Voltage measurement compensation in high voltage systems

Abstract

A method for obtaining characteristic measurement values ​​K and α of an electrical system including at least two terminals, the method comprising: injecting a reference voltage at a first terminal of the at least two terminals; measuring a voltage at a second terminal of the at least two terminals to provide a measured voltage, the second terminal being grounded; measuring an amplitude ratio between the injected reference voltage and the measured voltage to provide a K value; and measuring a phase angle difference between the injected reference voltage and the measured voltage to provide an angle value α.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Australian Provisional Patent Application No. 2019901217 filed on April 9, 2019.

[0003] The entire contents of this priority application are incorporated herein by reference. Technical Field

[0004] The present application relates to the effects of crosstalk on voltage measurements. Background Art

[0005] In any electrical system with two or more conductors that are close enough to each other, the effect of the current carried by one conductor will be felt by the other conductor due to the electromagnetic field generated by the current in one conductor overlapping with the second conductor, thereby inducing a current in the second conductor. This effect is called crosstalk and can cause harmful effects in an electrical system.

[0006] In electrical systems with high voltages, such as electrical switchgear in power distribution systems, this effect is even greater. Due to capacitive coupling, this effect will also affect voltage measurements in such systems, making it difficult to obtain accurate voltage measurements due to the difficulty in shielding the voltage measurement circuits from this effect.

[0007] Inaccurate voltage measurements in such systems may prevent certain functions or procedures (such as "sync check") from being implemented. Summary of the invention

[0008] According to a first aspect, a method for obtaining characteristic measurement values ​​K and α of an electrical system comprising at least two terminals is provided, the method comprising: injecting a reference voltage at a first terminal of the at least two terminals; measuring a voltage at a second terminal of the at least two terminals to provide a measured voltage, the second terminal being grounded; measuring an amplitude ratio between the injected reference voltage and the measured voltage to provide a K value; and measuring a phase angle difference between the injected reference voltage and the measured voltage to provide an angle value α.

[0009] According to a second aspect, a method of providing compensated voltage measurements of voltage measurements in an electrical system including errors caused by crosstalk is provided, the method comprising: receiving voltage measurements of the electrical system; and removing at least a capacitive component of the errors caused by the crosstalk to provide compensated voltage measurements.

[0010] According to a third aspect, a method of determining a compensation algorithm for compensating voltage measurements of an electrical system is provided, the compensation algorithm comprising one or more compensation coefficients; the method comprises deriving the one or more compensation coefficients based on a circuit characterizing the electrical system.

[0011] According to a fourth aspect, a method for providing compensated voltage measurement values ​​of voltage measurement values ​​in an electrical system is provided, the method comprising: measuring a voltage at a measurement terminal of the electrical system to provide a voltage measurement value, and determining the compensated voltage measurement value based on the voltage measurement value and at least one crosstalk coefficient calculated during an initial characterization phase, wherein the initial characterization phase comprises: injecting a reference voltage signal at a first terminal of the electrical system; measuring a capacitive coupling signal at the terminal according to the reference voltage signal; comparing the reference voltage signal with the measured capacitive coupling signal; and calculating at least one crosstalk coefficient based on the comparison of the reference voltage signal with the measured capacitive coupling signal.

[0012] According to a fifth aspect, there is provided a device for controlling an electrical system based on one or more voltage measurement values ​​of the electrical system, the device comprising: an input for receiving data corresponding to one or more voltage measurement values; a data processor for processing the received data and for generating data corresponding to compensated voltage measurement values; and an output for controlling the electrical system according to the compensated voltage measurement values; wherein the processor includes executable software for causing the processor to execute one or more of the methods according to the second and fourth aspects.

[0013] According to a sixth aspect, there is provided a non-transitory computer readable medium containing executable code for causing a processor to perform one or more of the methods according to the second and fourth aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Various aspects and embodiments will be discussed with reference to the accompanying drawings, in which:

[0015] Figure 1A Photographs showing embodiments of electrical systems to which aspects described herein may be applied, and in particular, showing medium voltage switchgear;

[0016] Figure 1B Shows Figure 1A A schematic diagram of the interior of a pole of an electrical system;

[0017] Figure 1C Shows Figure 1B The circuit equivalent of the impedance of an electrical system;

[0018] Figure 2 A diagram showing the crosstalk effect of all other voltages in the electrical system on the measured voltage V2;

[0019] Figure 3 shows the display using Figure 2 A representation of the circuit shown of how the current produced by the RVD resistor is measured by R3;

[0020] Figure 4 The waveforms of the injected voltage signal V1 and the measured voltage signal V2 are shown, which are error waveforms generated by the crosstalk effect of V1 on V2measured;

[0021] Figure 5 A flow chart showing a method of characterizing a crosstalk voltage in order to obtain a crosstalk coefficient for a compensation algorithm;

[0022] Figure 6 Shows Figure 1B A simple representation of the circuit equivalent of ;

[0023] Figure 7 shows a source V1 and a resulting crosstalk V2 Figure 6 Circuit;

[0024] Figure 8 shows the circuit impedance used to calculate Figure 7 Circuit;

[0025] Fig. 9 The crosstalk effect is shown for calculating the circuit impedance. Figure 8 The Thevenin equivalent circuit of

[0026] Fig.10 shows a polar plot of U used to calculate circuit impedance;

[0027] Fig.11 Shows Figures 8 to 10 The waveforms of U and UR3 in the circuit;

[0028] Fig.12 Shows Figure 8 A circuit showing the calculated impedance of the circuit;

[0029] Fig.13A shows the waveform of the step function injected into U1 and the measured response waveform U2 in another embodiment of the characterization circuit;

[0030] Fig. 13B It shows that when calculating the characterization parameters Fig.13A Use of waveforms;

[0031] Fig.14 A flow chart showing a generalized method of providing a compensated voltage measurement affected by crosstalk;

[0032] Fig.15 A flow chart showing a method of providing compensated voltage measurements according to another aspect;

[0033] Fig.16A An embodiment of an apparatus for performing the various compensation methods described herein is shown;

[0034] Fig. 16B An example of an actual switchgear controller for use with various aspects described herein is shown;

[0035] Fig.17 Shown for use with electrical systems Fig.16A and Fig. 16B Representation of the equipment;

[0036] Fig.18A shows a waveform of voltage measurements including crosstalk errors measured at terminals of an electrical system;

[0037] Fig.18B Shows the Fig.15 After the device processing, the crosstalk error is removed Fig.18A The waveform of the voltage measurement value;

[0038] Fig.19 shows an extended Thevenin equivalent circuit for deriving the relationship used to calculate internal impedance; and

[0039] Fig. 20 Another Thevenin equivalent circuit used to derive the relationship used to calculate the internal impedance is shown. DETAILED DESCRIPTION

[0040] Figure 1A An example of an electrical system 500 is shown to which various aspects described herein may be applied. In this example, the electrical system 500 is a medium voltage switchgear pole. Figure 1B A switching device 500 having two HV resistors 510, 520 is shown (specifically, as shown in FIG. Figure 1A In this view, two parasitic capacitances 10, 20 present between two resistors 510, 520 are shown.

[0041] Figure 1C Shown by Figure 1A The simplified circuit of the resistive voltage divider (RVD) formed by the HV resistors 510 and 520 and the resistors R3 and R4 is equivalent, and the parasitic capacitors 10 and 20 are also shown.

[0042] Figure 2 A representative diagram is shown of the effect of a voltage V1 on the source side of the same phase and voltages U1, U2, W1, W2 on the source and load sides of the other two phases on a particular voltage measurement V2 on the load side in a multi-phase electrical system such as switchgear 500.

[0043] In practice, the measured value of voltage V2 will be affected by the presence of these other voltages (V1, U1, U2, W1, W2), resulting in an error in the measured voltage. This error may adversely affect the operation of the electrical system 500, for example, preventing the safe implementation of a "synchronization check" used to ensure safe operation of switches in the system.

[0044] Various aspects described herein allow the effects of crosstalk from these other voltage sources to be identified and compensated for in order to provide compensated voltage measurements that more accurately reflect the actual voltage at the measurement point.

[0045] Figure 3 Shows Figure 1A , Figure 1B and Figure 1C An equivalent circuit of an electrical system is provided to illustrate the steps of measuring the effect of different voltages on the measured voltage according to some aspects. Figure 3 In the example shown, the effect of voltage V1 on measured voltage V2measured is performed by injecting a known reference voltage signal V1 in the circuit as shown. Resistor RVD is an electrical system in Figure 1C In Figure 1B Rv1 and RV2 (Rv1=R9+R10 and Rv2=R1+R5) in FIG. 5 represent effective resistances in the path, and R3 is the resistance of the voltage measurement circuit.

[0046] In this regard, voltage measurement errors are used to characterize each electrical system (e.g., switchgear) to allow generation of an algorithm for providing compensated voltage measurements for each terminal or bushing of the electrical system 500.

[0047] When a reference voltage is applied or injected to one bushing, it can be seen that the voltage measured on all other grounded bushings is not zero. This is due to the injection of current Cd (U C ) / dt is caused by the parasitic capacitance C, such as Figure 3 shown.

[0048] Figure 4 Shows the basis Figure 3 A graph of the waveforms of the injected reference voltage V1 and the resulting measured voltage V2measured is shown. Based on the graph, the characteristics of the error waveform (V2measured) can be determined for characterizing the electrical system and calculating coefficients of the algorithm for providing compensated voltage measurements. In particular, based on Figure 4From this graph, it is possible to determine the value K, i.e. the ratio of the injected signal V1 and the error signal V2measured, and also the phase angle difference α between the injected reference signal V1 and the error signal V2measured. In this respect, the error signal generated by the crosstalk is also called capacitive coupling voltage or Vcrosstalk, which is the signal measured during this characterization phase, with the terminals being grounded.

[0049] Once obtained, these values ​​may be used in a number of different ways to provide compensated voltage measurements to remove at least a portion of the error signal introduced by crosstalk effects, as will be described in more detail below.

[0050] Figure 3 and Figure 4 The process of determining the effect of V1 on the measured voltage V2 is shown. In order to consider the effect of all voltages in the electrical system on V2, the same process is used for all other voltages. For example, to determine the effect of U1 on V2, a reference signal U1 is injected at the terminals of U1, with all other terminals or bushings grounded, and the signal at V2 is measured. These results using injected signal U1 instead of injected signal V1 provide the following: Figure 4 The waveform shown.

[0051] Once all combinations of voltage pairs have been measured for V2 (resulting in 5 sets of K and α measurements), the same process is performed for each of the other voltages U1, U2, V1, W1, and W2. When all measurements are completed, 30 crosstalk (K) and angle (α) values ​​will be obtained, as shown in the following table:

[0052]

[0053] It should be understood that in some embodiments, a calibration step may be performed before starting the above process to ensure that all phases receive the same injection voltage. In some embodiments, the calibration step may be performed after crosstalk compensation.

[0054] like Figure 5 As shown, in a generalized form, a method for obtaining characteristic measurement values ​​K and α of an electrical system including at least two terminals (in some embodiments, there are at least three terminals, including a common terminal) is provided, the method comprising: in step 600, injecting a reference voltage at a first terminal of the at least two terminals; in step 610, measuring a capacitive coupling voltage at a second terminal of the at least two terminals to provide a capacitive coupling voltage, the second terminal being grounded; in step 620, measuring an amplitude ratio between the injected reference voltage and the capacitive coupling voltage to provide a K value; and in step 630, measuring a phase angle difference between the injected reference voltage and the capacitive coupling voltage to provide an angle value α.

[0055] In some embodiments, when there are more than two terminals, as described above, the above steps are performed for each terminal pair to obtain the K value and the angle α value for each terminal pair. For example, if there are two terminals T1 and T2, the above steps are performed twice, once for T1T2 (i.e., the reference voltage V is injected at T1). ref And measure the capacitive coupling voltage V at T2 crosstalk ), once for T2T1 (i.e., inject reference voltage V at T2 ref And measure the capacitive coupling voltage V at T1 crosstalk ). For three terminals T1, T2 and T3, the pairings would be T1T2, T2T1, T2T3, T3T2, T1T3 and T3T1. It will be appreciated that the parameter measured at the terminals is the voltage at the terminals, so V1 is the voltage at terminal T1, V2 is the voltage at terminal T2, etc., and so these pairings can be equivalently written as V1V2, V2V1, V2V3, V3V2, V1V3 and V3V1, as previously described.

[0056] Once the above process has been performed, and one or more voltage pair measurements have been obtained to provide corresponding characteristic measurements K and α values, various means of generating compensated voltage measurements can be implemented according to various aspects. These aspects will now be described in detail with respect to the voltage pair V1V2 (i.e., the effect of the voltage V1 on the measured voltage V2), however, it should be understood that the same process can be applied to one or more other voltage pairs to provide at least partially compensated voltage measurements.

[0057] It should also be understood that although the greatest effect will be achieved by applying the various techniques to all voltage pairs in the electrical system, even when the various techniques are applied to one voltage pair, some portion of the error from crosstalk on a particular voltage measurement may be removed or compensated. For example, the process may apply only to the effect of V1 on V2 (V1V2); or to the effect of V1 on V2 (V1V2), W1 on V2 (W1V2), and U1 on V2 (U1V2); or to the effect of U2 on V2 (U2V2).

[0058] According to one aspect, the K value and the α value obtained from the above process can be used to determine the compensation coefficient for use in the compensation algorithm shown in Equation 1:

[0059]

[0060] in:

[0061] V2comp is the compensation voltage measurement value of the measurement value V2;

[0062] V2measured is the measured voltage;

[0063] KcU1V2 is the capacitance coefficient determined for the effect of U1 on V2;

[0064] KcV1V2 is the capacitance coefficient determined for the effect of V1 on V2;

[0065] KcW1V2 is the capacitance coefficient determined for the effect of W1 on V2;

[0066] KcU2V2 is the capacitance coefficient determined for the effect of U2 on V2;

[0067] KcW2V2 is the capacitance coefficient determined for the effect of W2 on V2.

[0068] Kcxx and K2xx may be calculated for capacitive crosstalk during the circuit characterization phase according to K2 = (R5 + R3) / (R1 + R5 + R3) (see further below for more details on circuit characteristics).

[0069] Once the coefficients have been calculated for a given electrical system, the above equation can be used in real time as voltage measurements are made on the electrical assembly in use. In particular, according to one aspect, as raw voltage measurements U1, U2, V1, V2, W1 and W2 are taken at the terminals of the electrical system, calculations are performed to determine the voltage change (dv) difference from the previous sample taken, which provides the dv / dt value for the above equation. In practice, the time difference between the raw voltage measurements is provided by the sampling rate of the device making the measurement, which will be described in more detail below.

[0070] According to other embodiments, the compensation algorithm is provided by:

[0071]

[0072] in:

[0073] V2comp is the compensation voltage measurement value of the measurement value V2;

[0074] V2measured is the measured voltage;

[0075] P V1V2 is the percentage of crosstalk to V2 that comes from V1;

[0076] α is the angle measured;

[0077] K1 V1V2 =10 / 2π.f (t is in ms);

[0078] K2 V1V2 =(R5+R3) / (R1+R5+R3);

[0079] Reference below Figures 8 to 11 A complete derivation of this equation (2) is provided.

[0080] When the errors from all bushings are removed, equation (2) becomes:

[0081]

[0082] In some embodiments, when α is close to 90 degrees (e.g., between 80 degrees and 90 degrees), the resistive component of the crosstalk error can be ignored, and equation (3) can be modified to remove only the capacitive component of the error from the crosstalk, and can be simplified to:

[0083]

[0084] In some embodiments, when only the capacitive component is removed and the K2xx coefficient = 1, equation (4) can be further simplified to:

[0085]

[0086] The compensation value may then be stored in a memory, displayed on a display screen, and / or used to control further functions of the electrical system 500 , such as a synchronization check.

[0087] When the electrical system 500 (in this example, Figure 1A The compensation process can be used to provide more accurate voltage measurements in real time when the complete recloser system 500 is in operation to reduce the deleterious effects of crosstalk on voltage measurements during functions such as sync check. During the sync check, the utility adjusts the amplitude and waits for the signals to be in phase before closing the switch. Without compensation, the amplitude is unreliable in this case.

[0088] In some embodiments where the system is a single-phase system with only 2 terminals providing voltages V1 and V2, only components related to the V2V1 relationship and the V1V2 relationship are used. In such embodiments, the equation becomes:

[0089]

[0090] and

[0091]

[0092] In other embodiments, in a multi-phase system, it will be appreciated that benefits may still be obtained by using only one or more other measurements of other phases to obtain a more accurate compensated measurement. For example, an improved compensated V2 measurement may be obtained by considering only the effects of U1 and V1, or W1 and V1, or U2 and W2.

[0093] Any consideration of the effect of any one or more other voltages on the measured voltage, and removing at least part of that effect, will provide a voltage value that is closer to the true value, and therefore provide a benefit.

[0094] In other aspects, further refinement can be obtained by further refining the compensation voltage using a recursive method. In these aspects, the following algorithm can be used:

[0095]

[0096] In some cases, where the measured angle α value is close to 90° (e.g., approximately 85°, approximately 86°, approximately 87°, approximately 88°, or approximately 89°), then the resistance effect is negligible as described above, and the resistance effect is ignored. In other cases where the measured angle α value is lower, such as between approximately 30° and approximately 40°, between approximately 40° and approximately 50°, between approximately 50° and approximately 60°, and between approximately 60° and approximately 70°), the resistance effect is more prevalent and the resistance effect can be taken into account when removing the error signal. It should be understood that for each available electrical system and DSP capabilities, it can be determined what angle will be considered close enough to 90 degrees so that the resistance component is ignored. In some of these embodiments, the resistance component KR is obtained from the following formula

[0097]

[0098] Where P V1V2 (percentage of crosstalk) and α are based on the above reference Figures 2 to 5 The measured values ​​described are obtained (note that when V2 is grounded, k2*V2=0).

[0099] In this application, the equation also includes a resistance component:

[0100] In simple terms, considering the effect of V1 on V2, the equation becomes

[0101]

[0102] For a more complete compensation, considering all pairings in the electrical system 500, the following equation may be used:

[0103]

[0104] In other aspects, further refinement can be achieved by using higher orders, including 2nd, 3rd, 4th, 5th and higher orders.

[0105] The second order equation including the resistance component is as follows:

[0106]

[0107] According to other aspects, instead of obtaining the compensation coefficients, i.e., the capacitance and resistance coefficients, based on Ksinα and Kcosα as described above, the K value and α value obtained as described above can be used to characterize the electrical system by explicitly calculating the values of all the internal impedances R1, R5, and C of the electrical system. These calculated impedance values can then be used to derive the compensation coefficients, as described below.

[0108] Figures 6 to 11 For deriving these impedance values. Figure 6 Shows Figure 1B A simpler representation of the equivalent circuit. Figure 7 Shows a circuit Figure 6 Showing a source V1 and a resulting crosstalk V2. Figure 8 Shows an equivalent schematic diagram of a phase of the electrical system or the switching device 500, and Fig. 9 Shows a simplified schematic diagram converted into an equivalent Thevenin model. Fig.10 Shows the phasor diagram of U, and Fig.11 Shows the waveforms of the components U and U R3 of.

[0109] It can be seen from these diagrams that V2measured = V2 + error (E), where the error E is given by

[0110] E = A.R3.i1 = Kc dUc / dt

[0111] where Uc = U - U R , and U = V1 – k2.V2

[0112] If UR << Uc, then when the crosstalk is mainly capacitive, E = Kc.(dV1 / dt – k2.dV2 / dt), where K2 = (R5 + R3) / (R1 + R5 + R3) and Kc = K1.Pc (where Pc is the crosstalk in %, and K1 = (10 / 2π)f), considering t in milliseconds.

[0113] It should be understood that in most cases, the measured resistor value R3 is much smaller than the HV resistors R1 and R5, i.e., R3 can be neglected. It should also be understood that usually Zc << R, so Uc ≈ U. In this case, the effect of R on the crosstalk can be neglected, and the crosstalk is mainly capacitive.

[0114] Therefore, in these cases, the error voltage of a terminal / bushing can be expressed as:

[0115]

[0116] An equivalent circuit of the electrical system can be generated and, knowing the input parameters (input voltage, frequency, percentage of measured crosstalk (K), measured angle α, RVD and R3), all internal impedances R1, R5 and C can be calculated.

[0117] The following equation provides the relationship for calculating impedance:

[0118] R1 = γRVD, where γ = i1 / i

[0119] R5=RVD–R1

[0120] These relationships are further developed below.

[0121] From these calculated internal impedances, the equivalent circuit can be determined. Fig.12 Shows Figure 8 The equivalent circuit of the model, where the known input is U1max = 100V, U1 crosstalk on U2 = 52.85%, U1 / U2 angle = 65°, RVD = 2GΩ, R3 = 91kΩ, frequency = 50Hz, sampling frequency = 20ks / s. Using the above equations (and the following derivation), the internal impedance is calculated to be R1 = 400Ω, R5 = 1600Ω, and C = 4.63pF.

[0122] In another possible method of characterizing the circuit, the impedance of the circuit can be calculated by injecting a step function at U1 and measuring the pulse response at U2 with the U2 terminals grounded, as previously described with reference to Figures 2 to 4 In this regard, Figure 4 The waveform is Fig.13A and Fig. 13B The waveform shown is substituted.

[0123] Fig.13A The response U2 to a square wave signal injected by U1 is shown (U1 = 300V square wave at 500Hz). Knowing the maximum UR3 (the value of R3 is provided by the manufacturer or can be easily measured directly), R5 can be determined by the following equation:

[0124] MaxUR3=U1.R3 / (R5+R3)

[0125] From this, R1 can also be found using the following equation:

[0126] R1 = RVD-R5; and

[0127] R=R1 / / (R5+R3).

[0128] In addition, if Fig. 13B As shown, you can then use Fig. 13B The response waveform time constant RC (T = RC) is used to find C.

[0129] Knowing the internal impedance of the circuit being characterized, the error E can be calculated and the error for each voltage pair removed. E can be determined using the following relationship:

[0130] Kc=K1Pc

[0131] Where K1=10f / 2π

[0132] And Pc = Percent Crosstalk K (using the above reference Figures 2 to 5 Described method measurement)

[0133] K2=(R5+R3) / (R1+R5+R3)

[0134] Therefore, the following equation can be used to compensate the measured voltage Vmeas at the terminal to provide a compensation voltage that reduces at least a portion of the error caused by crosstalk in the system:

[0135]

[0136] In some electrical systems, K2 is very close to 1, and so the above equation can be simplified to:

[0137]

[0138] Therefore, in a broad sense, Fig.14 As shown, a method for providing compensated voltage measurement values ​​of voltage measurement values ​​in an electrical system including errors from crosstalk is provided, the method comprising: in step 700, receiving original voltage measurement values ​​of the electrical system; and in step 710, removing at least the capacitive component of the error from the crosstalk to provide a compensated voltage measurement value.

[0139] According to another broad aspect, Fig.15 As shown, a method for providing compensated voltage measurement values ​​of voltage measurement values ​​in an electrical system is provided, the method comprising: in step 800, measuring voltage at a measurement terminal of the electrical system to provide a voltage measurement value; and in step 810, determining the compensated voltage measurement value based on the voltage measurement value and at least one crosstalk coefficient calculated during an initial characterization phase.

[0140] As previously described, in some embodiments, the initial characterization phase includes: injecting a reference voltage signal at a first terminal of the electrical system; measuring a capacitive coupling signal at the terminal based on the reference voltage signal; comparing the reference voltage signal with the measured capacitive coupling signal; and calculating at least one crosstalk coefficient based on the comparison of the reference voltage signal with the measured capacitive coupling signal.

[0141] According to another aspect, a controller 200 is provided for use with an electrical system / switch device 500 to implement voltage compensation as described in the various aspects above. Fig.16A As shown, the controller 200 includes an input having a filter and a surge protection unit 210 for receiving analog voltage measurements from terminals or bushings of an electrical system such as a switchgear or recloser 500. These raw measurements are provided to an A / D converter, and in some embodiments, such as Fig.16A As shown, the A / D converter is provided by the device ADS13XE0X (16ks / s) provided by Texas Instruments, Inc.

[0142] The digital data is then provided to a digital signal processor (DSP) 230, which in some embodiments may be Fig.16A As shown, the DSP 230 is provided as a device STM32F446 (3.2ks / s) of the company STMicroelectronics. The device stores executable instructions to allow the implementation of the above-mentioned various methods to provide compensation voltage values, which can be used for storage in a memory, display on a display unit and / or for controlling elements of an electrical system, such as when implementing a synchronization check process.

[0143] The following is a code sample suitable for implementing an example of one of the above methods:

[0144] / *!

[0145] *************************************************************

[0146] *@Succinct compensation sample voltage data. This is required for the E38 switch.

[0147] *Use this form to calculate the error:

[0148] *errors[U1]=KU2U1*(dU2dU1)

[0149] *+KV1U1*(dV1dU1)

[0150] *+KW1U1*(dW1dU1)

[0151] *+KV2U1*(dV2dU1)

[0152] *+KW2U1*(dW2dU1);

[0153] *Where dUx is calculated as the previous sample

[0154] *Then subtract it from the measured value

[0155] *Do this for all casings

[0156] *

[0157] *@Note adc_v_spi.wlse_data[bushing][sample] is modified

[0158] *Add approximately 4% to the load being processed

[0159] *

[0160] *************************************************************

[0161] * @param[in] Samples in progress (0 to SAMPLES_PER_2P5MS)

[0162] *

[0163] *************************************************************

[0164] * @return empty value

[0165] *

[0166] *************************************************************

[0167] * /

[0168] inline void compensate(u8_t sample)

[0169] {

[0170] static float K[NUM_CVTs][NUM_CVTs];

[0171] static Bool first_time=true;

[0172] float dvolts[NUM_CVTs];

[0173] if(first_time)

[0174] {

[0175] first_time=false;

[0176] float src_factor=0.032184944f / ((Ts)*1000.0f);

[0177] float load_factor=0.031548916f / ((Ts)*1000.0f);

[0178] K[CVT1][CVT4]=5.57f*src_factor;

[0179] K[CVT4][CVT1]=1.84f*load_factor;

[0180] K[CVT2][CVT5]=5.86f*src_factor;

[0181] K[CVT5][CVT2]=1.99f*load_factor;

[0182] K[CVT3][CVT6]=5.84f*src_factor;

[0183] K[CVT6][CVT3]=1.85f*load_factor;

[0184] K[CVT1][CVT2]=0.62f*src_factor;

[0185] K[CVT1][CVT5]=0.19f*src_factor;

[0186] K[CVT1][CVT3]=0.09f*src_factor;

[0187] K[CVT1][CVT6]=0.14f*src_factor;

[0188] K[CVT2][CVT1]=0.74f*src_factor;

[0189] K[CVT2][CVT3]=0.74f*src_factor;

[0190] K[CVT2][CVT4]=1.29f*src_factor;

[0191] K[CVT2][CVT6]=0.18f*src_factor;

[0192] K[CVT3][CVT1]=0.09f*src_factor;

[0193] K[CVT3][CVT2]=0.42f*src_factor;

[0194] K[CVT3][CVT4]=0.14f*src_factor;

[0195] K[CVT3][CVT5]=1.29f*src_factor;

[0196] K[CVT4][CVT2]=0.87f*load_factor;

[0197] K[CVT4][CVT3]=0.12f*load_factor;

[0198] K[CVT4][CVT5]=0.21f*load_factor;

[0199] K[CVT4][CVT6]=0.06f*load_factor;

[0200] K[CVT5][CVT1]=0.11f*load_factor;

[0201] K[CVT5][CVT3]=0.95f*load_factor;

[0202] K[CVT5][CVT4]=0.23f*load_factor;

[0203] K[CVT5][CVT6]=0.29f*load_factor;

[0204] K[CVT6][CVT1]=0.16f*load_factor;

[0205] K[CVT6][CVT2]=0.14f*load_factor;

[0206] K[CVT6][CVT4]=0.08f*load_factor;

[0207] K[CVT6][CVT5]=0.33f*load_factor;

[0208] }

[0209] / / This needs to be done before any error calculations, since all voltage differences are used for all bushings

[0210] for(size_t bushing=CVT1; bushing <NUM_CVTs;bushing++)

[0211] {

[0212] dvolts[bushing]=adc_v_spi.wlse_data[bushing][sample]adc_

[0213] v_spi.previous_sample[bushing];

[0214] adc_v_spi.previous_sample[bushing]=adc_v_spi.wlse_data[bushing][sampl e];

[0215] }

[0216] / / Now for each bushing calculate the error contribution of all other bushings

[0217] float v_error;

[0218] for(size_t bushing=CVT1; bushing <NUM_CVTs;bushing++)

[0219] {

[0220] v_error=0.0f;

[0221] for(size_t other_bushing=CVT1; other_bushing <NUM_CVTs;other_bushing++)

[0222] {

[0223] if(other_bushing! = bushing)

[0224] v_error+=K[other_bushing][bushing]*(dvolts[other_bushing]dvolts[bushing]);

[0225] }

[0226] adc_v_spi.wlse_data[bushing][sample]=

[0227] v_error;

[0228] }

[0229] }

[0230] Fig.16A The controller 200 also includes an EEPROM 240, a flash memory 250, and a main processor 260. In this embodiment, the main processor 260 is provided by a Sitara ARM Cortex AM3358 processor provided by Texas Instruments. Each block is powered by a power supply 280, which is controlled by a power supply monitor 270, which is provided by a device TPS65218 provided by Texas Instruments.

[0231] It should be understood that although specific device identification has been provided in this embodiment, those skilled in the art will appreciate that any other suitable device configurations and components may be used.

[0232] Fig. 16B shows a reference Fig.16A Photograph of an example switchgear controller 200 of the structure shown and described.

[0233] Fig.17 An embodiment of an apparatus 200 that receives voltage output data from an electrical system 500, such as an electrical switching device such as a recloser or RVD, is shown. Fig.17 Shown is a measured voltage value Vmeas output from electrical system 500 and input to each of U1, U2, V1, V2, W1, and W2 of device 200. The output of device 200 is a compensated voltage measurement Vcomp of each of U1, U2, V1, V2, W1, and W2.

[0234] In some embodiments and applications, the compensated voltage measurements are then used to control various aspects of the electrical system, as previously described.

[0235] Fig.18A The waveform of a measured voltage signal V2 measured at the V2 terminal of the electrical system is shown (which is the input to the filter 210 of the apparatus 200). It will be appreciated that this measurement will contain errors E from crosstalk from each of the other voltages V1, U1, U2, W1 and W2.

[0236] Fig.18BShows the compensated voltage V2comp resulting from applying one or more of the above methods, which effectively removes the crosstalk error or a portion of the crosstalk error, thereby providing a voltage measurement value that is closer to the actual voltage that appears at the V2 terminal than the voltage value measured by the device.

[0237] Then, this compensated voltage measurement value can be used to control one or more functions of the electrical system 500, such as a synchronization check, or any other function that requires an accurate voltage measurement value.

[0238] Then in a broad sense, there is provided a device for controlling an electrical system based on one or more voltage measurement values of the electrical system, the device comprising: an input for receiving data corresponding to the one or more voltage measurement values; a data processor for processing the received data and for generating data corresponding to a compensated voltage measurement value; and an output for controlling the electrical system according to the compensated voltage measurement value; wherein the processor includes executable software that causes the processor to perform one or more of the above methods.

[0239] In another broad sense, there is also provided a non-transitory computer-readable medium containing executable code for causing a processor to perform one or more of the above methods.

[0240] Derivation

[0241] As previously mentioned, various relationships have been used to obtain the various impedances of the equivalent circuit. Now, reference will be made to Fig.19 and Fig. 20 to derive these relationships.

[0242] Fig.19 Shows Fig. 9 the extended Thevenin equivalent circuit shown. Considering that R6 = R3 + R5, RVD = R5 + R1, where R3 << RVD, and γ = R1 / RVD, the following holds:

[0243] A) R6 voltage = voltage (R1 / / R6) {considering that R1 is in parallel with R6 when V2 = 0}

[0244] R6.i1 = i(R1.R6) / (R1 + R6)

[0245] i = R6.i1.(R1 + R6) / R1.R6)

[0246] Therefore, I = i1(RVD + R3) / R1

[0247] Considering that R1 = γ*RVD and R3 << RVD, it can be concluded that i1 ≈ γ.i

[0248] B) According to Figure 18, R = R1 / / R6 = R1*R6 / (R1 + R6)

[0249] where R6 = R5 + R3,

[0250] since R3 << R5; R6 ≈ R5, and R ≈ R1*R5 / (R1 + R5)

[0251] By substituting R1 and R5 with γ*RVD and (1 - γ)RVD respectively,

[0252] R ≈ RVD*γ(1 - γ), which can also be written as: γ 2 -γ + R / RVD = 0

[0253] This quadratic equation can be solved for two values:

[0254] and

[0255]

[0256] C) U 2 = (R*i) 2 + (Zc*i) 2

[0257] Zc = R*Tan(α), where the angle α between the injected voltage and the crosstalk is measured

[0258]

[0259] Therefore,

[0260]

[0261] Accordingly, it is obtained that:

[0262] i1 ≈ γ.i (where γ = R1 / RVD) ……………………………………(A)

[0263]

[0264]

[0265] Then, using (A) and (B), it is obtained that:

[0266]

[0267] Then substituting i in (C) with the above equation, it is obtained

[0268] Therefore:

[0269] [make ],but

[0270]

[0271] therefore:

[0272] The final equation can be simplified to: RVD 2 .R 2 +4D 2 .RVD.R+4D 4 -2D 2 RVD 2 =0, But R can only be positive, so the actual result is:

[0273] in

[0274] Based on this, all components can be calculated as follows:

[0275] UR3 = PV1V2*R3 / RVD, where PVIV2 = the crosstalk percentage of V1 to V2 when V2 is shorted to ground.

[0276] i1=UR3 / R3 (we know UR3 and R3)

[0277] in

[0278] Zc=R.Tan(a)

[0279]

[0280] (in: )

[0281]

[0282] R5=RVD-R1

[0283] The various forms of crosstalk compensation algorithms described above work by simulating the error and then removing it from the measured value. This simulation can be simplified to include only one pole and the effect of one side on the other side (for example, V1 on V2). The different calculations for each pole pair can then be combined in an algorithm as described previously.

[0284] The algorithm is based on the following equations, which are based on Fig.19 The Thevenin model:

[0285] U=V1-V2*(R3+R5) / (R1+R3+R5)

[0286] i=(U-Uc) / R[where U(0)=0)]

[0287] ∫(i.dt)[=previous i+i(t)*0.001*t(ms)]

[0288] Uc = (1 / C)*∫(i.dt) [Use the calculated ∫(j.dt) until the previous sample]

[0289] Based on this, the measured error is calculated as E(t)=R1.(i)t.

[0290] The calculation of the factor K1dV1 / dtMax=V1Max is explained below.

[0291] The capacitive crosstalk on V2 caused by the voltage applied on V1 is called kV1V2:

[0292] kV1V2=k1*PV1V2

[0293] in:

[0294]

[0295] PV1V2 = Percentage of V2 crosstalk from V1 to V2 (here PV1V2 = 5.86, because when V2 = 0, the crosstalk is 5.86% V1)

[0296] K1=Make Factor required to have 1% amplitude equal to V1

[0297]

[0298] The factor K1 can be calculated as follows:

[0299] The original signal of amplitude A is V1(t)=A.sin(ωt).

[0300] Considering that the signal has frequency f, V1(t)=A.sin(2π.ft).

[0301] So the derivative of this signal is DV1(t)=A.2π.f.cos(2π.ft).

[0302] To obtain the same amplitude as V1, DV1 must be multiplied by the factor 1 / (2π.f).

[0303] Considering that t is in milliseconds, in order to have the same amplitude as V1, for 100% of V1, DV1 must be multiplied by the factor 1000 / 2π.f.

[0304] To obtain the same amplitude as V1 at 1%, DV1 must be multiplied by the factor

[0305] Therefore, since a 50 Hz signal was used during calibration, k1 = 10 / 2π.f = 0.03183, and for a crosstalk of 5.86%, kV1V2 = 5.86 x 0.03183 = 0.187.

[0306] Although generally described above with reference to electrical switching devices and / or medium to high voltage applications, it should be understood that various aspects are equally applicable to other applications, including low voltage applications, audio systems, communication systems, and medical equipment, where crosstalk may affect voltage measurements at one or more points in the system, and various aspects are used when any analog circuit is not perfectly isolated from noise and noise sources are sampled. This can improve measurement accuracy in a variety of applications including automotive electronics, avionics, and sensors.

[0307] It should also be understood that the various methods and systems described may be used to compensate for crosstalk caused by capacitive coupling of current rather than voltage.

[0308] Those skilled in the art will appreciate that any of a variety of techniques and technologies may be used to represent information and signals. For example, data, instructions, commands, information, signals, bits, symbols, and chips may be referenced throughout the above description and may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0309] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits and algorithmic steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software or instructions or a combination of the two. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits and steps have been generally described above according to their functions. Whether this function is implemented as hardware or software depends on specific application and the design constraints imposed on the entire system. Those skilled in the art can implement the described function in different ways for each specific application, but this implementation decision should not be interpreted as causing the scope of the various aspects described herein to depart.

[0310] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein can be directly embodied in hardware, in a software module run by a processor, or in a combination of the two. For hardware implementations, processing can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or their combinations. Software modules, also referred to as computer programs, computer codes or instructions, can include many source code or target code segments or instructions, and can reside in any computer-readable medium, such as RAM memory, flash memory, ROM memory, EPROM memory, registers, hard disks, removable disks, CD-ROMs, DVD-ROMs, Blu-ray discs, or any other form of computer-readable medium. In some aspects, computer-readable media can include non-temporary computer-readable media (e.g., tangible media). In addition, for other aspects, computer-readable media can include temporary computer-readable media (e.g., signals). The above combination should also be included in the scope of computer-readable media. On the other hand, computer-readable media can be integrated into a processor. The processor and computer readable medium may reside in an ASIC or related device. The software code may be stored in a storage unit, and the processor may be configured to execute them. The memory unit may be implemented inside the processor or outside the processor. In the case of external implementation of the processor, the memory unit may be communicatively coupled to the processor by various means known in the art.

[0311] In addition, it should be understood that the modules and / or other suitable means for performing the methods and techniques described herein can be downloaded and / or otherwise obtained by a computing device. For example, such a device can be coupled to a server to facilitate the transfer of the device for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage device (e.g., RAM, ROM, a physical storage medium such as a compact disk (CD) or a floppy disk, etc.), so that the computing device can obtain the various methods when the storage device is coupled to the device or provided to the device. In addition, any other suitable technology for providing the methods and techniques described herein to the device can be utilized.

[0312] In one form, an aspect may include a computer program product for performing the methods or operations presented herein. For example, such a computer program product may include a computer (or processor) readable medium having stored (and / or encoded) thereon instructions that may be executed by one or more processors to perform the operations described herein. For some aspects, the computer program product may include packaging materials.

[0313] The method disclosed herein includes one or more steps or actions for implementing the method. The method steps and / or actions can be interchangeable with each other without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions can be modified without departing from the scope of the claims.

[0314] The system can be a computer-implemented system, including a display device, a processor, a memory, and an input device. The memory can include instructions that cause the processor to run the method described herein. The processor, the memory, and the display device can be included in a standard computing device, such as a desktop computer, a portable computing device, such as a laptop computer or a tablet computer, or they can be included in a customized device or system. The computing device can be a single computing or programmable device, or a distributed device including several components that are operably (or functionally) connected via a wired or wireless connection. An embodiment of the computing device includes a central processing unit (CPU), a memory, a display device, and can include input devices such as a keyboard, a mouse, etc. The CPU includes an input / output interface, an arithmetic and logic unit (ALU), and a control unit and a program counter element, which communicates with input and output devices (such as input devices and display devices) through an input / output interface. The input / output interface can include a network interface and / or a communication module for communicating with an equivalent communication module in another device using a predefined communication protocol (e.g., Bluetooth, Zigbee, IEEE802.15, IEEE 802.11, TCP / IP, UDP, etc.). A graphics processing unit (GPU) may also be included. The display device may include a flat-panel display (e.g., LCD, LED, plasma, touch screen, etc.), a projector, a CRT, etc. The computing device may include a single CPU (single core) or multiple CPUs (multi-core), or multiple processors. The computing device may use a parallel processor, a vector processor, or a distributed computing device. The memory is operably coupled to one or more processors and may include RAM and ROM components and may be disposed inside or outside the device. The memory may be used to store an operating system and additional software modules or instructions. One or more processors may be configured to load and run software modules or instructions stored in the memory.

[0315] Throughout the specification and following claims, unless the context requires otherwise, the words "comprise" and "comprising" and variations such as "including" and "comprising", will be understood to imply the inclusion of stated integers or groups of integers but not the exclusion of any other integers or groups of integers.

[0316] The reference to any prior art in this specification is not, and should not be taken as, any form of suggestion that such prior art forms part of the common general knowledge.

[0317] Those skilled in the art will appreciate that the use of the various aspects is not limited to the specific applications described. They are also not limited to the embodiments described for the specific elements and / or features described or depicted herein. It should be understood that the various aspects are not limited to the disclosed one or more embodiments, but are capable of various rearrangements, modifications and substitutions without departing from the scope set forth and defined by the appended claims.

Claims

1. A method for obtaining characteristic measurement values ​​K and α of an electrical system comprising at least two terminals, the method comprising: injecting a reference voltage at a first terminal of the at least two terminals; measuring a voltage at a second terminal of the at least two terminals to provide a measured voltage, the second terminal being grounded; measuring the amplitude ratio between the injected reference voltage and the measured voltage to provide a K value; as well as The phase angle difference between the injected reference voltage and the measured voltage is measured to provide an angle value α.

2. The method of claim 1 further comprising repeating the steps of claim 1 for each terminal pair to obtain a paired terminal-specific K value and angle value α for each terminal pair.

3. A method of providing a compensated voltage measurement of a voltage measurement in an electrical system, the voltage measurement including an error from crosstalk, the method comprising: receiving a voltage measurement of the electrical system; as well as removing at least the capacitive component of the error from the crosstalk to provide a compensated voltage measurement, The capacitive component is determined using the K and the α obtained according to the method of claim 1 .

4. The method of claim 3, wherein: The capacitive component is determined by multiplying a capacitance coefficient by a change in voltage relative to a previously measured voltage measurement, and wherein the determination of the capacitance coefficient uses K and α.

5. The method of claim 4, wherein: The capacitance coefficient is determined by Ksin(α).

6. The method of claim 4, wherein: The capacitance coefficient is determined based on an impedance value obtained from a characterization equivalent circuit of the electrical system, and wherein the determination of the impedance value uses the K and the α.

7. The method of any one of claims 3 to 5, further comprising removing a resistance component of the error.

8. The method of claim 7, wherein: The resistance component is determined by Kcos(α).

9. A method as claimed in any one of claims 3 to 5, comprising applying the following function: in: V2comp is the compensation voltage measurement value of the measurement value V2; V2measured is the measured voltage; KcU1V2 is the capacitance coefficient determined for the effect of U1 on V2; KcV1V2 is the capacitance coefficient determined for the effect of V1 on V2; KcW1V2 is the capacitance coefficient determined for the effect of W1 on V2; KcU2V2 is the capacitance coefficient determined for the effect of U2 on V2; KcW2V2 is the capacitance coefficient determined for the effect of W2 on V2; dU1 / dt is the voltage change between the voltage measurement value U1 and the previously measured voltage measurement value U1; dV2 / dt is the voltage change between the voltage measurement value V2 and the previously measured voltage measurement value V2; dV1 / dt is the voltage change between the voltage measurement value V1 and the previously measured voltage measurement value V1; dW1 / dt is the voltage change between the voltage measurement value W1 and the previously measured voltage measurement value W1; dU2 / dt is the voltage change between the voltage measurement value U2 and the previously measured voltage measurement value U2; as well as dW2 / dt is the voltage change between the voltage measurement value W2 and the previously measured voltage measurement value W2.

10. The method of claim 7, comprising applying the function: in: V2comp is the compensation voltage measurement value of the measurement value V2; V2measured is the measured voltage; KcU1V2 is the capacitance coefficient determined for the effect of U1 on V2; KcV1V2 is the capacitance coefficient determined for the effect of V1 on V2; KcW1V2 is the capacitance coefficient determined for the effect of W1 on V2; KcU2V2 is the capacitance coefficient determined for the effect of U2 on V2; KcW2V2 is the capacitance coefficient determined for the effect of W2 on V2; dU1 / dt is the voltage change between the voltage measurement value U1 and the previously measured voltage measurement value U1; dV2 / dt is the voltage change between the voltage measurement value V2 and the previously measured voltage measurement value V2; dV1 / dt is the voltage change between the voltage measurement value V1 and the previously measured voltage measurement value V1; dW1 / dt is the voltage change between the voltage measurement value W1 and the previously measured voltage measurement value W1; dU2 / dt is the voltage change between the voltage measurement value U2 and the previously measured voltage measurement value U2; dW2 / dt is the voltage change between the voltage measurement value W2 and the previously measured voltage measurement value W2; U1 is the measured voltage U1; V1 is the measured voltage V1; V2 is the measured voltage V2; W1 is the measured voltage W1; U2 is the measured voltage U2; W2 is the measured voltage W2; KRU1V1 is the resistance coefficient determined for the effect of U1 on V1; KRV1V2 is the resistance coefficient determined for the effect of V1 on V2; KRW1V2 is the resistance coefficient determined for the effect of W1 on V2; KRU2V2 is the resistivity determined for the effect of U2 on V2; and KRW2V2 is the resistivity determined for the effect of W2 on V2.

11. The method of claim 6, comprising applying the function: in: KCU1V2 is the capacitance coefficient of the effect of U1 on V2; KCV1V2 is the capacitance coefficient of the effect of V1 on V2; KCW1V2 is the capacitance coefficient of the effect of W1 on V2; KCU2V2 is the capacitance coefficient of the effect of U2 on V2; KCW2V2 is the capacitance coefficient of the effect of W2 on V2; dU1 / dt is the voltage change between the voltage measurement value U1 and the previously measured voltage measurement value U1; dV2 / dt is the voltage change between the voltage measurement value V2 and the previously measured voltage measurement value V2; dV1 / dt is the voltage change between the voltage measurement value V1 and the previously measured voltage measurement value V1; dW1 / dt is the voltage change between the voltage measurement value W1 and the previously measured voltage measurement value W1; dU2 / dt is the voltage change between the voltage measurement value U2 and the previously measured voltage measurement value U2; as well as dW2 / dt is the voltage change between the voltage measurement value W2 and the previously measured voltage measurement value W2.

12. The method of claim 3, wherein the error is provided by in: E is the error from the crosstalk of V1 to V2; Kc is the capacitance coefficient of error; K2 is the error component; dV1 / dt is the change in voltage V1 during sampling time dt relative to the previously measured voltage V1; dV2 / dt is the change in voltage V2 during sampling time dt relative to the previously measured voltage V2.

13. The method of claim 6, comprising applying the function: in: KCU1V2 is the capacitance coefficient of the effect of U1 on V2; KCV1V2 is the capacitance coefficient of the effect of V1 on V2; KCW1V2 is the capacitance coefficient of the effect of W1 on V2; KCU2V2 is the capacitance coefficient of the effect of U2 on V2; KCW2V2 is the capacitance coefficient of the effect of W2 on V2; dU1 / dt is the voltage change between the voltage measurement value U1 and the previously measured voltage measurement value U1; dV2 / dt is the voltage change between the voltage measurement value V2 and the previously measured voltage measurement value V2; dV1 / dt is the voltage change between the voltage measurement value V1 and the previously measured voltage measurement value V1; dW1 / dt is the voltage change between the voltage measurement value W1 and the previously measured voltage measurement value W1; dU2 / dt is the voltage change between the voltage measurement value U2 and the previously measured voltage measurement value U2; dW2 / dt is the voltage change between the voltage measurement value W2 and the previously measured voltage measurement value W2; K2U1V2 is the error E of V2 U1V2 The coefficient factor of the effect of ; K2V1V2 is the error E of V2 V1V2 The coefficient factor of the effect of ; K2W1V2 is the coefficient factor of the effect of W1 on V2; K2U2V2 is the coefficient factor for the effect of U2 on V2; and K2W2V2 is the coefficient factor of the effect of W2 on V2.

14. A method for determining a compensation algorithm for compensating voltage measurements of an electrical system, the compensation algorithm comprising one or more compensation coefficients; the method comprising deriving the one or more compensation coefficients based on a circuit characterizing the electrical system, wherein the derivation of the one or more compensation coefficients uses the K and the α obtained according to the method of claim 1.

15. A method for providing compensated voltage measurements of voltage measurements in an electrical system, the method comprising: measuring a voltage at a measurement terminal of the electrical system to provide a voltage measurement, and A compensated voltage measurement is determined based on the voltage measurement and at least one crosstalk coefficient calculated during an initial characterization phase, wherein the calculation of the at least one crosstalk coefficient uses the K and the α obtained according to the method of claim 1 .

16. The method of claim 15, wherein: The at least one crosstalk coefficient corresponds to a capacitive component of a comparison of the reference voltage signal and the measured capacitive coupling signal.

17. An apparatus for controlling an electrical system based on one or more voltage measurements of the electrical system, the apparatus comprising: an input for receiving data corresponding to the one or more voltage measurements; a data processor for processing the received data and for generating data corresponding to the compensation voltage measurement value; as well as an output for controlling the electrical system based on the compensation voltage measurement; The processor comprises executable software, and the executable software is used to enable the processor to execute the method as claimed in any one of claims 3 to 13.

18. A non-transitory computer-readable medium containing executable codes for causing a processor to execute the method according to any one of claims 3 to 13.

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