A multi-functional and multi-purpose cable partial discharge detection sensor

Abstract

The present invention relates to the technical field of detection sensors, and particularly relates to a multi-functional and multi-purpose cable partial discharge detection sensor, which includes a signal output port, a first quick-connect open terminal, a second quick-connect open terminal, a third quick-connect open terminal, a fourth quick-connect open terminal, a waterproof connector, a signal input lead, and a metal housing. The signal output port and the first quick-connect open terminal are connected to a built-in small high-frequency pulse current sensor HFCT. The built-in small high-frequency pulse current sensor HFCT and the third quick-connect open terminal are connected to a capacitor, and the capacitor is connected to an impedance regulator; the present invention can be used in cooperation with a foil film electrode; it can also be externally connected to other types of high-frequency pulse current sensors HFCT or high-frequency pulse voltage sensors PDD for high-resistance partial discharge testing; it can also be externally connected to a filter to improve the signal-to-noise ratio of partial discharge detection and achieve the effect of filtering out noise; it can also be externally connected to an analog partial discharge signal generator for the inspection and calibration of the partial discharge detection system.

Description

Technical Field

[0001] The present invention relates to the technical field of detection sensors, and particularly to a multi-functional and multi-purpose cable partial discharge detection sensor. Background Art

[0002] With the rapid development of the power grid, the demand for electricity is increasing day by day. A large number of high-voltage and large-cross-section power cables are put into operation. The on-line partial discharge detection of cable lines under operating conditions has become one of the effective means for cable insulation condition detection and evaluation. In order to determine whether the detected signal is a partial discharge, various partial discharge detection methods and partial discharge sensors are often required.

[0003] Prior Art 1, ground wire detection method. As Figure 12 shown, the partial discharge signal of the cable is detected by the pulse current method. The high-frequency pulse current sensor HFCT is installed on the metal armor grounding lead of the cable intermediate joint, and then transmitted to the on-site partial discharge signal processing device LS for signal processing, and finally transmitted to the background data processing center MS for signal analysis and judgment. This method requires that the intermediate joint or terminal must have a grounding wire capable of installing the high-frequency pulse current sensor HFCT, but many grounding wires are wrapped and hidden by explosion-proof boxes and cannot install HFCT on the grounding wire. At this time, the partial discharge test cannot be carried out.

[0004] Prior Art 2, foil film electrode method. As Figure 13 shown, the partial discharge signal of the cable is detected by the foil film electrode method. The metal foil film electrode is installed on the cable body at both ends of the cable intermediate joint or the outer sheath of the cable joint. The partial discharge signal is capacitively coupled to the high-frequency pulse voltage sensor PDD through the capacitance formed by the power equipment shell and the metal foil film electrode, and finally transmitted to the background data processing center MS for signal analysis and judgment. The metal foil film electrode and the high-frequency pulse voltage sensor PDD are used for high-resistance testing. Although the sensitivity is high, the voltage-type radiation noise is very large. When the ambient noise is large, it affects the detection and judgment of the partial discharge signal. This partial discharge detection method can only be equipped with one sensor for partial discharge detection and cannot be compared with other sensors.

[0005] Prior Art 3, single sensor. Existing partial discharge sensors are usually single-functional partial discharge detections and cannot be equipped with other sensors for comparative testing.

[0006] Prior Art 4, large ambient noise and low signal-to-noise ratio of partial discharge testing. In order to eliminate the influence of the ambient noise at the test site on the partial discharge test, various filters have been set in many partial discharge test instruments, but the ambient noise is still complex. The inherent filters cannot cope with the changing ambient noise on site, and also result in a low signal-to-noise ratio during testing.

[0007] In the prior art 5, it is difficult to inject artificial simulated partial discharge signals for calibration and inspection. When using the foil film electrode method to detect partial discharge, if it is necessary to inject simulated partial discharge signals into the cable, an additional set of metal foil film electrodes needs to be installed on the cable to achieve the injection of simulated signals. This injection method is complex in operation and low in test efficiency.

[0008] Summarize the existing partial discharge grounding wire detection method and foil film electrode detection method, and the following problem points exist:

[0009] 1. The grounding wire is hidden and it is impossible to install an HFCT for partial discharge detection. When the grounding wire of the cable joint or terminal in the test site is hidden and it is impossible to install a high-frequency pulse current sensor HFCT sensor, it is impossible to use HFCT for low-resistance partial discharge testing.

[0010] 2. The existing foil film electrode method can only achieve the detection of one type of partial discharge sensor and cannot externally connect other sensors for comparative detection. Moreover, when using a metal foil film electrode plus a high-frequency pulse voltage sensor PDD for high-resistance testing, although the sensitivity is high, the radiation noise of the voltage-type sensor is very large, which affects the detection and judgment of partial discharge signals.

[0011] 3. The existing partial discharge sensors have a single function and are only used as a single sensor, and there is no interface for installing other sensors.

[0012] 4. To inject simulated partial discharge signals, an additional set of metal foil film electrodes needs to be installed on the cable to achieve the injection of simulated signals. The operation is complex and the test efficiency is not high.

[0013] 5. The ambient noise at the test site is variable, and the inherent filter configured in the partial discharge test instrument cannot cope with the variable ambient noise at the test site.

[0014] Based on this, the present invention designs a multi-functional and multi-purpose cable partial discharge detection sensor to solve the above problems. Summary of the Invention

[0015] The purpose of the present invention is to provide a multi-functional and multi-purpose cable partial discharge detection sensor to solve the problems such as the inability to install an HFCT sensor on the grounding wire, the single function of the foil film electrode partial discharge detection, and the large ambient noise mentioned in the above background technology.

[0016] To achieve the above object, the present invention provides the following technical solution: A multifunctional and multi-purpose cable partial discharge detection sensor, including a signal output port, a first quick-connect open terminal, a second quick-connect open terminal, a third quick-connect open terminal, a fourth quick-connect open terminal, a waterproof connector, a signal input lead, and a metal shell. The signal output port and the first quick-connect open terminal are jointly connected to a built-in small high-frequency pulse current sensor HFCT. The built-in small high-frequency pulse current sensor HFCT and the third quick-connect open terminal are jointly connected to a capacitor, and the capacitor is connected to an impedance regulator, and the impedance regulator is connected to a waterproof connector on one side. The second quick-connect open terminal and the fourth quick-connect open terminal are connected to the waterproof connector on the other side, and the two waterproof connectors are connected to a signal input lead.

[0017] The built-in small high-frequency pulse current sensor HFCT includes a magnetic core, a detection coil T2, a matching resistor, a signal output terminal, an impedance regulator, a capacitor, and an input coil T1. The detection coil T2 is evenly wound on one side of the magnetic core, and both ends of the detection coil T2 are connected to the signal output terminal. The matching resistor is connected in parallel with the signal output terminal. The input coil T1 is wound on the other side of the magnetic core, and the input coil T1 is connected in series with the impedance regulator and the capacitor.

[0018] The impedance regulator includes a variable inductor and a variable capacitor. The range of the variable inductor is 0.1 to 500 μH, and the range of the variable capacitor is 10 pF to 500 nF.

[0019] The range of the matching resistor is 10 Ω to 100 KΩ, and the output impedance is matched with the partial discharge in-situ signal processing device LS.

[0020] The first quick-connect open terminal, the second quick-connect open terminal, the third quick-connect open terminal, and the fourth quick-connect open terminal are easy-to-install and easy-to-remove terminals. A certain safety distance is maintained between adjacent terminals, and the insulation ability between the terminals should be greater than 20 kV.

[0021] The waterproof connector and the metal shell are IP68 waterproof connectors and waterproof boxes.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. High signal-to-noise ratio detection. Its built-in high-frequency pulse current sensor HFCT can perform low-resistance partial discharge detection, and the built-in HFCT has a high signal-to-noise ratio.

[0024] 2. Synchronous detection of multiple sensors, which can be used in conjunction with foil film electrodes, or external high-frequency pulse current sensors (HFCTs) of other types can be connected to the quick-connect terminals for low-resistance partial discharge detection. Additionally, external high-frequency pulse voltage sensors (PDDs) can be connected for high-resistance partial discharge testing. It can achieve simultaneous synchronous composite comparison detection of two partial discharge sensors of the same type or different types.

[0025] 3. Frequency selection filtering (windowing method), low-pass, high-pass, and band-pass filters can be connected to the quick-connect terminals, enabling selection of a frequency band with a higher signal-to-noise ratio for partial discharge testing.

[0026] 4. Frequency selection filtering (trap method), band-stop filters can be connected to the quick-connect terminals. For specific noises, they are grounded in advance to bypass the noises, thereby achieving the effect of noise removal.

[0027] 5. Analog signal injection verification, the quick-connect terminals can be externally connected to an analog partial discharge signal generator to verify and calibrate the local partial discharge signal processing device (LS), or detect the performance of the partial discharge detection sensor, or detect whether the sensors (two electrodes and the built-in HFCT) and the sensing circuit (cables and cable joints) are in good condition.

[0028] 6. External standard signal series connection injection for status recording, the effectiveness of the sensor can be evaluated by detecting the external signal and comparing it with the initial state.

[0029] 7. High safety, the quick-connect terminals have sufficient safety spacing, high safety, and a protection circuit to avoid breakdown of the cable protective layer by impulse overvoltage and switching overvoltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for describing the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0031] Figure 1 It is a schematic structural diagram of the present invention;

[0032] Figure 2 It is a schematic internal structural diagram of the present invention;

[0033] Figure 3 It is a schematic structural diagram of the built-in small high-frequency pulse current sensor (HFCT) of the present invention;

[0034] Figure 4 It is a schematic diagram of the composition of the low-resistance partial discharge detection system for externally connecting a test device to the present invention;

[0035] Figure 5Schematic diagram for the present invention to externally connect other types of high-frequency pulse current sensors HFCT for low-resistance partial discharge detection;

[0036] Figure 6 Schematic diagram for the present invention to externally connect high-frequency pulse voltage sensors PDD for high-resistance partial discharge detection;

[0037] Figure 7 Schematic diagram of the composition of the partial discharge detection system for the present invention by externally connecting low-pass, high-pass, and band-pass filters;

[0038] Figure 8 Schematic diagram of the composition of the partial discharge detection system for the present invention by externally connecting a stopband filter;

[0039] Figure 9 Schematic diagram of the composition of the inspection and calibration system for the partial discharge detection system of the present invention by connecting an analog partial discharge signal generator in series;

[0040] Figure 10 Schematic diagram of the composition of the inspection and calibration system for the partial discharge detection system of the present invention by connecting an external analog partial discharge signal generator in series;

[0041] Figure 11 Schematic diagram of the composition of the inspection and calibration system for the partial discharge detection system of the present invention by connecting an analog partial discharge signal generator in parallel

[0042] Figure 12 Schematic diagram of the installation of the high-frequency pulse current sensor HFCT on the grounding lead of the cable intermediate joint in the prior art;

[0043] Figure 13 Schematic diagram of the installation of a metal foil film electrode plus a high-frequency pulse voltage sensor PDD on the cable intermediate joint in the prior art.

[0044] In the attached drawings, the list of components represented by each reference numeral is as follows:

[0045] 1. Signal output port; 2. First quick-connect open terminal; 3. Second quick-connect open terminal; 4. Third quick-connect open terminal; 5. Fourth quick-connect open terminal; 6. Waterproof joint; 7. Signal input lead; 8. Metal shell; 9. Impedance regulator; 10. Capacitor; 11. Built-in small high-frequency pulse current sensor HFCT; 111. Magnetic core; 112. Detection coil T2; 113. Matching resistor; 114. Signal output end; 115. Impedance regulator; 116. Capacitor; 117. Input coil T1. Detailed implementation manners

[0046] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0047] Embodiment 1

[0048] Please refer to Figures 1-3 , the present invention provides a technical solution: a multi-functional and multi-purpose cable partial discharge detection sensor, including a signal output port 1, a first quick-connect open terminal 2, a second quick-connect open terminal 3, a third quick-connect open terminal 4, a fourth quick-connect open terminal 5, a waterproof joint 6, a signal input lead 7, and a metal housing 8. The signal output port 1 uses a quick-connect terminal and is connected to the on-site partial discharge signal processing device, and can transmit the detected partial discharge signal to the on-site partial discharge signal processing device LS. The signal output port 1 and the first quick-connect open terminal 2 are jointly connected to an internal small high-frequency pulse current sensor HFCT11. The internal small high-frequency pulse current sensor HFCT11 and the third quick-connect open terminal 4 are jointly connected to a capacitor 10. The capacitor 10 is connected to an impedance regulator 9, and the impedance regulator 9 is connected to a waterproof joint 6 on one side. The second quick-connect open terminal 3 and the fourth quick-connect open terminal 5 are connected to the waterproof joint 6 on the other side. The two waterproof joints 6 are connected to a signal input lead 7. The signal input lead 7 can reach a withstand voltage level of more than 10 kV and can protect the circuit from shock wave damage.

[0049] The internal small high-frequency pulse current sensor HFCT11 includes a magnetic core 111, a detection coil T2112, a matching resistor 113, a signal output terminal 114, an impedance regulator 115, a capacitor 116, and an input coil T1117. The magnetic core 111 is a manganese-zinc magnetic core with an inner diameter of 10 mm, an outer diameter of 15.8 mm, a height of 14 mm, and a cross-sectional area of 81 mm. The signal output terminal 114 uses a quick-connect terminal. The detection coil 112 uses enameled wire, with 1 to 10 turns. The detection coil T2112 is evenly wound on one side of the magnetic core 111, and both ends of the detection coil T2112 are connected to the signal output terminal 114. The matching resistor 113 is connected in parallel with the signal output terminal 114. The input coil T1117 is wound on the other side of the magnetic core 111, and the input coil T1117 is connected in series with the impedance regulator 115 and the capacitor 116. The capacitance value range of the capacitor 116 is 5000 - 100000 pF, which is used to block direct current and pass alternating current. The detection frequency of the internal small high-frequency pulse current sensor HFCT is as high as 100 MHz, and it has a wide detection range, high sensitivity, miniaturization, and portability.

[0050] The impedance regulator 115 includes an adjustable inductor and an adjustable capacitor. The range of the adjustable inductor is 0.1 - 500 μH, and the range of the adjustable capacitor is 10 pF - 500 nF. The signal loop impedance regulator realizes the selection of the maximum signal-to-noise ratio of the signal.

[0051] The range of the matching resistor 113 is 10 Ω - 100 KΩ, and the output impedance matches that of the partial discharge in-situ signal processing device LS.

[0052] The first quick-connect open terminal 2, the second quick-connect open terminal 3, the third quick-connect open terminal 4, and the fourth quick-connect open terminal 5 are easy-to-install and easy-to-remove terminals. A certain safety distance is maintained between two adjacent terminals, and the insulation ability between the terminals should be greater than 20 kV, which can prevent the flashover breakdown caused by the overvoltage of line switch operation, the intrusion of lightning voltage, and the impact voltage of ground fault. The quick-connect terminal has a load-bearing capacity of 1.5 - 2 catties, and it can be connected to other types of high-frequency pulse current sensors HFCT or high-frequency pulse voltage partial discharge sensors PDD for partial discharge testing, or connected to an analog partial discharge signal generator for the calibration and correction of the partial discharge in-situ signal processing device LS..

[0053] The waterproof connector 6 and the metal shell 8 are IP68 waterproof connectors and waterproof boxes, which can be waterproof for a long time, have very good sealing performance, can prevent the entry and erosion of water, and can also prevent the performance degradation caused by the entry of dust.

[0054] A specific application of this embodiment is: connecting an external testing device for low-resistance partial discharge live detection or partial discharge on-line monitoring:

[0055] As shown in Figure 4 of the system of this embodiment, before testing, the quick-connect terminals 2 and 3 on the multi-functional and multi-purpose cable partial discharge detection sensor are short-circuited through leads. During testing, the metal foil film electrodes are installed on the outer sheaths at both ends of the cable intermediate joint. The metal foil film electrodes at both ends are connected to the multi-functional and multi-purpose cable partial discharge detection sensor through leads. Its signal output port 1 is connected to the partial discharge in-situ signal processing device LS through a coaxial cable. The partial discharge in-situ signal processing device LS is connected to the background data processing center MS by wired or wireless means.

[0056] A capacitor is formed between the metal foil film electrode and the cable armor to construct a partial discharge detection circuit. When there is a partial discharge signal, the partial discharge signal can be coupled out through the metal foil film electrode and transmitted to the multi-functional and multi-purpose cable partial discharge detection sensor. The built-in small high-frequency pulse current sensor HFCT in it detects the partial discharge signal and transmits it to the partial discharge in-situ signal processing device LS through a coaxial cable for processing. Finally, the signal is transmitted to the background data processing center MS by wired or wireless means. Special testing software is deployed on the MS for partial discharge signal analysis, judgment, display, and storage.

[0057] Embodiment Two

[0058] It can be externally connected to other types of high-frequency pulse current sensors HFCT and high-frequency pulse voltage sensors PDD, so that it can be used alone with HFCT or PDD sensors for low-resistance or high-resistance partial discharge tests, or composite comparison tests using the same type or different types of partial discharge sensors can be carried out simultaneously.

[0059] The system of this embodiment is as Figure 5 and Figure 6 shown. Before the test, the quick connection terminals 2 and 3 on the multi-functional and multi-purpose cable partial discharge detection sensor are short-circuited through leads, and other high-frequency pulse current sensors HFCT are externally connected to the leads, or a high-frequency pulse voltage sensor PDD is connected in parallel to the quick connection terminals 4 and 5 of the partial discharge detection sensor. During the test, the metal foil film electrodes are installed on the outer sheaths at both ends of the cable intermediate joint, and the metal foil film electrodes at both ends are connected to the multi-functional and multi-purpose cable partial discharge detection sensor through leads. Other types of high-frequency pulse current sensors HFCT or high-frequency pulse voltage sensors PDD are connected to the local partial discharge signal processing device LS through coaxial cables, and the local partial discharge signal processing device LS is connected to the background data processing center MS by wired or wireless means.

[0060] A capacitor is formed between the metal foil film electrode and the cable armor to construct a partial discharge detection circuit. When there is a partial discharge signal, the partial discharge signal can be coupled out through the metal foil film electrode and transmitted to the multi-functional and multi-purpose cable partial discharge detection sensor. The high-frequency pulse current sensor HFCT on the quick connection terminals 2 and 3 or the high-frequency pulse voltage sensor PDD on 4 and 5 detects the partial discharge signal and transmits it to the local partial discharge signal processing device LS through the coaxial cable for processing. Finally, the signal is transmitted to the background data processing center MS by wired or wireless means, and a dedicated test software is deployed on the MS for partial discharge signal analysis, judgment, display and storage.

[0061] During the partial discharge test, composite comparison tests of the low-resistance type built-in small high-frequency pulse current sensor HFCT and other types of HFCT can also be realized; composite comparison tests of the built-in small high-frequency pulse current sensor HFCT and the high-resistance type high-frequency pulse voltage sensor PDD; composite comparison tests of other types of HFCT and the high-resistance type high-frequency pulse voltage sensor PDD. By comparing the detection results of different sensors, the reliability of partial discharge detection is improved. The installation methods of several sensors are as Figure 4 、 Figure 5 、 Figure 6 .

[0062] Embodiment 3

[0063] External low-pass, high-pass and band-pass filters are used to improve the signal-to-noise ratio of partial discharge detection, or an external band-stop filter is used to bypass specific frequency noises to achieve the effect of noise filtering.

[0064] The system of this embodiment is as Figure 7 and Figure 8 shown. Before the test, a low-pass filter, a high-pass filter, and a band-pass filter are connected between the quick connection terminals 2 and 3 of the multi-functional cable partial discharge detection sensor, or the quick connection terminals 2 and 3 are short-circuited, and a band-stop filter is added between 4 and 5. During the test, the metal foil film electrodes are installed on the outer sheaths at both ends of the cable intermediate joint. The metal foil film electrodes at both ends are connected to the multi-functional cable partial discharge detection sensor through leads. Its signal output port 1 is connected to the on-site partial discharge signal processing device LS through a coaxial cable. The on-site partial discharge signal processing device LS is connected to the background data processing center MS by wire or wireless means.

[0065] A capacitor is formed between the metal foil film electrode and the cable armor to construct a partial discharge detection circuit. When there is a partial discharge signal, the partial discharge signal can be coupled out through the metal foil film electrode and transmitted to the multi-functional cable partial discharge detection sensor. After being filtered by the low-pass, high-pass, and band-pass filters externally connected between terminals 2 and 3, or the band-stop filter between the quick connection terminals 4 and 5, the signal is transmitted to the built-in small high-frequency pulse current sensor HFCT, and the signal is output through the output port 1 of the sensor, and then transmitted to the on-site partial discharge signal processing device LS through a coaxial cable for processing. Finally, the signal is transmitted to the background data processing center MS through a network cable or wirelessly. A dedicated test software is deployed on the MS for partial discharge signal analysis, judgment, display, and storage.

[0066] Embodiment 4

[0067] An external analog partial discharge signal generator is used to test and calibrate the partial discharge detection system.

[0068] The system of this embodiment is as Figures 9-11As shown, before the test, an analog partial discharge signal generator is connected in series to the quick connection terminals 2 and 3 or 2 and 4 of the multi-functional and multi-purpose cable partial discharge detection sensor, or an analog partial discharge signal generator is connected in parallel to the quick connection terminals 4 and 5. During the test, the metal foil film electrodes are installed on the outer sheaths at both ends of the cable intermediate joint. The metal foil film electrodes at both ends are connected to the multi-functional and multi-purpose cable partial discharge detection sensor through leads. The positive pole of the analog partial discharge signal generator is connected to one end of the quick connection terminal of the partial discharge detection sensor, and the negative pole is connected to the other end of the quick terminal to inject an analog partial discharge signal into the cable. The magnitude of the analog signal can also be adjusted through the impedance regulator to the optimal signal-to-noise ratio frequency band. The adjusted signal is detected by the HFCT on the multi-functional and multi-purpose cable partial discharge detection sensor and output to the on-site partial discharge signal processing device LS through the coaxial signal line for processing. Finally, the signal is transmitted to the background data processing center MS by wire or wirelessly. Through these methods, the on-site partial discharge signal processing device LS can be calibrated and corrected, or the performance of the partial discharge detection sensor can be detected, or whether the sensor (two electrodes and the built-in HFCT) and the sensing circuit (cable and cable joint) are in good condition can be detected.

[0069] The product models provided by the present invention are only used for this technical solution based on the structural characteristics of the product. The product will be adjusted and modified after purchase to make it more matching and conforming to the technical solution of the present invention. It is an optimal application technical solution of this technical solution. The product model can be replaced and modified according to the required technical parameters, which is well-known to those skilled in the art. Therefore, those skilled in the art can clearly obtain the corresponding usage effects through the technical solution provided by the present invention.

[0070] In the description of this specification, the description referring to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0071] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not elaborate on all the details, nor do they limit the present invention to only the specific implementation manners. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A multi-functional and multi-purpose cable partial discharge detection sensor, comprising a signal output port (1), a first quick-connect open terminal (2), a second quick-connect open terminal (3), a third quick-connect open terminal (4), a fourth quick-connect open terminal (5), a waterproof joint (6), a signal input lead (7), and a metal shell (8), characterized in that: The signal output port (1) and the first quick-connect open terminal (2) are jointly connected to a built-in small high-frequency pulse current sensor HFCT (11). The built-in small high-frequency pulse current sensor HFCT (11) and the third quick-connect open terminal (4) are jointly connected to a first capacitor (10). The first capacitor (10) is connected to a first impedance regulator (9). The first impedance regulator (9) is connected to a waterproof connector (6) on one side. The second quick-connect open terminal (3), the fourth quick-connect open terminal (5) are connected to the waterproof connector (6) on the other side. The two waterproof connectors (6) are connected to the signal input lead (7). The built-in small high-frequency pulse current sensor HFCT (11) includes a magnetic core (111), a detection coil T2 (112), a matching resistor (113), a signal output terminal (114), a second impedance regulator (115), a second capacitor (116) and an input coil T1 (117). The detection coil T2 (112) is evenly wound on one side of the magnetic core (111), and both ends of the detection coil T2 (112) are connected to the signal output terminal (114). The matching resistor (113) is connected in parallel with the signal output terminal (114). The input coil T1 (117) is wound on the other side of the magnetic core (111). The input coil T1 (117) is connected in series with the second impedance regulator (115) and the second capacitor (116). The first quick-connect open terminal (2), the second quick-connect open terminal (3), the third quick-connect open terminal (4), the fourth quick-connect open terminal (5) are easy-to-install and easy-to-remove terminals. A certain safety distance is maintained between adjacent terminals, and the insulation ability between the terminals is greater than 20 kV.

2. The multifunctional and multi-purpose partial discharge detection sensor for cables according to claim 1, characterized in that: The second impedance regulator (115) includes an adjustable inductor and an adjustable capacitor. The range of the adjustable inductor is 0.1 - 500 μH, and the range of the adjustable capacitor is 10 pF - 500 nF.

3. The multifunctional and multi-purpose partial discharge detection sensor for cables according to claim 1, characterized in that: The range of the matching resistor (113) is 10 Ω - 100 KΩ, and the output impedance matches the partial discharge in-situ signal processing device LS.

4. A multi-functional and multi-purpose cable partial discharge detection sensor according to claim 1, characterized in that: The waterproof connector (6) is an IP68 waterproof connector, and the metal shell (8) is an IP68 waterproof box.

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