How to adjust the electricity meter

Abstract

A method for adjusting an electricity meter (1), the method comprising the following steps: measuring the frequency of a power distribution network (3); adjusting a measuring module (10) by using a first calibration parameter generated during a stage of calibrating the electricity meter if the difference between the frequency of the power distribution network and a first frequency is less than a first predetermined threshold; calculating a second calibration parameter based on the first calibration parameter and based on an adaptation parameter if the difference between the frequency of the power distribution network and the first frequency is greater than or equal to the first predetermined threshold, and adjusting the measuring module (10) by using the second calibration parameter.

Description

Technical Field

[0001] The present invention relates to the field of electricity meters. Background Art

[0002] Some electricity meters are designated and designed to operate in multiple countries having power grids for distributing electrical energy operating at different frequencies.Such meters must measure the distributed electrical energy with an accuracy that complies with regulations in force in each of these countries.

[0003] The frequencies of the power grids in question are typically 50 Hertz (Hz) and 60 Hz, and therefore some electricity meters must comply with several different standards simultaneously. For measuring active energy in 50 Hz countries, the applicable standard for obtaining approval under the Measuring Instruments Directive (MID) is EN 50470-3, while in 60 Hz countries, IEC 62053-21 applies in the absence of external current transformers, while IEC 62053-22 applies in the presence of external current transformers. For measuring reactive energy in both 50 Hz and 60 Hz countries, IEC 62053-24 applies, covering both the absence and presence of external current transformers.

[0004] Typically, all electricity meters are adjusted with calibration parameters defined in the factory.At the end of the meter manufacturing phase, the calibration parameters are determined individually for each meter and stored in the meter.

[0005] However, the optimal values ​​for some of those calibration parameters depend on the frequency of the power distribution network.

[0006] In order to enable an electricity meter to ensure the required level of accuracy at both 50 Hz and 60 Hz, one known solution is to manually configure the meter (50 Hz or 60 Hz) when it is put into use. Two sets of calibration parameters are pre-stored in the meter, one for 50 Hz and the other for 60 Hz, in order to avoid loss of metering accuracy in either case. Such an electricity meter is indeed considered MID-compliant in its 50 Hz configuration.

[0007] However, during the calibration phase carried out in the factory, this solution requires measurements to generate two sets of calibration parameters (one for each frequency), and this is done for each meter manufactured. The duration of this calibration phase is not negligible (typically on the order of tens of minutes per meter and per frequency), so that the solution significantly increases the cost of manufacturing each meter.

[0008] Another known solution is to design electricity meters suitable for operation over a wide range of grid frequencies (typically 45 Hz to 65 Hz), which are therefore compatible with 50 Hz and 60 Hz frequencies without requiring any configuration or adjustment when commissioning. Consequently, such meters have "intermediate" calibration parameters, which results in a reduction in metering accuracy compared to pure 50 Hz or pure 60 Hz meters.

[0009] Purpose of the Invention

[0010] It is therefore an object of the present invention to reduce the cost and improve the accuracy of electricity meters suitable for connection to grids of different frequencies. Summary of the Invention

[0011] To achieve this object, a method for adjusting a measuring module of an electricity meter connected to a power distribution network is provided, the method comprising the following steps implemented in the electricity meter after the electricity meter has been installed in an operating position:

[0012] · collecting at least one measurement of the frequency of the power distribution network;

[0013] adjusting the measurement module by using first calibration parameters generated during a calibration phase performed before the meter was installed in the operating location and stored in the meter, if the difference between the frequency of the power distribution network and the first frequency is less than a first predetermined threshold;

[0014] If the difference between the frequency of the power distribution network and the first frequency is greater than or equal to a first predetermined threshold, calculating a second calibration parameter from the first calibration parameter and from the adaptation parameter, and adjusting the measurement module by using the second calibration parameter.

[0015] Therefore, when the electricity meter is put into use, it measures the frequency of the power distribution network. If the frequency is equal to or very close to the first frequency, the electricity meter adjusts the measurement module using the first calibration parameter. Otherwise, the electricity meter generates a second calibration parameter corresponding to the measured frequency and adjusts the measurement module using the second calibration parameter.

[0016] In both cases, the measuring module of the electricity meter is adjusted by means of calibration parameters defined in an accurate manner, taking into account the frequency of the distribution network to which the electricity meter is connected.

[0017] The electricity meter is therefore able to perform very accurate measurements regardless of the frequency of the distribution network.The stage of calibrating the electricity meter in the factory is performed only at a single frequency (the first frequency), thereby reducing the cost of the electricity meter.

[0018] There is also provided an adjustment method as described above, wherein the adaptation parameter comprises a first adaptation parameter evaluated at a first frequency and a second adaptation parameter evaluated at a second frequency, the second frequency causing a difference between the frequency of the power distribution network and the second frequency to be less than a second predetermined threshold.

[0019] There is also provided a regulation method as described above, wherein for each phase line of the power distribution network, a measurement module is arranged to acquire measurements of the phase voltage and the phase current present on said phase line, the measurement module comprising at least one low-pass filter arranged to suppress harmonics from the phase voltage and the phase current to generate the phase voltage and the phase current, the adaptation parameters comprising parameters of the low-pass filter.

[0020] There is also provided an adjustment method as described above, wherein the parameters of the low-pass filter include a modulus of a Z-transform of a transfer function of the low-pass filter at a first frequency and a modulus of the Z-transform at a second frequency.

[0021] There is also provided an adjustment method as described above, wherein the first calibration parameter includes a first parameter and And the second calibration parameters include the second parameter and These parameters are incorporated into the multiplication factors used to multiply the fundamental phase voltage and the fundamental phase current in order to estimate the raw reactive power supplied by the distribution network, the second calibration parameter and It is obtained by the following calculation:

[0022]

[0023]

[0024] wherein |H(Z)1| is the modulus of the Z-transform of the transfer function of the low-pass filter at a first frequency, and wherein |H(Z)2| is the modulus of the Z-transform of the transfer function of the low-pass filter at a second frequency.

[0025] The adjustment method as described above is also provided, wherein the parameters of the low-pass filter further include the phase of the Z transform at the first frequency and the phase of the Z transform at the second frequency.

[0026] There is also provided a method of regulation as described above, the electricity meter comprising or being connected to a current sensor comprising a current transformer and arranged to produce a measurement of the phase current, the adaptation parameter comprising at least one parameter of the current transformer.

[0027] There is also provided an adjustment method as described above, wherein the adaptation parameters further comprise at least one parameter of at least one electronic component of a current measurement circuit, the current measurement circuit being connected to the current transformer.

[0028] There is also provided an adjustment method as described above, wherein the electronic component is an amplifier.

[0029] Also provided is an adjustment method as described above, wherein the first calibration parameter also includes a harmonic Phase shift and basic phase shift And the second calibration parameter also includes the phase shift with harmonics and basic phase shift These measurement modules use these calibration parameters to estimate the compensated active power and compensated reactive power as delivered by the distribution network, with phase shifts of the harmonics and basic phase shift It is obtained by the following calculation:

[0030]

[0031] as well as

[0032]

[0033] in is the phase of the Z transform at the first frequency, is the phase of the Z transform at the second frequency, is the phase of the current transformer at the first frequency, is the phase of the current transformer at the second frequency, is the phase of the amplifier of the current measurement circuit at the first frequency, and is the phase of the amplifier of the current measurement circuit at the second frequency.

[0034] There is also provided a regulation method as described above, wherein for each phase line of the distribution network, the electricity meter is arranged to measure and sample the phase voltage and phase current present on said phase line so as to produce a measurement of the phase voltage and phase current present on said phase line, the sampling frequency being a multiple of both the first frequency and the second frequency.

[0035] An electric meter is also provided. The electric meter includes a measuring module and a processor component, and the adjustment method described above is implemented in the processor component.

[0036] There is also provided a computer program comprising instructions for causing a processor component of an electricity meter as described above to execute the steps of the adjustment method described above.

[0037] A computer-readable storage medium is also provided, which stores the computer program.

[0038] The present invention may be better understood in light of the following description of specific non-limiting implementations of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] References are made to the individual drawings:

[0040] [ Figure 1 ] Figure 1 An electricity meter is shown in which the regulation method of the invention is implemented. DETAILED DESCRIPTION

[0041] Reference Figure 1 , the electricity meter 1 of the present invention is a three-phase electricity meter for measuring the energy consumption of an electrical installation 2 supplied to a subscriber via a distribution network 3 .

[0042] The power distribution network 3 has three phase conductors Ph (for phases 1 , 2 and 3 ), together with a neutral conductor N.

[0043] The frequency of the power distribution network may be equal to 50 Hz (or very close to 50 Hz), or 60 Hz (or very close to 60 Hz).

[0044] The meter 1 has three input ports Pe, each connected to a respective one of the phase lines Ph of the distribution network 3, and one input port Pe connected to the neutral line N. The meter 1 also has four ports Ps connected to the installation 2 (three for the phase lines and one for the neutral line).

[0045] The electric meter 1 has an application part and a metering part. This description relates to the metering part.

[0046] The metrology part firstly comprises a processor component which is, for example, a general purpose processor, a processor dedicated to signal processing (called a digital signal processor (DSP)), a microcontroller, or indeed a programmable logic circuit such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC)).

[0047] In this example, the processor component is a microcontroller 4 (“measurement microcontroller”).

[0048] The metering section further comprises one or more memories 5 connected to or incorporated in the microcontroller 4. At least one of the memories 5 forms a computer-readable storage medium storing a computer program comprising instructions causing the microcontroller 4 to execute at least some of the steps of the adjustment method to be described below.

[0049] In addition to the microcontroller 4, the metering part includes, for example, each phase line Ph of the power distribution network 3, a voltage sensor 6, a voltage measurement circuit 7 connected to the voltage sensor 6, a current sensor 8, a current measurement circuit 9 connected to the current sensor 8, and a measurement module 10. Figure 1 , elements 6 to 10 are shown for only one of the phases Ph, but the electricity meter 1 has such elements for each phase Ph. The implementation of the invention is described below for only one phase Ph, however, the invention is implemented in the same way for each of the other phases Ph.

[0050] The voltage sensor 6 comprises resistors forming a voltage divider bridge adapted to generate a voltage less than or equal to 3.3 V from the voltage of the grid 3. The voltage measurement circuit 7 comprises a first analog-to-digital converter (ADC). The voltage measurement circuit 7 generates a measurement of the phase voltage U present on the phase line Ph.

[0051] The current sensor 8 comprises a current transformer. The current measurement circuit 9 comprises a second ADC and electronic components including at least one amplifier. The current measurement circuit 9 generates a measurement of the phase current I flowing in the phase line Ph.

[0052] The measurement module 10 is a digital module implemented in the measurement microcontroller 4 of the electricity meter 1. The measurement module 10 is connected to the voltage measurement circuit 7 and the current measurement circuit 9.

[0053] The measurement module 10 comprises at least one low pass filter 11 arranged to suppress harmonics from the phase voltages and currents to generate the phase voltages and currents.

[0054] Specifically, the measurement module 10 includes a first low-pass filter 11 a connected to the voltage measurement circuit 7 and a second low-pass filter 11 b connected to the current measurement circuit 9 .

[0055] In this example, the first and second low-pass filters 11a and 11b are two identical Butterworth filters, and thus can be considered as a repeated single filter 11.

[0056] For filtering the fundamental frequency (both for voltage and current, and both for “fundamental frequency” calibration and for measuring reactive energy), the filter 11 used is a first-order Butterworth filter H(Z) which is the same both at 50 Hz and 60 Hz.

[0057] The Z transform of a first-order Butterworth filter is expressed as follows:

[0058] in

[0059] The coefficient "a" of the filter is selected to have a 3dB cutoff frequency of 75 Hz.

[0060] When the sampling frequency f E =3000Hz, to obtain a 3dB cutoff frequency of 75Hz, choose the following values:

[0061] a=0.833033065947701.

[0062] The measurement module 10 also includes a number of calculation modules for evaluating the active power, reactive power, root mean square (RMS) voltage and RMS current distributed by the power distribution network 3 via the phase line Ph. The measurement module 10 also uses a number of calibration parameters in order to perform these calculations. The calibration parameters are as follows: K, K U ,K I 、

[0063] Phase voltage U multiplied by the voltage parameter K U The multiplication factor of , in order to obtain the compensated voltage U '. This multiplication factor is equal to (1 + K U ).

[0064] Phase current I multiplied by the current parameter K I The multiplication factor of , in order to obtain the compensated current I '. This multiplication factor is equal to (1 + K I ).

[0065] The module 15 detects the compensated voltage U′ and the compensated current I′ and generates the original active power P.

[0066] The module 16 acquires the compensated voltage U′ and the compensated current and generates the original reactive power Q.

[0067] The module 17 in matrix form acquires the raw active power P and the raw reactive power Q and it evaluates the compensated measure of active power P' and the compensated measure of reactive power Q' by calculating:

[0068]

[0069]

[0070] The module 18 acquires the compensated voltage U' and it calculates the RMS voltage squared: Parameter K U_NOISE is added to the RMS voltage squared, and the square root of this addition is then calculated to obtain the compensated RMS voltage U″ RMS .

[0071] Module 19 acquires the compensated current and it calculates the RMS current squared: Parameter K I_NOISE Added to the RMS current square, and then calculating the square root of this addition to obtain the compensated RMS current I″ RMS .

[0072] Calibration parameter K UCompensates for variations in the gain applied to the phase voltage due to components of the voltage measurement circuit 7 at the output from the first ADC (and in particular due to tolerances on the resistance of the resistors). It is applied after offset cancellation in order to avoid adding gain to the offset.

[0073] Calibration parameter K I Compensates for variations in the gain applied to the phase voltage due to components of the current measurement circuit 9 at the output from the second ADC (and in particular due to tolerances on the resistance of the resistors). It is applied after offset cancellation in order to avoid adding gain to the offset.

[0074] Parameter K U and K I It is signed.

[0075] Calibration parameter K U_NOISE Compensate for the influence of the inherent white noise of the meter 1 and the quantization noise of the first ADC on the measurement of the RMS voltage of the phase line Ph. It should be observed that in most cases, K U_NOISE =0.

[0076] Calibration parameter K I_NOISE Compensate for the influence of the inherent white noise of the meter 1 and the quantization noise of the second ADC on the measurement of the RMS voltage of the phase line Ph. Typically, for high current ranges, K I_NOISE =0.

[0077] The calibration parameter K compensates for gain variations in the voltage measurement circuit 7 and the current measurement circuit 9 .

[0078] Calibration parameters Phase changes in the voltage measuring circuit 7 and the current measuring circuit 9 and in particular phase changes due to internal transformers are compensated.

[0079] More generally, the parameters K and Used to compensate the measurement so that it is insensitive to the gain and phase offsets imposed by the acquisition device as a whole (ie, the sensor as well as the electronic components of the measurement circuitry).

[0080] The measurement module 10 performs certain calculations by using the phase voltage U with harmonics and the phase current I with harmonics; in this case, the measurement module does not use the low-pass filters 11 a and 11 b (the filters are “bypassed”).

[0081] Measurement module 10 also utilizes the fundamental phase voltage U (i.e., without harmonics) and fundamental phase current I (i.e., without harmonics); in this case, measurement module 10 utilizes low-pass filters 11a and 11b. For example, reactive power can be measured using the fundamental phase voltage and current. Low-pass filters 11a and 11b are also used to perform a "basic" calibration, as described below.

[0082] Therefore, in reality, there are two sets of calibration parameters (associated with the same frequency):

[0083] "Harmonic" calibration parameters K, K U , K I , K U_NOISE , K I_NOISE and as well as

[0084] "Basic" calibration parameters K, K U , K I , K U_NOISE , K I_NOISE and

[0085] In operation, the calibration parameters "with harmonics" are used to adjust the measurement module 10 while it performs measurements "with harmonics" - ie without using the low-pass filters 11a and 11b.

[0086] In operation, the "basic" calibration parameters are used to adjust the measurement module 10 while it is performing a "basic" measurement - ie while using the first low-pass filter 11a and / or the second low-pass filter 11b.

[0087] Typically, the calibration parameters are defined and then stored in the electricity meter 1 during a calibration phase performed at the factory, after the stage of manufacturing the electricity meter 1 and therefore before the electricity meter is delivered and installed in its working position at the customer's premises (the place where it is put into use).

[0088] In order to ensure that the measurements performed by the electricity meter 1 are sufficiently accurate, it is necessary to define calibration parameters while taking into account the frequency of the distribution network 3 .

[0089] However, as described above, the electricity meter 1 can be connected to a power distribution network having a first frequency (specifically 50 Hz) or to a power distribution network having a second frequency (specifically 60 Hz).

[0090] During the calibration phase, calibration parameters are generated only for the first frequency (50 Hz) and stored in the electricity meter 1 : they are called “first” calibration parameters.

[0091] The electricity meter 1 is then delivered, subsequently installed in its operating location and started up. Activation of the electricity meter 1 is followed by a short initialization period (often lasting 5 seconds). The acquisition of metering measurements begins after this initialization phase.

[0092] The adjustment method of the invention is performed during an initialization period and has the purpose of defining the calibration parameters that will be used to adjust the measurement module 10 .

[0093] The microcontroller 4 acquires at least one measurement of the frequency of the power distribution network. The microcontroller 4 is naturally capable of performing this or these measurements itself.

[0094] The measured frequency is the frequency of the phase voltage on the first phase line. If there is no voltage on the first phase line, the meter 1 measures the frequency on the second phase line. If there is no voltage on the second phase line, the meter 1 measures the frequency on the third phase line.

[0095] If the difference between the frequency of the power distribution network 3 and the first frequency (50 Hz) is smaller than a first predetermined threshold, the microcontroller 4 uses the first calibration parameter to adjust the measurement module 10. For example, the first predetermined threshold may be in the range of 1 Hz to 5 Hz.

[0096] If the difference between the frequency of the power distribution network 3 and the first frequency (50 Hz) is greater than a first predetermined threshold, the microcontroller 4 adjusts the measurement module 10 using the second calibration parameter.

[0097] In order to determine that the frequency of the power distribution network 3 indeed corresponds to 60 Hz, the microcontroller 4 verifies that the difference between the frequency of the power distribution network 3 and the second frequency is smaller than a second predetermined threshold (which may be equal to the first predetermined threshold, for example).

[0098] If yes, the microcontroller 4 calculates the second calibration parameter from the first calibration parameter and from the adaptation parameter.

[0099] The adaptation parameters include a first adaptation parameter evaluated at a first frequency and a second adaptation parameter evaluated at a second frequency.

[0100] It should be observed that among the calibration parameters used in this example, there are some that are independent of the frequency of the power distribution network 3 (and therefore do not need to be recalculated): these are the calibration parameters “with harmonics” K, K U , K I , K U_NOISE , and K I_NOISE , and the “basic” calibration parameters K, K U_NOISE , and K I_NOISE .

[0101] However, the “basic” calibration parameter K U and K IIndeed, it depends on the frequency of the power distribution network 3. The microcontroller 4 therefore calculates the frequency of the first calibration parameter K U1 and K I1 Generates the second "base" calibration parameters and

[0102] Likewise, the "basic" calibration parameters depends on the frequency of the power distribution network 3. The microcontroller 4 is therefore calibrated according to a first "basic" parameter Generates the second "base" calibration parameters (Basic phase shift).

[0103] Likewise, the calibration parameters "with harmonics" depends on the frequency of the power distribution network 3. The microcontroller 4 is therefore based on the first calibration parameter "with harmonics" Generating a second calibration parameter "with harmonics" (Phase shift with harmonics).

[0104] The adaptation parameters include parameters of the low-pass filter 11 .

[0105] The parameters of the low-pass filter 11 include the modulus of the Z-transform of the transfer function of the low-pass filter 11 at a first frequency and the modulus of the Z-transform at a second frequency.

[0106] As mentioned above, the first calibration parameters include the first parameter and K I1 , and the second calibration parameters include the second parameter and These parameters are incorporated into the multiplication factors for multiplying the basic phase voltage U and the basic phase current I in order to estimate the raw reactive power Q provided by the power distribution network 3. Second parameter and It is obtained by the following calculation:

[0107]

[0108]

[0109] wherein |H(Z)1| is the modulus of the Z-transform of the transfer function of the low-pass filter 11 at a first frequency, and wherein |H(Z)2| is the modulus of the Z-transform of the transfer function of the low-pass filter 11 at a second frequency.

[0110] The adaptation parameters therefore include the moduli |H(Z)1| and |H(Z)2|.

[0111] Phase Shift and It is obtained as follows.

[0112] The adaptation parameters include other parameters of the low-pass filter 11 and in particular the Z-transform of the transfer function of the low-pass filter 11 and its phase at the first frequency and its phase at the second frequency.

[0113] At the fundamental frequency, therefore consider:

[0114]

[0115] in is the phase of the Z transform at the first frequency and is the phase of the Z transform at the second frequency.

[0116] The adaptation parameters also include parameters of the current transformer (current transformer 8 ).

[0117] Consider the difference in phase shift of the current transformer at a first frequency (50 Hz) and a second frequency (60 Hz):

[0118]

[0119] in is the phase of the current transformer at the first frequency and is the phase of the current transformer at the second frequency.

[0120] These parameters are provided by the manufacturer or supplier of the transformer, so they are pre-stored in the electricity meter 1 .

[0121] The adaptation parameters also include parameters of at least one electronic component of the current measurement circuit 9 connected to the current transformer. These electronic components include an amplifier.

[0122] Therefore, taking into account the difference in phase shift associated with the operational amplifier at the first frequency (50 Hz) and the second frequency (60 Hz), as determined during the design phase:

[0123]

[0124] in is the phase of the amplifier in the current measurement circuit at the first frequency, and is the phase of the amplifier at the second frequency.

[0125] The microcontroller 4 then calculates:

[0126]

[0127] as well as

[0128]

[0129] Naturally, once the microcontroller 4 has “decided” on the second calibration parameters to use, this choice is permanent (the frequency of the grid does not vary significantly) and once the second calibration parameters have been defined, they are stored in a memory (e.g. flash memory) of the metering part.

[0130] Therefore, the electricity meter 1 automatically calibrates the measurement module 10 according to the frequency of the power distribution network 3 .

[0131] As described above, for each phase line Ph, the voltage measurement circuit 7 has a first ADC and the current measurement circuit 9 has a second ADC.

[0132] Thus, for each phase Ph, the electricity meter 1 measures and samples the phase voltage and the phase current present on said phase Ph so as to produce measurements of the phase voltage U and the phase current I present on said phase Ph. These measurements are then transmitted to the measurement module 10 .

[0133] Advantageously, the sampling frequency is a multiple of the first and second frequencies. In this example, sampling is performed at 3000 Hz, so that 60 samples per cycle are processed at 50 Hz and 50 samples per cycle are processed at 60 Hz. The fact that this occurs "exactly" serves to avoid any fluctuations in the power and energy measurements within the "one second" corresponding to sampling 3000 samples.

[0134] Naturally, the invention is not limited to the implementations described, but covers any variant coming within the ambit of the invention as defined by the appended claims.

[0135] The above description relates to a specific implementation in which the first calibration parameters (as predefined and previously stored) are 50 Hz parameters, and the second calibration parameters (defined, if necessary, when the meter is put into use) are 60 Hz parameters. Naturally, it is entirely possible to perform calibration at 60 Hz and derive the 50 Hz calibration parameters.

[0136] The same principle can naturally be applied to grid frequencies other than 50 Hz and 60 Hz, and can also be applied when more than two grid frequencies are considered at startup. The principle continues to be to use the first calibration parameters of the first frequency to derive the calibration parameters for the other frequencies. It is then advantageous to select the sampling frequency in such a way that the number of samples per cycle is an integer at all frequencies. The coefficient "a" of the Butterworth filter is then also adapted.

[0137] The calibration parameters used when implementing the present invention may be different from those described above. For example, the matrix 17 does not have to be used in all cases.

[0138] The low-pass filters 11a and 11b do not have to be identical, and they do not have to be Butterworth filters. Other filters, such as Chebyshev filters, can also be used. The advantage of the Butterworth filter is that the "rejection" is very fast and the gain exhibited in the passband is relatively constant.

[0139] Of course, the electric meter in which the present invention is implemented is not necessarily a three-phase electric meter. It may be a single-phase electric meter. In this case, Figure 1 The circuit diagram is applicable to single-phase line Ph.

Claims

1. A method for adjusting a measuring module (10) of an electricity meter (1) connected to a power distribution network (3), said method comprising the following steps implemented in said electricity meter (1) after said electricity meter (1) has been installed in an operating position: Acquiring at least one measurement of the frequency of the power distribution network (3); adjusting the measuring module (10) by using first calibration parameters generated during a calibration phase performed before installing the meter in an operating location and stored in the meter, if the difference between the frequency of the power distribution network and a first frequency is less than a first predetermined threshold; If the difference between the frequency of the power distribution network and the first frequency is greater than or equal to the first predetermined threshold, a second calibration parameter is calculated based on the first calibration parameter and based on an adaptation parameter, and the measurement module (10) is adjusted by using the second calibration parameter, the adaptation parameter comprising a first adaptation parameter evaluated at the first frequency and a second adaptation parameter evaluated at a second frequency, the second frequency being such that the difference between the frequency of the power distribution network and the second frequency is less than a second predetermined threshold.

2. The adjustment method according to claim 1, wherein: For each phase line (Ph) of the power distribution network (3), the measurement module (10) is arranged to acquire measurements of the phase voltage and phase current present on the phase line, the measurement module comprising at least one low-pass filter (11) arranged to suppress harmonics from the phase voltage and the phase current so as to produce a fundamental phase voltage and a fundamental phase current, the adaptation parameters comprising parameters of the low-pass filter (11).

3. The adjustment method according to claim 2, wherein: The parameters of the low-pass filter include a modulus of a Z-transform of a transfer function of the low-pass filter at a first frequency and a modulus of the Z-transform at a second frequency.

4. The adjustment method according to claim 3, wherein: The first calibration parameters include a first parameter and And the second calibration parameter includes a second parameter and The parameter is incorporated into a multiplication factor for multiplying the basic phase voltage and the basic phase current in order to estimate the raw reactive power supplied by the power distribution network, the second calibration parameter being and It is obtained by the following calculation: wherein |H(Z)1| is the modulus of the Z transform of the transfer function of the low-pass filter (11) at the first frequency, and wherein |H(Z)2| is the modulus of the Z transform of the transfer function of the low-pass filter (11) at the second frequency.

5. The adjustment method according to claim 3, wherein: The parameters of the low-pass filter also include the phase of the Z-transform at the first frequency and the phase of the Z-transform at the second frequency.

6. The adjustment method according to claim 5, wherein: The electricity meter comprises or is connected to a current sensor (8) comprising a current transformer and arranged to produce a measurement of the phase current, the adaptation parameters also comprising at least one parameter of the current transformer.

7. The adjustment method according to claim 6, wherein: The adaptation parameters also include at least one parameter of at least one electronic component of a current measurement circuit (9) connected to the current transformer.

8. The adjustment method according to claim 7, wherein: The electronic component is an amplifier.

9. The adjustment method according to claim 8, wherein: The first calibration parameter also includes a harmonic Phase shift and basic phase shift The second calibration parameter also includes harmonics Phase shift and basic phase shift The measurement module (10) uses these calibration parameters to estimate the compensated active power and compensated reactive power delivered by the power distribution network (3), the phase shift with harmonics and the basic phase shift It is obtained by the following calculation: as well as in is the phase of the Z transform at the first frequency, is the phase of the Z transform at the second frequency, is the phase of the current transformer at the first frequency, is the phase of the current transformer at the second frequency, is the phase of the amplifier of the current measurement circuit at the first frequency, and is the phase of the amplifier of the current measurement circuit at the second frequency.

10. The adjustment method according to claim 1, wherein: For each phase line (Ph) of the power distribution network (3), the electricity meter (1) is arranged to measure and sample the phase voltage and the phase current present on the phase line so as to produce a measurement of the phase voltage and the phase current present on the phase line, the sampling frequency being a multiple of both the first frequency and the second frequency.

11. An electricity meter (1) comprising a measuring module (10) and a processor assembly (4), wherein the adjustment method according to any of the preceding claims is implemented.

12. A computer program product comprising instructions causing the processor component (4) of the electricity meter (1) according to claim 11 to perform the steps of the adjustment method according to any one of claims 1 to 10.

13. A computer-readable storage medium having stored thereon a computer program comprising instructions, said instructions causing the processor component (4) of the electricity meter (1) according to claim 11 to perform the steps of the adjustment method according to any one of claims 1 to 10.

Images