors used and offers great flexibility in the choice of said sensors.

[0018] In addition, a calibration method as described above is proposed, which also includes the following steps: calculating a first active calibration power and a first reactive calibration power based on a first calibration current measurement and a first reference voltage measurement, and calculating a first reference active power and a first reference reactive power based on the first reference current measurement and the first reference voltage measurement, and calculating a first calibration parameter based on the first active calibration power, the first reactive calibration power, the first reference active power and the first reference reactive power.

[0019] In addition, a calibration method as described above is proposed, which also includes a second step that is similar to the first step, but is implemented using a second reference phase and a second calibrated reference Rogowski sensor instead of a first reference phase and a first reference Rogowski sensor, the first step and the second step making it possible to generate combined calibration parameters of the Rogowksi sensor to be calibrated.

[0020] Furthermore, a calibration method as described above is proposed, the second step making it possible to generate a second calibration parameter, the method further comprising the step of calculating the arithmetic mean of the first calibration parameter and the second calibration parameter to generate a combined calibration parameter.

[0021] In addition, a calibration method as described above is proposed, wherein the second step includes the step of calculating a second reference active power and a second reference reactive power, and the method also includes the following steps: calculating the arithmetic mean of the first reference active power and the second reference active power to obtain the average reference active power, and calculating the arithmetic mean of the first reference reactive power and the second reference reactive power to obtain the average reference reactive power, and the combined calibration parameters are obtained based on the first active calibration power, the first reactive calibration power, the average reference active power and the average reference reactive power.

[0022] In addition, a calibration method as described above is proposed, wherein the first step includes the step of positioning a first reference Rogowski sensor on the phase to be calibrated, wherein the second step includes the step of positioning a second reference Rogowski sensor on the phase to be calibrated, and wherein the step of acquiring the first step and the step of acquiring the second step are performed simultaneously.

[0023] Furthermore, a calibration method as described above is proposed, wherein the calibration parameters comprise the gain and dephasing of a current measurement chain comprising the Rogowski sensor to be calibrated and an internal processing circuit integrated in the meter and comprising an integrator.

[0024] Furthermore, a polyphase electricity meter is proposed, comprising a processing unit arranged to implement a calibration method as described above.

[0025] In addition, a multiphase electricity meter as described above is proposed, which also includes a human-machine interface, and the processing unit is arranged to communicate with an operator via the human-machine interface so that he positions the Rogowski sensor to be calibrated and / or the first reference Rogowski sensor and / or the second reference Rogowski sensor so as to implement the calibration method, and when the calibration method has been performed, reposition the Rogowski sensor to be calibrated and / or the first reference Rogowski sensor and / or the second reference Rogowski sensor in their nominal position so as to return the meter and the Rogowski sensors to the nominal configuration.

[0026] Furthermore, a computer program is proposed, comprising instructions for driving a processing unit of a polyphase electricity meter as described above to execute the steps of the calibration method as described above.

[0027] In addition, there is proposed a recording medium readable by a computer on which a computer program such as described above is recorded.

[0028] The invention may be better understood from the following description of certain non-limiting embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Reference will be made to the accompanying drawings, in which:

[0030] Figure 1 Represents a three-phase electricity meter and three Rogowski sensors, each located on a separate phase, in their nominal operating positions;

[0031] Figure 2 is similar to Figure 1 , the sensor to be calibrated is located on the first reference phase;

[0032] Figure 3 is similar to Figure 1 , the sensor to be calibrated is located on the second reference phase;

[0033] Figure 4 is similar to Figure 1 , the first reference sensor is located on the phase to be calibrated;

[0034] Figure 5 is similar to Figure 1 , the first reference sensor and the second reference sensor are located on the phase to be calibrated;

[0035] Figure 6 Detailed description of the steps of the calibration method according to the first embodiment of the present invention;

[0036] Figure 7 1 and 2 show the steps of a calibration method according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0037] refer to Figure 1 , the calibration method according to the first embodiment of the present invention is implemented in a three-phase electricity meter 1. The meter 1 is used to measure the electric energy provided to the facility by the distribution network 2, which includes three phases: PhA, PhB and PhC.

[0038] Meter 1 uses Rogowski sensors CA, CB, CC to measure the current flowing on each phase. The Rogowski sensors are located outside meter 1. Each Rogowski sensor is connected to meter 1 by a wire that may be several meters long. When meter 1 is in operation and when the Rogowski sensors are installed in their nominal position ( Figure 1 ), sensor CA is positioned on phase PhA by connecting to current input IA of meter 1, sensor CB is positioned on phase PhB by connecting to current input IB of meter 1, and sensor CC is positioned on phase PhC by connecting to current input IC of meter 1. Therefore, Figure 1 The interface architecture of the instrument 1 is shown during startup and in a permanent stable state.

[0039] For each Rogowski sensor, the meter 1 comprises an internal processing circuit including an integrator; each Rogowski sensor and associated internal processing circuit forms a “current measurement chain.” Of course, certain components of the internal processing circuit may be common to the three current measurement chains.

[0040] The meter 1 also comprises a voltage input UA connected to the phase PhA, a voltage input UB connected to the phase PhB and a voltage input UC connected to the phase PhC. The meter 1 comprises voltage sensors connected to the voltage inputs and making it possible to measure the voltage on each phase.

[0041] The instrument 1 also comprises a man-machine interface 3 (MMI) which makes it possible for an operator to communicate with the instrument 1. The MMI 3 here comprises a screen situated on the front face of the instrument 1, and the buttons themselves, also situated on the front face of the instrument 1, which make it possible for the operator to navigate in the menus displayed on the screen, and to return instructions to control certain functions implemented by the instrument 1.

[0042] The meter 1 also comprises a processing unit 4 comprising at least one processing component 5 adapted to execute program instructions to implement the calibration method according to the invention. The program is stored in a memory 6 of the processing unit 4, which is integrated in or connected to the processing component 5. The processing component 5 is, for example, a conventional processor, a microcontroller, a DSP (digital signal processor) or a programmable logic such as an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0043] refer to Figure 2 , firstly, a calibration method according to a first embodiment of the present invention is described.

[0044] Figure 2 Corresponds to a situation in which a new sensor CC has to be installed, for example because the previous sensor CC is faulty. The new sensor CC is not known to the instrument 1 and must therefore be calibrated. The calibration is therefore performed on site (not in the factory or workshop), i.e. after the instrument 1 has been delivered and installed at the customer's site. The other sensors CA and CB are operational and have been calibrated at the factory (just like the previous sensor CC). The calibration method uses reference measurements made by one or both sensors CA and CB to calibrate the new sensor CC.

[0045] The operator first places the meter 1 into calibration mode using the menu displayed on the screen of the meter 1.

[0046] Therefore, the operator designates the sensor to be calibrated as sensor CC. The operator then informs the first phase reference, for example here phase PhB. The calibrated sensor CB is located on the first reference phase and acts as the first reference sensor.

[0047] The processing unit 4 therefore communicates with the operator via the screen and asks him to position the sensor CC on the phase PhB.

[0048] After this positioning step, two sensors are positioned on phase PhB: sensor CB and sensor CC.

[0049] Thus, the processing unit 4 of the meter 1 knows that the sensor to be calibrated is the sensor connected to the current input IC (sensor CC) and that the first reference sensor is the sensor connected to the current input IB (sensor CB).

[0050] Thus, the processing unit 4 acquires a first calibration current measurement produced by the sensor CC, a first reference current measurement produced by the sensor CB, and a first reference voltage measurement. The first reference voltage measurement is a voltage measurement on a first positioned phase, on which the sensors CC and CB are positioned after the positioning step. Thus, the first positioned phase is phase PhB. The first reference voltage measurement is produced by a voltage sensor connected to the voltage input UB.

[0051] Thus, the processing unit 4 uses the first calibration current measurement, the first reference current measurement and the first reference voltage measurement to generate first calibration parameters of the Rogowski sensor to be calibrated (sensor CC).

[0052] More specifically, the processing unit 4 calculates the first active calibration power P according to the first calibration current measurement and the first reference voltage measurement. m and the first reactive calibration power Q m , and calculating a first reference active power P according to the first reference current measurement and the first reference voltage measurement ref and the first reference reactive power Q ref , and calculate the first calibration parameter according to the first active calibration power, the first reactive calibration power, the first reference active power, and the first reference reactive power.

[0053] The first calibration parameters of sensor CC include the gain K1 and dephasing of all current measurement chains of sensor CC. Includes the gain and dephasing of the internal integrator of sensor CC and instrument 1.

[0054] In order to determine the calibration parameters K1 and Processing unit 4 uses two unknown quantities (K1 and )Solve the following two systems of equations:

[0055]

[0056]

[0057] For example, a typical value for K1 is 5 / 10000 (e.g., 2000A of current returns 1V). The typical value is 0.05°.

[0058] It is important to note that by "measuring" (current, voltage), this does not necessarily mean a single measurement, but rather multiple measurements taken over a certain period of time (e.g., one minute) and processed (e.g., averaging or filtering) to obtain a combined measurement.

[0059] Therefore, the processing unit 4 records and uses the first calibration parameters to calibrate the sensor CC.

[0060] Therefore, the processing unit 4 asks the operator via the MMI 3 to correctly reposition the sensors in their nominal positions in order to return the meter 1 and the sensors to the nominal configuration. Here, in this case, the processing unit 4 repositions the sensor CC on the phase PhC (the sensors CA and CB have not been moved).

[0061] refer to Figure 3 , possibly repeating the first calibration step just described. Thus, two calibration steps are performed similar to the first calibration step, but using instead of the first reference phase (PhB) and the first reference Rogowski sensor (CB) a second reference phase (PhA) and a second reference Rogowski sensor (CA) already calibrated and intended to operate, to be connected to the meter 1 by positioning on the second reference phase (PhA). The first and second steps make it possible to produce merged calibration parameters (more precise) of the Rogowski sensor CC to be calibrated. Thus, by first positioning the sensor CC on phase PhB ( Figure 2 ), then by positioning sensor CC on phase PhA ( Figure 3 ), not one but two calibrations are performed. The first calibration step makes it possible to obtain the first calibration parameters K1 and The second calibration step makes it possible to obtain the second calibration parameters K2 and

[0062] The second calibration parameter is obtained by calculating the second active calibration power and the second reactive calibration power, and the second reference active power and the second reference reactive power.

[0063] The second active calibration power and the second reactive calibration power are calculated from the second calibration current measurement (generated by sensor CC) and from the second reference voltage measurement (on phase PhA). The second reference active power and the second reference reactive power are calculated from the second reference current measurement (generated by sensor CA) and from the second reference voltage measurement (on phase PhA).

[0064] The processing unit 4 thus generates combined calibration parameters.

[0065] For example, the processing unit 4 calculates the arithmetic mean of the first calibration parameter and the second calibration parameter (ie, on the one hand, the mean of K1 and K2 and, on the other hand, to generate the combined calibration parameters.

[0066] Reference now Figure 4 A calibration method according to a second embodiment of the present invention is described.

[0067] The sensor to be calibrated is still sensor CC. The operator first specifies not the first reference phase, but the first reference sensor, here sensor CB.

[0068] The processing unit 4 therefore asks the operator to position the sensor CB on the phase to be calibrated, here the phase PhC. The phase to be calibrated is the phase on which the sensor to be calibrated is intended to be positioned in operation.

[0069] Therefore, two sensors are located on phase PhC: the sensor to be calibrated CC and the first reference sensor CB.

[0070] The processing unit 4 of the meter 1 knows that the Rogowski sensor to be calibrated is the sensor (sensor CC) connected to the current input (IC) and that the first reference sensor is the sensor (sensor CB) connected to the current input IB.

[0071] The processing unit 4 thus acquires a first calibration current measurement produced by the sensor CC, a first reference current measurement produced by the sensor CB and a first reference voltage measurement on the phase PhC (on which the sensor to be calibrated CC and the first reference sensor are positioned after the positioning step).

[0072] The first reference voltage measurement is generated by a voltage sensor connected to the voltage input UC.

[0073] Thus, the processing unit 4 uses the first calibration current measurement, the first reference current measurement and the first reference voltage measurement to generate first calibration parameters of the sensor CC.

[0074] More specifically, the processing unit 4 calculates the first active calibration power P according to the first calibration current measurement and the first reference voltage measurement. m and the first reactive calibration power Q m , and calculating a first reference active power P according to the first reference current measurement and the first reference voltage measurement ref and the first reference reactive power Q ref The processing unit calculates a first calibration parameter from the first active calibration power, the first reactive calibration power, the first reference active power, and the first reference reactive power.

[0075] The first calibration parameters include the gain K1 and the dephasing of the first current measurement chain of the sensor CC.

[0076] In order to determine the calibration parameters K1 and Processing unit 4 uses two unknown quantities (K1 and )Analytically, the system of two equations is:

[0077]

[0078]

[0079] Therefore, the processing unit 4, via the MMI 3, asks the operator to correctly reposition the sensors in their nominal positions in order to make the meter 1 operational. Here, in this case, the processing unit 4 repositions the sensor CB on the phase PhB (the sensors CA and CC have not been moved).

[0080] refer to Figure 5 , possibly repeating the first calibration step just described. A second calibration step similar to the first calibration step is thus performed, but not with the first reference Rogowski sensor (CB), but with the second reference Rogowski sensor (CA).

[0081] Thus, not one but two simultaneous calibrations are performed by first positioning the sensor CB on the phase to be calibrated CC and then by positioning the sensor CA on the phase to be calibrated CC.

[0082] Performing the first calibration step and the second calibration step simultaneously makes it possible to generate combined calibration parameters of the Rogowski sensor CC to be calibrated.

[0083] The first calibration step makes it possible to calculate the first active calibration power P m and the first reactive calibration power Q m , and the first reference active power P ref1 and the first reference reactive power Q ref1 The second calibration step makes it possible to calculate simultaneously the second reference active power and P ref2 The second reference reactive power Q ref2 .

[0084] Therefore, the processing unit 4 calculates the first reference active power P ref1 and the second reference active power P ref2 The arithmetic mean of the reference active power P is obtained. ref , and calculate the first reference reactive power Q ref1 and the second reference reactive power Q ref2 The arithmetic mean of the average reference reactive power Q ref .

[0085] The combined calibration parameter is based on the first active calibration power P m , the first reactive calibration power Q m , average reference active power P ref and average reference reactive power Q ref Obtained.

[0086] Therefore, processing unit 4 uses two unknown quantities (K1 and ) to solve the two systems of equations.

[0087]

[0088]

[0089] in and

[0090] Reference now Figure 6 A flow chart describing a calibration method according to a first embodiment of the invention is shown below. Thus, the Rogowski sensor to be calibrated (sensor CC) is positioned on the reference phase that has been selected, or, if two reference phases are selected, on each reference phase successively.

[0091] The method starts at step E0.

[0092] In order to start the calibration method, the operator must previously enter a password protecting access to the MMI 3 of the instrument 1 (step E1 ), which is then required to actually enter the calibration mode (step E2 ).

[0093] The operator therefore programs the phase to be calibrated (phase PhC) (step E3 ).

[0094] The processing unit 4 then requests the operator, via the MMI 3 , to input the number of reference phases (step E4 ).

[0095] After step E4 , in the case where there is only one reference phase, the processing unit 4 asks the operator via the MMI 3 to enter the reference phase (step E5 ) and then positions the Rogowski sensor to be calibrated (sensor CC) on the reference phase (here, for example, on phase PhB): step E6 .

[0096] The processing unit 4 therefore awaits confirmation from the operator that the positioning has actually been carried out. This confirmation is made by the operator via the MMI 3. The meter 1 enters the actual calibration mode.

[0097] The processing unit 4 obtains the calibration current measurement (sensor CC), the reference current measurement (sensor CB) and the reference voltage measurement (phase CB) and determines the calibration parameters K and (Step E7) For example, the measurement is performed over a period of one minute.

[0098] Therefore, the calibration parameters K and The calibration parameters for the new Rogowksi sensor (ie, sensor CC) are stored in meter 1 .

[0099] After step E4 , in the presence of two reference phases (phase PhB and phase PhA), processing unit 4 first asks the operator, via MMI 3 , to position sensor CC on phase PhB (first reference phase): step E8 .

[0100] The processing unit 4 awaits confirmation that the positioning has actually been performed.

[0101] The processing unit 4 obtains a first calibration current measurement (sensor CC), a first reference current measurement (sensor CB) and a first reference voltage measurement (phase CB), and determines first calibration parameters K1 and (Step E9) For example, the measurement is performed over a period of one minute.

[0102] The processing unit 4 then asks the operator, via the MMI 3 , to position the sensor CC on the phase PhA (second reference phase): step E10 .

[0103] The processing unit 4 awaits confirmation that the positioning has actually been performed.

[0104] The processing unit 4 obtains the second calibration current measurement (sensor CC), the second reference current measurement (sensor CA) and the second reference voltage measurement (phase CA), and determines the second calibration parameters K2 and (Step E11) For example, measurement is performed over a period of one minute.

[0105] Finally, the processing unit 4 calculates the arithmetic mean of K1 and K2 on the one hand and calculates and The arithmetic mean of and thus the combined calibration parameters are generated. The combined calibration parameters are stored and used as calibration parameters for the new Rogowski sensor (sensor CC): step E12.

[0106] After step E7 or step E12, the processing unit 4 requests the operator via the MMI 3 to Figure 1 Put the Rogowski sensor back in place (step E13).

[0107] When the processing unit 4 receives confirmation that the positioning has in fact been carried out (step E14 ), the meter 1 exits the calibration mode and returns to the normal mode (step E15 ). The calibration method is completed (step E16 ).

[0108] Reference now Figure 7 A flowchart of a calibration method according to a second embodiment of the present invention is described below.

[0109] This time the first reference sensor (here sensor CB) is brought to phase PhC to be calibrated of the Rogowski sensor to be calibrated (sensor CC), or the reference sensors (sensor CB and sensor CA) are brought to phase CC.

[0110] The method starts at step E0.

[0111] In order to start the calibration method, the operator must previously enter a password protecting access to the MMI 3 of the meter 1 (step E21 ), which then requires actual entry into the calibration mode (step E22 ).

[0112] The operator therefore programs the phase to be calibrated (phase PhC) (step E23 ).

[0113] The processing unit 4 then asks the operator, via the MMI 3 , to input the number of reference sensors (step E24 ).

[0114] After step E24 , in the case where there is only one reference sensor, the processing unit 4 asks the operator, via the screen of the MMI 3 , to indicate the reference sensor (step E25 ) and then positions the reference sensor (sensor CB) on the phase to be calibrated (on phase PhC): step E26 .

[0115] The processing unit 4 therefore awaits confirmation from the operator that the positioning has actually been carried out. This confirmation is made by the operator via the MMI 3 .

[0116] The processing unit 4 obtains the calibration current measurement (sensor CC), the reference current measurement (sensor CB) and the reference voltage measurement (phase CC) and determines the calibration parameters K and (Step E27) For example, the measurement is performed over a period of one minute.

[0117] Therefore, the calibration parameters K and The calibration parameters for the new Rogowksi sensor (ie, sensor CC) are stored in meter 1 .

[0118] After step E24 , in the presence of two reference sensors (sensor CB and sensor CA), processing unit 4 requests the operator, via MMI 3 , to position the first reference sensor CB on phase PhC and the second reference sensor CA on phase PhC (step E8 ).

[0119] The processing unit 4 awaits confirmation that the positioning has actually been performed.

[0120] The processing unit 4 obtains a first calibration current measurement (sensor CC), a first reference current measurement (sensor CB) and a first reference voltage measurement (phase CC), and determines first calibration parameters K1 and

[0121] The processing unit 4 simultaneously acquires a second reference current measurement (sensor CA) and determines the second calibration parameters K2 and (Step E29). The processing unit 4 thus uses the first calibration current measurement and the first reference voltage measurement to determine the second calibration parameters K2 and

[0122] The measurements of step E29 are carried out simultaneously here, for example, over a period of one minute.

[0123] Finally, the processing unit 4 calculates the arithmetic mean of K1 and K2 on the one hand and calculates and The arithmetic mean of and thus the combined calibration parameters are generated. The combined calibration parameters are stored and used as calibration parameters for the new Rogowski sensor (sensor CC): step E30.

[0124] After step E27 or step E30, the processing unit 4 requests the operator via the MMI 3 to Figure 1 Configuration of Put the Rogowski sensor back in place: Step E31.

[0125] When the processing unit 4 receives confirmation that the positioning has in fact been carried out (step E32 ), the meter 1 exits the calibration mode and returns to the normal mode (step E33 ). The calibration method is completed (step E34 ).

[0126] Note that during step E30, it is not necessary to select K1, K2, and The combined calibration parameters are obtained from the average reference reactive power (which itself is obtained from P ref1 and P ref2 obtained) and from the average reference reactive power (itself from Q ref1 and Q ref2 Get the combined calibration parameters.

[0127] Of course, the invention is not limited to the described embodiments but encompasses any variant coming within the scope of the invention, such as defined by the claims.

[0128] The present invention can be implemented with a multiphase meter connected to any number of phases (greater than or equal to two phases).

[0129] Figures 1 to 5 The architecture may include, in addition to the three network voltage inputs UA, UB and UC, a neutral wire coming from the network and entering the meter (hence the reference to a "four-wire network").

[0130] The present invention can be applied to meters based on (or not based on) MID.

[0131] It should be noted that during implementation of the calibration method it is possible to detect whether the Rogowski sensor is correctly mounted (from the direction of the current flow) and to generate an alarm in case it is mounted upside down.

Claims

1. A method for the on-site calibration of a Rogowski sensor (CC) to be calibrated, said sensor being intended in operation to be connected to a polyphase electricity meter (1) by being positioned on the phase to be calibrated, said method being characterized in that it comprises the following first step: - positioning the Rogowski sensor to be calibrated on a first reference phase (PhB), positioning an already calibrated first reference Rogowski sensor (CB) on said first reference phase, or positioning said first reference Rogowski sensor on said phase to be calibrated; - after said positioning step, obtaining a first calibration current measurement produced by said Rogowski sensor to be calibrated (CC), a first reference current measurement produced by said first reference Rogowski sensor (CB) and a first positioning phase (PhB; PhC), wherein the Rogowski sensor to be calibrated and the first reference Rogowski sensor are positioned in the first positioning phase (PhB; PhC); - Using the first calibration current measurement, the first reference current measurement and the first reference voltage measurement to generate first calibration parameters of the Rogowski sensor to be calibrated.

2. The calibration method according to claim 1, characterized in that: The following steps are also included: A first active calibration power and a first reactive calibration power are calculated based on the first calibration current measurement and the first reference voltage measurement, and a first reference active power and a first reference reactive power are calculated based on the first reference current measurement and the first reference voltage measurement, and the first calibration parameter is calculated based on the first active calibration power, the first reactive calibration power, the first reference active power and the first reference reactive power.

3. The calibration method according to claim 2, characterized in that: Also included is a second step that is similar to the first step, but is implemented using a second reference phase (PhA) and a calibrated second reference Rogowski sensor (CA) instead of the first reference phase and the first reference Rogowski sensor, wherein the first step and the second step can produce combined calibration parameters of the Rogowksi sensor to be calibrated.

4. The calibration method according to claim 3, characterized in that: The second step can generate a second calibration parameter, and the method further comprises the step of calculating an arithmetic mean of the first calibration parameter and the second calibration parameter to generate the combined calibration parameter.

5. The calibration method according to claim 3, characterized in that: The second step includes the step of calculating a second reference active power and a second reference reactive power, the method also includes the step of calculating the arithmetic mean of the first reference active power and the second reference active power to obtain an average reference active power, and the step of calculating the arithmetic mean of the first reference reactive power and the second reference reactive power to obtain an average reference reactive power, and the combined calibration parameter is calculated based on the first active calibration power, the first reactive calibration power, the average reference active power and the average reference reactive power.

6. The calibration method according to claim 3, characterized in that: The first step comprises the step of positioning the first reference Rogowski sensor (CB) on the phase to be calibrated (PhC), wherein the second step comprises the step of positioning the second reference Rogowski sensor (CA) on the phase to be calibrated (PhC), and wherein the step of acquiring the measurements of the first step and the step of acquiring the measurements of the second step are performed simultaneously.

7. The calibration method according to claim 1 or 2, characterized in that: The calibration parameters include the gain and dephasing of a current measurement chain comprising the Rogowski sensor (CC) to be calibrated and an internal processing circuit integrated in the meter and comprising an integrator.

8. A polyphase electricity meter comprising a processing unit (4) arranged to implement a calibration method as claimed in one of claims 3 to 6.

9. The multiphase electric meter according to claim 8, characterized in that: The multiphase electricity meter further comprises a human-machine interface (3), the processing unit (4) being arranged to communicate with an operator via the human-machine interface (3) so as to cause him to position the Rogowski sensor to be calibrated (CC) and / or the first reference Rogowski sensor (CB) and / or the second reference Rogowski sensor (CA) so as to implement the calibration method and, when the calibration method has been performed, to reposition the Rogowski sensor to be calibrated and / or the first reference Rogowski sensor and / or the second reference Rogowski sensor in their nominal positions so as to return the electricity meter and the Rogowski sensors to the nominal configuration.

10. A computer-readable recording medium having a computer program including instructions recorded thereon, wherein the instructions drive the multi-phase electricity meter (1) according to claim 8 or 9 to execute the steps of the calibration method according to any one of claims 1 to 7.

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