Induced voltage measurement method, apparatus and system for loop impedance clamp meter

Abstract

Disclosed in the present invention are an induced voltage measurement method, apparatus and system for a loop impedance clamp meter. The method is executed by a loop impedance clamp meter, and comprises: controlling a voltage excitation coil to generate a first excitation voltage at a first frequency in a loop to be measured, so as to acquire from a voltage measurement loop a first induced current corresponding to the first frequency; and on the basis of the first induced current and a preset inductive resistance in the voltage measurement loop, performing calculation to obtain a first induced voltage corresponding to the first induced current, and on the basis of the number of turns of a transformer coil corresponding to the loop to be measured and the number of turns of a voltage measurement coil, obtaining an actual induced voltage in the loop to be measured after the loop to be measured is excited by the voltage excitation coil. The present invention solves the technical problems in the prior art of high difficulty and low accuracy involved in induced voltage measurement, and the induced voltage measurement being easily affected by external environmental factors.

Description

Loop impedance clamp meter induced voltage measurement method, device and system TECHNICAL FIELD

[0001] The present application relates to the technical field of voltage measurement, and in particular to a loop impedance clamp meter induced voltage measurement method and device. BACKGROUND

[0002] In engineering projects, in order to measure the impedance of a circuit, a tool called a loop impedance clamp meter is usually used. The method of measuring through the loop impedance clamp meter relies on a key parameter, namely the induced voltage, because in practical applications, the loop impedance clamp meter cannot be directly used to measure the value of the induced voltage. In field operations, due to technical limitations, the induced voltage reading cannot be directly obtained from the clamp meter.

[0003] Currently, the induced voltage can be measured by converting the secondary side induced voltage from the primary voltage or directly measuring the induced voltage. However, the core material of the clamp meter for measuring loop impedance is usually a slope film alloy. The ambient temperature and humidity during measurement, the degree of fit and cleanliness of the clamp core interface, and the degree of wear of the interface core have a great impact on the magnetic permeability of the slope film alloy core, causing the magnetic density to change greatly. Therefore, even if the number of turns of the secondary winding and the primary-secondary ratio remain unchanged, the induced voltage will change greatly, and even if the number of turns of the secondary winding and the primary-secondary ratio remain unchanged, the induced voltage obtained will also change greatly, resulting in low measurement accuracy. SUMMARY

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

[0005] To solve the above technical problems, the present application provides a loop impedance clamp meter induced voltage measurement method, which is executed by a loop impedance clamp meter, comprising:

[0006] A voltage excitation coil is controlled to generate a first excitation voltage of a first frequency in a to-be-measured loop, so as to obtain a first induced current corresponding to the first frequency in a voltage measurement loop; wherein the voltage measurement loop and the voltage excitation coil are both arranged in the loop impedance clamp meter, the to-be-measured loop is a loop required for impedance measurement by the loop impedance clamp meter, the voltage measurement loop includes a voltage measurement coil, and the transformer coil corresponding to the to-be-measured loop, the voltage measurement coil and the voltage excitation coil are all arranged in the same core;

[0007] According to the first induced current and a preset induced 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 corresponding to the to-be-measured circuit and the voltage measurement coil, an actual induced voltage in the to-be-measured circuit after the to-be-measured circuit is excited by the voltage excitation coil is obtained.

[0008] As a preferred solution, it further comprises:

[0009] The first excitation voltage is taken as a target induced voltage generated by the voltage excitation coil in the to-be-measured circuit.

[0010] According to the target induced voltage and the first induced voltage, a first influence degree coefficient and a second influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the to-be-measured circuit when corresponding to the target induced voltage and the first induced voltage are respectively calculated.

[0011] If the ratio between the first influence degree coefficient and the second influence degree coefficient is greater than a preset range, an abnormal signal of the interface of the loop impedance clamp meter is generated, and an alarm is given.

[0012] If the ratio between the first influence degree coefficient and the second influence degree coefficient is not greater than the preset range, the normal work of the loop impedance clamp meter is maintained.

[0013] As a preferred solution, 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 to-be-measured circuit when corresponding to the target induced voltage and the first induced voltage are calculated, comprising: E0=4.44×f1×N J ×K0, K0=B0×S0 E1=4.44×f1×N J ×K1, K1=B1×S1

[0014] Wherein, 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 permeability of the interface of the loop impedance clamp meter in an ideal state, S0 is the cross-sectional area of the voltage excitation coil on the interface of the loop impedance clamp meter in an ideal state, K0 is the first influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the to-be-measured circuit in an ideal state, B1 is the permeability of the interface of the loop impedance clamp meter in an actual state, S1 is the cross-sectional area of the voltage excitation coil on the interface of the loop impedance clamp meter in an actual state, and K1 is the second influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the to-be-measured circuit in an actual state.

[0015] As a preferred solution, it further comprises:

[0016] The control voltage excitation coil generates a second excitation voltage of a second frequency in the to-be-tested loop, so that a second induced current of the second frequency is obtained in the voltage measurement loop;

[0017] According to the second induced current and a preset induced resistance in the voltage measurement loop, a second induced voltage corresponding to the second induced current is calculated.

[0018] As a preferred solution, 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 loop, and the actual induced voltage in the to-be-tested loop after the to-be-tested loop is excited by the voltage excitation coil is obtained according to the number of turns of the transformer coil corresponding to the to-be-tested loop and the voltage measurement coil.

[0019] According to the first induced current and the second induced current and the preset induced resistance in the voltage measurement loop, the first induced voltage corresponding to the first induced current and the second induced voltage corresponding to the second induced current are calculated.

[0020] The first induced voltage and the second induced voltage are verified according to the first excitation voltage and the second excitation voltage, so that 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 are obtained, and the first difference and the second difference are compared.

[0021] If the first difference is less than the second difference, the actual induced voltage in the to-be-tested loop after the to-be-tested loop is excited by the voltage excitation coil is calculated according to the number of turns of the transformer coil corresponding to the to-be-tested loop and the voltage measurement coil and the first induced voltage.

[0022] If the first difference is greater than the second difference, the actual induced voltage in the to-be-tested loop after the to-be-tested loop is excited by the voltage excitation coil is calculated according to the number of turns of the transformer coil corresponding to the to-be-tested loop and the voltage measurement coil and the second induced voltage.

[0023] Correspondingly, the application also provides a loop impedance clamp meter induced voltage measurement device, comprising an acquisition module and a calculation module.

[0024] The acquisition module is configured to control the voltage excitation coil to generate a first excitation voltage of a first frequency in the to-be-measured loop, so as to acquire a first induced current corresponding to the first frequency in the voltage measurement loop; wherein the voltage measurement loop and the voltage excitation coil are both arranged in the loop impedance clamp meter, the to-be-measured loop is a loop required by the loop impedance clamp meter to perform impedance measurement, the voltage measurement loop comprises a voltage measurement coil, and the transformer coil corresponding to the to-be-measured loop, the voltage measurement coil and the voltage excitation coil are all arranged in the same iron core.

[0025] The calculation module is configured to calculate a first induced voltage corresponding to the first induced current according to the first induced current and a preset induced resistance in the voltage measurement loop, and obtain an actual induced voltage in the to-be-measured loop after the to-be-measured loop is excited by the voltage excitation coil according to the number of turns of the transformer coil corresponding to the to-be-measured loop and the voltage measurement coil.

[0026] Correspondingly, the present application also provides a loop impedance clamp meter induced voltage measurement system for performing the loop impedance clamp meter induced voltage measurement method according to any one of the above, comprising a loop impedance clamp meter and a to-be-measured loop; the to-be-measured loop is provided with a transformer coil.

[0027] The loop impedance clamp meter comprises a processor and a voltage measurement loop and a voltage excitation coil connected to the processor.

[0028] The processor is configured to control the voltage excitation coil to generate a first excitation voltage of a first frequency in the to-be-measured loop, so as to acquire a first induced current corresponding to the first frequency in the voltage measurement loop; wherein the voltage measurement loop and the voltage excitation coil are both arranged in the loop impedance clamp meter, the to-be-measured loop is a loop required by the loop impedance clamp meter to perform impedance measurement, the voltage measurement loop comprises a voltage measurement coil, and the transformer coil corresponding to the to-be-measured loop, the voltage measurement coil and the voltage excitation coil are all arranged in the same iron core; a first induced voltage corresponding to the first induced current is calculated according to the first induced current and a preset induced resistance in the voltage measurement loop, and an actual induced voltage in the to-be-measured loop after the to-be-measured loop is excited by the voltage excitation coil is obtained according to the number of turns of the transformer coil corresponding to the to-be-measured loop and the voltage measurement coil.

[0029] As a preferred solution, the processor is further configured to:

[0030] The first excitation voltage is taken as a target induced voltage generated by the voltage excitation coil in the to-be-measured loop.

[0031] According to the target induced voltage and the first induced voltage, a first influence degree coefficient and a second influence degree coefficient of an interface of the loop impedance clamp meter on a voltage in the loop under test are calculated respectively when the target induced voltage and the first induced voltage are corresponding;

[0032] If a ratio between the first influence degree coefficient and the second influence degree coefficient is greater than a preset range, an abnormal signal of the interface of the loop impedance clamp meter is generated and an alarm is given.

[0033] If the ratio between the first influence degree coefficient and the second influence degree coefficient is not greater than the preset range, normal work of the loop impedance clamp meter is maintained.

[0034] As a preferred solution, the processor is further configured to control the voltage excitation coil to generate a second excitation voltage of a second frequency in the loop under test, so as to obtain a second induced current of the second frequency in the voltage measurement loop; and calculate a second induced voltage corresponding to the second induced current according to the second induced current and a preset induced resistance in the voltage measurement loop.

[0035] As a preferred solution, 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 loop, and the actual induced voltage in the loop under test after the loop under test is excited by the voltage excitation coil is obtained according to the number of turns of the transformer coil corresponding to the loop under test and the voltage measurement coil, and specifically includes:

[0036] The first induced voltage corresponding to the first induced current and the second induced voltage corresponding to the second induced current are calculated according to the first induced current and the second induced current and the preset induced resistance in the voltage measurement loop.

[0037] The first induced voltage and the second induced voltage are verified according to the first excitation voltage and the second excitation voltage, so as 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.

[0038] If the first difference is less than the second difference, the actual induced voltage in the loop under test after the loop under test is excited by the voltage excitation coil is calculated according to the number of turns of the transformer coil corresponding to the loop under test and the voltage measurement coil and the first induced voltage.

[0039] If the first difference value is greater than the second difference value, the actual induced voltage in the to-be-tested loop is calculated according to the number of turns of the transformer coil corresponding to the to-be-tested loop and the voltage measurement coil and the second induced voltage.

[0040] Compared with the prior art, the embodiment of the present application has the following beneficial effects:

[0041] The technical solution of the present application aims at the problem that the difference between the originally factory-calculated induced voltage and the actual induced voltage in the field is large in the existing loop impedance clamp meter, and improves the measurement function principle of the induced voltage. The voltage excitation coil is controlled in the loop impedance clamp meter, a first excitation voltage of a first frequency is generated in the to-be-tested loop, so that a first induced current corresponding to the first frequency is obtained in the voltage measurement loop, and based on the number of turns of the transformer coil corresponding to the to-be-tested loop and the voltage measurement coil, the actual induced voltage in the to-be-tested loop is calculated according to the first induced current and a preset induced resistance in the voltage measurement loop. The difference caused by the different states of the amorphous alloy core can be reduced, the requirement of loop impedance calculation accuracy is met, and the accuracy and universality of the loop impedance parameter measurement of the loop impedance clamp meter are greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] Fig. 1 is a step flowchart of a loop impedance clamp meter induced voltage measurement method provided by an embodiment of the present application;

[0043] Fig. 2 is a structure diagram of a loop impedance clamp meter induced voltage measurement device provided by an embodiment of the present application;

[0044] Fig. 3 is a structure diagram of a loop impedance clamp meter induced voltage measurement system provided by an embodiment of the present application;

[0045] Fig. 4 is a principle diagram of loop impedance measurement of a loop impedance clamp meter provided by an embodiment of the present application. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0047] Embodiment one

[0048] Please refer to Fig. 1, which is a loop impedance clamp meter induced voltage measurement method provided by an embodiment of the present application, executed by a loop impedance clamp meter, including the following steps S101-S102:

[0049] Step S101: control the voltage excitation coil to generate a first excitation voltage of a first frequency in the to-be-measured loop, so as to obtain a first induced current of the first frequency in the voltage measurement loop; wherein, the voltage measurement loop and the voltage excitation coil are arranged in the loop impedance clamp meter, the to-be-measured loop is a loop required to be measured by the loop impedance clamp meter, the voltage measurement loop includes a voltage measurement coil, and the to-be-measured loop corresponding transformer coil, the voltage measurement coil and the voltage excitation coil are arranged in the same iron core.

[0050] In the embodiment, by controlling the voltage excitation coil to generate an excitation voltage of a specific frequency in the to-be-measured loop, a corresponding induced current is induced, and then the precise measurement of the loop impedance is realized. By precise control of the excitation coil, a first excitation voltage of a specific frequency is generated, so that the induced current is detected. In order to detect the first induced current, the voltage measurement coil must be able to respond to the change of the magnetic field generated by the excitation coil. It should be noted that the iron core needs to select a core material with high magnetic permeability and low loss, and the design of the iron core needs to be able to uniformly distribute the magnetic field and reduce magnetic saturation and hysteresis loss.

[0051] In the embodiment, the detected first induced current signal needs to be subjected to appropriate signal processing and analysis to extract information about the loop impedance, including but not limited to signal amplification, filtering and conversion to digital signals and the like. In order to ensure the accuracy of the measurement results, the entire system needs to be calibrated and tested strictly, including the output stability of the excitation coil, the sensitivity of the measurement coil and the frequency response of the entire system.

[0052] In the embodiment, for the secondary winding(s) on the same iron core of the transformer, the induced voltage E is only related to the number of turns N of the winding. The voltage measurement loop winding (turns N1) of the loop impedance clamp meter and the to-be-measured loop winding (turns N2) belong to the same iron core; when N1=N2, the induced voltage E1 of the voltage measurement loop and the induced voltage E2 of the impedance measurement loop are the same, 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 according to the ratio between the voltage measurement loop winding and the to-be-measured loop winding.

[0053] It can be understood that by introducing a first excitation voltage of a specific frequency into the to-be-measured circuit, the first induced current can be more accurately induced, so that the measurement of the circuit impedance is more accurate. By integrating the voltage measurement circuit and the voltage excitation coil inside the circuit impedance clamp meter, external connections and potential interference are reduced, and the reliability and stability of the measurement are improved. Since all measurement components are integrated inside the clamp meter, the operator does not need to make complex settings and connections, simplifying the measurement process and reducing the difficulty of operation, and further ensuring the consistency and stability of the magnetic field by arranging the to-be-measured circuit corresponding transformer coil, the voltage measurement coil and the voltage excitation coil in the same core, thereby improving the accuracy of the measurement result.

[0054] Step S102: According to the first induced current and the preset induced 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 to-be-measured circuit corresponding transformer coil and the voltage measurement coil, an actual induced voltage in the to-be-measured circuit after the to-be-measured circuit is excited by the voltage excitation coil is obtained.

[0055] As a preferred scheme of the embodiment, the circuit impedance clamp meter further comprises:

[0056] The first excitation voltage is taken as a target induced voltage generated by the voltage excitation coil in the to-be-measured circuit; according to the target induced voltage and the first induced voltage, a first influence degree coefficient and a second influence degree coefficient of the interface of the circuit impedance clamp meter on the voltage in the to-be-measured circuit are respectively calculated; if the ratio between the first influence degree coefficient and the second influence degree coefficient is greater than a preset range, an abnormal signal of the interface of the circuit impedance clamp meter is generated and an alarm is given; if the ratio between the first influence degree coefficient and the second influence degree coefficient is not greater than the preset range, the circuit impedance clamp meter remains in normal working state.

[0057] In the embodiment, the first excitation voltage generated by the circuit impedance clamp meter is taken as a target induced voltage pre-set by the clamp meter, that is, as a voltage tried to be generated by the voltage excitation coil in the to-be-measured circuit. Further, according to the target induced voltage and the first induced voltage measured actually, two influence degree coefficients are respectively calculated; wherein the influence degree coefficients reflect the influence degree of the interface on the measurement result, and the preset range can be determined based on experience or standard test. When the ratio of the two influence degree coefficients exceeds the preset range, the system generates an abnormal signal and triggers an alarm to prompt the user that the interface may have a problem. At the same time, the interface state is continuously monitored, and if the ratio is always within the preset range, the circuit impedance clamp meter remains in normal working state. In order to realize accurate abnormal detection, the collected data need to be properly processed and analyzed, including data cleaning, noise filtering and outlier detection, etc.

[0058] In the embodiment, by calculating and comparing two different influence degree coefficients, the accuracy of the measurement result can be ensured not to be affected by the interface abnormality; meanwhile, the interface state of the loop impedance clamp meter can be monitored in real time, and possible abnormal conditions can be found and alarmed in time, so as to avoid false measurement results. By generating an abnormal signal and alarming, potential problems can be found in advance, so that the maintenance work can be more preventive, and the possibility of equipment failure can be reduced. Through the loop impedance clamp meter, the user can realize the monitoring and alarming of the interface state without additional operation or equipment, simplifying the use process.

[0059] As a preferred scheme of the embodiment, when the target induced voltage and the first induced voltage are calculated, 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 to-be-measured loop include: E0=4.44×f1×N J ×K0, K0=B0×S0 E1=4.44×f1×N J ×K1, K1=B1×S1

[0060] Wherein, 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 in an ideal state, S0 is the cross-sectional area of the voltage excitation coil on the interface of the loop impedance clamp meter in an ideal state, K0 is the first influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the to-be-measured loop in an ideal state, B1 is the magnetic permeability of the interface of the loop impedance clamp meter in an actual state, S1 is the cross-sectional area of the voltage excitation coil on the interface of the loop impedance clamp meter in an actual state, and K1 is the second influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the to-be-measured loop in an actual state. Preferably, the first frequency f1=1500Hz, and the second frequency f2=2000Hz

[0061] As a preferred scheme of the embodiment, the application further includes:

[0062] controlling the voltage excitation coil to generate a second excitation voltage of a second frequency in the to-be-measured loop, so as to obtain a second induced current corresponding to the second frequency in the voltage measurement loop; and calculating a second induced voltage corresponding to the second induced current according to the second induced current and a preset induced resistance in the voltage measurement loop.

[0063] As a preferred scheme of the embodiment, the first induced voltage corresponding to the first induced current is calculated according to the first induced current and a preset induced resistance in the voltage measurement circuit, and the actual induced voltage in the to-be-measured circuit after the voltage excitation coil excites the to-be-measured circuit is obtained according to the number of turns of the transformer coil corresponding to the to-be-measured circuit and the voltage measurement coil, specifically comprising:

[0064] The first induced voltage corresponding to the first induced current and the second induced voltage corresponding to the second induced current are calculated according to the first induced current and the second induced current and the preset induced resistance in the voltage measurement circuit, the first induced voltage and the second induced voltage are verified according to the first excitation voltage and the second excitation voltage, thereby obtaining the first difference value between the first induced voltage and the first excitation voltage and the second difference value between the second induced voltage and the second excitation voltage, and the first difference value and the second difference value are compared; if the first difference value is less than the second difference value, the actual induced voltage in the to-be-measured circuit after the voltage excitation coil excites the to-be-measured circuit is calculated according to the number of turns of the transformer coil corresponding to the to-be-measured circuit and the voltage measurement coil and the first induced voltage; if the first difference value is greater than the second difference value, the actual induced voltage in the to-be-measured circuit after the voltage excitation coil excites the to-be-measured circuit is calculated according to the number of turns of the transformer coil corresponding to the to-be-measured circuit and the voltage measurement coil and the second induced voltage.

[0065] In the embodiment, by calculating and comparing the difference values between the first induced voltage, the second induced voltage and the corresponding first excitation voltage and second excitation voltage, the actual induced voltage in the to-be-measured circuit can be more accurately determined, 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 excluded, thereby enhancing the reliability of the measurement system. At the same time, two sets of difference values are obtained by one-time calculation, and the actual induced voltage is determined according to the difference values, thereby simplifying the measurement process and reducing the required time and resources. Further, the embodiment can adapt to different measurement conditions and to-be-measured circuit characteristics, by flexibly selecting the corresponding induced current and excitation voltage, it is ensured that accurate measurement results can be obtained in various situations, and the actual induced voltage is determined by comparing two sets of difference values, which helps to reduce the influence of external factors on the measurement results; preferably, the preset induced resistance is 150Ω.

[0066] In the embodiment, the first induced current I 01and the second induced current I 01 And in combination with the preset induced resistance R=150Ω, the corresponding induced voltage can be calculated, which can reduce the difference between the actual induced voltage caused by the different states of the slope film alloy core, meet the accuracy requirement of loop impedance measurement, greatly improve the accuracy and universality of the loop impedance parameter measured by the loop impedance clamp meter, and avoid the influence of the environmental temperature, humidity, the fitting degree and cleanliness of the clamp core interface, and the wear of the interface core on the excitation voltage acting on the measured loop.

[0067] The above embodiment has the following effects:

[0068] The technical scheme of the present application aims at the problem that the difference between the measured induced voltage before factory delivery and the actual induced voltage in the field is large in the existing loop impedance clamp meter, improves the measurement function principle of the induced voltage, controls the voltage excitation coil in the loop impedance clamp meter, generates the first excitation voltage of the first frequency in the measured loop, obtains the first induced current corresponding to the first frequency in the voltage measurement loop, and calculates the actual induced voltage in the measured loop based on the number of turns of the transformer coil and the voltage measurement coil corresponding to the measured loop, and the preset induced resistance in the voltage measurement loop, which can reduce the difference between the actual induced voltage caused by the different states of the slope film alloy core, meet the accuracy requirement of loop impedance measurement, and greatly improve the accuracy and universality of the loop impedance parameter measured by the loop impedance clamp meter.

[0069] Embodiment two

[0070] Please refer to Fig. 2, which is a loop impedance clamp meter induced voltage measurement device provided by the present application, comprising: an acquisition module 201 and a calculation module 202;

[0071] The acquisition module 201 is used to control the voltage excitation coil to generate the first excitation voltage of the first frequency in the measured loop, so as to obtain the first induced current corresponding to the first frequency in the voltage measurement loop; wherein the voltage measurement loop and the voltage excitation coil are both arranged in the loop impedance clamp meter, the measured loop is the loop required for impedance measurement by the loop impedance clamp meter, the voltage measurement loop includes a voltage measurement coil, and the transformer coil corresponding to the measured loop, the voltage measurement coil and the voltage excitation coil are all arranged in the same core;

[0072] The calculation module 202 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 measured loop after the voltage excitation coil excites the measured loop according to the number of turns of the transformer coil corresponding to the measured loop and the voltage measurement coil.

[0073] As a preferred solution, it further comprises:

[0074] The first excitation voltage is used to generate a target induction voltage in the to-be-tested circuit as a voltage excitation coil;

[0075] According to the target induction voltage and the first induction voltage, a first influence degree coefficient and a second influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the to-be-tested circuit are calculated respectively when the target induction voltage and the first induction voltage are corresponding;

[0076] If the ratio between the first influence degree coefficient and the second influence degree coefficient is greater than a preset range, an abnormal signal of the interface of the loop impedance clamp meter is generated, and an alarm is given.

[0077] If the ratio between the first influence degree coefficient and the second influence degree coefficient is not greater than the preset range, the normal work of the loop impedance clamp meter is maintained.

[0078] As a preferred solution, 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 to-be-tested circuit when the target induction voltage and the first induction voltage are corresponding include: E0=4.44×f1×N J ×K0, K0=B0×S0 E1=4.44×f1×N J ×K1, K1=B1×S1

[0079] Wherein, E0 is the target induction voltage, E1 is the first induction voltage, f1 is the first frequency, N J is the number of turns of the voltage excitation coil, B0 is the permeability of the interface of the loop impedance clamp meter in an ideal state, S0 is the cross-sectional area of the voltage excitation coil on the interface of the loop impedance clamp meter in an ideal state, K0 is the first influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the to-be-tested circuit in an ideal state, B1 is the permeability of the interface of the loop impedance clamp meter in an actual state, S1 is the cross-sectional area of the voltage excitation coil on the interface of the loop impedance clamp meter in an actual state, and K1 is the second influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the to-be-tested circuit in an actual state.

[0080] As a preferred solution, it further comprises:

[0081] The voltage excitation coil is controlled to generate a second excitation voltage of a second frequency in the to-be-tested circuit, so as to obtain a second induction current of the second frequency in the voltage measurement circuit;

[0082] According to the second induction current and a preset induction resistance in the voltage measurement circuit, a second induction voltage corresponding to the second induction current is calculated.

[0083] As a preferred solution, the first induced voltage corresponding to the first induced current is calculated according to the first induced current and a preset induced resistance in the voltage measurement loop, and the actual induced voltage in the to-be-tested loop after the voltage excitation coil excites the to-be-tested loop is obtained according to the number of turns of the transformer coil corresponding to the to-be-tested loop and the voltage measurement coil, specifically comprising:

[0084] The first induced voltage corresponding to the first induced current and the second induced voltage corresponding to the second induced current are calculated according to the first induced current and the second induced current and the preset induced resistance in the voltage measurement loop.

[0085] The first induced voltage and the second induced voltage are verified according to the first excitation voltage and the second excitation voltage, so as to obtain a first difference value between the first induced voltage and the first excitation voltage and a second difference value between the second induced voltage and the second excitation voltage, and the first difference value and the second difference value are compared.

[0086] If the first difference value is less than the second difference value, the actual induced voltage in the to-be-tested loop after the voltage excitation coil excites the to-be-tested loop is calculated according to the number of turns of the transformer coil corresponding to the to-be-tested loop and the voltage measurement coil and the first induced voltage.

[0087] If the first difference value is greater than the second difference value, the actual induced voltage in the to-be-tested loop after the voltage excitation coil excites the to-be-tested loop is calculated according to the number of turns of the transformer coil corresponding to the to-be-tested loop and the voltage measurement coil and the second induced voltage.

[0088] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described device can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0089] The above embodiments have the following effects:

[0090] The technical scheme of the present application aims at the problem that the difference between the measured induced voltage before factory delivery and the actual induced voltage in the field is large in the existing loop impedance clamp meter, and improves the measurement function principle of the induced voltage, controls the voltage excitation coil in the loop impedance clamp meter, generates a first excitation voltage of a first frequency in the to-be-measured loop, thereby obtains a first induced current corresponding to the first frequency in the voltage measurement loop, and calculates the actual induced voltage in the to-be-measured loop based on the number of turns of the transformer coil corresponding to the to-be-measured loop and the voltage measurement coil, and further based on the first induced current and the preset induced resistance in the voltage measurement loop, which can reduce the difference between the actual induced voltage and the induced voltage caused by the different states of the slope film alloy core, meet the loop impedance measurement accuracy requirement, and greatly improve the accuracy and universality of the loop impedance parameter measurement of the loop impedance clamp meter.

[0091] Embodiment three

[0092] Please refer to Fig. 3, which is a loop impedance clamp meter induced voltage measurement system provided by the present application, used for executing the loop impedance clamp meter induced voltage measurement method as described in the above embodiment one, comprising: a loop impedance clamp meter and a to-be-measured loop; the to-be-measured loop is provided with a transformer coil.

[0093] The loop impedance clamp meter comprises a processor, and a voltage measurement loop and a voltage excitation coil connected with the processor.

[0094] In the present embodiment, the loop impedance clamp meter is mainly used for measuring the impedance of the to-be-measured loop, please refer to Fig. 4, which is a principle diagram of the loop impedance clamp meter measuring the impedance of the to-be-measured loop, and 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.

[0095] The processor is used for controlling the voltage excitation coil to generate a first excitation voltage of a first frequency in the to-be-measured loop, thereby obtaining a first induced current corresponding to the first frequency in the voltage measurement loop; wherein the voltage measurement loop and the voltage excitation coil are arranged in the loop impedance clamp meter, the to-be-measured loop is a loop required for impedance measurement by the loop impedance clamp meter, the voltage measurement loop comprises a voltage measurement coil, and the transformer coil corresponding to the to-be-measured loop, the voltage measurement coil and the voltage excitation coil are arranged in the same core; according to the first induced current and the preset induced resistance in the voltage measurement loop, a 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 to-be-measured loop and the voltage measurement coil, the actual induced voltage in the to-be-measured loop after the to-be-measured loop is excited by the voltage excitation coil is obtained.

[0096] As a preferred scheme, the processor is further used for:

[0097] The first excitation voltage is used as a target induction voltage generated by the voltage excitation coil in the to-be-tested loop; according to the target induction voltage and the first induction voltage, a first influence degree coefficient and a second influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the to-be-tested loop corresponding to the target induction voltage and the first induction voltage are respectively calculated; if the ratio between the first influence degree coefficient and the second influence degree coefficient is greater than a preset range, an abnormal signal of the interface of the loop impedance clamp meter is generated, and an alarm is given. If the ratio between the first influence degree coefficient and the second influence degree coefficient is not greater than the preset range, the normal work of the loop impedance clamp meter is maintained.

[0098] As a preferred solution, 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 to-be-tested loop corresponding to the target induction voltage and the first induction voltage are calculated, and include: E0=4.44×f1×N J ×K0, K0=B0×S0 E1=4.44×f1×N J ×K1, K1=B1×S1

[0099] Wherein, E0 is the target induction voltage, E1 is the first induction voltage, f1 is the first frequency, N J is the number of turns of the voltage excitation coil, B0 is the permeability of the interface of the loop impedance clamp meter in an ideal state, S0 is the cross-sectional area of the voltage excitation coil on the interface of the loop impedance clamp meter in an ideal state, K0 is the first influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the to-be-tested loop in an ideal state, B1 is the permeability of the interface of the loop impedance clamp meter in an actual state, S1 is the cross-sectional area of the voltage excitation coil on the interface of the loop impedance clamp meter in an actual state, and K1 is the second influence degree coefficient of the interface of the loop impedance clamp meter on the voltage in the to-be-tested loop in an actual state.

[0100] As a preferred solution, the processor is further configured to control the voltage excitation coil to generate a second excitation voltage of a second frequency in the to-be-tested loop, so as to obtain a second induction current corresponding to the second frequency in the voltage measurement loop; and calculate a second induction voltage corresponding to the second induction current according to the second induction current and a preset induction resistance in the voltage measurement loop.

[0101] As a preferred solution, the first induction voltage corresponding to the first induction current is calculated according to the first induction current and the preset induction resistance in the voltage measurement loop, and the actual induction voltage in the to-be-tested loop after the to-be-tested loop is excited by the voltage excitation coil is obtained according to the number of turns of the transformer coil corresponding to the to-be-tested loop and the voltage measurement coil, and specifically includes:

[0102] According to the first induced current and the second induced current, and a preset induced resistance 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; the first induced voltage and the second induced voltage are verified according to the first excitation voltage and the second excitation voltage, so that 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 are obtained, and the first difference and the second difference are compared; if the first difference is less than the second difference, then according to the number of turns of the transformer coil corresponding to the to-be-measured loop and the voltage measurement coil and the first induced voltage, an actual induced voltage in the to-be-measured loop after the to-be-measured loop is excited by the voltage excitation coil is calculated; if the first difference is greater than the second difference, then according to the number of turns of the transformer coil corresponding to the to-be-measured loop and the voltage measurement coil and the second induced voltage, the actual induced voltage in the to-be-measured loop after the to-be-measured loop is excited by the voltage excitation coil is calculated.

[0103] In the embodiment, the loop impedance clamp meter further comprises a current measurement coil, a current acquisition unit and a voltage excitation unit. The current measurement coil is used to measure the induced current in the to-be-measured loop, and the current acquisition unit filters, amplifies and digitizes the induced current measured by the current measurement coil, so as to input into the processor. The voltage excitation unit is used to receive the control signal of the processor, and then digitizes the digital signal output by the processor and performs power amplification, so as to generate and induce the output signal through the voltage excitation coil.

[0104] It should be noted that if the impedance of the to-be-measured loop is inductive, then Z=R+jωL=R+j(2×π×f×L); if the loop impedance is capacitive, then The simultaneous equations can be obtained as follows:

[0105] X1=(2×π×f×L) or X2=(2×π×f×L) or

[0106] In the formula, I 01、 I 02 are the induced current values in the voltage measurement loop measured at frequencies f1 and f2 respectively, I 11、 I 12 are the current values of the current measurement coil measured at frequencies f1 and f2 respectively, E 01 is the first induced voltage, E 02 is the second induced voltage, Z1 and Z2 are the impedances at frequencies f1 and f2 respectively, L is the inductance, and C is the capacitance.

[0107] The above embodiment is implemented, and has the following effects:

[0108] The technical scheme of the present application aims at the problem that the difference between the calculated induced voltage before factory delivery and the actual induced voltage in the field is large in the existing loop impedance clamp meter, and improves the measurement function principle of the induced voltage. The control voltage excitation coil is controlled in the loop impedance clamp meter, the first excitation voltage of the first frequency is generated in the to-be-measured loop, so that the first induced current corresponding to the first frequency is obtained in the voltage measurement loop, and based on the number of turns of the transformer coil corresponding to the to-be-measured loop and the voltage measurement coil, the actual induced voltage in the to-be-measured loop is calculated according to the first induced current and the preset induced resistance in the voltage measurement loop. The difference between the actual induced voltage and the actual induced voltage caused by the different states of the slope film alloy core can be reduced, the loop impedance calculation accuracy requirement can be met, and the accuracy and universality of the loop impedance clamp meter in measuring the loop impedance parameters are greatly improved.

[0109] The above specific embodiments further illustrate the purpose, technical scheme and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. It is particularly pointed out that any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for measuring induced voltage using a loop impedance clamp meter, 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, 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; 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.

2. The method for measuring induced voltage using a loop impedance clamp meter according to claim 1, wherein: Also includes: Using the first excitation voltage as the target induced voltage generated by the voltage excitation coil in the circuit to be tested; 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; If the ratio between the first influence coefficient and 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 a preset range, the loop impedance clamp meter is maintained to operate normally.

3. The method for measuring induced voltage using a loop impedance clamp meter according to claim 2, wherein: 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 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.

4. The method for measuring induced voltage using a loop impedance clamp meter according to claim 1, wherein: 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 based on the second induced current and a preset induced resistance in the voltage measurement loop.

5. The method for measuring induced voltage using a loop impedance clamp meter according to claim 4, wherein: The step of calculating 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 obtaining 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, specifically includes: 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; 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; 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; 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.

6. A loop impedance clamp meter induced voltage measurement device, characterized in that: include: Acquisition module and calculation module; 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; 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.

7. A loop impedance clamp meter induced voltage measurement system, characterized in that: The method for measuring induced voltage using a loop impedance clamp meter according to any one of claims 1 to 5 comprises: a loop impedance clamp meter and a circuit to be measured; a transformer coil is provided on the circuit to be measured; The loop impedance clamp meter includes: a processor, and a voltage measurement circuit 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, 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.

8. The loop impedance clamp meter induced voltage measurement system according to claim 7, characterized in that: The processor is further configured to: Using the first excitation voltage as the target induced voltage generated by the voltage excitation coil in the circuit to be tested; 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; If the ratio between the first influence coefficient and 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 a preset range, the loop impedance clamp meter is maintained to operate normally.

9. The loop impedance clamp meter induced voltage measurement system according to claim 7, characterized in that: The processor is further configured 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 inductive resistance in the voltage measurement circuit.

10. The loop impedance clamp meter induced voltage measurement system according to claim 9, characterized in that: The step of calculating 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 obtaining 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, specifically includes: 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; 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; 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; 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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