Coaxial cable circulation detection method and system in cross interconnection grounding mode

Abstract

The invention discloses a cross interconnection grounding coaxial cable circulation detection method and system, and the method comprises the steps: screwing a flexible Rogowski coil into a forward ring and a reverse ring, and enabling the forward ring and the reverse ring to form an 8-shaped structure; the grounding wire of the phase to be measured and the main grounding wire are sleeved in the forward ring at the same time, and the grounding wire of the other phase is sleeved in the reverse ring; and finally, obtaining the actual circulating current of the ground wire of the to-be-detected phase by obtaining the current detection value of the flexible Rogowski coil. According to the method, a flexible Rogowski coil is screwed into a forward loop and a reverse loop on the basis of the relation between the total grounding current and the circulating current value of each phase in a cross interconnection grounding mode, and the actual circulating current of the phase to be detected is calculated directly by reading the current detection value; the method can be used for conveniently, rapidly, safely and accurately carrying out the loop current test, avoids the tedious operation of repeatedly opening and closing the loop current box during loop current detection, reduces the safety risk of hot-line work, and can accurately and reliably measure the loop current value.

Description

Technical Field

[0001] The invention belongs to the field of cross-connection grounding detection, and in particular relates to a coaxial cable circulation current detection method and system in a cross-connection grounding mode. Background Art

[0002] In the actual application of high-voltage single-core cables, the detection of the circulating current of the cable sheath is an important link to ensure the safe and stable operation of the cable. The cross-interconnection grounding method is a common grounding method in transmission cables. It connects the metal sheaths of different phases through coaxial cables to form a complex grounding network. Although this grounding method helps to reduce the induced voltage and circulating current on the metal sheath of the cable, it also increases the difficulty of detecting the circulating current. Since the circulating currents of the inner and outer cores of the coaxial cable are independent of each other and may not be synchronized, traditional detection methods are difficult to accurately distinguish and measure the circulating currents of each phase, resulting in the inability to comprehensively and accurately evaluate the grounding status and operating conditions of the cable.

[0003] At present, there are two main methods commonly used in the industry to detect circulating current: one is to use a clamp ammeter to directly clamp the circulating current value. The clamp ammeter is widely used because of its simple operation and fast measurement. However, when the cable adopts the cross-connected grounding method, different phases of metal sheath circulating currents flow through the inner and outer cores of the coaxial cable respectively. At this time, if a clamp ammeter is used to directly clamp the coaxial cable for measurement, the current value obtained is actually the vector superposition value of the inner and outer core circulating currents. Since vector superposition may produce mutual cancellation or enhancement effects, the measured value may be greater than or less than the actual current value, and thus cannot accurately reflect the actual operating condition of the cable. The second method is to use a Rogowski coil to directly obtain the circulating current value and transmit it back to the remote end through optical fiber for monitoring. As an AC current sensor, the Rogowski coil has a wide frequency response range and fast instantaneous response capability, and is suitable for high-frequency and large current measurements. However, in conventional detection methods, in a cross-connected grounding system, since the direction and size of the circulating currents of the inner and outer cores of the coaxial cable may be different, the Rogowski coil will also be affected by vector superposition when obtaining current. It is impossible to provide timely warnings for risks such as excessive circulating currents, which affects the operation of power equipment.

[0004] It can be seen that when measuring the coaxial cable in the cross-interconnected grounding system using the existing coaxial cable circulating current detection measures, the actual circulating current value measured is the vector sum of the inner core and the outer core of the phase to be measured, and its value may be greater than or less than the actual current value, which is difficult to reflect the actual operating condition of the cable. Due to the influence of the vector superposition effect, the measurement accuracy is difficult to guarantee. Summary of the invention

[0005] The present invention aims to provide a coaxial cable circulation current detection method and system in a cross-interconnected grounding mode, so as to solve the technical problem that when measuring the coaxial cable in the cross-interconnected grounding system, the measurement accuracy is difficult to ensure due to the influence of the vector superposition effect when using the coaxial cable circulation current detection measures in the existing cross-interconnected grounding mode.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: A coaxial cable circulating current detection method in a cross-connected grounding mode, comprising: The flexible Rogowski coil is twisted into a forward loop and a reverse loop, so that the forward loop and the reverse loop form an 8-shaped structure; The phase grounding wire to be tested and the main grounding wire are simultaneously sleeved in the forward loop, and the other phase grounding wire is sleeved in the reverse loop, wherein the head of the other phase grounding wire is cross-connected with the tail of the phase grounding wire to be tested; The current detection value of the flexible Rogowski coil is obtained, and the actual circulating current of the phase-to-ground wire to be tested is calculated.

[0007] Furthermore, the method for detecting the actual circulating current of the phase A grounding wire specifically includes: Put the A-phase grounding wire and the main grounding wire into the forward ring at the same time, and put the B-phase grounding wire into the reverse ring; The first detection value of the flexible Rogowski coil is obtained, and the actual circulating current of the A-phase grounding wire is calculated.

[0008] Furthermore, the specific formula for the actual circulating current of the phase A grounding wire is: The actual circulating current of the phase A grounding wire = the first detection value of the flexible Rogowski coil ÷ 3.

[0009] Furthermore, the method for detecting the actual circulating current of the phase B grounding wire specifically includes: Put the B-phase grounding wire and the main grounding wire into the forward ring at the same time, and put the C-phase grounding wire into the reverse ring; The second detection value of the flexible Rogowski coil is obtained, and the actual circulating current of the B-phase grounding wire is calculated.

[0010] Furthermore, the specific formula for the actual circulating current of the phase B grounding wire is: The actual circulating current of the phase B grounding wire = the second detection value of the flexible Rogowski coil ÷ 3.

[0011] Furthermore, the method for detecting the actual circulating current of the C-phase grounding wire specifically includes: Put the C-phase grounding wire and the main grounding wire into the forward ring at the same time, and put the A-phase grounding wire into the reverse ring; The third detection value of the flexible Rogowski coil is obtained, and the actual circulating current of the C-phase grounding wire is calculated.

[0012] Furthermore, the specific formula of the actual circulating current of the C phase grounding wire is: The actual circulating current of the phase C grounding wire = the third detection value of the flexible Rogowski coil ÷ 3.

[0013] Further, the flexible Rogowski coil comprises a body, on which a coil, a power switch button, a data hold button, a liquid crystal display, a voltage input socket and a coil opening knob are arranged; The coil is fixed to the body by opening the coil knob; The voltage input socket is provided at the tail of the body and is used to supply power to the flexible Rogowski coil; The power switch button and the data hold button are symmetrically arranged, the power switch button is used to disconnect the flexible Rogowski coil, and the data hold button is used to hold the current detection value; The liquid crystal display screen is arranged on the handle of the main body and is used for displaying the detected values.

[0014] Furthermore, the specific calculation formula for the actual circulating current of the phase-to-ground wire to be measured is as follows:

[0015]

[0016] Among them, I a Indicates the detection value of phase A; I b Indicates the detection value of phase B; I c Indicates the C phase detection value; I s Indicates the total ground current detection value; A i Indicates the current value of the core in phase A; B i Indicates the current value of the core in phase B; C i A0 represents the inner core current value of phase C; B0 represents the outer core current value of phase B; C0 represents the outer core current value of phase C.

[0017] A coaxial cable circulation current detection system in a cross-connected grounding mode, used to implement the steps of the coaxial cable circulation current detection method in the cross-connected grounding mode, including: A detection value acquisition module is used to obtain the current detection value of the flexible Rogowski coil; A circulating current calculation module, used to calculate the actual circulating current of the phase-to-ground wire to be tested according to the current detection value of the flexible Rogowski coil; The current detection value of the flexible Rogowski coil is obtained by the following methods, including: The flexible Rogowski coil is screwed into a forward ring and a reverse ring, wherein the forward ring and the reverse ring form an 8-shaped structure; the phase grounding wire to be tested and the main grounding wire are simultaneously sleeved in the forward ring, and the other phase grounding wire is sleeved in the reverse ring, wherein the head of the other phase grounding wire is cross-connected with the tail of the phase grounding wire to be tested.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The invention provides a coaxial cable circulating current detection method in a cross-interconnected grounding mode, wherein the method adopts the method of twisting a flexible Rogowski coil into a forward ring and a reverse ring, so that the forward ring and the reverse ring form an 8-shaped structure; then the phase grounding wire to be tested and the total grounding wire are simultaneously sleeved in the forward ring, and the other phase grounding wire is sleeved in the reverse ring, and the head of the other phase grounding wire is cross-interconnected with the tail of the phase grounding wire to be tested; finally, the actual circulating current of the phase grounding wire to be tested is calculated by obtaining the current detection value of the flexible Rogowski coil; based on the relationship between the total grounding current and the circulating current value of each phase in the cross-interconnected grounding mode, the method twists the flexible Rogowski coil into a forward ring and a reverse ring, and directly calculates the actual circulating current of the phase to be tested by reading the current detection value; the method can conveniently, quickly, safely and accurately perform circulating current testing, avoids the tedious operation of repeatedly opening and closing the circulating current box during circulating current detection, reduces the safety risk of live working, and can accurately and reliably measure the circulating current value.

[0019] Preferably, in the present invention, the A-phase grounding wire and the main grounding wire are simultaneously sleeved in the forward loop, and the B-phase grounding wire is sleeved in the reverse loop, and the actual circulating current of the A-phase grounding wire is calculated by obtaining the first detection value of the flexible Rogowski coil; similarly, the B-phase grounding wire and the main grounding wire are simultaneously sleeved in the forward loop, and the C-phase grounding wire is sleeved in the reverse loop, and the actual circulating current of the B-phase grounding wire is calculated by obtaining the second detection value of the flexible Rogowski coil; and the C-phase grounding wire and the main grounding wire are simultaneously sleeved in the forward loop, and the A-phase grounding wire is sleeved in the reverse loop, and the actual circulating current of the C-phase grounding wire is calculated by obtaining the third detection value of the flexible Rogowski coil; the specific operation process in actual application is clarified, which helps operators to quickly and accurately obtain the circulating current data of each phase grounding wire, thereby improving detection efficiency and accuracy.

[0020] Preferably, in the present invention, the flexible Rogowski coil includes a body, a coil, a power switch button, a data hold button, a liquid crystal display, a voltage input socket and a coil opening knob; such a design makes the flexible Rogowski coil easier to operate and maintain, while also improving its stability and durability; the detection value is displayed in real time on the liquid crystal display, further improving the user experience and detection efficiency.

[0021] Preferably, in the present invention, the principle is that in cross-interconnected grounding, there is a special relationship between the actual circulating current of the grounding wire of the phase to be measured and the total grounding current, the total grounding current is the sum of the inner core currents of each phase, the detection current of each phase is the vector sum of the inner core current and the outer core current of each phase, and the outer core current of each phase is equal to the reverse inner core current value of the cross-interconnected phase, and then the inner core current of each phase, that is, the actual circulating current value of each phase, can be obtained; based on this principle, the actual circulating current value of each phase can be conveniently and quickly detected accurately and reliably.

[0022] The present invention also provides a coaxial cable circulating current detection system with a cross-connected grounding method, which is used to implement the steps of the above-mentioned coaxial cable circulating current detection method. The system can conveniently and quickly complete the measurement of the coaxial cable circulating current value, and can provide timely warnings for risks such as excessive circulating current, thereby avoiding affecting the operation of power equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the structure of a flexible Rogowski coil provided in an embodiment of the present invention; Figure 2 A flow chart of a coaxial cable circulating current detection method in a cross-connected grounding mode provided by an embodiment of the present invention; Figure 3 A detection principle diagram of a coaxial cable circulating current detection method in a cross-connected grounding mode provided by an embodiment of the present invention; Figure 4 A schematic diagram of the internal structure of a cross-connected grounding box provided in an embodiment of the present invention; Figure 5 A schematic diagram of detecting the actual circulating current of the A-phase grounding wire in a coaxial cable circulating current detection method in a cross-connected grounding mode provided by an embodiment of the present invention; Figure 6 A schematic diagram of detecting the actual circulating current of the B-phase grounding wire in a coaxial cable circulating current detection method in a cross-connected grounding mode provided by an embodiment of the present invention; Figure 7 A schematic diagram of detecting the actual circulating current of the C-phase grounding wire of a coaxial cable circulating current detection method in a cross-connected grounding mode provided by an embodiment of the present invention.

[0024] Reference numerals: 1-Coil, 2-Power switch button, 3-Data hold button, 4-LCD display, 5-Voltage input jack, 6-Open coil knob. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0026] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0027] Example 1 As mentioned in the background technology, currently, there are two main methods commonly used in the industry to detect circulating current: one is to use a clamp ammeter to directly clamp the circulating current value. The clamp ammeter is widely used because of its simple operation and fast measurement. However, when the cable adopts the cross-connected grounding method, different phases of metal sheath circulating currents flow through the inner and outer cores of the coaxial cable respectively. At this time, if a clamp ammeter is used to directly clamp the coaxial cable for measurement, the current value obtained is actually the vector superposition value of the inner and outer core circulating currents. Since vector superposition may produce mutual cancellation or enhancement effects, the measured value may be greater than or less than the actual current value, and thus cannot accurately reflect the actual operating condition of the cable. The second method is to use a Rogowski coil to directly obtain the circulating current value and transmit it back to the remote end through optical fiber for monitoring. As an AC current sensor, the Rogowski coil has a wide frequency response range and fast instantaneous response capability, and is suitable for high-frequency and large current measurements. However, in conventional detection methods, in a cross-connected grounding system, since the direction and size of the circulating currents of the inner and outer cores of the coaxial cable may be different, the Rogowski coil will also be affected by vector superposition when obtaining current. It is impossible to provide timely warnings for risks such as excessive circulating currents, which affects the operation of power equipment.

[0028] like Figure 2 In order to achieve the above objectives and solve the above problems, the present invention provides a coaxial cable circulating current detection method in a cross-connected grounding mode, comprising the following steps: S1: twist the flexible Rogowski coil into a forward loop and a reverse loop, so that the forward loop and the reverse loop form an 8-shaped structure; S2: The phase grounding wire to be tested and the main grounding wire are simultaneously sleeved in the forward ring, and the other phase grounding wire is sleeved in the reverse ring, wherein the head of the other phase grounding wire is cross-connected with the tail of the phase grounding wire to be tested; S3: Obtain the current detection value of the flexible Rogowski coil and calculate the actual circulating current of the phase-to-ground wire to be tested.

[0029] like Figure 1 As shown, in this embodiment, the specific structure of the flexible Rogowski coil is adopted, including: a main body and a coil 1, a power switch button 2, a data hold button 3, a liquid crystal display 4, a voltage input socket 5 and a coil opening knob 6 arranged on the main body; the coil 1 is fixed to the main body by opening the coil knob 6; the voltage input socket 5 is opened at the tail of the main body, and is used to power the flexible Rogowski coil by connecting to a power source; the power switch button 2 and the data hold button 3 are symmetrically arranged, the power switch button 2 is responsible for disconnecting the flexible Rogowski coil, and the data hold button 3 is used to maintain the current detection value and complete the reading of the value in a stable state; the liquid crystal display 4 is arranged on the handle of the main body, and is used to display the detection value. The detection value is displayed in real time through the liquid crystal display 4, which further improves the user experience and detection efficiency.

[0030] like Figure 4 As shown, Figure 4 The internal structure diagram of the cross-connected grounding box shows that the head of phase B is connected to the tail of phase A; the head of phase A is connected to the tail of phase C; the head of phase C is connected to the tail of phase B. The principle of the above method is:

[0031]

[0032] Among them, I a Indicates the detection value of phase A; I b Indicates the detection value of phase B; I c Indicates the C phase detection value; I s Indicates the total ground current detection value; A i Indicates the current value of the core in phase A; B i Indicates the current value of the core in phase B; C i A0 represents the inner core current value of phase C; B0 represents the outer core current value of phase B; C0 represents the outer core current value of phase C.

[0033] There is a special relationship between the actual circulating current of the phase grounding wire to be tested and the total grounding current. The total grounding current is the sum of the inner core currents of each phase. The detection current of each phase is the vector sum of the inner core current and the outer core current of each phase, and the outer core current of each phase is equal to the reverse inner core current value of the cross-interconnected phase. The inner core current of each phase, that is, the actual circulating current value of each phase, can be obtained. Based on this principle, the actual circulating current value of each phase can be easily and quickly detected accurately and reliably.

[0034] Combination Figure 3 As shown, in this embodiment, taking the A phase grounding wire as an example, the current value I a is the vector sum of the inner core current of phase A and the outer core current of phase A; in the cross-connection mode, the outer core current of phase A is the reverse inner core current value of phase C; from this, the inner core current value of phase A can be derived, that is, the actual circulating current value of phase A is (total ground current detection value + phase A detection value - phase B detection value) ÷ 3. Figure 5 As shown, here, the flexible Rogowski coil is twisted into a forward loop and a reverse loop, so that the forward loop and the reverse loop form an 8-shaped structure ( Figure 5 In the figure 8 structure of the flexible Rogowski coil after being twisted, Figure 6 and Figure 7 The same as in the example above), and the total grounding wire and the A-phase grounding current are put into a loop in the forward direction, and the B-phase circulating current is taken in the reverse direction. In this way, the actual circulating current value of the A-phase can be obtained by directly reading the first detection value of the current flexible Rogowski coil and dividing it by 3 according to the first detection value of the flexible Rogowski coil.

[0035] Similarly, if Figure 6 As shown, to measure the actual circulating current of phase B, the total grounding wire and the phase B grounding current are placed in a loop in the forward direction, and the phase C circulating current is taken in the reverse direction.

[0036] like Figure 7 As shown, the actual circulating current of phase C is measured, the total grounding wire and the grounding current of phase C are put in a loop in the forward direction, and the circulating current of phase A is taken in the reverse direction.

[0037] It can be seen that the present embodiment provides a coaxial cable circulation current detection method with a cross-connected grounding method. During the detection process, the present method realizes the detection of the coaxial cable circulation current by designing a specific flexible Rogowski coil structure (the forward ring and the reverse ring form an 8 shape) and cleverly arranging the socketing method of the grounding wire. This design not only improves the accuracy of the detection, but also simplifies the operation process, making the cable circulation current detection in a complex environment more convenient and efficient.

[0038] Example 2 The present embodiment also provides a coaxial cable circulating current detection system with a cross-connected grounding method, which can implement the steps of the coaxial cable circulating current detection method provided in Example 1, specifically including a detection value acquisition module, used to obtain the current detection value of the flexible Rogowski coil; a circulating current calculation module, used to calculate the actual circulating current of the phase-to-ground wire to be measured according to the current detection value of the flexible Rogowski coil; wherein the current detection value of the flexible Rogowski coil is obtained by the following method, specifically including: screwing the flexible Rogowski coil into a forward ring and a reverse ring, wherein the forward ring and the reverse ring form an 8-shaped structure; simultaneously sleeve the phase-to-ground wire to be measured and the main grounding wire in the forward ring, and sleeve the other phase-to-ground wire in the reverse ring, wherein the head of the other phase-to-ground wire is cross-connected with the tail of the phase-to-ground wire to be measured.

[0039] By adopting the coaxial cable circulating current detection system with the cross-connected grounding method provided in this embodiment or the coaxial cable circulating current detection method with the cross-connected grounding method mentioned in Example 1, in the process of detecting the circulating current of the cross-connected box, the on-site staff can perform the circulating current test more conveniently, quickly, safely and accurately by adopting the above-mentioned system or method, avoiding the tedious operation of repeatedly opening and closing the circulating current box during the circulating current detection, reducing the safety risk of live working, and accurately and reliably measuring the circulating current value to accurately judge whether the circulating current value exceeds the standard. After multiple reliable tests, the detection time is reduced from 26 minutes to 2 minutes, and the measurement error does not exceed 5% of the measured value; at the same time, the use of this method can improve the economic benefits of the entire industry, and specific examples are as follows: The evaluation is mainly based on three aspects: reduced workload, reduced safety hazards, and the economic benefits generated by accurate circulation measurement values: 1. Economic benefits from reduced workload Annual cost savings = (26-2) / 60×1800×3×50.83 yuan = 109,800 yuan Description: A city has 200 sets of 220kV cross-connection boxes and 322 sets of 110kV cross-connection boxes. According to the operation and maintenance regulations, the circulating current of 220kV should be measured at least 4 times a year and 110kV twice, plus special inspections and inspections of newly put into use equipment, a total of more than 1,800 times.

[0040] 2. Economic benefits from reducing potential safety hazards: Annual cost savings = 1800 × 0.1% × 1 million yuan = 1.8 million yuan Note: Since unpacking and testing the circulating current is a live operation, there is a risk of direct contact with current above 50A, so there is a possibility of serious electric shock injuries. According to the "Regulations on Reporting, Investigation and Handling of Production Safety Accidents", the economic loss caused is at least 1 million yuan. According to the risk probability estimate, it will occur once in every thousand times.

[0041] 3. Economic benefits generated by accurate measurement of circulation: Annual cost savings = 1800 × 0.3% × 350,000 yuan = 1.89 million yuan Note: Directly measuring the coaxial cable circulating current will only measure the circulating current value of the two phases superimposed. The coaxial cable circulating current detection method proposed in this embodiment can measure the true circulating current value, thereby issuing an early warning for risks such as excessive circulating current to avoid affecting equipment operation.

[0042] 4. Total: Annual cost savings: 109,800+180,000+189,000=3,799,800 Yuan.

[0043] It can be seen that the coaxial cable circulating current detection method using the cross-connected grounding method provided by the present invention can generate great economic benefits.

[0044] This method can be used to measure the true circulating current value, ensuring the accuracy of the test results, thereby giving early warning of risks such as excessive circulating current to avoid affecting equipment operation.

[0045] In summary, the present invention provides a coaxial cable circulating current detection method and system in a cross-connected grounding mode, which has the following advantages over the existing detection methods: Firstly, the flexible Rogowski coil is twisted into an 8-shaped structure of a forward ring and a reverse ring by design, and the ground wire of the phase to be tested, the main ground wire and the ground wire of another phase are cleverly sleeved in the forward ring and the reverse ring respectively, so as to realize the accurate detection of the coaxial cable circulating current under the cross-connected grounding mode. This method overcomes the difficulty of traditional detection methods in distinguishing and accurately measuring the circulating current of each phase in a complex grounding system, and improves the accuracy and reliability of detection; secondly, specific detection methods and calculation formulas are given for the A phase, B phase and C phase ground wires respectively, so that the operator can quickly obtain the actual circulating current value of each phase ground wire according to the standardized process; this phase detection method not only improves the detection efficiency, but also ensures the accuracy and consistency of the data, providing strong support for subsequent cable maintenance and troubleshooting. In addition, the design of the flexible Rogowski coil also fully considers the user experience; by integrating the coil, power switch button, data hold button, LCD display, voltage input jack and coil opening knob and other components, the detection tool is not only powerful but also easy to operate. The user can view the detection values ​​in real time through the LCD screen and conveniently control the detection process through the power switch button and the data hold button, which greatly improves the convenience and flexibility of the detection work; this method has shown significant advantages in the detection of coaxial cable circulating current in the cross-connected grounding method, including improving detection accuracy, simplifying operation procedures, and enhancing user experience, providing a strong technical guarantee for the safe and stable operation of the cable.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0047] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and the disclosed concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0048] The further detailed description made in the disclosure cannot be used to determine that the specific implementation modes of the present invention are limited to these. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the protection scope of the present invention determined by the submitted claims.

Claims

1. A method for detecting circulating current of a coaxial cable in a cross-connected grounding mode, characterized in that: include: The flexible Rogowski coil is twisted into a forward loop and a reverse loop, so that the forward loop and the reverse loop form an 8-shaped structure; The phase grounding wire to be tested and the main grounding wire are simultaneously sleeved in the forward loop, and the other phase grounding wire is sleeved in the reverse loop, wherein the head of the other phase grounding wire is cross-connected with the tail of the phase grounding wire to be tested; The current detection value of the flexible Rogowski coil is obtained, and the actual circulating current of the phase-to-ground wire to be tested is calculated.

2. The method for detecting circulating current of a coaxial cable in a cross-connected grounding mode according to claim 1, characterized in that: The detection method of the actual circulating current of the phase A grounding wire specifically includes: Put the A-phase grounding wire and the main grounding wire into the forward ring at the same time, and put the B-phase grounding wire into the reverse ring; The first detection value of the flexible Rogowski coil is obtained, and the actual circulating current of the A-phase grounding wire is calculated.

3. The method for detecting circulating current of a coaxial cable in a cross-connected grounding mode according to claim 2, characterized in that: The specific formula for the actual circulating current of phase A grounding wire is: The actual circulating current of the phase A grounding wire = the first detection value of the flexible Rogowski coil ÷ 3.

4. The method for detecting circulating current of a coaxial cable in a cross-connected grounding mode according to claim 1, characterized in that: The detection method of the actual circulating current of the phase B grounding wire specifically includes: Put the B-phase grounding wire and the main grounding wire into the forward ring at the same time, and put the C-phase grounding wire into the reverse ring; The second detection value of the flexible Rogowski coil is obtained, and the actual circulating current of the B-phase grounding wire is calculated.

5. The method for detecting circulating current of a coaxial cable in a cross-connected grounding mode according to claim 4, characterized in that: The specific formula for the actual circulating current of the phase B grounding wire is: The actual circulating current of the phase B grounding wire = the second detection value of the flexible Rogowski coil ÷ 3.

6. The method for detecting circulating current of a coaxial cable in a cross-connected grounding mode according to claim 1, characterized in that: The detection method of the actual circulating current of the C phase grounding wire specifically includes: Put the C-phase grounding wire and the main grounding wire into the forward ring at the same time, and put the A-phase grounding wire into the reverse ring; The third detection value of the flexible Rogowski coil is obtained, and the actual circulating current of the C-phase grounding wire is calculated.

7. The method for detecting coaxial cable circulating current in a cross-connected grounding mode according to claim 6, characterized in that: The specific formula for the actual circulating current of the C phase grounding wire is: The actual circulating current of the phase C grounding wire = the third detection value of the flexible Rogowski coil ÷ 3.

8. The method for detecting coaxial cable circulating current in a cross-connected grounding mode according to claim 1, characterized in that: The flexible Rogowski coil comprises a body, on which a coil (1), a power switch button (2), a data hold button (3), a liquid crystal display (4), a voltage input socket (5) and a coil opening knob (6) are arranged; The coil (1) is fixed to the body by opening the coil knob (6); The voltage input socket (5) is provided at the rear of the body and is used to supply power to the flexible Rogowski coil; The power switch button (2) and the data holding button (3) are symmetrically arranged, the power switch button (2) is used to disconnect the flexible Rogowski coil, and the data holding button (3) is used to hold the current detection value; The liquid crystal display screen (4) is arranged on the handle of the main body and is used to display the detection value.

9. The method for detecting circulating current of a coaxial cable in a cross-connected grounding mode according to claim 1, characterized in that: The specific calculation formula for the actual circulating current of the phase-to-ground wire to be measured is as follows: Among them, I a Indicates the detection value of phase A; I b Indicates the detection value of phase B; I c Indicates the C phase detection value; I s Indicates the total ground current detection value; A i Indicates the current value of the core in phase A; B i Indicates the current value of the core in phase B; C i A0 represents the inner core current value of phase C; B0 represents the outer core current value of phase B; C0 represents the outer core current value of phase C.

10. A coaxial cable circulation detection system with cross-connection grounding, characterized in that: The steps for implementing the coaxial cable circulating current detection method of the cross-connection grounding method according to any one of claims 1 to 9 include: A detection value acquisition module is used to obtain the current detection value of the flexible Rogowski coil; A circulating current calculation module, used to calculate the actual circulating current of the phase-to-ground wire to be tested according to the current detection value of the flexible Rogowski coil; The current detection value of the flexible Rogowski coil is obtained by the following methods, including: The flexible Rogowski coil is screwed into a forward ring and a reverse ring, wherein the forward ring and the reverse ring form an 8-shaped structure; the phase grounding wire to be tested and the main grounding wire are simultaneously sleeved in the forward ring, and the other phase grounding wire is sleeved in the reverse ring, wherein the head of the other phase grounding wire is cross-connected with the tail of the phase grounding wire to be tested.

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