Capacitive current measuring method and system

Abstract

The invention discloses a capacitance current measurement method and system, and the method comprises the steps: carrying out N times of measurement on an arc suppression coil grounding circuit, obtaining N parameters, N being an integer greater than 1, N times of measurement being in one-to-one correspondence with N parameters, the arc suppression coil grounding circuit comprising a host arc suppression coil and a slave arc suppression coil, the host arc suppression coil and the slave arc suppression coil run in parallel, and the parameter is a system capacitive reactance value or a reactance value of the slave arc suppression coil or a system capacitive current; m parameters are determined from the N parameters, the M parameters are parameters located in a preset interval in the N parameters, the preset interval is a confidence interval determined by normal distribution statistical analysis based on the N parameters, and M is a positive integer smaller than or equal to N; performing first processing on the M parameters to obtain M data, wherein the first processing is used for suppressing high-frequency noise interference; a target capacitive current is determined based on the M data. The method can improve the measurement precision of the capacitive current of the system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power distribution network risk analysis and control, and particularly relates to a measurement method and system of a capacitive current. BACKGROUND

[0002] In a large substation and a multi-zone power supply system, parallel operation of arc suppression coils is a mainstream scheme for improving the reliability of ground fault compensation. The arc suppression coil can effectively control and compensate the system capacitive current in the power grid, thereby reducing the influence of the ground fault on the stability of the system.

[0003] The scheme of parallel operation of arc suppression coils depends on accurate measurement of the system capacitive current. However, the existing measurement technology faces severe challenges: accurate measurement of the system capacitive current requires an 18-bit analog-to-digital converter (ADC) resolution to ensure the accuracy of the measurement result. However, the commonly used chip limit is only 16 bits, and using this chip for measurement will cause a large error, thereby affecting the effect of parallel operation of the arc suppression coil, reducing the reliability of the ground fault compensation, and increasing the operation risk of the system.

[0004] Therefore, how to improve the measurement accuracy of the system capacitive current needs further research. SUMMARY

[0005] The embodiments of the present application provide a measurement method and system of a capacitive current to realize accurate measurement of the system capacitive current.

[0006] In a first aspect, the embodiments of the present application provide a measurement method of a capacitive current, comprising: measuring an arc suppression coil grounding circuit N times to obtain N parameters, the N being an integer greater than 1, the N measurements corresponding one-to-one to the N parameters, the arc suppression coil grounding circuit comprising a master arc suppression coil and a slave arc suppression coil, the master arc suppression coil and the slave arc suppression coil operating in parallel, and the parameters being a system capacitive reactance value or a reactance value of the slave arc suppression coil or a system capacitive current; determining M parameters from the N parameters, the M parameters being parameters in a preset interval in the N parameters, the preset interval being a confidence interval determined based on normal distribution statistical analysis of the N parameters, and the M being a positive integer less than or equal to the N; performing first processing on the M parameters to obtain M data, the first processing being used to suppress high-frequency noise interference; determining a target capacitive current based on the M data.

[0007] In the embodiment of the present application, the method removes N-M abnormal values from N parameters by normal distribution modeling to obtain M parameters, improves data quality, performs first processing on the M parameters to obtain M data, and suppresses high-frequency noise interference; and determines a target capacitor current based on the M data, thereby improving the measurement accuracy of the system capacitor current.

[0008] In combination with the first aspect, in a possible implementation, the parameter is the system capacitor current; and the determining of the target capacitor current based on the M data includes: averaging the M data to obtain the target capacitor current.

[0009] In combination with the first aspect, in a possible implementation, the parameter is the system reactance value or the reactance value of the slave arc suppression coil; and the determining of the target capacitor current based on the M data includes: averaging the M data to obtain a target parameter; and obtaining the target capacitor current based on the target parameter.

[0010] In combination with the first aspect, in a possible implementation, the first processing is Gaussian filtering.

[0011] In combination with the first aspect, in a possible implementation, the preset interval is , the is a mean value of the N parameters, and the is a standard deviation of the N parameters.

[0012] In the embodiment of the present application, the method removes abnormal values by criterion, that is, removes parameters located outside the range from N parameters, improves data quality, and thus improves the accuracy of data analysis.

[0013] In combination with the first aspect, in a possible implementation, the arc suppression coil grounding circuit further includes a first grounding transformer configured to mount the master arc suppression coil; and the N measurements on the arc suppression coil grounding circuit to obtain N parameters include: performing N measurement processes to obtain the N parameters, the N parameters including an i-th parameter, and the i being a positive integer less than or equal to the N; The N times of measurement processes include the i th measurement process, the i th measurement process includes injecting P signals into the neutral point of the first grounding transformer, the P signals have different frequencies, and P is an integer greater than 1; a parameter set is collected, the parameter set includes an output current of the master arc suppression coil corresponding to each of the P signals, an injected current of the neutral point of the first grounding transformer, and a voltage of the neutral point of the first grounding transformer; and the i th parameter is determined based on the frequencies of the P signals and the parameter set.

[0014] With reference to the first aspect, in a possible implementation, the arc suppression coil grounding circuit further includes a first damping resistor in series with the slave arc suppression coil; the i th parameter is determined based on the frequencies of the P signals and the parameter set, and P is equal to 3; or the i th parameter is determined based on the frequencies of the P signals, the parameter set, and a resistance value of the first damping resistor, and P is equal to 2.

[0015] In the embodiment of the present application, the method can complete the measurement of N parameters by injecting two or three signals into the neutral point of the first grounding transformer, thereby improving the flexibility of the system. If the measurement of the i th parameter is completed by injecting three signals into the neutral point of the first grounding transformer, the resistance value of the first damping resistor does not need to be set, and the calculation is more flexible and simple.

[0016] With reference to the first aspect, in a possible implementation, the frequencies of the P signals are respectively } and the is determined based on times of the .

[0017] With reference to the first aspect, in a possible implementation, P is equal to 3, the frequencies of the P signals are respectively } and the is 8 times of the , the is 16 times of the .

[0018] With reference to the first aspect, in a possible implementation, the arc suppression coil grounding circuit further includes a ground capacitance; in the N times of measurement, the capacitance value of the ground capacitance is a same value and the gear of the slave arc suppression coil is a same gear.

[0019] In the embodiment of the present application, the accuracy of the system capacitance current measurement is improved by controlling variables, such as fixing the capacitance value of the ground capacitance and the gear of the slave arc suppression coil.

[0020] In combination with the first aspect, in a possible implementation, the i-th measurement process satisfies a first condition, and the first condition includes at least one of the following: The amplitude of the P signals does not exceed a first threshold value; The frequency of the P signals does not exceed a second threshold value; The change value of the ambient temperature of the arc suppression coil grounding circuit is less than a third threshold value; The change value of the ambient humidity of the arc suppression coil grounding circuit is less than a fourth threshold value; The multiple ADC sampling clocks are synchronized, and the multiple ADCs are used to collect the output current of the host arc suppression coil, the injected current of the neutral point of the first grounding transformer, and the voltage of the neutral point of the first grounding transformer.

[0021] In the embodiments of the present application, the amplitude or frequency of the injected P signals is kept stable, which can improve the signal quality; the ambient temperature and humidity are kept constant, which can reduce external interference; the multiple ADC sampling clocks are kept synchronized, which can eliminate timing jitter; therefore, the i-th measurement process satisfying the first condition can improve the measurement accuracy of the system capacitive current.

[0022] In a second aspect, the embodiments of the present application provide a system for measuring a capacitive current, including: A measurement unit configured to measure an arc suppression coil grounding circuit for N times to obtain N parameters, where N is an integer greater than 1, the N measurements correspond to the N parameters one by one, the arc suppression coil grounding circuit includes a host arc suppression coil and a slave arc suppression coil, the host arc suppression coil and the slave arc suppression coil operate side by side, and the parameters are system capacitive reactance values or reactance values of the slave arc suppression coil or system capacitive currents; A first determination unit configured to determine M parameters from the N parameters, where the M parameters are parameters in a preset interval in the N parameters, the preset interval is a confidence interval determined based on normal distribution statistical analysis of the N parameters, and M is a positive integer less than or equal to N; A processing unit configured to perform first processing on the M parameters to obtain M data, where the first processing is used to suppress high-frequency noise interference; A second determination unit configured to determine a target capacitive current based on the M data.

[0023] In a third aspect, the embodiments of the present application provide an electronic device including a memory, a processor, and executable program code stored in the memory and executable on the processor, and the processor executes the executable program code to perform the steps of the method as described in the first aspect.

[0024] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium, and the computer readable storage medium stores an executable program code. The executable program code includes execution instructions for performing the steps of the method in the first aspect.

[0025] In a fifth aspect, an embodiment of the present application provides a computer program product. The computer program product includes a non-transitory computer readable storage medium storing a computer program. The computer program is operable to cause a computer to perform some or all of the steps of the method described in the first aspect of the embodiments of the present application. The computer program product can be a software installation package. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0027] Figure 1 is an equivalent schematic diagram of parallel operation of an arc-extinguishing coil provided by an embodiment of the present application.

[0028] Figure 2 is a schematic diagram of an arc-extinguishing coil grounding system provided by an embodiment of the present application.

[0029] Figure 3 is a flowchart of a measurement method of a capacitive current provided by an embodiment of the present application.

[0030] Figure 4 is a functional unit composition block diagram of a measurement system of a capacitive current provided by an embodiment of the present application.

[0031] Figure 5 is a functional unit composition block diagram of another measurement system of a capacitive current provided by an embodiment of the present application.

[0032] Figure 6 is a structural schematic diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0033] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the drawings in the embodiments of the present application, so that those skilled in the art can better understand the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0034] The terms "first", "second", and the like in the description and claims of the present application and the above drawings are used to distinguish different objects, and are not used to describe a particular order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed or can optionally include other steps or units inherent to the process, method, product or device.

[0035] Reference herein to "embodiments" means that the particular features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0036] In large substations and multi-zone power supply systems, parallel operation of arc suppression coils is the mainstream scheme to improve the reliability of ground fault compensation, and its equivalent principle is shown in Figure 1 In Figure 1 , the equivalent principle diagram of parallel operation of arc suppression coils includes a voltage source US, a master arc suppression coil XH1, a slave arc suppression coil XH2, a master arc suppression coil tail end damping resistor Rn1, a slave arc suppression coil tail end damping resistor Rn2, an inductor L0, a system damping resistor Rc and a system capacitor C. Parallel operation of arc suppression coils can effectively control and compensate the system capacitor current in the power grid, thereby reducing the impact of ground faults on system stability.

[0037] The parallel operation of arc suppression coils relies on the accurate measurement of the system's capacitive current. However, existing measurement techniques face significant challenges: accurate measurement of the system's capacitive current requires an 18-bit ADC resolution to ensure the accuracy of the measurement results. However, currently used chips have a maximum resolution of only 16 bits, and practical measurements show that a 16-bit ADC retaining 4 decimal places has an error exceeding 100%. For example, when measuring a system capacitance of 38.43 microfarads (µF), the error reaches as high as 128.8%. This error affects the effectiveness of parallel operation of the arc suppression coils, reduces the reliability of ground fault compensation, and increases the operational risk of the system.

[0038] In large substations and multi-zone power supply systems, there are complex interactions between the inductance of the master arc suppression coil, the inductance of the slave arc suppression coil, the damping resistor at the tail end of the master arc suppression coil, the damping resistor at the tail end of the slave arc suppression coil, and the system capacitance, forming a multi-dimensional coupling network that complicates measurement and analysis. Traditional single-frequency injection methods cannot effectively solve this coupling problem, especially when the system capacitance is greater than 26.53uF, where the measurement error increases sharply to 4.16%. While dual-frequency injection methods offer some improvement, they may lead to unsolvable problems in certain situations. Furthermore, dual-frequency injection methods require pre-setting the resistance value of the damping resistor at the tail end of the slave arc suppression coil, but this value includes 1%-5% of the coil's DC resistance (in the 10Ω range), introducing a pre-set error that leads to distorted capacitance current calculations (error sensitivity reaches [value missing]). (18.5%); The three-frequency injection method does not require preset parameters, but it requires solving a binary quartic equation. High-frequency sampling distortion increases the risk of the equation having no solution.

[0039] To address the aforementioned problems, this application provides a method and system for measuring capacitive current. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0040] Please see Figure 2 , Figure 2 This is a schematic diagram of an arc suppression coil grounding system provided by example in this application. The embodiments of this application can obtain the above-mentioned parameter set through the arc suppression coil grounding system, thereby determining the target capacitive current.

[0041] In an example, the arc suppression coil grounding system includes a bus, a first zigzag type (ZNy type) grounding transformer (or referred to as a first ZNy type grounding transformer JDB1 or a first grounding transformer), a second ZNy type grounding transformer JDB2, a master arc suppression coil XH1, a slave arc suppression coil XH2, a master arc suppression coil tail end damping resistor Rn1, a slave arc suppression coil tail end damping resistor (or referred to as a first damping resistor) Rn2, a first current transformer CT1, a second current transformer CT2, a signal source Y, a single-phase voltage booster transformer BYQ, a voltage transformer PT1, a system damping resistor Rc, and line-to-ground capacitors C1 to Cn.

[0042] The bus is a device for transmitting and distributing electric energy in a power system (such as a large substation and a multi-zone power supply system); the first ZNy type grounding transformer JDB1 is used to draw a neutral point and mount a master arc suppression coil; the second ZNy type grounding transformer JDB2 is used to draw a neutral point and mount a slave arc suppression coil; the first current transformer CT1 is used to collect an output current of the master arc suppression coil; the second current transformer CT2 is used to collect an injected current of a neutral point of the first grounding transformer; the voltage transformer PT1 is used to collect a voltage of the neutral point of the first grounding transformer; the signal source Y is used to output P signals; and the single-phase voltage booster transformer BYQ is used to amplify the signals output by the signal source.

[0043] In an implementation, the arc suppression coil grounding system includes an arc suppression coil grounding circuit, which includes the first ZNy type grounding transformer JDB1, the second ZNy type grounding transformer JDB2, the master arc suppression coil XH1, the slave arc suppression coil XH2, the master arc suppression coil tail end damping resistor Rn1, the first damping resistor Rn2, the system damping resistor Rc, and the line-to-ground capacitors C1 to Cn. The arc suppression coil grounding circuit can be used to improve the reliability of grounding fault compensation. The embodiments of the present application can collect an output current of the master arc suppression coil, an injected current of a neutral point of the first grounding transformer, and a voltage of the neutral point of the first grounding transformer corresponding to each of P signals by connecting the first current transformer CT1, the second current transformer CT2, the signal source Y, the single-phase voltage booster transformer BYQ, and the voltage transformer PT1 in the arc suppression coil grounding circuit, so as to realize measurement of a system capacitance current.

[0044] The embodiments of the present application provide a method for measuring a capacitance current, which will be described in detail below with reference to the accompanying drawings.

[0045] Please refer to Figure 3 , Figure 3 is a flowchart of a method for measuring a capacitance current provided in an example of the present application. The method includes the following steps or all of the steps: S301: The electronic device measures the arc suppression coil grounding circuit N times to obtain N parameters, N is an integer greater than 1, the N times of measurement corresponds to the N parameters one by one, the arc suppression coil grounding circuit includes a master arc suppression coil and a slave arc suppression coil, the master arc suppression coil and the slave arc suppression coil operate side by side, and the parameter is a system capacitive reactance value or a reactance value of the slave arc suppression coil or a system capacitive current.

[0046] In one implementation, the arc suppression coil grounding circuit further includes a first grounding transformer (such as a first ZNy type grounding transformer JDB1 in Figure 2 ) for mounting the master arc suppression coil; the electronic device can measure the arc suppression coil grounding circuit N times to obtain N parameters, which can include: the electronic device performs N measurement processes to obtain N parameters, and the N parameters include an i-th parameter, i is a positive integer less than or equal to N.

[0047] The N measurement processes include an i-th measurement process, and the i-th measurement process includes: the electronic device injects P signals into the neutral point of the first grounding transformer, the frequencies of the P signals are different, and P is an integer greater than 1; a parameter set is collected, the parameter set includes the output current of the master arc suppression coil, the injected current of the neutral point of the first grounding transformer, and the voltage of the neutral point of the first grounding transformer corresponding to each of the P signals; based on the frequencies of the P signals and the parameter set, the i-th parameter is determined, and the parameter can be a system capacitive reactance value or a reactance value of the slave arc suppression coil or a system capacitive current.

[0048] Optionally, the frequencies of the P signals are respectively , determined based on multiples of . For example, P is equal to 2, and the frequencies of the P signals are respectively , determined based on multiples of , such as is 8 times ; for another example, P is equal to 3, and the frequencies of the P signals are respectively , and determined based on multiples of , such as is 8 times , is 16 times .

[0049] Optionally, the P can be equal to 2 or 3. The arc suppression coil grounding circuit further comprises a first damping resistor, the first damping resistor is connected in series with the slave arc suppression coil, if the i th parameter is determined based on the frequency of the P signals and the parameter set, the P can be equal to 3; or, if the i th parameter is determined based on the frequency of the P signals, the parameter set and the resistance value of the first damping resistor, the P can be equal to 2.

[0050] For example, if the resistance value of the first damping resistor is a known quantity, the i th measurement process can comprise: the electronic device injects 2 signals into the neutral point of the first grounding transformer, the frequencies of the 2 signals can be and 8 ; the electronic device collects the output current of the host arc suppression coil, the injected current of the neutral point of the first grounding transformer and the voltage of the neutral point of the first grounding transformer corresponding to each of the 2 signals; the electronic device can determine the i th parameter based on the resistance value of the first damping resistor, the output current of the host arc suppression coil corresponding to each of the 2 signals, the injected current of the neutral point of the first grounding transformer and the voltage of the neutral point of the first grounding transformer.

[0051] For another example, if the resistance value of the first damping resistor is an unknown quantity, the i th measurement process can comprise: the electronic device injects 3 signals into the neutral point of the first grounding transformer, the frequencies of the 3 signals can be , 8 and 16 ; the electronic device collects the output current of the host arc suppression coil, the injected current of the neutral point of the first grounding transformer and the voltage of the neutral point of the first grounding transformer corresponding to each of the 3 signals; the electronic device can determine the i th parameter based on the output current of the host arc suppression coil corresponding to each of the 3 signals, the injected current of the neutral point of the first grounding transformer and the voltage of the neutral point of the first grounding transformer.

[0052] The following will be described in conjunction with the arc suppression coil grounding system shown in Figure 2 , two methods for determining the system capacitive current and the reactance value of the slave arc suppression coil are exemplarily introduced.

[0053] Method 1: the resistance value of the first damping resistor is known, the electronic device can determine the system capacitive current by double-frequency injection method.

[0054] Exemplarily, the electronic device can inject 2 signals into the neutral point of the first grounding transformer, the 2 signals are divided into low-frequency signals and high-frequency signals according to the size of the frequency.

[0055] The circuit diagram of the arc suppression coil grounding system shown in Figure 2 can be obtained as follows: (1); (2); (3).

[0056] wherein a, b and c are measured values, a and b are respectively the real part and the imaginary part of the high-frequency injection calculated admittance minus the low-frequency injection calculated admittance, and c is the real part of the low-frequency injection calculated admittance; the high-frequency injection calculated admittance is obtained based on the output current of the host machine arc suppression coil corresponding to the high-frequency signal, the injection current of the neutral point of the first grounding transformer and the voltage of the neutral point of the first grounding transformer, and the low-frequency injection calculated admittance is obtained based on the output current of the host machine arc suppression coil corresponding to the low-frequency signal, the injection current of the neutral point of the first grounding transformer and the voltage of the neutral point of the first grounding transformer; is the ratio of the frequency of the high-frequency signal to the frequency of the low-frequency signal, is an integer greater than 1; is the resistance value of the first damping resistance; is the reactance value of the slave arc suppression coil when injecting the low-frequency signal; is the capacitive reactance value of the system when injecting the low-frequency signal; is the resistance value of the system damping resistance.

[0057] When the resistance value of the first damping resistance in formula (1), formula (2) and formula (3) is a known value, the other three unknown parameters , and can be calculated by substituting formula (1) to solve a quartic equation.

[0058] Let (4); then, (5).

[0059] Substituting into formula (2) can calculate .

[0060] Next, according to the frequency of the high-frequency signal and the frequency of the low-frequency signal, two impedance relationship formulas can be obtained, and by solving the equation, the impedance parameters of the system and the reactance value of the slave arc suppression coil can be accurately calculated.

[0061] For example, the frequency of the high-frequency signal is , the frequency of the low-frequency signal is , and the ratio of the frequency of the high-frequency signal to the frequency of the low-frequency signal is , is an integer greater than 1, i.e. the above .

[0062] (6); (7).

[0063] wherein, is the difference between the current vector of the variable signal source and the current vector of the host arc suppression coil at the same time when the variable signal source outputs frequency; is the neutral point voltage vector value of the first grounding transformer when the variable signal source outputs frequency, and is the reference vector; is the ratio of the neutral point voltage vector of the first grounding transformer when the variable signal source outputs frequency, and ; is the ratio of the neutral point voltage vector of the first grounding transformer when the variable signal source outputs frequency, and ; is the difference between the current vector of the variable signal source (such as the above signal source) and the current vector of the host arc suppression coil at the same time when the variable signal source outputs frequency; is the imaginary unit; is the system capacitive reactance value when frequency is injected; is the ground resistance value of the system. The admittance obtained by the above formula (6) - formula (7) is

[0064] , , , then the following can be obtained: ; Simplifying the above formula, the following can be obtained: ; Therefore, the following can be obtained: (8); (9); Decomposing formula (8), the following can be obtained: ; Further arrangement, get: ; Let: (10) The above formula (8) only one unknown , therefore can be calculated : (11); Square the above formula, get: (12); Drop invalid value, get actual slave arc suppression coil reactance value : (13); The calculation results (13) into formula (9) can be calculated out of system capacity value : (14); From the above, the system capacity can be directly converted to get: ; The calculation of and into formula (5) can be calculated to get the system resistance to ground value .

[0065] To formula (5) is simplified, let the calculation results , that is , Further simplification, can get: ; ; (15); Wherein, for measurement and calculation value, the system resistance to ground value for the real part of the system impedance value, the imaginary part This is not needed, this application does not make superfluous here.

[0066] The calculation results (14) for frequency transformation, get the system under power frequency to ground capacity : ; (16); System capacitor current According to the system bus phase voltage Divided by the system capacitance Obtained: ; Then the system capacitance Can be directly converted to: .

[0067] Method 2: The resistance of the first damping resistor is unknown, and the electronic device can determine the system capacitance current by the three-frequency injection method.

[0068] For example, the electronic device injects three signals into the neutral point of the first grounding transformer, and the frequencies of the three signals are , 8 and 16 .

[0069] Here, the formula (8) in the above method 1 is directly quoted without further derivation: ; Where, is the frequency multiple of , since the frequencies of the three injected signals are , 8 and 16 , the following equations are established with 8 and 16 as examples: ; ; ; After simplifying the above two equations, we can get: ; (17); Where, is the measured value when = 8, is the output current of the host arc suppression coil, the injection current of the neutral point of the first grounding transformer, and the voltage of the neutral point of the first grounding transformer based on the signal with a frequency of 8 ; is the measured value when = 16, is the output current of the host arc suppression coil, the injection current of the neutral point of the first grounding transformer, and the voltage of the neutral point of the first grounding transformer based on the signal with a frequency of 16 .

[0070] ​ R1 is the resistance value of the first damping resistor; X2 is the reactance value of the slave arc suppression coil when injecting a signal with a frequency of .

[0071] Define the intermediate variables , and as follows: ; ; ; Substitute and into the above formula to expand, we get: ; ; ; ; (18).

[0072] Substitute formula (18) into the above formula (8) to calculate the reactance value of the slave arc suppression coil .

[0073] ; ; ; (19); Then the slave arc suppression coil inductance value L2 can be converted to obtain: .

[0074] Substitute the calculated and into formula (14), and take =8 and =16 as an example to establish equations to calculate the system capacitive reactance value .

[0075] The system capacitance can be directly converted to obtain: ; The frequency of the calculated result is transformed to obtain the system ground capacitive reactance at power frequency : ; ; System capacitance current i.e. according to the system bus phase voltage divided by the system earth capacitance gives: ; Optionally, the i-th measurement process satisfies a first condition, and the first condition comprises at least one of: amplitudes of the P signals do not exceed a first threshold; frequencies of the P signals do not exceed a second threshold; a change value of an ambient temperature where the arc suppression coil grounding circuit is located is less than a third threshold; a change value of an ambient humidity where the arc suppression coil grounding circuit is located is less than a fourth threshold; a plurality of ADC sampling clocks are synchronized, and the plurality of ADCs are used to collect an output current of the host arc suppression coil, an injected current of a neutral point of the first grounding transformer, and a voltage of the neutral point of the first grounding transformer. For example, the first condition can refer to that the amplitudes / frequencies of the P signals are stable, the temperature and humidity of the environment where the arc suppression coil grounding circuit is located are constant, and the plurality of ADC sampling clocks are synchronized.

[0076] Optionally, the electronic device can perform N measurements on the arc suppression coil grounding circuit, and the N measurements are independent of each other. For example, N can be greater than or equal to 30.

[0077] Illustratively, the arc suppression coil grounding circuit further comprises a ground capacitance, and in the N measurements, the capacitance value of the ground capacitance is the same value and the gear of the slave arc suppression coil is the same gear.

[0078] S302: The electronic device determines M parameters from the N parameters, the M parameters are parameters in a preset interval in the N parameters, the preset interval is a confidence interval determined based on normal distribution statistical analysis of the N parameters, and M is a positive integer less than or equal to N.

[0079] Illustratively, the N parameters can be N system capacitance currents, the electronic device determines M system capacitance currents from the N system capacitance currents, and the preset interval is a confidence interval determined based on normal distribution statistical analysis of the N system capacitance currents. Illustratively, the N parameters can be N system capacitance values, the electronic device determines M system capacitance values from the N system capacitance values, and the preset interval is a confidence interval determined based on normal distribution statistical analysis of the N system capacitance values. Illustratively, the N parameters can be N reactance values of slave arc suppression coils, the electronic device determines M reactance values of slave arc suppression coils from the N reactance values of slave arc suppression coils, and the preset interval is a confidence interval determined based on normal distribution statistical analysis of the N reactance values of slave arc suppression coils.

[0080] Optionally, the electronic device can construct a normal distribution model based on the N parameters, discard data points in the N parameters that are out of the range of the preset interval, and obtain the M parameters.

[0081] Optionally, the preset interval can be Electronic devices can discard N parameters that exceed the limit. From the range of data points, we obtain M parameters, where, Let N be the mean of the parameters. Let N be the standard deviation of the N parameters.

[0082] in, , ,in, The first of N parameters One parameter.

[0083] S303: The electronic device performs a first processing on M parameters to obtain M data. The first processing is used to suppress high-frequency noise interference.

[0084] Optionally, the first processing can be Gaussian filtering, whereby the electronic device can perform Gaussian filtering on the M parameters to obtain M data.

[0085] For example, the M parameters include the first... Parameters The M data points include the first... Data , For a positive integer less than or equal to M, the electronic device can apply formula (20) to the first... Parameters Perform Gaussian filtering to obtain the first... Data .

[0086] (20); in, Let M be the mean of the M parameters. The standard deviation of M parameters.

[0087] Optionally, It can be the mathematical expectation of M parameters.

[0088] S304: Electronic equipment determines the target capacitor current based on M data points.

[0089] In one implementation, the parameter is the system capacitor current. Then, the M data points are the M system capacitor currents that have undergone the first processing. The electronic device calculates the average of these M data points to determine the target capacitor current.

[0090] In another implementation, the parameter is the system capacitive reactance value or the reactance value of the slave arc suppression coil. Then, the M data are the M system capacitive reactance values ​​or slave arc suppression coil reactance values ​​that have undergone the first processing. The electronic device calculates the average of the M data to obtain the target parameter. Based on the target parameter, the electronic device determines the target capacitor current.

[0091] For example, if the parameter is the system capacitive reactance value, then the M data points are the M system capacitive reactance values ​​that have undergone the first processing. The electronic device calculates the average of the M data points to obtain the target parameter, which is the system capacitive reactance value. Based on this target parameter, the electronic device determines the target capacitor current.

[0092] For example, if the parameter is the reactance value of the slave arc suppression coil, then the M data points are the reactance values ​​of the slave arc suppression coils that have undergone the first processing. The electronic device calculates the average of the M data points to obtain the target parameter, which is the reactance value of the slave arc suppression coil. Based on this target parameter, the electronic device determines the target capacitor current.

[0093] In the embodiments of this application, the electronic device determines the target capacitor current based on the target parameters. For example, the method of determining the system capacitor current based on the system capacitive reactance value or the reactance value of the slave arc suppression coil can refer to method 1 or method 2 in step S301 above, which will not be elaborated here.

[0094] To verify the capacitance current measurement method described in the embodiments of this application, the measurement results of several experiments are presented below as an example. The experimental circuit is as follows: Figure 2 As shown.

[0095] For example, the application scenarios of this application embodiment can be power substations, distribution rooms, or other scenarios. These application scenarios may include transformers, circuit breakers, capacitors, busbars, grounding devices, cables, and conductors, etc., wherein transformers are used to change voltage levels to adapt to different power transmission demands; circuit breakers are used for circuit protection, disconnecting the circuit when an overload or short circuit is detected; capacitors are used to store energy and regulate voltage; busbars are used to connect various devices and transmit electrical energy; grounding devices are used to ensure the safety of equipment and personnel and prevent electric shock; and cables and conductors are used to transmit power and signals.

[0096] The embodiments of this application are used to measure the system capacitive current to ensure the normal operation of the grounding device.

[0097] Experiment 1: The slave arc suppression coil XH2 is fixed at position 1. The theoretical inductance of the slave arc suppression coil (i.e., the slave inductance in Tables 1 and 2) is 1213.6mH. The resistance of the damping resistor Rn2 at the tail end of the slave arc suppression coil is 10Ω. The master arc suppression coil is tuned to the resonance compensation position according to the number of outgoing lines. A signal source (or injection source) injects signals of different frequencies into the neutral point of the first ZNy type grounding transformer JDB1 connected to the master arc suppression coil. The output current of the master arc suppression coil, the injected current at the neutral point of the first ZNy type grounding transformer JDB1, and the voltage at the neutral point of the first ZNy type grounding transformer JDB1 are collected and calculated.

[0098] For example, the measurement results of the regression number (i.e. the above N) of 50 or 30 are shown in Table 1: Table 1

[0099] For example, the measurement results of the regression number of 20 or 1 are shown in Table 2: Table 2

[0100] From Table 1 and Table 2, it can be seen that under the same system environment, with the increase of the measurement regression number, the calculation error of the inductance of the slave arc suppression coil, the system damping resistance and the system capacitance current decreases, and the error is acceptable above 30 times.

[0101] Experiment 2: The slave arc suppression coil XH2 is fixed at 5 gears, the theoretical inductance of the slave arc suppression coil (i.e. the slave inductance in Table 3 and Table 4) is 579.46 mH, the resistance value of the damping resistance Rn2 at the tail end of the slave arc suppression coil is 10Ω, and the master arc suppression coil is adjusted to the resonance compensation gear according to the number of outgoing lines. The signal source injects signals of different frequencies into the neutral point of the first ZNy type grounding transformer JDB1 with the master arc suppression coil, and collects the output current of the master arc suppression coil, the injected current of the neutral point of the first ZNy type grounding transformer JDB1 and the voltage of the neutral point of the first ZNy type grounding transformer JDB1 for calculation.

[0102] For example, the measurement results of the regression number of 50 or 30 are shown in Table 3: Table 3

[0103] For example, the measurement results of the regression number of 20 or 1 are shown in Table 4: Table 4

[0104] From Table 3 and Table 4, it can be seen that under the same system environment, with the increase of the measurement regression number, the calculation error of the inductance of the slave arc suppression coil, the system damping resistance and the system capacitance current decreases, and the error is acceptable above 30 times.

[0105] Experiment 3: The slave arc suppression coil XH2 is fixed at 9th gear, the theoretical inductance of the slave arc suppression coil (i.e. the slave inductance in Table 5 and Table 6) is 369.7mH, the resistance value of the tail end damping resistor Rn2 of the slave arc suppression coil is 10Ω, and the master arc suppression coil is tuned to the resonance compensation gear according to the number of outgoing lines. The signal source injects signals of different frequencies into the neutral point of the first ZNy type grounding transformer JDB1 mounted with the master arc suppression coil, and the output current of the master arc suppression coil, the injected current of the neutral point of the first ZNy type grounding transformer JDB1 and the voltage of the neutral point of the first ZNy type grounding transformer JDB1 are collected for calculation.

[0106] For example, the measurement results of 50 or 30 times of regression are shown in Table 5: Table 5

[0107] For example, the measurement results of 20 or 1 times of regression are shown in Table 6: Table 6

[0108] As can be seen from Table 5 and Table 6, under the same system environment, with the increase of the number of measurement regression times, the calculation errors of the inductance of the slave arc suppression coil, the system damping resistor and the system capacitance current are reduced, and the errors are acceptable above 30 times.

[0109] As can be seen from the above, in the embodiments of the present application, by using the hierarchical frequency optimization strategy (such as selecting the signal combination of frequencies 8 and 16 to reduce the dimension equation to a linearly solvable equation), the ADC error compensation algorithm (such as the method of screening M parameters and performing first processing on the M parameters to compensate for the error caused by the low resolution of the ADC) and the damping resistor real-time calculation method (the system damping resistor can be calculated in real time through the parameter set and the frequency of P signals, so as to eliminate the 0.1Ω level direct resistance interference), the system capacitance current measurement error is less than 0.5% under 16-bit ADC, which is 10 times higher in precision than the traditional scheme, and solves the parameter decoupling problem of parallel operation of arc suppression coils.

[0110] Consistent with the above embodiments, please refer to Figure 4 , Figure 4 is a functional unit composition block diagram of a capacitance current measurement system provided by the embodiments of the present application, as Figure 4As shown, the capacitor current measurement system 40 comprises: a measurement unit 41 configured to perform N measurements on an arc suppression coil grounding circuit to obtain N parameters, N being an integer greater than 1, the N measurements corresponding to the N parameters one by one, the arc suppression coil grounding circuit comprising a master arc suppression coil and a slave arc suppression coil, the master arc suppression coil and the slave arc suppression coil operating in parallel, the parameters being system capacitive reactance, reactance of the slave arc suppression coil or system capacitor current; a first determination unit 42 configured to determine M parameters from the N parameters, the M parameters being parameters in a preset interval in the N parameters, the preset interval being a confidence interval determined based on normal distribution statistical analysis of the N parameters, M being a positive integer less than or equal to N; a processing unit 43 configured to perform first processing on the M parameters to obtain M data, the first processing being used to suppress high-frequency noise interference; and a second determination unit 44 configured to determine a target capacitor current based on the M data.

[0111] In one possible embodiment, the parameters are the system capacitor current; and the second determination unit 44 is specifically configured to average the M data to obtain the target capacitor current.

[0112] In one possible embodiment, the parameters are the system capacitive reactance or the reactance of the slave arc suppression coil; and the second determination unit 44 is specifically configured to: average the M data to obtain a target parameter; and obtain the target capacitor current based on the target parameter.

[0113] In one possible embodiment, the first processing is Gaussian filtering.

[0114] In one possible embodiment, the preset interval is , wherein is a mean value of the N parameters, and is a standard deviation of the N parameters.

[0115] In a possible embodiment, the arc suppression coil grounding circuit further comprises a first grounding transformer configured to mount the host arc suppression coil; and the measurement unit 41 is specifically configured to: perform N measurement processes to obtain the N parameters, the N parameters comprising an i-th parameter, i being a positive integer less than or equal to N; wherein the N measurement processes comprise an i-th measurement process, the i-th measurement process comprising: injecting P signals into a neutral point of the first grounding transformer, the P signals having different frequencies, P being an integer greater than 1; collecting a parameter set, the parameter set comprising an output current of the host arc suppression coil corresponding to each of the P signals, an injected current of the neutral point of the first grounding transformer, and a voltage of the neutral point of the first grounding transformer; and determining the i-th parameter based on the frequencies of the P signals and the parameter set.

[0116] In a possible embodiment, the arc suppression coil grounding circuit further comprises a first damping resistor connected in series with the slave arc suppression coil; the i-th parameter is determined based on the frequencies of the P signals and the parameter set, and P is equal to 3; or the i-th parameter is determined based on the frequencies of the P signals, the parameter set, and a resistance value of the first damping resistor, and P is equal to 2.

[0117] In a possible embodiment, the frequencies of the P signals are respectively } and the frequencies of the P signals are respectively determined based on the frequencies of the P signals are respectively

[0118] In a possible embodiment, P is equal to 3, the frequencies of the P signals are respectively } and the frequencies of the P signals are respectively frequencies of the P signals are respectively frequencies of the P signals are respectively .

[0119] In a possible embodiment, the arc suppression coil grounding circuit further comprises a ground capacitor; in the N measurement processes, the ground capacitor has a same capacitance value and the slave arc suppression coil has a same gear.

[0120] In a possible embodiment, the i-th measurement process satisfies a first condition, and the first condition comprises at least one of: an amplitude of the P signals does not exceed a first threshold; a frequency of the P signals does not exceed a second threshold; a change of an ambient temperature where the arc suppression coil grounding circuit is located is less than a third threshold; a change of an ambient humidity where the arc suppression coil grounding circuit is located is less than a fourth threshold; a plurality of analog-to-digital converters (ADCs) are synchronized in sampling clock, and the plurality of ADCs are used to collect an output current of the host arc suppression coil, an injected current of a neutral point of the first grounding transformer, and a voltage of the neutral point of the first grounding transformer.

[0121] In the case of employing an integrated unit, please refer to Figure 5 , Figure 5 is another function unit composition block diagram of a capacitive current measurement system provided by the embodiment of the application, as Figure 5 shown, the capacitive current measurement system 40 comprises a communication module 501 and a processing module 502. The processing module 502 is configured to control and manage actions of the capacitive current measurement system 40, for example, to perform steps of the measurement unit 41, the first determination unit 42, the processing unit 43 and the second determination unit 44, and / or to perform other processes of the technology described herein. The communication module 501 is configured to interact between the capacitive current measurement system 40 and other devices.

[0122] As shown in Figure 5 , the capacitive current measurement system 40 can further comprise a storage module 503, and the storage module 503 is configured to store program codes and data of the capacitive current measurement system 40.

[0123] The processing module 502 can be a processor or a controller, for example, a central processing unit (CPU), a general processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a transistor logic device, a hardware component or any combination thereof. It can implement or execute various exemplary logical blocks, modules and circuits described in combination with the disclosure. The processor can also be a combination of computing functions, for example, a combination of one or more microprocessors, a combination of DSP and microprocessor, etc.

[0124] The communication module 501 can be a transceiver, a radio frequency (RF) circuit, a communication interface, or the like. The storage module 503 can be a memory.

[0125] All related content of each scenario involved in the method embodiments can be cited to the function description of the corresponding function module, and will not be repeated here. The capacitive current measurement system 40 can perform the capacitive current measurement method described above. Figure 3 The capacitive current measurement method shown in the figure.

[0126] Please refer to Figure 6 , Figure 6 is a structural schematic diagram of an electronic device proposed in an embodiment of the present application, as Figure 6 shown, the electronic device 600 includes a processor 610, a memory 620, a communication interface 630, and one or more programs 621, the one or more programs 621 are stored in the memory and configured to be executed by the processor, the program includes part or all steps of any capacitive current measurement method described in the method embodiments when executed, the processor, the memory and the communication interface are connected to each other and complete the communication work between each other.

[0127] The memory can be a volatile memory such as a dynamic random access memory (DRAM), or a non-volatile memory such as a mechanical hard disk. The memory is used to store a set of executable program codes, and the processor is used to call the executable program codes stored in the memory, and can execute part or all steps of any capacitive current measurement method described in the capacitive current measurement method embodiments.

[0128] The embodiments of the present application also provide a computer readable storage medium, wherein the computer readable storage medium stores a computer program for electronic data exchange, and the computer program causes a computer to execute part or all steps of any method described in the method embodiments, and the computer includes an electronic device.

[0129] The embodiments of the present application also provide a computer program product, and the computer program product includes a non-transitory computer readable storage medium storing a computer program, and the computer program is operable to cause a computer to execute part or all steps of any method described in the method embodiments. The computer program product can be a software installation package, and the computer includes an electronic device.

[0130] It should be noted that, for the above-mentioned various method embodiments, for the purpose of simple description, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited by the action sequence described, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present application.

[0131] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0132] In several embodiments provided by the present application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely schematic, and the division of the units is only a logical function division. In actual implementation, another division mode can be adopted, for example, a plurality of units or components can be combined or integrated into another system, or some features can be omitted or not executed. In addition, the coupling or direct coupling or communication connection between the units or components shown or discussed can be indirect coupling or communication connection through some interfaces, apparatuses or units, and can be electrical or other forms.

[0133] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on a plurality of network units. According to actual needs, part or all of the units can be selected to achieve the purpose of the present embodiment scheme.

[0134] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically independently, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software program module.

[0135] If the integrated unit is realized in the form of a software program module and sold or used as an independent product, it can be stored in a computer readable memory. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a memory and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned memory includes: a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0136] A person of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by a program instructing relevant hardware, and the program can be stored in a computer readable memory, which can include a flash disk, a read-only memory, a random access memory, a magnetic disk or an optical disk, etc.

[0137] The embodiments of the present application are described in detail above, and specific examples are applied in this paper to describe the principles and embodiments of the present application. The above description of the embodiments is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific embodiments and application scope will be changed; in summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A method for measuring capacitive current, characterized in that, include: The arc suppression coil grounding circuit is measured N times to obtain N parameters, where N is an integer greater than 1. The N measurements correspond one-to-one with the N parameters. The arc suppression coil grounding circuit includes a master arc suppression coil and a slave arc suppression coil, which operate in parallel. The parameters are the system capacitive reactance value, the reactance value of the slave arc suppression coil, or the system capacitive current. M parameters are determined from the N parameters, wherein the M parameters are parameters that fall within a preset interval from the N parameters, and the preset interval is a confidence interval determined based on normal distribution statistical analysis of the N parameters, wherein M is a positive integer less than or equal to N; The M parameters are subjected to a first processing to obtain M data, and the first processing is used to suppress high-frequency noise interference; The target capacitor current is determined based on the M data points.

2. The method according to claim 1, characterized in that, The parameter is the system capacitor current; determining the target capacitor current based on the M data includes: The target capacitor current is obtained by averaging the M data points.

3. The method according to claim 1, characterized in that, The parameter is the system capacitive reactance value or the reactance value of the slave arc suppression coil; determining the target capacitor current based on the M data includes: The target parameter is obtained by averaging the M data points. The target capacitor current is obtained based on the target parameters.

4. The method according to any one of claims 1-3, characterized in that, The first processing step is Gaussian filtering.

5. The method according to any one of claims 1-3, characterized in that, The preset interval is: The The mean of the N parameters, the Let be the standard deviation of the N parameters.

6. The method according to any one of claims 1-3, characterized in that, The arc suppression coil grounding circuit further includes a first grounding transformer, which is used to mount the main unit's arc suppression coil; the N measurements of the arc suppression coil grounding circuit yield N parameters, including: Perform N measurement processes to obtain the N parameters, where the N parameters include the i-th parameter, and i is a positive integer less than or equal to N; The N measurement processes include the i-th measurement process, which includes: injecting P signals into the neutral point of the first grounding transformer, wherein the P signals have different frequencies and P is an integer greater than 1; acquiring a parameter set, wherein the parameter set includes the output current of the host arc suppression coil corresponding to each of the P signals, the injected current of the neutral point of the first grounding transformer, and the voltage of the neutral point of the first grounding transformer; and determining the i-th parameter based on the frequencies of the P signals and the parameter set.

7. The method according to claim 6, characterized in that, The arc suppression coil grounding circuit further includes a first damping resistor, which is connected in series with the slave arc suppression coil; The i-th parameter is determined based on the frequencies of the P signals and the parameter set, where P equals 3; Alternatively, the i-th parameter is determined based on the frequencies of the P signals, the parameter set, and the resistance value of the first damping resistor, where P equals 2.

8. The method according to claim 6, characterized in that, The frequencies of the P signals are respectively { }, the The Based on the above The multiple is determined.

9. The method according to claim 8, characterized in that, Where P equals 3, the frequencies of the P signals are respectively { }, the 8 times the stated The 16 times the stated .

10. The method according to claim 6, characterized in that, The arc suppression coil grounding circuit also includes a ground capacitance; in the N measurements, the capacitance value of the ground capacitance is the same and the range of the slave arc suppression coil is the same.

11. The method according to claim 6, characterized in that, The i-th measurement process satisfies a first condition, which includes at least one of the following: The amplitudes of the P signals do not exceed a first threshold. Alternatively, the frequencies of the P signals do not exceed the second threshold. Alternatively, the change in ambient temperature at which the arc suppression coil grounding circuit is located is less than the third threshold. Alternatively, the change in ambient humidity where the arc suppression coil grounding circuit is located is less than the fourth threshold. Alternatively, multiple analog-to-digital converters (ADCs) can be clocked synchronously, and these ADCs can be used to acquire the output current of the host arc suppression coil, the injection current of the neutral point of the first grounding transformer, and the voltage of the neutral point of the first grounding transformer.

12. A system for measuring capacitive current, characterized in that, include: The measurement unit is used to perform N measurements on the arc suppression coil grounding circuit to obtain N parameters, where N is an integer greater than 1. The N measurements correspond one-to-one with the N parameters. The arc suppression coil grounding circuit includes a master arc suppression coil and a slave arc suppression coil, which operate in parallel. The parameters are the system capacitive reactance value, the reactance value of the slave arc suppression coil, or the system capacitive current. The first determining unit is configured to determine M parameters from the N parameters, wherein the M parameters are parameters that fall within a preset interval from the N parameters, the preset interval is a confidence interval determined based on normal distribution statistical analysis of the N parameters, and M is a positive integer less than or equal to N; The processing unit is used to perform a first processing on the M parameters to obtain M data, wherein the first processing is used to suppress high-frequency noise interference; The second determining unit is used to determine the target capacitor current based on the M data.

13. An electronic device, characterized in that, The device includes: a memory, a processor, and executable program code stored in the memory and executable on the processor, wherein the processor executes the executable program code to perform the steps of the capacitive current measurement method as described in any one of claims 1-11.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores executable program code, the executable program code including execution instructions for performing the steps of the capacitive current measurement method as described in any one of claims 1-11.

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