A loop impedance clamp meter induced voltage measurement method, device and system

Abstract

The present invention discloses a loop impedance clamp meter induced voltage measurement method, device and system, which is performed by the loop impedance clamp meter, and the method includes: controlling a voltage excitation coil to generate a first excitation voltage of a first frequency in a circuit to be measured, thereby obtaining a first induced current corresponding to the first frequency in a voltage measurement circuit; calculating a first induced voltage corresponding to the first induced current according to the first induced current and a preset induction resistor in the voltage measurement circuit, and obtaining the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured according to the number of turns of the transformer coil corresponding to the circuit to be measured and the voltage measurement coil. The present invention solves the technical problems in the prior art that the induced voltage is difficult to measure, has low accuracy, and is easily affected by external environmental factors.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage measurement, and in particular to a method and device for measuring induced voltage using a loop impedance clamp meter. Background Art

[0002] In engineering projects, a loop impedance clamp meter is often used to measure circuit impedance. This measurement relies on a key parameter: the induced voltage. This is because, in practice, it's impossible to directly measure the induced voltage using a loop impedance clamp meter. In field operations, due to technical limitations, it's not possible to directly obtain induced voltage readings from the clamp meter.

[0003] Currently, induced voltage can be measured by converting the primary voltage into the secondary induced voltage, or by directly measuring the induced voltage. However, because the core material of the clamp meter used to measure loop impedance is typically slope-film alloy, the ambient temperature and humidity during measurement, the fit and cleanliness of the clamp core interface, and the degree of core wear at the interface significantly affect the magnetic permeability of the slope-film alloy core, causing significant fluctuations in magnetic flux density. Therefore, even if the number of secondary winding turns and the primary-to-secondary ratio remain unchanged, the induced voltage will vary significantly, resulting in low measurement accuracy. Summary of the Invention

[0004] The present invention provides a method and device for measuring induced voltage using a loop impedance clamp meter, so as to solve the technical problems in the prior art of high difficulty, low accuracy and easy influence of external environmental factors in measuring induced voltage.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a method for measuring induced voltage using a loop impedance clamp meter, which is performed by the loop impedance clamp meter and includes:

[0006] The voltage excitation coil is controlled to generate a first excitation voltage of a first frequency in the circuit to be measured, thereby obtaining a first induced current corresponding to the first frequency in the voltage measurement circuit; wherein the voltage measurement circuit and the voltage excitation coil are both arranged in a loop impedance clamp meter, the circuit to be measured is a circuit required by the loop impedance clamp meter to perform impedance measurement, the voltage measurement circuit includes a voltage measurement coil, and the transformer coil corresponding to the circuit to be measured, the voltage measurement coil, and the voltage excitation coil are all arranged in the same iron core;

[0007] A first induced voltage corresponding to the first induced current is calculated based on the first induced current and a preset inductive resistance in the voltage measurement circuit. Furthermore, an actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured.

[0008] As a preferred solution, it also includes:

[0009] Using the first excitation voltage as the target induced voltage generated by the voltage excitation coil in the circuit to be tested;

[0010] Calculating, based on the target induced voltage and the first induced voltage, a first influence coefficient and a second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop when the interface corresponds to the target induced voltage and the first induced voltage, respectively;

[0011] If the ratio of the first influence coefficient to the second influence coefficient is greater than a preset range, an interface abnormality signal corresponding to the loop impedance clamp meter is generated and an alarm is issued.

[0012] If the ratio of the first influence coefficient to the second influence coefficient is not greater than a preset range, the loop impedance clamp meter is maintained to operate normally.

[0013] As a preferred solution, when the target induced voltage and the first induced voltage are obtained by calculation, the first influence coefficient and the second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop include:

[0014] E0=4.44×f1×N J ×K0,K0=B0×S0

[0015] E1=4.44×f1×N J ×K1, K1=B1×S1

[0016] Among them, E0 is the target induced voltage, E1 is the first induced voltage, f1 is the first frequency, N J is the number of turns of the voltage excitation coil, B0 is the magnetic permeability of the interface of the loop impedance clamp meter under ideal conditions, S0 is the cross-sectional area of ​​the voltage excitation coil on the interface of the loop impedance clamp meter under ideal conditions, K0 is the first influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop under ideal conditions, B1 is the magnetic permeability of the interface of the loop impedance clamp meter under actual conditions, S1 is the cross-sectional area of ​​the voltage excitation coil on the interface of the loop impedance clamp meter under actual conditions, and K1 is the second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop under actual conditions.

[0017] As a preferred solution, it also includes:

[0018] Controlling the voltage excitation coil to generate a second excitation voltage of a second frequency in the circuit to be measured, thereby obtaining a second induced current corresponding to the second frequency in the voltage measurement circuit;

[0019] A second induced voltage corresponding to the second induced current is calculated based on the second induced current and a preset induced resistance in the voltage measurement loop.

[0020] As a preferred solution, the first induced voltage corresponding to the first induced current is calculated based on the first induced current and a preset inductive resistance in the voltage measurement circuit, and the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured, specifically including:

[0021] Calculating a first induced voltage corresponding to the first induced current and a second induced voltage corresponding to the second induced current based on the first induced current and the second induced current and a preset induction resistor in the voltage measurement circuit;

[0022] Verifying the first induced voltage and the second induced voltage according to the first excitation voltage and the second excitation voltage to obtain a first difference between the first induced voltage and the first excitation voltage, and a second difference between the second induced voltage and the second excitation voltage, and comparing the first difference with the second difference;

[0023] If the first difference is less than the second difference, then calculating the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured based on the number of turns of the transformer coil and the voltage measuring coil corresponding to the circuit to be measured and the first induced voltage;

[0024] If the first difference is greater than the second difference, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is calculated based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured and the second induced voltage.

[0025] Accordingly, the present invention also provides a loop impedance clamp meter induced voltage measurement device, comprising: an acquisition module and a calculation module;

[0026] The acquisition module is configured to control the voltage excitation coil to generate a first excitation voltage of a first frequency in the circuit to be measured, thereby acquiring a first induced current corresponding to the first frequency in the voltage measurement circuit; wherein the voltage measurement circuit and the voltage excitation coil are both arranged in a loop impedance clamp meter, the circuit to be measured is a circuit required for impedance measurement by the loop impedance clamp meter, the voltage measurement circuit includes a voltage measurement coil, and the transformer coil corresponding to the circuit to be measured, the voltage measurement coil, and the voltage excitation coil are all arranged in the same iron core;

[0027] The calculation module is configured to calculate a first induced voltage corresponding to the first induced current based on the first induced current and a preset inductive resistance in the voltage measurement circuit, and to obtain an actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured.

[0028] Accordingly, the present invention further provides a loop impedance clamp meter induced voltage measurement system for performing any one of the loop impedance clamp meter induced voltage measurement methods described above, comprising: a loop impedance clamp meter and a circuit to be measured; a transformer coil is provided on the circuit to be measured;

[0029] The loop impedance clamp meter includes: a processor, and a voltage measurement circuit and a voltage excitation coil connected to the processor;

[0030] The processor is used to control the voltage excitation coil to generate a first excitation voltage of a first frequency in the circuit to be measured, thereby obtaining a first induced current corresponding to the first frequency in the voltage measurement circuit; wherein, the voltage measurement circuit and the voltage excitation coil are both arranged in a loop impedance clamp meter, the circuit to be measured is a circuit required for impedance measurement by the loop impedance clamp meter, the voltage measurement circuit includes a voltage measurement coil, and the transformer coil corresponding to the circuit to be measured, the voltage measurement coil and the voltage excitation coil are all arranged in the same iron core; based on the first induced current and the preset induction resistance in the voltage measurement circuit, the first induced voltage corresponding to the first induced current is calculated, and based on the number of turns of the transformer coil corresponding to the circuit to be measured and the voltage measurement coil, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained.

[0031] As a preferred solution, the processor is further configured to:

[0032] Using the first excitation voltage as the target induced voltage generated by the voltage excitation coil in the circuit to be tested;

[0033] Calculating, based on the target induced voltage and the first induced voltage, a first influence coefficient and a second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop when the interface corresponds to the target induced voltage and the first induced voltage, respectively;

[0034] If the ratio of the first influence coefficient to the second influence coefficient is greater than a preset range, an interface abnormality signal corresponding to the loop impedance clamp meter is generated and an alarm is issued.

[0035] If the ratio of the first influence coefficient to the second influence coefficient is not greater than a preset range, the loop impedance clamp meter is maintained to operate normally.

[0036] As a preferred embodiment, the processor is further used to: control the voltage excitation coil to generate a second excitation voltage of a second frequency in the circuit to be measured, thereby obtaining a second induced current corresponding to the second frequency in the voltage measurement circuit; and calculate a second induced voltage corresponding to the second induced current based on the second induced current and a preset induction resistance in the voltage measurement circuit.

[0037] As a preferred solution, the first induced voltage corresponding to the first induced current is calculated based on the first induced current and a preset inductive resistance in the voltage measurement circuit, and the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured, specifically including:

[0038] Calculating a first induced voltage corresponding to the first induced current and a second induced voltage corresponding to the second induced current based on the first induced current and the second induced current and a preset induction resistor in the voltage measurement circuit;

[0039] Verifying the first induced voltage and the second induced voltage according to the first excitation voltage and the second excitation voltage to obtain a first difference between the first induced voltage and the first excitation voltage, and a second difference between the second induced voltage and the second excitation voltage, and comparing the first difference with the second difference;

[0040] If the first difference is less than the second difference, then calculating the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured based on the number of turns of the transformer coil and the voltage measuring coil corresponding to the circuit to be measured and the first induced voltage;

[0041] If the first difference is greater than the second difference, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is calculated based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured and the second induced voltage.

[0042] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0043] The technical solution of the present invention addresses the problem of a large difference between the induced voltage measured before leaving the factory and the actual induced voltage on site in the existing loop impedance clamp meter. The principle of the induced voltage measurement function is improved. The voltage excitation coil is controlled in the loop impedance clamp meter to generate a first excitation voltage of a first frequency in the loop to be measured, thereby obtaining a first induced current corresponding to the first frequency in the voltage measurement loop. Based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the loop to be measured, the actual induced voltage in the loop to be measured is calculated according to the first induced current and the preset induced resistance in the voltage measurement loop. This can reduce the difference between the actual induced voltage and the state of the slope film alloy core, meet the accuracy requirements of the loop impedance measurement, and greatly improve the accuracy and universality of the loop impedance clamp meter in measuring loop impedance parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 : A flow chart of the steps of a method for measuring induced voltage with a loop impedance clamp meter provided by an embodiment of the present invention;

[0045] Figure 2 : A structural diagram of a loop impedance clamp meter induced voltage measurement device provided by an embodiment of the present invention;

[0046] Figure 3 : A structural diagram of a loop impedance clamp meter induced voltage measurement system provided by an embodiment of the present invention;

[0047] Figure 4 : Schematic diagram of the loop impedance measurement performed by the loop impedance clamp meter provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] Example 1

[0050] Please refer to Figure 1, a loop impedance clamp meter induced voltage measurement method provided by an embodiment of the present invention, performed by the loop impedance clamp meter, includes the following steps S101-S102:

[0051] Step S101: Control the voltage excitation coil to generate a first excitation voltage of a first frequency in the circuit to be measured, thereby obtaining a first induced current corresponding to the first frequency in the voltage measurement circuit; wherein, the voltage measurement circuit and the voltage excitation coil are both arranged in a loop impedance clamp meter, the circuit to be measured is a circuit required for impedance measurement by the loop impedance clamp meter, the voltage measurement circuit includes a voltage measurement coil, and the transformer coil corresponding to the circuit to be measured, the voltage measurement coil and the voltage excitation coil are all arranged in the same iron core.

[0052] In this embodiment, a voltage-controlled excitation coil generates an excitation voltage of a specific frequency in the circuit under test, thereby inducing a corresponding induced current and achieving accurate measurement of the loop impedance. The excitation coil is precisely controlled to generate a first excitation voltage of a specific frequency, thereby detecting the induced current. To detect the first induced current, the voltage measurement coil must be able to respond to changes in the magnetic field generated by the excitation coil. It should be noted that the core material must be selected with high magnetic permeability and low loss, and the core design must be able to evenly distribute the magnetic field to reduce magnetic saturation and hysteresis losses.

[0053] In this embodiment, the detected first induced current signal undergoes appropriate signal processing and analysis to extract information about the loop impedance, including but not limited to signal amplification, filtering, and conversion to a digital signal. To ensure the accuracy of the measurement results, the entire system requires rigorous calibration and testing, including calibration of the excitation coil's output stability, the measurement coil's sensitivity, and the overall system's frequency response.

[0054] In this embodiment, the induced voltage E of the secondary winding(s) on the same transformer core is solely related to the number of turns N. The voltage measurement loop winding (number of turns N1) and the measured loop winding (number of turns N2) of the loop impedance clamp meter share the same core. When N1 = N2, the induced voltage E1 of the voltage measurement loop and the induced voltage E2 of the impedance measurement loop are identical, i.e., E1 = E2. When N1 ≠ N2, the induced voltage E1 of the voltage measurement loop and the induced voltage E2 of the impedance measurement loop can also be calculated based on the ratio between the voltage measurement loop winding and the measured loop winding.

[0055] It is understandable that by introducing a first excitation voltage of a specific frequency into the circuit to be measured, the first induced current can be induced more accurately, thereby making the measurement of the loop impedance more precise. By integrating the voltage measurement circuit and the voltage excitation coil within the loop impedance clamp meter, external connections and potential interference can be reduced, thereby improving the reliability and stability of the measurement. Since all measurement components are integrated into the clamp meter, the operator does not need to perform complex settings and connections, which simplifies the measurement process and reduces the difficulty of operation. The transformer coil, voltage measurement coil, and voltage excitation coil corresponding to the circuit to be measured are then placed in the same iron core to ensure the consistency and stability of the magnetic field, thereby improving the accuracy of the measurement results.

[0056] Step S102: Based on the first induced current and the preset induction resistance in the voltage measurement circuit, a first induced voltage corresponding to the first induced current is calculated, and based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured, an actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained.

[0057] As a preferred solution of this embodiment, it also includes:

[0058] The first excitation voltage is used as a target induced voltage generated by the voltage excitation coil in the circuit to be measured; a first influence coefficient and a second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the circuit to be measured corresponding to the target induced voltage and the first induced voltage are calculated respectively based on the target induced voltage and the first induced voltage; if the ratio of the first influence coefficient to the second influence coefficient is greater than a preset range, an interface abnormality signal corresponding to the loop impedance clamp meter is generated and an alarm is issued. If the ratio of the first influence coefficient to the second influence coefficient is not greater than the preset range, the loop impedance clamp meter maintains normal operation.

[0059] In this embodiment, the first excitation voltage generated by the loop impedance clamp meter is used as the target induced voltage pre-set to be output by the clamp meter, that is, as the voltage that the voltage excitation coil attempts to generate in the circuit to be measured. Then, two influence degree coefficients are calculated based on the target induced voltage and the first induced voltage actually measured. The influence degree coefficient reflects the degree of influence of the interface on the measurement result, and the preset range can be determined based on experience or standard testing. When the ratio of the two influence degree coefficients exceeds the preset range, the system will generate an abnormal signal and trigger an alarm to prompt the user that there may be a problem with the interface. At the same time, the interface status will be continuously monitored. If the ratio is always within the preset range, the normal working state of the loop impedance clamp meter will be maintained. In order to achieve accurate anomaly detection, the collected data needs to be properly processed and analyzed, including data cleaning, noise filtering, and outlier detection.

[0060] In this embodiment, by calculating and comparing two different influence coefficients, the accuracy of measurement results is ensured to be unaffected by interface anomalies. Simultaneously, the loop impedance clamp meter's interface status is monitored in real time, allowing for the timely detection and alarm of potential anomalies, thereby avoiding erroneous measurement results. The generation of abnormality signals and alarms helps identify potential problems in advance, making maintenance more preventative and reducing the likelihood of equipment failure. The loop impedance clamp meter allows users to monitor interface status and provide alarms without requiring additional operation or equipment, streamlining the user experience.

[0061] As a preferred solution of this embodiment, when the target induced voltage and the first induced voltage are obtained by calculation, the first influence coefficient and the second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop include:

[0062] E0=4.44×f1×N J ×K0,K0=B0×S0

[0063] E1=4.44×f1×N J ×K1, K1=B1×S1

[0064] Among them, E0 is the target induced voltage, E1 is the first induced voltage, f1 is the first frequency, N J is the number of turns of the voltage excitation coil, B0 is the magnetic permeability of the interface of the loop impedance clamp meter under ideal conditions, S0 is the cross-sectional area of ​​the voltage excitation coil on the interface of the loop impedance clamp meter under ideal conditions, K0 is the first degree of influence coefficient of the interface of the loop impedance clamp meter on the voltage in the loop to be measured under ideal conditions, B1 is the magnetic permeability of the interface of the loop impedance clamp meter under actual conditions, S1 is the cross-sectional area of ​​the voltage excitation coil on the interface of the loop impedance clamp meter under actual conditions, and K1 is the second degree of influence coefficient of the interface of the loop impedance clamp meter on the voltage in the loop to be measured under actual conditions. Preferably, the first frequency f1 = 1500 Hz, and the second frequency f2 = 2000 Hz

[0065] As a preferred solution of this embodiment, the present invention further includes:

[0066] The voltage excitation coil is controlled to generate a second excitation voltage of a second frequency in the circuit to be measured, thereby obtaining a second induced current corresponding to the second frequency in the voltage measurement circuit; and a second induced voltage corresponding to the second induced current is calculated based on the second induced current and a preset inductive resistance in the voltage measurement circuit.

[0067] As a preferred solution of this embodiment, the first induced voltage corresponding to the first induced current is calculated based on the first induced current and the preset inductive resistance in the voltage measurement circuit, and the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured, specifically including:

[0068] According to the first induced current and the second induced current, and the preset inductive resistance in the voltage measurement circuit, a first induced voltage corresponding to the first induced current and a second induced voltage corresponding to the second induced current are calculated; according to the first excitation voltage and the second excitation voltage, the first induced voltage and the second induced voltage are verified to obtain a first difference between the first induced voltage and the first excitation voltage, and a second difference between the second induced voltage and the second excitation voltage, and the first difference and the second difference are compared; if the first difference is less than the second difference, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is calculated based on the number of turns of the transformer coil corresponding to the circuit to be measured and the voltage measurement coil and the first induced voltage; if the first difference is greater than the second difference, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is calculated based on the number of turns of the transformer coil corresponding to the circuit to be measured and the voltage measurement coil and the second induced voltage.

[0069] In this embodiment, by calculating and comparing the difference between the first induced voltage, the second induced voltage and the corresponding first excitation voltage and the second excitation voltage, the actual induced voltage in the circuit to be measured can be determined more accurately, thereby improving the accuracy of the entire measurement process. At the same time, by verifying and comparing the induced voltages under two different excitation voltages, possible measurement errors and system deviations can be identified and eliminated, thereby enhancing the reliability of the measurement system. At the same time, by obtaining two sets of differences through a one-time calculation and determining the actual induced voltage based on these differences, the measurement process is simplified and the required time and resources are reduced. Furthermore, this embodiment can adapt to different measurement conditions and characteristics of the circuit to be measured, and by flexibly selecting the corresponding induced current and excitation voltage, it ensures that accurate measurement results can be obtained in various situations, and then the actual induced voltage is determined by comparing the two sets of differences, which helps to reduce the influence of external factors on the measurement results; preferably, the preset sensing resistance is 150Ω.

[0070] In this embodiment, the voltage measurement circuit and the logic operation are coordinated and the first induced current I of the voltage measurement circuit under different frequencies (for example, 1500 Hz and 2000 Hz) is measured on site. 01and the second induced current I 01 , combined with the preset sensing resistance R = 150Ω, the corresponding induced voltage can be calculated, which can reduce the difference between the actual induced voltage and the state of the slope film alloy core, meet the accuracy requirements of the loop impedance measurement, and greatly improve the accuracy and universality of the loop impedance clamp meter in measuring the loop impedance parameters, avoiding the influence of the ambient temperature and humidity during measurement, the fit and cleanliness of the clamp core interface, and the wear of the core at the interface on the excitation voltage acting on the circuit to be measured.

[0071] The implementation of the above embodiment has the following effects:

[0072] The technical solution of the present invention addresses the problem of a large difference between the induced voltage measured before leaving the factory and the actual induced voltage on site in the existing loop impedance clamp meter. The principle of the induced voltage measurement function is improved. The voltage excitation coil is controlled in the loop impedance clamp meter to generate a first excitation voltage of a first frequency in the loop to be measured, thereby obtaining a first induced current corresponding to the first frequency in the voltage measurement loop. Based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the loop to be measured, the actual induced voltage in the loop to be measured is calculated according to the first induced current and the preset induced resistance in the voltage measurement loop. This can reduce the difference between the actual induced voltage and the state of the slope film alloy core, meet the accuracy requirements of the loop impedance measurement, and greatly improve the accuracy and universality of the loop impedance clamp meter in measuring loop impedance parameters.

[0073] Example 2

[0074] See also Figure 2 , which is a loop impedance clamp meter induced voltage measurement device provided by the present invention, including: an acquisition module 201 and a calculation module 202;

[0075] The acquisition module 201 is configured to control a voltage excitation coil to generate a first excitation voltage of a first frequency in a circuit to be measured, thereby acquiring a first induced current corresponding to the first frequency in a voltage measurement circuit; wherein the voltage measurement circuit and the voltage excitation coil are both disposed in a loop impedance clamp meter, the circuit to be measured is a circuit required for impedance measurement by the loop impedance clamp meter, the voltage measurement circuit includes a voltage measurement coil, and a transformer coil corresponding to the circuit to be measured, the voltage measurement coil, and the voltage excitation coil are all disposed in a same iron core;

[0076] The calculation module 202 is configured to calculate a first induced voltage corresponding to the first induced current based on the first induced current and a preset inductive resistance in the voltage measurement circuit, and to obtain an actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured.

[0077] As a preferred solution, it also includes:

[0078] Using the first excitation voltage as the target induced voltage generated by the voltage excitation coil in the circuit to be tested;

[0079] Calculating, based on the target induced voltage and the first induced voltage, a first influence coefficient and a second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop when the interface corresponds to the target induced voltage and the first induced voltage, respectively;

[0080] If the ratio of the first influence coefficient to the second influence coefficient is greater than a preset range, an interface abnormality signal corresponding to the loop impedance clamp meter is generated and an alarm is issued.

[0081] If the ratio of the first influence coefficient to the second influence coefficient is not greater than a preset range, the loop impedance clamp meter is maintained to operate normally.

[0082] As a preferred solution, when the target induced voltage and the first induced voltage are obtained by calculation, the first influence coefficient and the second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop include:

[0083] E0=4.44×f1×N J ×K0,K0=B0×S0

[0084] E1=4.44×f1×N J ×K1, K1=B1×S1

[0085] Among them, E0 is the target induced voltage, E1 is the first induced voltage, f1 is the first frequency, N J is the number of turns of the voltage excitation coil, B0 is the magnetic permeability of the interface of the loop impedance clamp meter under ideal conditions, S0 is the cross-sectional area of ​​the voltage excitation coil on the interface of the loop impedance clamp meter under ideal conditions, K0 is the first influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop under ideal conditions, B1 is the magnetic permeability of the interface of the loop impedance clamp meter under actual conditions, S1 is the cross-sectional area of ​​the voltage excitation coil on the interface of the loop impedance clamp meter under actual conditions, and K1 is the second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop under actual conditions.

[0086] As a preferred solution, it also includes:

[0087] Controlling the voltage excitation coil to generate a second excitation voltage of a second frequency in the circuit to be measured, thereby obtaining a second induced current corresponding to the second frequency in the voltage measurement circuit;

[0088] A second induced voltage corresponding to the second induced current is calculated based on the second induced current and a preset induced resistance in the voltage measurement loop.

[0089] As a preferred solution, the first induced voltage corresponding to the first induced current is calculated based on the first induced current and a preset inductive resistance in the voltage measurement circuit, and the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured, specifically including:

[0090] Calculating a first induced voltage corresponding to the first induced current and a second induced voltage corresponding to the second induced current based on the first induced current and the second induced current and a preset induction resistor in the voltage measurement circuit;

[0091] Verifying the first induced voltage and the second induced voltage according to the first excitation voltage and the second excitation voltage to obtain a first difference between the first induced voltage and the first excitation voltage, and a second difference between the second induced voltage and the second excitation voltage, and comparing the first difference with the second difference;

[0092] If the first difference is less than the second difference, then calculating the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured based on the number of turns of the transformer coil and the voltage measuring coil corresponding to the circuit to be measured and the first induced voltage;

[0093] If the first difference is greater than the second difference, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is calculated based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured and the second induced voltage.

[0094] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working process of the device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0095] The implementation of the above embodiment has the following effects:

[0096] The technical solution of the present invention addresses the problem of a large difference between the induced voltage measured before leaving the factory and the actual induced voltage on site in the existing loop impedance clamp meter. The principle of the induced voltage measurement function is improved. The voltage excitation coil is controlled in the loop impedance clamp meter to generate a first excitation voltage of a first frequency in the loop to be measured, thereby obtaining a first induced current corresponding to the first frequency in the voltage measurement loop. Based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the loop to be measured, the actual induced voltage in the loop to be measured is calculated according to the first induced current and the preset induced resistance in the voltage measurement loop. This can reduce the difference between the actual induced voltage and the state of the slope film alloy core, meet the accuracy requirements of the loop impedance measurement, and greatly improve the accuracy and universality of the loop impedance clamp meter in measuring loop impedance parameters.

[0097] Example 3

[0098] See also Figure 3 , which is a loop impedance clamp meter induced voltage measurement system provided by the present invention, used to perform the loop impedance clamp meter induced voltage measurement method as described in the first embodiment above, including: a loop impedance clamp meter and a loop to be measured; a transformer coil is provided on the loop to be measured.

[0099] The loop impedance clamp meter includes: a processor, and a voltage measurement loop and a voltage excitation coil connected to the processor.

[0100] In this embodiment, the loop impedance clamp meter is mainly used to measure the impedance of the circuit to be measured. Figure 4 , which is a schematic diagram of a loop impedance clamp meter measuring the impedance of a loop to be measured. It should be noted that the voltage measurement coil and the voltage excitation coil of the voltage measurement loop are integrated and arranged in the loop impedance clamp meter.

[0101] The processor is used to control the voltage excitation coil to generate a first excitation voltage of a first frequency in the circuit to be measured, thereby obtaining a first induced current corresponding to the first frequency in the voltage measurement circuit; wherein, the voltage measurement circuit and the voltage excitation coil are both arranged in a loop impedance clamp meter, the circuit to be measured is a circuit required for impedance measurement by the loop impedance clamp meter, the voltage measurement circuit includes a voltage measurement coil, and the transformer coil corresponding to the circuit to be measured, the voltage measurement coil and the voltage excitation coil are all arranged in the same iron core; based on the first induced current and the preset induction resistance in the voltage measurement circuit, the first induced voltage corresponding to the first induced current is calculated, and based on the number of turns of the transformer coil corresponding to the circuit to be measured and the voltage measurement coil, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained.

[0102] As a preferred solution, the processor is further configured to:

[0103] The first excitation voltage is used as a target induced voltage generated by the voltage excitation coil in the circuit to be measured; a first influence coefficient and a second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the circuit to be measured corresponding to the target induced voltage and the first induced voltage are calculated respectively based on the target induced voltage and the first induced voltage; if the ratio of the first influence coefficient to the second influence coefficient is greater than a preset range, an interface abnormality signal corresponding to the loop impedance clamp meter is generated and an alarm is issued. If the ratio of the first influence coefficient to the second influence coefficient is not greater than the preset range, the loop impedance clamp meter maintains normal operation.

[0104] As a preferred solution, when the target induced voltage and the first induced voltage are obtained by calculation, the first influence coefficient and the second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop include:

[0105] E0=4.44×f1×N J ×K0,K0=B0×S0

[0106] E1=4.44×f1×N J ×K1, K1=B1×S1

[0107] Among them, E0 is the target induced voltage, E1 is the first induced voltage, f1 is the first frequency, N J is the number of turns of the voltage excitation coil, B0 is the magnetic permeability of the interface of the loop impedance clamp meter under ideal conditions, S0 is the cross-sectional area of ​​the voltage excitation coil on the interface of the loop impedance clamp meter under ideal conditions, K0 is the first influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop under ideal conditions, B1 is the magnetic permeability of the interface of the loop impedance clamp meter under actual conditions, S1 is the cross-sectional area of ​​the voltage excitation coil on the interface of the loop impedance clamp meter under actual conditions, and K1 is the second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop under actual conditions.

[0108] As a preferred embodiment, the processor is further used to: control the voltage excitation coil to generate a second excitation voltage of a second frequency in the circuit to be measured, thereby obtaining a second induced current corresponding to the second frequency in the voltage measurement circuit; and calculate a second induced voltage corresponding to the second induced current based on the second induced current and a preset induction resistance in the voltage measurement circuit.

[0109] As a preferred solution, the first induced voltage corresponding to the first induced current is calculated based on the first induced current and a preset inductive resistance in the voltage measurement circuit, and the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured, specifically including:

[0110] According to the first induced current and the second induced current, and the preset inductive resistance in the voltage measurement circuit, a first induced voltage corresponding to the first induced current and a second induced voltage corresponding to the second induced current are calculated; according to the first excitation voltage and the second excitation voltage, the first induced voltage and the second induced voltage are verified to obtain a first difference between the first induced voltage and the first excitation voltage, and a second difference between the second induced voltage and the second excitation voltage, and the first difference and the second difference are compared; if the first difference is less than the second difference, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is calculated based on the number of turns of the transformer coil corresponding to the circuit to be measured and the voltage measurement coil and the first induced voltage; if the first difference is greater than the second difference, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is calculated based on the number of turns of the transformer coil corresponding to the circuit to be measured and the voltage measurement coil and the second induced voltage.

[0111] In this embodiment, the loop impedance clamp meter also includes a current measuring coil, a current acquisition unit and a voltage excitation unit. The current measuring coil is used to measure the induced current in the loop to be measured, and the current acquisition unit filters, amplifies and performs analog-to-digital conversion on the induced current measured by the current measuring coil, and then inputs it into the processor; and the voltage excitation unit is used to receive the control signal of the processor, and then perform digital-to-analog conversion on the digital signal output by the processor, and perform power amplification, so that the output signal is passed through the voltage excitation coil to generate and induce the excitation voltage.

[0112] It should be noted that if the impedance of the circuit to be measured is inductive, then Z = R + jωL = R + j (2 × π × f × L); if the impedance of the circuit to be measured is capacitive, then Solving the equations simultaneously yields:

[0113] X1=(2×π×f×L) or

[0114] X2=(2×π×f×L) or

[0115] Where, I 01、 I 02 are the induced current values ​​in the voltage measurement circuit measured at frequencies f1 and f2, respectively. 11、 I 12 are the current values ​​of the current measuring coil measured at frequencies f1 and f2, respectively, and E 01 is the first induced voltage, E 02 is the second induced voltage, Z1 and Z2 are impedances at frequencies f1 and f2 respectively, L is inductance, and C is capacitance.

[0116] The implementation of the above embodiment has the following effects:

[0117] The technical solution of the present invention addresses the problem of a large difference between the induced voltage measured before leaving the factory and the actual induced voltage on site in the existing loop impedance clamp meter. The principle of the induced voltage measurement function is improved. The voltage excitation coil is controlled in the loop impedance clamp meter to generate a first excitation voltage of a first frequency in the loop to be measured, thereby obtaining a first induced current corresponding to the first frequency in the voltage measurement loop. Based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the loop to be measured, the actual induced voltage in the loop to be measured is calculated according to the first induced current and the preset induced resistance in the voltage measurement loop. This can reduce the difference between the actual induced voltage and the state of the slope film alloy core, meet the accuracy requirements of the loop impedance measurement, and greatly improve the accuracy and universality of the loop impedance clamp meter in measuring loop impedance parameters.

[0118] The specific embodiments described above further illustrate the objectives, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A loop impedance clamp meter induced voltage measurement method, characterized in that: Performed by a loop impedance clamp meter, including: The voltage excitation coil is controlled to generate a first excitation voltage of a first frequency in the circuit to be measured, so as to obtain a first induced current corresponding to the first frequency in the voltage measurement circuit; wherein the voltage measurement circuit and the voltage excitation coil are both arranged in a loop impedance clamp meter, the circuit to be measured is a circuit required for impedance measurement by the loop impedance clamp meter, the voltage measurement circuit includes a voltage measurement coil, and the transformer coil corresponding to the circuit to be measured, the voltage measurement coil and the voltage excitation coil are all arranged in the same iron core; According to the first induced current and the preset induction resistance in the voltage measurement circuit, a first induced voltage corresponding to the first induced current is calculated, and according to the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured, an actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained; The first excitation voltage is used as a target induced voltage generated by the voltage excitation coil in the circuit to be measured; when the first influence degree coefficient and the second influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the circuit to be measured corresponding to the target induced voltage and the first induced voltage are calculated respectively according to the target induced voltage and the first induced voltage; if the ratio between the first influence degree coefficient and the second influence degree coefficient is greater than a preset range, an interface abnormality signal corresponding to the loop impedance clamp meter is generated, and an alarm is issued; if the ratio between the first influence degree coefficient and the second influence degree coefficient is not greater than the preset range, the normal operation of the loop impedance clamp meter is maintained.

2. A loop impedance clamp meter induced voltage measurement method as claimed in claim 1, characterized in that: When the target induced voltage and the first induced voltage are obtained by calculation, the first influence coefficient and the second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop include: E0=4.44×f1×N J ×K0,K0=B0×S0 E1=4.44×f1×N J ×K1, K1=B1×S1 Where E0 is the target induced voltage, E1 is the first induced voltage, f1 is the first frequency, N J is the number of turns of the voltage excitation coil, B0 is the magnetic permeability of the interface of the loop impedance clamp meter under ideal conditions, S0 is the cross-sectional area of ​​the voltage excitation coil on the interface of the loop impedance clamp meter under ideal conditions, K0 is the first influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop under ideal conditions, B1 is the magnetic permeability of the interface of the loop impedance clamp meter under actual conditions, S1 is the cross-sectional area of ​​the voltage excitation coil on the interface of the loop impedance clamp meter under actual conditions, and K1 is the second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the measured loop under actual conditions.

3. A loop impedance clamp meter induced voltage measurement method as claimed in claim 1, characterized in that: Also includes: Controlling the voltage excitation coil to generate a second excitation voltage of a second frequency in the circuit to be measured, thereby obtaining a second induced current corresponding to the second frequency in the voltage measurement circuit; A second induced voltage corresponding to the second induced current is calculated according to the second induced current and a preset induced resistance in the voltage measurement loop.

4. A loop impedance clamp meter induced voltage measurement method as claimed in claim 3, characterized in that: The first induced voltage corresponding to the first induced current is calculated according to the first induced current and the preset induced resistance in the voltage measurement circuit, and the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained according to the turns of the transformer coil corresponding to the circuit to be measured and the voltage measurement coil, specifically including: According to the first induced current and the second induced current, and a preset induction resistor in the voltage measurement loop, a first induced voltage corresponding to the first induced current and a second induced voltage corresponding to the second induced current are calculated; Verifying the first induced voltage and the second induced voltage according to the first excitation voltage and the second excitation voltage, thereby obtaining a first difference between the first induced voltage and the first excitation voltage, and a second difference between the second induced voltage and the second excitation voltage, and comparing the first difference with the second difference; If the first difference is smaller than the second difference, then according to the number of turns of the transformer coil and the voltage measuring coil corresponding to the circuit to be measured and the first induced voltage, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is calculated; If the first difference is greater than the second difference, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is calculated based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured and the second induced voltage.

5. A loop impedance clamp meter induced voltage measurement device, characterized in that: include: Acquisition module and calculation module; The acquisition module is used to control the voltage excitation coil to generate a first excitation voltage of a first frequency in the circuit to be measured, so as to obtain a first induced current corresponding to the first frequency in the voltage measurement circuit; wherein the voltage measurement circuit and the voltage excitation coil are both arranged in a loop impedance clamp meter, the circuit to be measured is a circuit required for impedance measurement by the loop impedance clamp meter, the voltage measurement circuit includes a voltage measurement coil, and the transformer coil corresponding to the circuit to be measured, the voltage measurement coil and the voltage excitation coil are all arranged in the same iron core; The calculation module is used to calculate the first induced voltage corresponding to the first induced current according to the first induced current and the preset induced resistance in the voltage measurement loop, and obtain the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured according to the number of turns of the transformer coil corresponding to the circuit to be measured and the voltage measurement coil; use the first excitation voltage as the target induced voltage generated by the voltage excitation coil in the circuit to be measured; calculate the first influence degree coefficient and the second influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the circuit to be measured corresponding to the target induced voltage and the first induced voltage respectively according to the target induced voltage and the first induced voltage; if the ratio between the first influence degree coefficient and the second influence degree coefficient is greater than a preset range, generate an interface abnormality signal of the corresponding loop impedance clamp meter and issue an alarm; if the ratio between the first influence degree coefficient and the second influence degree coefficient is not greater than the preset range, maintain the normal operation of the loop impedance clamp meter.

6. A loop impedance clamp meter induced voltage measurement system, characterized in that: The method for measuring induced voltage with a loop impedance clamp meter according to any one of claims 1 to 4 comprises: a loop impedance clamp meter and a loop to be measured; a transformer coil is arranged on the loop to be measured; The loop impedance clamp meter comprises: a processor, and a voltage measurement loop and a voltage excitation coil connected to the processor; The processor is used to control the voltage excitation coil to generate a first excitation voltage of a first frequency in the circuit to be measured, so as to obtain a first induced current corresponding to the first frequency in the voltage measurement circuit; wherein the voltage measurement circuit and the voltage excitation coil are both arranged in a loop impedance clamp meter, the circuit to be measured is a circuit required for impedance measurement by the loop impedance clamp meter, the voltage measurement circuit includes a voltage measurement coil, and the transformer coil corresponding to the circuit to be measured, the voltage measurement coil and the voltage excitation coil are all arranged in the same iron core; according to the first induced current and the preset induction resistance in the voltage measurement circuit, the first induced voltage corresponding to the first induced current is calculated, and according to the number of turns of the transformer coil corresponding to the circuit to be measured and the voltage measurement coil , obtaining the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured; using the first excitation voltage as the target induced voltage generated by the voltage excitation coil in the circuit to be measured; and calculating, according to the target induced voltage and the first induced voltage, respectively obtaining the first influence coefficient and the second influence coefficient of the interface of the loop impedance clamp meter on the voltage in the circuit to be measured corresponding to the target induced voltage and the first induced voltage; if the ratio between the first influence coefficient and the second influence coefficient is greater than a preset range, generating an interface abnormality signal corresponding to the loop impedance clamp meter and giving an alarm; if the ratio between the first influence coefficient and the second influence coefficient is not greater than a preset range, maintaining the normal operation of the loop impedance clamp meter.

7. A loop impedance clamp meter induced voltage measurement system as claimed in claim 6, characterized in that: The processor is further used to: control the voltage excitation coil to generate a second excitation voltage of a second frequency in the circuit to be measured, thereby obtaining a second induced current corresponding to the second frequency in the voltage measurement circuit; and calculate a second induced voltage corresponding to the second induced current based on the second induced current and a preset induction resistor in the voltage measurement circuit.

8. The loop impedance clamp meter induced voltage measurement system according to claim 7, characterized in that: The first induced voltage corresponding to the first induced current is calculated according to the first induced current and the preset induced resistance in the voltage measurement circuit, and the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is obtained according to the turns of the transformer coil corresponding to the circuit to be measured and the voltage measurement coil, specifically including: According to the first induced current and the second induced current, and a preset induction resistor in the voltage measurement loop, a first induced voltage corresponding to the first induced current and a second induced voltage corresponding to the second induced current are calculated; Verifying the first induced voltage and the second induced voltage according to the first excitation voltage and the second excitation voltage, thereby obtaining a first difference between the first induced voltage and the first excitation voltage, and a second difference between the second induced voltage and the second excitation voltage, and comparing the first difference with the second difference; If the first difference is smaller than the second difference, then according to the number of turns of the transformer coil and the voltage measuring coil corresponding to the circuit to be measured and the first induced voltage, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is calculated; If the first difference is greater than the second difference, the actual induced voltage in the circuit to be measured after the voltage excitation coil excites the circuit to be measured is calculated based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the circuit to be measured and the second induced voltage.

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