Impedance detection circuit, method, device and equipment applied to switch cabinet, storage medium and program product

Abstract

The embodiment of the invention provides an impedance detection circuit, method, device and equipment applied to a switch cabinet, a storage medium and a program product. The circuit comprises a data processing device, a vector network analyzer, a flexible capacitive sensor and a to-be-tested circuit belonging to a switch loop in the switch cabinet, the at least two flexible capacitive sensors and the to-be-tested circuit are connected in series to form a series branch; one end of the series branch is connected with a first port of the vector network analyzer, and the other end of the series branch is connected with a second port of the vector network analyzer; a first port of the vector network analyzer sends out a high-frequency excitation voltage signal, and the first port and a second port receive electrical data generated by the high-frequency excitation voltage signal; and the data processing equipment determines the impedance of the circuit to be tested according to the electrical data and the capacitance value of the flexible capacitive sensor. The circuit is used for achieving the technical effect of accurately measuring the impedance of an electrical connection part in the switch cabinet on the premise of not influencing the normal power supply of the switch cabinet.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to an impedance detection circuit, method, device, equipment, storage medium and program product applied to a switch cabinet. Background Art

[0002] In power systems, with increasing loads and increasingly complex operating environments, the reliability and safety of switchgear are becoming increasingly important. Measuring the impedance of electrical connection components within switchgear (such as busbars, circuit breakers, and contactors) provides a crucial basis for assessing equipment operating status and identifying potential faults.

[0003] In related technologies, methods for measuring the impedance of electrical connections within switchgear include contact measurement and non-contact measurement. Contact measurement involves disconnecting the power supply and measuring the electrical connections using a measuring device, or by removing some of the electrical connections and measuring the removed components using a measuring device to obtain the impedance. Non-contact measurement utilizes the principle of electromagnetic induction, using an inductive magnetic head to monitor electrical data such as current and voltage in the switchgear's internal circuits in real time. The impedance of the internal electrical connections is then calculated based on the monitored electrical data.

[0004] Based on the above analysis, the impedance accuracy of contactless measurement is low, as power outages can affect the switchgear's normal power supply. Non-contact measurement, on the other hand, suffers from magnetic field influences on the magnetic head's monitoring results. The strong magnetic field inside the high-voltage switchgear environment results in low accuracy. Therefore, accurately measuring the impedance of electrical connections within a switchgear without disrupting its normal power supply has become a pressing technical challenge. Summary of the Invention

[0005] The embodiments of the present application provide an impedance detection circuit, method, device, equipment, storage medium and program product applied to a switch cabinet, so as to achieve the technical effect of accurately measuring the impedance of the electrical connection components inside the switch cabinet without affecting the normal power supply of the switch cabinet.

[0006] In a first aspect, an embodiment of the present application provides an impedance detection circuit applied to a switch cabinet, comprising:

[0007] A data processing device, a vector network analyzer, at least two flexible capacitive sensors and a circuit to be tested; the circuit to be tested belongs to a switch circuit in a switch cabinet; the at least two flexible capacitive sensors and the circuit to be tested are connected in series to form a series branch;

[0008] One end of the series branch is connected to the first port of the vector network analyzer, and the other end of the series branch is connected to the second port of the vector network analyzer;

[0009] The first port of the vector network analyzer sends a high-frequency excitation voltage signal, and the first port and the second port receive electrical data, where the electrical data is the electrical data generated by the high-frequency excitation voltage signal passing through the series branch;

[0010] The data processing device is connected to the signal output end of the vector network analyzer, receives the electrical data output by the signal output end of the vector network analyzer, and determines the impedance of the circuit to be tested according to the electrical data and the capacitance values ​​of the at least two flexible capacitive sensors.

[0011] In a possible implementation, the flexible capacitive sensor includes a mountable flexible electrode sheet, and the mountable flexible electrode sheet and a portion of the circuit to be tested mounted thereon form a capacitor.

[0012] In one possible implementation, the circuit to be tested includes a high-voltage cable and a first busbar in the switch cabinet, the high-voltage cable includes a metal high-voltage core and an insulation layer wrapped around the metal high-voltage core, and the first busbar is any phase busbar among the high-voltage three-phase busbars in the switch cabinet; the high-voltage cable is located at a first end of the circuit to be tested, and the first busbar is located at a second end of the circuit to be tested;

[0013] The at least two flexible capacitive sensors include a first flexible capacitive sensor and a second flexible capacitive sensor; wherein,

[0014] The mountable flexible electrode sheet of the first flexible capacitive sensor is mounted on a portion of the insulation layer of the high-voltage cable;

[0015] The mountable flexible electrode sheet of the second flexible capacitive sensor is mounted on a portion of the insulating layer of the first busbar.

[0016] In a second aspect, an embodiment of the present application provides an impedance detection method applied to a switch cabinet, comprising:

[0017] Sending a high-frequency excitation voltage signal to a series branch by a vector network analyzer, wherein the series branch is composed of at least two flexible capacitive sensors connected in series and a circuit to be tested;

[0018] acquiring electrical data received by the vector network analyzer, the electrical data being generated by the series branch through the high-frequency excitation voltage signal;

[0019] The impedance of the circuit to be tested is determined according to the electrical data and the capacitance values ​​corresponding to the at least two flexible capacitive sensors.

[0020] In a possible implementation, the electrical data includes: a first reflection coefficient of a first port of the vector network analyzer, a second reflection coefficient of a second port of the vector network analyzer, a first transmission gain from the first port to the second port, and a second transmission gain from the second port to the first port.

[0021] In a possible implementation, determining the impedance of the circuit to be tested based on the electrical data and capacitance values ​​corresponding to at least two flexible capacitive sensors includes:

[0022] determining a first impedance based on the first reflection coefficient, the second reflection coefficient, the first transmission gain, and the second transmission gain;

[0023] determining a second impedance based on capacitance values ​​of the at least two flexible capacitive sensors;

[0024] The impedance of the circuit to be tested is determined according to the first impedance and the second impedance.

[0025] In a third aspect, an embodiment of the present application provides an impedance detection device for a switch cabinet, comprising:

[0026] A signal sending module, configured to send a high-frequency excitation voltage signal to a series branch through a vector network analyzer, wherein the series branch includes at least two flexible capacitive sensors connected in series and a circuit to be tested;

[0027] an acquisition module, configured to acquire electrical data captured by the vector network analyzer, the electrical data being generated by the series branch through the high-frequency excitation voltage signal;

[0028] The determination module is configured to determine the impedance of the circuit to be tested based on the electrical data and the capacitance values ​​corresponding to the at least two flexible capacitive sensors.

[0029] In a fourth aspect, an embodiment of the present application provides an impedance detection device for a switch cabinet, comprising: a memory, a processor;

[0030] The memory stores computer-executable instructions;

[0031] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the above second aspect and / or various possible implementations of the second aspect.

[0032] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored. When the computer-executable instructions are executed by a processor, they are used to implement the above second aspect and / or various possible implementation methods of the second aspect.

[0033] In a sixth aspect, an embodiment of the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the above second aspect and / or various possible implementation methods of the second aspect.

[0034] The impedance detection circuit, method, device, equipment, storage medium and program product applied to the switch cabinet provided in the embodiments of the present application receive electrical data output by the output end of the vector network analyzer, and determine the impedance of the circuit to be tested based on the electrical data and the capacitance value of the flexible capacitive sensor; wherein the electrical data is generated by the high-frequency excitation voltage signal emitted by the first port of the vector network analyzer through the flexible capacitive sensor connected in series and the circuit to be tested belonging to the switch circuit in the switch cabinet; since the operating voltage in the switch circuit of the switch cabinet is a low-frequency voltage, under the low-frequency operating voltage, the flexible capacitive sensor connected in series and the circuit to be tested are equivalent to being open circuited, and the impedance detection circuit does not affect the normal power supply of the switch cabinet; at the same time, the electrical data used to determine the impedance of the circuit to be tested and the capacitance value of the flexible capacitive sensor are less affected by the magnetic field generated by the high-voltage environment inside the switch cabinet, thereby achieving the technical effect of accurately measuring the impedance of the electrical connection components inside the switch cabinet without affecting the normal power supply of the switch cabinet. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0036] Figure 1 A schematic structural diagram of an impedance detection circuit applied to a switch cabinet provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the structure of a switch cabinet test circuit provided in an embodiment of the present application;

[0038] Figure 3 A schematic diagram of the structure of the flexible capacitive sensor provided in an embodiment of the present application connected to a high-voltage cable;

[0039] Figure 4 A schematic diagram of the structure of the flexible capacitive sensor provided in an embodiment of the present application connected to a busbar;

[0040] Figure 5 A schematic flow chart of an impedance detection method applied to a switch cabinet provided in an embodiment of the present application;

[0041] Figure 6 Schematic diagram of the equivalent circuit structure of the test loop provided in the embodiment of the present application;

[0042] Figure 7A schematic cross-sectional view of a connection circuit for measuring the capacitance of a cylindrical capacitor using a fixture provided in an embodiment of the present application;

[0043] Figure 8 A schematic diagram of a partial circuit connection structure for measuring the capacitance value of a flexible capacitive sensor in an experiment provided in an embodiment of the present application;

[0044] Figure 9 A schematic diagram of a circuit connection structure for measuring the impedance of an 82 pF capacitor in an experiment provided in an embodiment of the present application;

[0045] Figure 10 Comparative results of experiments provided in the examples of this application;

[0046] Figure 11 A schematic structural diagram of an impedance detection device applied to a switch cabinet provided in an embodiment of the present application;

[0047] Figure 12 A schematic structural diagram of an impedance detection device applied to a switch cabinet provided in an embodiment of the present application.

[0048] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0049] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0050] Switchgear is a critical piece of equipment in power systems, primarily used for the distribution, control, and protection of electrical energy. With increasing loads and increasingly complex operating environments, the reliability and safety of switchgear are becoming increasingly crucial. Measuring the impedance of electrical connection components within switchgear (such as busbars, circuit breakers, and contactors) provides a crucial basis for assessing equipment operating status and identifying potential faults.

[0051] In the related art, methods for measuring the impedance of electrical connections within switchgear include contact measurement and non-contact measurement. Contact measurement involves disconnecting the switchgear power supply and then measuring the electrical connections using a measuring device, or by removing some of the electrical connections and then measuring the removed electrical connections using a measuring device to obtain the impedance of the electrical connections. Disconnecting the power supply with contact measurement interrupts the normal power supply to the switchgear, impacting the production and daily life of electricity users. Furthermore, performing contact measurement in a high-voltage environment poses a threat to the safety of workers.

[0052] Non-contact measurement utilizes the principle of electromagnetic induction, using an inductive magnetic head to monitor electrical data such as current and voltage in the switchgear's internal circuits in real time. The impedance of internal electrical connections is then calculated based on the monitored current, voltage, and other electrical data. This measurement method eliminates the need for direct connection to the electrical components to be tested and can measure the impedance of electrical connections without interrupting the switchgear's power supply. However, the complex structure and high-voltage environment within the switchgear can generate strong magnetic field interference, which can easily affect the non-contact measurement signal of the inductive magnetic head. Furthermore, when the impedance in the switch circuit is large, the current in the switch circuit is small, and the inductive magnetic head is insufficient to capture subtle changes in impedance in the switch circuit. This results in low impedance accuracy for electrical connections measured using the non-contact measurement method.

[0053] In combination with the above scenario, it can be seen that in the related art, the impedance measurement of the electrical components inside the switch cabinet by contact measurement method affects the normal power supply of the switch cabinet due to the power-off operation, while the impedance measurement results obtained by measuring the impedance of the electrical components inside the switch cabinet by non-contact method have low accuracy.

[0054] The impedance detection circuit, method, device, equipment, storage medium and program product applied to the switch cabinet provided in this application are used to solve the above-mentioned technical problems.

[0055] The execution subject of the present invention may be a data processing device, or other device, system or equipment with data processing capabilities.

[0056] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0057] Figure 1 This is a schematic diagram of the structure of the impedance detection circuit applied to the switch cabinet provided in the embodiment of the present application, as shown in FIG. Figure 1 As shown, the impedance detection circuit 10 applied to the switch cabinet includes:

[0058] A data processing device 101, a vector network analyzer 102, at least two flexible capacitive sensors 103, 104 and a circuit to be tested 105; the circuit to be tested 105 belongs to a switch circuit in a switch cabinet; the at least two flexible capacitive sensors 103, 104 and the circuit to be tested 105 are connected in series to form a series branch;

[0059] One end of the series branch is connected to the first port 106 of the vector network analyzer 102, and the other end of the series branch is connected to the second port 107 of the vector network analyzer 102;

[0060] The first port 106 of the vector network analyzer 102 sends a high-frequency excitation voltage signal, and the first port 106 and the second port 107 receive electrical data, where the electrical data is electrical data generated by the high-frequency excitation voltage signal passing through the series branch;

[0061] The data processing device 101 is connected to the signal output terminal 108 of the vector network analyzer 102, receives electrical data output by the signal output terminal 108 of the vector network analyzer 102, and determines the impedance of the circuit to be tested 105 based on the electrical data and the capacitance values ​​of at least two flexible capacitive sensors 103 and 104.

[0062] It should be noted that the vector network analyzer and at least two flexible capacitive sensors connected in series and the circuit to be tested together constitute a series test loop, the first end of the circuit to be tested is connected in series with at least one flexible capacitive sensor, the second end of the circuit to be tested is connected in series with at least one flexible capacitive sensor, and the vector network analyzer, the flexible capacitive sensor and the test loop are electrically connected via a power line. Wherein, the flexible capacitive sensor includes a mountable flexible electrode sheet, and the mountable flexible electrode sheet and the portion of the circuit to be tested to which it is mounted form a capacitor. The first end of the circuit to be tested is connected to the first port of the vector network analyzer through at least one flexible capacitive sensor, and the second end of the circuit to be tested is connected to the second port of the vector network analyzer through at least one flexible capacitive sensor, wherein the mountable flexible electrode sheet of the flexible capacitive sensor is mounted on the portion of the circuit to be tested at the first end or the second end of the circuit to be tested, and at the same time, the flexible capacitive sensor is connected to the port of the vector network analyzer via the power line, thereby forming a capacitor between the mountable flexible electrode sheet of the flexible capacitive sensor and the mounted portion of the circuit to be tested.

[0063] Since the operating frequency of the switch circuit of the switch cabinet is generally 50 Hz, the frequency range of the high-frequency excitation voltage signal emitted by the first port of the flexible capacitive sensor vector network analyzer can be 1 MHz to several hundred MHz, and the capacitance formed by the mountable flexible electrode sheet and the part mounted thereon in the test circuit presents a high-resistance (or open-circuit) characteristic to the 50 Hz power frequency, and a low-resistance characteristic to the high-frequency excitation voltage signal. Therefore, using a high-frequency excitation voltage signal to test the impedance of the circuit to be tested can generate electrical data in the test circuit without affecting the normal power supply of the switch circuit of the switch cabinet, thereby realizing the impedance measurement of the electrical connection components inside the switch cabinet without interrupting the power supply to the switch cabinet.

[0064] The circuit to be tested can be determined according to the measurement requirements.

[0065] As an example, depending on measurement requirements, the circuit to be tested may be a portion of a switch circuit in a switchgear cabinet, which includes at least one electrical connection component (e.g., a circuit breaker). Depending on the measurement requirements, the test circuit may be used to measure the impedance of the at least one electrical connection component.

[0066] An impedance detection circuit applied to a switch cabinet provided in an embodiment of the present application receives electrical data output by an output end of a vector network analyzer, and determines the impedance of a circuit to be tested based on the electrical data and the capacitance value of a flexible capacitive sensor; wherein the electrical data is generated by a high-frequency excitation voltage signal emitted by a first port of the vector network analyzer through a flexible capacitive sensor connected in series and a circuit to be tested belonging to a switch circuit in the switch cabinet; since the operating voltage in the switch circuit of the switch cabinet is a low-frequency voltage, under the low-frequency operating voltage, the flexible capacitive sensor connected in series and the circuit to be tested are equivalent to being open circuited, and the impedance detection circuit does not affect the normal power supply of the switch cabinet; at the same time, the electrical data used to determine the impedance of the circuit to be tested and the capacitance value of the flexible capacitive sensor are less affected by the magnetic field generated by the high-voltage environment inside the switch cabinet, thereby achieving the technical effect of accurately measuring the impedance of electrical connection components inside the switch cabinet without affecting the normal power supply of the switch cabinet.

[0067] The following further illustrates the technical solution of the present application by taking the measurement of the impedance of the line to be tested between the high-voltage cable of the switch circuit in the switch cabinet and any phase busbar in the high-voltage three-phase busbar as an example.

[0068] Figure 2 A schematic diagram of the structure of the switch cabinet test circuit provided in the embodiment of the present application is shown as follows: Figure 2As shown, A is the busbar room of the switch cabinet, B is the trolley room of the switch cabinet, C is the cable room of the switch cabinet, and D is the relay room of the switch cabinet; the circuit to be tested includes a high-voltage cable 201 and a first busbar 202 in the switch cabinet, the high-voltage cable 201 is located at the first end of the circuit to be tested, and the first busbar 202 is located at the second end of the circuit to be tested, and at least two flexible capacitive sensors include a first flexible capacitive sensor 103 and a second flexible capacitive sensor 104. Specifically, the first port 106 of the vector network analyzer 102 is connected to the power line and is connected to the high-voltage cable 201 of the switch cabinet through the first flexible capacitive sensor 103; the second port 107 of the vector network analyzer 102 is connected to the power line and is connected to the first busbar 202 of any phase in the high-voltage three-phase busbar of the switch cabinet through the second flexible capacitive sensor 104; in the switch loop, the circuit to be tested including the high-voltage cable 201 and the first busbar 202 also includes an electrical connection component current transformer 203 and a circuit breaker 204.

[0069] Figure 3 This is a structural diagram of the flexible capacitive sensor provided in the embodiment of the present application connected to the high-voltage cable, as shown in FIG. Figure 3 As shown, the high-voltage cable 201 includes a metal high-voltage core 301 and an insulating layer 302 surrounding the metal high-voltage core 301. The mountable flexible electrode sheet of the first flexible capacitive sensor 103 is mounted on a portion of the insulating layer 302 of the high-voltage cable 201. The first flexible capacitive sensor 103 is connected to the power line 303. The mountable flexible electrode sheet of the first flexible capacitive sensor 103 and the metal high-voltage core 301 of the high-voltage cable 201 form a cylindrical capacitor.

[0070] Figure 4 A schematic diagram of the structure of the flexible capacitive sensor connected to the busbar provided in the embodiment of the present application is shown as follows: Figure 4 As shown, the mountable flexible electrode sheet of the second flexible capacitive sensor 104 is mounted on a portion of the insulating layer 402 of the first busbar 401. At the same time, the second flexible capacitive sensor 104 is connected to the power line 403. The mountable flexible electrode sheet of the second flexible capacitive sensor 104 and the first busbar 401 form a flat capacitor.

[0071] The constructed switchgear test circuit includes two capacitors, a portion of the switchgear circuit to be tested, and a vector network analyzer. This test circuit can be used to apply a high-frequency excitation voltage signal to a flexible capacitive sensor through the vector network analyzer. The electrical data received by the vector network analyzer can then be used to determine the impedance of the circuit to be tested. Because of the presence of the two capacitors, the high-frequency excitation voltage signal is used to detect the impedance of the circuit to be tested within the test circuit without affecting the normal operation of the switchgear circuit at a 50 Hz power frequency.

[0072] The following further illustrates the technical solution of the present application by taking the use of the switch cabinet test circuit constructed as above to test the impedance of the electrical connection components inside the switch cabinet as an example. Figure 5 The flow chart of the impedance detection method applied to the switch cabinet provided in the embodiment of the present application is as follows: Figure 5 As shown, the method includes:

[0073] S501 , sending a high-frequency excitation voltage signal to a series branch through a vector network analyzer, where the series branch consists of at least two flexible capacitive sensors connected in series and a circuit to be tested.

[0074] For example, the frequency of the high-frequency excitation voltage signal can be set to 1 MHz by a data processing device, and the first port of the vector network analyzer can be controlled to emit a 1 MHz high-frequency excitation voltage signal, thereby generating electrical data in the switch cabinet test circuit.

[0075] S502 : Acquire electrical data received by a vector network analyzer, where the electrical data is generated by the series branch through a high-frequency excitation voltage signal.

[0076] For example, a first port and a second port of a vector network analyzer can receive electrical data generated by a 1 MHz high-frequency excitation voltage signal emitted by the first port through the first flexible capacitive sensor, the second flexible capacitive sensor, and the circuit under test in the switchgear circuit. The electrical data includes: a first reflection coefficient of the first port of the vector network analyzer, a second reflection coefficient of the second port of the vector network analyzer, a first transmission gain from the first port to the second port, and a second transmission gain from the second port to the first port. The electrical data can be obtained by reading the measurement display data on the vector network analyzer screen.

[0077] S503 : Determine the impedance of the circuit to be tested according to the electrical data and the capacitance values ​​corresponding to the at least two flexible capacitive sensors.

[0078] In some specific implementations, the above S503 includes:

[0079] First, a first impedance is determined according to the first reflection coefficient, the second reflection coefficient, the first transmission gain, and the second transmission gain.

[0080] It should be noted that the total impedance in the test loop includes the impedance of at least two flexible capacitive sensors and the impedance of the circuit to be tested. Therefore, the impedance of the circuit to be tested can be determined based on the measured total impedance and the impedance of at least two flexible capacitive sensors. Figure 6 The equivalent circuit structure diagram of the test loop provided in the embodiment of the present application is as follows: Figure 6As shown, the capacitors 601 and the circuit to be tested 602 corresponding to the two flexible capacitive sensors are connected in series, and the measured total impedance includes the sum of the impedances of the two capacitors 601 and the impedance of the test circuit 602.

[0081] Specifically, the first impedance can be determined by the following formula (1), where the first impedance represents the total impedance obtained by measurement:

[0082] (1);

[0083] Where Z M Represents the first impedance; S 11 represents the first reflection coefficient of the first port of the vector network analyzer; S 22 represents the second reflection coefficient of the second port of the vector network analyzer; S 12 represents the first transmission gain from the first port to the second port; S 21 represents the second transmission gain from the second port to the first port; 50 represents that the internal impedance of the vector network analyzer is 50 ohms.

[0084] Second, determining a second impedance according to capacitance values ​​of at least two flexible capacitive sensors.

[0085] The impedance of the at least two flexible capacitive sensors is determined by the capacitance values ​​of the at least two flexible capacitive sensors.

[0086] As an example, the capacitance value of the flexible capacitive sensor may be calculated by measuring the length, width, and area of ​​the mounting region of the flexible capacitive sensor.

[0087] For a cylindrical capacitor formed by the mountable flexible electrode sheet of the first flexible capacitive sensor and the metal high-voltage core of the high-voltage cable, the capacitance value of the cylindrical capacitor can be calculated by the following formula (2):

[0088] (2);

[0089] Where C1 represents the capacitance of the cylindrical capacitor; ε0 represents the dielectric constant of vacuum; ε r1 represents the relative dielectric constant of the main insulation of the high-voltage cable; H represents the height of the cylindrical capacitor (i.e., the length of the flexible capacitive sensor coating); ln represents the logarithmic function with the natural constant e (approximately 2.71828) as the base; R b Indicates the main insulation radius of the high-voltage cable; R a Indicates the radius of the metal high-voltage core of the high-voltage cable.

[0090] For the flat plate capacitor formed by the mountable flexible electrode sheet of the second flexible capacitive sensor and the first busbar, the capacitance value of the flat plate capacitor can be calculated by the following formula (3):

[0091] (3);

[0092] Where, C2 represents the capacitance value of the plate capacitor; ε r2 represents the relative dielectric constant of the insulation layer of the first busbar; G represents the mounting area of ​​the second flexible capacitive sensor; and n represents the thickness of the insulation layer of the first busbar.

[0093] As another example, a fixture can be used to measure the capacitance of a flexible capacitive sensor. To obtain the capacitance of a cylindrical capacitor formed by the mountable flexible electrode sheet of a first flexible capacitive sensor and the metal high-voltage core of a high-voltage cable, a second high-voltage cable of the same model as the high-voltage cable is required. To obtain the capacitance of a planar capacitor formed by the mountable flexible electrode sheet of a second flexible capacitive sensor and the first busbar, a second busbar of the same model as the first busbar is required.

[0094] Figure 7 A schematic cross-sectional view of a connection circuit for measuring the capacitance of a cylindrical capacitor using a fixture provided in an embodiment of the present application is shown in FIG. Figure 7 As shown, the second high-voltage cable is fixed on the insulating support column 701 of the metal base 702 of the fixture; the first port 106 of the vector network analyzer is connected to the power line, and the power line is covered on the insulation layer 302 of the second high-voltage cable through the mountable flexible electrode sheet of the first flexible capacitive sensor 103; the second port 107 of the vector network analyzer is connected to the metal high-voltage core 301 of the second high-voltage cable through the power line to form a power circuit, which can measure the same capacitance value as the cylindrical capacitor in the test circuit.

[0095] After constructing the power circuit, a 1 MHz high-frequency excitation voltage signal is emitted through the first port of the vector network analyzer, thereby generating electrical data in the power circuit. Using the electrical data received by the vector network analyzer, the third impedance from the first port to the second port is calculated according to formula (1), and the capacitance value of the cylindrical capacitor is calculated according to the following formula (4):

[0096] (4);

[0097] Where C1 represents the capacitance of the cylindrical capacitor; j represents the imaginary unit of the complex number; f represents the frequency of the high-frequency excitation voltage signal; Z ca represents the third impedance from the first port to the second port.

[0098] Measuring the capacitance value of a flat-plate capacitor using the second busbar through a fixture is similar to measuring the capacitance value of a cylindrical capacitor using the second high-voltage cable through a fixture, and will not be repeated here.

[0099] It should be noted that both of the above two methods can obtain the capacitance value of the capacitor. Among them, there is a certain measurement error in calculating the capacitance value of the flexible capacitive sensor by measuring the length, width and area of ​​the mounting area of ​​the flexible capacitive sensor. Using a fixture to measure the capacitance value of the flexible capacitive sensor can reduce the measurement error to a certain extent.

[0100] After determining the capacitance value C1 of the cylindrical capacitor and the capacitance value C2 of the flat plate capacitor, the second impedance can be calculated according to the following formula (5). The second impedance represents the sum of the impedances of the cylindrical capacitor and the flat plate capacitor:

[0101] (5);

[0102] Where Z c represents the second impedance.

[0103] Third, the impedance of the circuit to be tested is determined according to the first impedance and the second impedance.

[0104] The impedance of the circuit to be tested can be determined according to the following formula (6):

[0105] (6);

[0106] Where Z L Indicates the impedance of the circuit to be tested.

[0107] The impedance detection method applied to a switch cabinet provided in the embodiment of the present application does not require modification of the existing switch circuit of the switch cabinet, and the high-frequency excitation voltage signal of the test circuit will not interfere with the switch circuit. Therefore, the impedance of the circuit to be tested can be measured without interrupting power supply. At the same time, the impedance of the circuit to be tested is calculated by the capacitance value of the capacitor and the electrical data received by the vector network analyzer, and is less affected by the magnetic field. Therefore, the measured impedance can be guaranteed to have high accuracy.

[0108] The following experimental data are provided to illustrate that the impedance measurement value obtained by the technical solution of the present application has high accuracy.

[0109] The object under test includes an 82 pF capacitor, which is used to replace the circuit under test. The fourth impedance of the 82 pF capacitor is measured using a vector network analyzer using the impedance detection method provided in this application. The fifth impedance of the 82 pF capacitor is also directly measured using an impedance analyzer. The effectiveness of the technical solution of this application is demonstrated by comparing the fourth and fifth impedances.

[0110] Specifically, the following steps are included:

[0111] Step 1: Measure the capacitance value of the flexible capacitive sensor.

[0112] Figure 8 This is a schematic diagram of a partial circuit connection structure for measuring the capacitance value of a flexible capacitive sensor in an experiment provided in an embodiment of the present application, as shown in FIG. Figure 8 As shown, the first end of power line 801 is connected to the first port of a vector network analyzer (not shown). The second end of power line 801 wraps around the first end of power line 803 via flexible capacitive sensor 802, forming a capacitor with the first end of power line 803. The second end of power line 803 is connected to the second port of the vector network analyzer. An experimental frequency is set, and an excitation voltage signal at the experimental frequency is transmitted through the first port of the vector network analyzer. Based on the electrical data received by the vector network analyzer, a first experimental capacitance value of the capacitor formed between flexible capacitive sensor 802 and the first end of power line 803 is calculated.

[0113] Figure 9 This is a schematic diagram of the circuit connection structure for measuring the impedance of an 82 pF capacitor in the experiment provided in the embodiment of this application. Figure 9 As shown, according to the same method as above, a second experimental capacitance value of the capacitance formed by the flexible capacitive sensor 903 and the first end of the power line 904 is measured and calculated.

[0114] Step 2: According to Figure 9 An experimental loop is formed by connecting the circuits. The impedance detection method provided in the present application is used to send an excitation voltage signal of the experimental frequency through the first port of the vector network analyzer 901. The fourth impedance of the capacitor of 82 pF is calculated based on the electrical data received by the vector network analyzer 901 and the first experimental capacitance value and the second experimental capacitance value.

[0115] Step 3: Use an impedance analyzer to measure the fifth impedance of the 82 pF capacitor at the same experimental frequency.

[0116] Step 4: Set multiple sets of excitation voltage signals with different experimental frequencies, repeat steps 1 to 3, obtain multiple sets of fourth impedances and fifth impedances under the excitation voltage signals with different experimental frequencies, and compare the multiple sets of fourth impedances and fifth impedances.

[0117] Figure 10 The comparison results of the experiments provided in the examples of this application are as follows: Figure 10 As shown, the values ​​of the fourth impedance and the fifth impedance in each group are comparable, thereby proving that the impedance measurement values ​​obtained by the technical solution of the present application have high accuracy.

[0118] Figure 11This is a structural diagram of an impedance detection device applied to a switch cabinet provided in an embodiment of the present application, as shown in FIG. Figure 11 As shown, the 110 provided in this embodiment includes:

[0119] A signal sending module 111 is configured to send a high-frequency excitation voltage signal to a series branch through a vector network analyzer, wherein the series branch includes at least two flexible capacitive sensors connected in series and a circuit to be tested;

[0120] an acquisition module 112 for acquiring electrical data captured by a vector network analyzer, the electrical data being generated by the series branch through a high-frequency excitation voltage signal;

[0121] The determination module 113 is configured to determine the impedance of the circuit to be tested according to the electrical data and the capacitance values ​​corresponding to the at least two flexible capacitive sensors.

[0122] In a possible implementation, the electrical data includes: a first reflection coefficient of a first port of the vector network analyzer, a second reflection coefficient of a second port of the vector network analyzer, a first transmission gain from the first port to the second port, and a second transmission gain from the second port to the first port.

[0123] In a possible implementation, the determination module 113 is further configured to determine the first impedance according to the first reflection coefficient, the second reflection coefficient, the first transmission gain, and the second transmission gain;

[0124] determining a second impedance based on capacitance values ​​of at least two flexible capacitive sensors;

[0125] The impedance of the circuit to be tested is determined according to the first impedance and the second impedance.

[0126] The impedance detection device for a switch cabinet provided in this embodiment can execute the method provided in the above method embodiment. Its implementation principle and technical effects are similar and will not be described in detail in this embodiment.

[0127] Figure 12 This is a schematic diagram of the structure of the impedance detection device applied to the switch cabinet provided in the embodiment of the present application. Figure 12 As shown, the impedance detection device 120 for a switch cabinet provided in this embodiment includes: at least one processor 121 and a memory 122. Optionally, the impedance detection device 120 for a switch cabinet further includes a communication component 123. The processor 121, the memory 122, and the communication component 123 are connected via a bus.

[0128] During the specific implementation process, at least one processor 121 executes the computer-executable instructions stored in the memory 122, so that the at least one processor 121 performs the above method.

[0129] The specific implementation process of the processor 121 can be found in the above-mentioned method embodiment. Its implementation principle and technical effects are similar and will not be repeated here in this embodiment.

[0130] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASICs), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly executed by a hardware processor or by a combination of hardware and software modules within the processor.

[0131] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage.

[0132] A bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be categorized as address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just one type of bus.

[0133] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0134] The present application also provides a computer-readable storage medium, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0135] The readable storage medium may be implemented by any type of volatile or non-volatile memory device, or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0136] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist in the device as discrete components.

[0137] The division of units is merely a logical functional division; actual implementations may employ alternative divisions, such as combining or integrating multiple units or components into another system, or omitting or disabling certain features. Furthermore, any direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units, either through an interface, electrical, mechanical, or other means.

[0138] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0139] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0140] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the method of the present invention. The aforementioned storage medium includes various media that can store program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0141] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0142] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. An impedance detection circuit applied to a switch cabinet, characterized in that: include: Data processing equipment, a vector network analyzer, at least two flexible capacitive sensors and a circuit to be tested; The circuit to be tested belongs to a switch circuit in a switch cabinet; The at least two flexible capacitive sensors and the circuit to be tested are connected in series to form a series branch; One end of the series branch is connected to the first port of the vector network analyzer, and the other end of the series branch is connected to the second port of the vector network analyzer; The first port of the vector network analyzer sends a high-frequency excitation voltage signal, and the first port and the second port receive electrical data, where the electrical data is the electrical data generated by the high-frequency excitation voltage signal passing through the series branch; The data processing device is connected to the signal output end of the vector network analyzer, receives the electrical data output by the signal output end of the vector network analyzer, and determines the impedance of the circuit to be tested according to the electrical data and the capacitance values ​​of the at least two flexible capacitive sensors.

2. The impedance detection circuit for switch cabinet according to claim 1, characterized in that: The flexible capacitive sensor comprises a mountable flexible electrode sheet, and the mountable flexible electrode sheet and a portion of the circuit to be tested mounted thereon form a capacitor.

3. The impedance detection circuit for a switch cabinet according to claim 1 or 2, characterized in that: The circuit to be tested includes a high-voltage cable and a first busbar in the switch cabinet, the high-voltage cable includes a metal high-voltage core and an insulation layer wrapped around the metal high-voltage core, and the first busbar is any phase busbar among the high-voltage three-phase busbars in the switch cabinet; the high-voltage cable is located at a first end of the circuit to be tested, and the first busbar is located at a second end of the circuit to be tested; The at least two flexible capacitive sensors include a first flexible capacitive sensor and a second flexible capacitive sensor; wherein, The mountable flexible electrode sheet of the first flexible capacitive sensor is mounted on a portion of the insulation layer of the high-voltage cable; The mountable flexible electrode sheet of the second flexible capacitive sensor is mounted on a portion of the insulating layer of the first busbar.

4. An impedance detection method applied to a switch cabinet, characterized in that: include: Sending a high-frequency excitation voltage signal to a series branch by a vector network analyzer, wherein the series branch is composed of at least two flexible capacitive sensors connected in series and a circuit to be tested; acquiring electrical data received by the vector network analyzer, the electrical data being generated by the series branch through the high-frequency excitation voltage signal; The impedance of the circuit to be tested is determined according to the electrical data and the capacitance values ​​corresponding to the at least two flexible capacitive sensors.

5. The method according to claim 4, characterized in that The electrical data includes a first reflection coefficient of a first port of the vector network analyzer, a second reflection coefficient of a second port of the vector network analyzer, a first transmission gain from the first port to the second port, and a second transmission gain from the second port to the first port.

6. The method according to claim 5, characterized in that Determining the impedance of the circuit to be tested based on the electrical data and the capacitance values ​​corresponding to the at least two flexible capacitive sensors includes: determining a first impedance based on the first reflection coefficient, the second reflection coefficient, the first transmission gain, and the second transmission gain; determining a second impedance based on capacitance values ​​of the at least two flexible capacitive sensors; The impedance of the circuit to be tested is determined according to the first impedance and the second impedance.

7. An impedance detection device for a switch cabinet, characterized in that: include: A signal sending module, configured to send a high-frequency excitation voltage signal to a series branch through a vector network analyzer, wherein the series branch includes at least two flexible capacitive sensors connected in series and a circuit to be tested; an acquisition module, configured to acquire electrical data captured by the vector network analyzer, the electrical data being generated by the series branch through the high-frequency excitation voltage signal; The determination module is configured to determine the impedance of the circuit to be tested based on the electrical data and the capacitance values ​​corresponding to the at least two flexible capacitive sensors.

8. An impedance detection device used in a switch cabinet, characterized in that: include: Memory, processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory, so that the processor performs the method according to any one of claims 4 to 6.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 4 to 6 when executed by a processor.

10. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 4 to 6 when executed by a processor.

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