CN115524641A - Detection method, device and detection equipment for cable sheath cross interconnection grounding system - Google Patents
Detection method, device and detection equipment for cable sheath cross interconnection grounding system Download PDFInfo
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- CN115524641A CN115524641A CN202211204021.6A CN202211204021A CN115524641A CN 115524641 A CN115524641 A CN 115524641A CN 202211204021 A CN202211204021 A CN 202211204021A CN 115524641 A CN115524641 A CN 115524641A
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- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/66—Testing of connections, e.g. of plugs or non-disconnectable joints
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/54—Testing for continuity
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
- G01R31/55—Testing for incorrect line connections
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Abstract
The invention discloses a method, a device and equipment for detecting a cable sheath cross-connection grounding system. The cross interconnection grounding system is provided with a first direct grounding side, a second direct grounding side and a cross interconnection grounding device, and the detection method comprises the following steps: acquiring a transmitting signal of a first direct grounding side and a receiving signal of a second direct grounding side, wherein the transmitting signal comprises three-phase harmonic signals at different preset frequency bands; determining whether the cross-connection grounding system has a connection fault according to the transmitting signal and the receiving signal; wherein the connection failure comprises: phase sequence connection error faults and disconnection faults. The invention detects the wiring condition of the grounding system by receiving and transmitting signals of different frequency bands of the grounding wires at two sides, realizes the electrified detection of long-distance and multi-section cross interconnection grounding, improves the detection safety of the cross interconnection grounding system, can implement the detection without disassembling the grounding box, is favorable for improving the detection precision and the detection efficiency, and saves the time cost and the labor cost.
Description
Technical Field
The invention relates to the technical field of power system wiring detection, in particular to a method, a device and equipment for detecting a cable sheath cross-connection grounding system.
Background
With the acceleration of the urbanization construction pace of China, the demand on power loads is increased rapidly, and cable lines become longer and longer. The shielding layer of the high-voltage single-core cable is grounded, and when the length of a cable line is far, a cross interconnection grounding method is generally adopted, so that the induced current of the cable core current to the shielding layer is mutually offset, the annular current on the protective layer is reduced or eliminated, the conveying capacity of the cable is improved, the breakdown of the outer protective layer of the cable is prevented, and the safe operation of the cable is ensured.
A section of cross-connect system typically consists of two end direct-connect grounding boxes and a middle cross-connect grounding box, each grounding box being disposed in a corresponding work well, and the distance between two adjacent work wells being about 600 to 800 meters. Due to the fact that the cross interconnection wiring mode is relatively complex, occasionally, due to carelessness of installation workers, the conditions that the wiring sequence of the grounding wires of the cross interconnection grounding box is wrong, the wiring is loose and virtual connection exists, and therefore, whether the cross interconnection wiring is correct or not needs to be detected before the circuit is completed and put into production or before the power is supplied after maintenance.
In the existing detection technology, usually, whether cross interconnection wiring is correct or not is detected through an operation and maintenance staff megger, in order to improve detection efficiency, interval type well selection detection can be adopted, for example, a second well is removed to measure a wiring mode leading to a first well and a third well, whether a phase sequence is correct or not, whether wiring is loose or loose and virtual connection or not is detected, a fourth well is also required to be removed to judge whether wiring from the third well to the fourth well is correct or not, the efficiency is low for a transmission cable with a complex wiring mode, a long distance and a plurality of cross interconnection sections, in addition, the grounding box at the whole line joint well is required to be disassembled and assembled, the workload is large, and time and labor are wasted. After the transmission cable is operated in a live mode, manual detection can be implemented only after power failure, normal use of a transmission system is affected, and the practicability is poor.
Disclosure of Invention
The invention provides a method, a device and equipment for detecting a cable sheath cross-connection grounding system, which aim to overcome the defects of low efficiency and large workload of the conventional grounding system detection method and have high automation degree.
According to an aspect of the present invention, there is provided a method for detecting a cross-connection grounding system of a cable sheath, the cross-connection grounding system having a first direct grounding side, a second direct grounding side and a cross-connection grounding device, the method comprising the steps of:
acquiring a transmitting signal of the first direct grounding side and a receiving signal of the second direct grounding side, wherein the transmitting signal comprises three-phase harmonic signals in different preset frequency bands;
determining whether the cross-interconnected grounding system has a connection fault according to the transmitting signal and the receiving signal;
wherein the connection failure comprises: phase sequence connection error faults and disconnection faults.
According to another aspect of the present invention, there is provided a device for detecting a cable sheath cross-connection grounding system, where the cross-connection grounding system is provided with a first direct grounding side, a second direct grounding side, and a cross-connection grounding device, and is configured to perform the method for detecting a cable sheath cross-connection grounding system according to any embodiment of the present invention, the device includes: the device comprises a signal transmitting device, a signal receiving device and a processing device;
the signal transmitting device is arranged on the first direct grounding side and used for outputting transmitting signals, and the transmitting signals comprise three-phase harmonic signals in different preset frequency bands;
the signal receiving device is arranged on the second direct grounding side and used for collecting received signals;
the processing device is used for determining whether the cross-interconnected grounding system has a connection fault according to the transmitting signal and the receiving signal;
wherein the connection failure comprises: phase sequence connection error faults and disconnection faults.
According to another aspect of the present invention, there is provided a detection apparatus comprising: the detection device for the cable sheath cross-connection grounding system.
According to the technical scheme of the embodiment of the invention, the transmission signal of the first direct grounding side and the receiving signal of the second direct grounding side are obtained, wherein the transmission signal comprises three-phase harmonic signals in different preset frequency bands, whether the cross interconnection grounding system has a connection fault or not is determined according to the receiving and sending conditions of the transmission signal and the receiving signal, the long-distance and multi-segment cross interconnection grounding live detection is realized, the detection safety of the cross interconnection grounding system is improved, the detection can be implemented without disassembling a grounding box, the detection precision and the detection efficiency are improved, and the time cost and the labor cost are saved.
It should be understood that the statements in this section do not necessarily identify key or critical features of the embodiments of the present invention, nor do they necessarily limit the scope of the invention. Other features of the present invention will become apparent from the following description.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a flowchart of a method for detecting a cable sheath cross-connection grounding system according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of two conventional correct cross-connect grounding system connections;
FIG. 3 is a schematic diagram of two conventional incorrect cross-connect grounding system connections;
fig. 4 is a flowchart of a method for detecting a cable sheath cross-connection grounding system according to a second embodiment of the present invention;
fig. 5 is a flowchart of another method for detecting a cable sheath cross-connection grounding system according to a second embodiment of the present invention;
fig. 6 is a schematic diagram of a cable sheath cross-connection grounding system according to a second embodiment of the present invention, illustrating a signal transmission direction;
fig. 7 is a flowchart of a method for detecting a cable sheath cross-connection grounding system according to a third embodiment of the present invention;
fig. 8 is a schematic structural diagram of a detection apparatus for a cable sheath cross-connection grounding system according to a fourth embodiment of the present invention.
Detailed Description
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Example one
The embodiment of the invention provides a method for detecting a cable sheath cross-connection grounding system, which is applicable to an application scene of detecting the completeness of a grounding system when a cable line is not operated before production and is also applicable to an application scene of detecting the completeness of a grounding system when a cable is operated in a live state, wherein the detection of the completeness of the grounding system comprises but is not limited to the following steps: the method for detecting whether the cable sheath cross-connection grounding system has connection faults can be executed by the detection device for the cable sheath cross-connection grounding system, the detection device can be realized in a hardware and/or software mode, and the detection device can be configured in the detection equipment provided by the invention.
In an embodiment of the present invention, the cross-connect grounding system is provided with a first direct grounding side, a second direct grounding side and a cross-connect grounding device, wherein the first direct grounding side is provided with a first direct grounding box, and a directly grounded three-phase cable (for example, an a/B/C three-phase cable) is arranged in the first direct grounding box; a second direct grounding box is arranged on the second direct grounding side, and a directly grounded three-phase cable is arranged in the second direct grounding box; the cross-connection grounding device may be a cross-connection grounding box, and cables on two sides in the cross-connection grounding box are cross-connected, for example, taking the cross-connection grounding box as an example, which is arranged between a section of adjacent cables and a section of adjacent cables, in the cross-connection grounding box, the phase a tail of the section of adjacent cables is connected with the phase B head of the section of adjacent cables, the phase B tail of the section of adjacent cables is connected with the phase C head of the section of adjacent cables, and the phase C tail of the section of adjacent cables is connected with the phase a head of the section of adjacent cables, so as to realize cross-connection grounding.
Fig. 1 is a flowchart of a method for detecting a cable sheath cross-connection grounding system according to an embodiment of the present invention. As shown in fig. 1, the method includes:
s110, acquiring a transmitting signal of a first direct grounding side and a receiving signal of a second direct grounding side, wherein the transmitting signal comprises three-phase harmonic signals in different preset frequency bands.
The signal transmitting device is arranged on the first direct grounding side, and for example, the grounding system is provided with a three-phase grounding cable, three signal transmitting devices can be arranged to inject transmitting signals into grounding cables of each phase respectively, and the transmitting signals injected into the grounding cables of each phase are in different preset frequency bands; the signal received by the second direct grounding side is received by the signal receiving device disposed on the second direct grounding side, and for example, the grounding system is provided with a three-phase grounding cable, three signal receiving devices may be disposed to detect the harmonic signals transmitted by the grounding cables, respectively.
In an embodiment of the present invention, the signal transmitting device may adopt a ring-shaped structure, and is sleeved or clamped and fixed at the three-phase grounding cable on the first direct grounding side, so as to inject transmitting signals of different preset frequency bands into the three-phase grounding cable respectively. Similarly, the signal receiving device may adopt a loop structure, and the three-phase grounding cable is sleeved or clamped and fixed at the second direct grounding side to detect whether the three-phase grounding cable receives the harmonic signal.
Optionally, the three-phase harmonic signals include an a-phase harmonic signal in the a-frequency band, a B-phase harmonic signal in the B-frequency band, and a C-phase harmonic signal in the C-frequency band; the frequencies of the frequency band a, the frequency band b and the frequency band c are not overlapped.
For example, the frequency difference between two of the a-band, the b-band and the c-band may be set to be greater than 2MHz, for example, the a-band may be set to be 5-10mhz, the b-band may be 15-20mhz, and the c-band may be set to be 25-30MHz, so that the different-phase grounding cables transmit harmonic signals with different frequencies and large differences, and the detection result is prevented from being influenced by mutual interference between three-phase harmonic signals.
S120, determining whether the cross-connection grounding system has a connection fault according to the transmitting signal and the receiving signal; wherein the connection failure comprises: phase sequence connection error faults and disconnection faults.
The phase sequence connection error fault refers to a wiring mode or a phase sequence error of a grounding wire of the cross interconnection grounding box, and the disconnection fault can include but is not limited to the situation of loose wiring and/or virtual connection.
In an embodiment of the present invention, phase sequence connection error faults include, but are not limited to: the wiring modes or phase sequences of different cross-connection grounding boxes in the same cross-connection section are inconsistent.
Illustratively, the following four work wells are arranged in the cross-connection section in sequence: the first working well, the second working well, the third working well and the fourth working well are taken as examples, the first working well is positioned on a first direct grounding side, and a first direct grounding box is arranged in the working well; the fourth working well is positioned on the second direct grounding side, and a second direct grounding box is arranged in the fourth working well; the second working well and the third working well are positioned at the middle joint of the cross interconnection section, and cross interconnection grounding boxes are arranged in the working wells.
Fig. 2 is a schematic diagram of two conventional correct cross-connect grounding system connections. Fig. 2 shows only two correct cross-interconnect wiring schemes by way of example, and not limitation.
As shown in a in fig. 2, in the cross-connection grounding box of the second working well, the tail of the phase a of the first section of cable is connected with the head of the phase C of the second section of cable, the tail of the phase C of the first section of cable is connected with the head of the phase B of the second section of cable, and the tail of the phase B of the first section of cable is connected with the head of the phase a of the second section of cable; in the cross interconnection grounding box of the third working well, the tail of the phase A of the second section of cable is connected with the head of the phase C of the third section of cable, the tail of the phase C of the second section of cable is connected with the head of the phase B of the third section of cable, and the tail of the phase B of the second section of cable is connected with the head of the phase A of the third section of cable, so that the phase A/phase B/phase C on the second direct grounding side is connected with the grounding cable to correspondingly receive the transmitting signal of the phase C/phase A/phase B. As shown in B of fig. 2, in the cross-connection grounding box of the second working well, the tail of the phase A of the first section of cable is connected with the head of the phase B of the second section of cable, and the tail of the phase B of the first section of cable is connected with the head of the phase C of the second section of cable; the tail of the C phase of the first section of cable is connected with the head of the A phase of the second section of cable; in the cross interconnection grounding box of the third working well, the tail of the phase A of the second section of cable is connected with the head of the phase B of the third section of cable, the tail of the phase B of the second section of cable is connected with the head of the phase C of the third section of cable, and the tail of the phase C of the second section of cable is connected with the head of the phase A of the third section of cable, so that the phase A/phase B/C of the second direct grounding side correspondingly receives the transmitting signals of the phase B/phase C/phase A.
Fig. 3 is a schematic diagram of two conventional wrong wiring methods of the cross-connect grounding system. Fig. 3 shows only two wrong cross-interconnect wiring schemes by way of example, and not limitation.
As shown in a of fig. 3, in the cross-connection grounding box of the second working well, the tail of the phase a of the first section of cable is connected with the head of the phase B of the second section of cable, and the tail of the phase B of the first section of cable is connected with the head of the phase C of the second section of cable; the tail of the C phase of the first section of cable is connected with the head of the A phase of the second section of cable; in the cross-connection grounding box of the third working well, the tail of the phase A of the second section of cable is connected with the head of the phase C of the third section of cable, the tail of the phase B of the second section of cable is connected with the head of the phase A of the third section of cable, and the tail of the phase C of the second section of cable is connected with the head of the phase B of the third section of cable; as shown in B of fig. 3, in the cross-connection grounding box of the second working well, the tail of the phase a of the first section of cable is connected with the head of the phase C of the second section of cable, and the tail of the phase B of the first section of cable is connected with the head of the phase a of the second section of cable; the tail of the C phase of the first section of cable is connected with the head of the B phase of the second section of cable; in the cross-connection grounding box of the third working well, the tail of the phase A of the second section of cable is connected with the head of the phase B of the third section of cable, the tail of the phase B of the second section of cable is connected with the head of the phase C of the third section of cable, and the tail of the phase C of the second section of cable is connected with the head of the phase A of the third section of cable; the connection method shown in a in fig. 3 and the connection method shown in b in fig. 3 both cause the ground circulation abnormality.
Specifically, as shown in fig. 2 and fig. 3, when detecting the grounding system, the three-phase grounding cable on the first direct grounding side transmits transmission signals (i.e., three-phase harmonic signals) in the frequency bands a, B, and C, respectively, and the three-phase harmonic signals are transmitted to the corresponding phases on the second direct grounding side through the three-phase cables interconnected in a crossing manner, for example, the transmission signals in the frequency band a are transmitted to the C-phase grounding cable on the second direct grounding side 2 through the first direct grounding box of the first work well, the phase a of the first section of cable, the cross interconnection grounding box of the second work well, the phase B of the second section of cable, the cross interconnection grounding box of the third work well, the phase C of the third section of cable, and the second direct grounding box of the fourth work well in sequence, so as to form a grounding loop current. And further, according to the frequency band of the received signal, matching analysis is carried out on the transmitting signal and the received signal of each phase, and logic analysis of correct or wrong wiring of the cross interconnection grounding system is achieved. Signals of the first direct grounding side and the second direct grounding side at two ends of the cross interconnection grounding system only need to be measured, signals of the cross interconnection grounding device do not need to be measured, detection efficiency is improved, and time and labor cost are saved.
According to the technical scheme provided by the embodiment of the invention, the transmission signal of the first direct grounding side and the receiving signal of the second direct grounding side are obtained, wherein the transmission signal comprises three-phase harmonic signals in different preset frequency bands, whether the cross interconnection grounding system has a connection fault or not is determined according to the receiving and sending conditions of the transmission signal and the receiving signal, the long-distance and multi-section cross interconnection grounding live detection is realized, the detection safety of the cross interconnection grounding system is improved, the detection can be implemented without disassembling a grounding box, the detection precision and the detection efficiency are improved, and the time cost and the labor cost are saved.
Example two
Fig. 4 is a flowchart of a method for detecting a cable sheath cross-connection grounding system according to a second embodiment of the present invention, and this embodiment further defines whether a connection fault exists in the cross-connection grounding system according to a transmission signal and a reception signal on the basis of the second embodiment. As shown in fig. 4, the method specifically includes:
s210, acquiring a transmitting signal of a first direct grounding side and a receiving signal of a second direct grounding side, wherein the transmitting signal comprises three-phase harmonic signals in different preset frequency bands.
And S220, acquiring a forward receiving frequency band of the received signal.
The forward receiving frequency band of the received signal refers to a frequency band in which a forward harmonic signal in the same direction as the transmitted signal is located in the received signal. The first direct grounding side sends out three-phase harmonic signals of different preset frequency bands, the three-phase harmonic signals are transmitted to the second direct grounding side through three-phase cables which are connected in a crossed mode, and when a circuit is not abnormal, the three-phase grounding cables on the second direct grounding side can receive corresponding harmonic signals.
It should be noted that, because the three-phase cables on the second direct grounding side are directly grounded and communicated with each other, except that the directly connected grounding cables receive the forward harmonic signals, the other two-phase grounding cables can induce and generate reverse harmonic signals, and the harmonic signals in the same direction as the transmission signals on the grounding cables can be identified by detecting the signal strength and the signal transmission direction of the received signals.
And S230, judging whether the forward receiving frequency band is matched with a preset frequency band.
If the forward receiving frequency bands of the three-phase grounding cable are all matched with the preset frequency band, executing step S240; if the forward receiving band of any phase does not match the predetermined band, step S250 is performed.
And S240, determining that the cross-connection grounding system has no disconnection fault.
And S250, determining that the cross-connection grounding system has a disconnection fault.
In the embodiment of the present invention, matching the forward receiving frequency band with the preset frequency band means that the forward receiving frequency band is in the preset frequency band of the transmission signal, and can cover all the preset frequency bands (for example, the frequency bands may include an a frequency band, a B frequency band, and a C frequency band) of the a/B/C three phases.
Specifically, whether a receiving device on the second direct grounding side detects three-phase forward harmonic signals respectively is judged, forward receiving frequency bands of all phases are compared with preset frequency bands of all transmitting signals, and if any phase does not receive the forward harmonic signals or the forward receiving frequency bands of the receiving signals do not belong to the preset frequency bands, a virtual connection or disconnection fault of the cross interconnection grounding system can be determined; if the three-phase grounding cables receive the forward harmonic signals and the forward receiving frequency band of the received signals is matched with the preset frequency band, the fact that the cross interconnection grounding system is in a good wiring state and no virtual connection or disconnection fault occurs can be determined.
Fig. 5 is a flowchart of another method for detecting a cable sheath cross-connection grounding system according to a second embodiment of the present invention, and this embodiment further defines whether there is a connection fault in the cross-connection grounding system according to the transmission signal and the reception signal based on the above embodiments.
As shown in fig. 5, the method specifically includes:
s310, acquiring a transmitting signal of a first direct grounding side and a receiving signal of a second direct grounding side, wherein the transmitting signal comprises three-phase harmonic signals in different preset frequency bands.
And S320, acquiring a three-phase receiving phase sequence of the received signal.
The three-phase reception phase sequence of the reception signal is a phase sequence arrangement of the reception signal of the three-phase cable on the second direct ground side.
In the embodiment of the present invention, three-phase harmonic signals in different preset frequency bands are transmitted on the first grounding side, for example, an a-phase harmonic signal in an a-frequency band, a B-phase harmonic signal in a B-frequency band, and a C-phase harmonic signal in a C-frequency band, the three-phase harmonic signals are respectively transmitted to the second direct grounding side through three-phase cables interconnected in a crossing manner, and the phase sequence of each phase of received signals can be determined by identifying the frequency band of the signals.
S330, comparing the phase sequence of the three-phase receiving phase sequence with a preset phase sequence, and determining whether a phase sequence connection error fault occurs in the cross-connection grounding system according to the phase sequence comparison result.
Wherein, the preset phase sequence comprises: the A phase/B phase/C of the second direct grounding side correspondingly receives the transmitting signal of the C phase/A phase/B phase; or the A phase/B phase/C phase of the second direct grounding side correspondingly receives the transmission signal of the B phase/C phase/A phase.
Specifically, for example, a phase a of a first direct grounding side transmits an a-band transmission signal, a phase B transmits a B-band transmission signal, and a phase C transmits a C-band transmission signal, where the a-phase/B-phase/C-phase of the first direct grounding side correspondingly receives a C-phase/a-phase/B-phase transmission signal, and the three-phase harmonic signal transmitted by the first direct grounding side is transmitted to the second direct grounding side through a cross-connected three-phase cable, and if the a-phase/B-phase/C-phase of the second direct grounding side respectively receives a C-band/a-band/B-band reception signal, it is determined that the cross-connected grounding system has no phase-sequence connection error fault; if the received signal of the a phase/B phase/C phase on the second direct ground side does not completely correspond to the received signal of the C-band/a-band/B-band, for example, the received signal of the a phase is in the a-band, the received signal of the B phase is in the B-band, and the received signal of the C phase is in the C-band, it may be determined that a phase sequence connection fault occurs in the cross-connected ground system, and at this time, a ground circulating current may be abnormal.
Fig. 6 is a schematic diagram of a cable sheath cross-connection grounding system according to a second embodiment of the present invention for detecting a signal transmission direction, and in the embodiment of fig. 6, a signal transmission path is exemplarily illustrated by taking a wiring manner shown by b in fig. 2 as an example, but a specific detection method is not limited.
As shown in fig. 6, the phase a grounding cable defining the first direct grounding side 1 transmits a signal of a frequency band, the phase B grounding cable of the first direct grounding side 1 transmits a signal of B frequency band, and the phase C grounding cable transmits a signal of C frequency band. Taking the a-frequency band transmission signal as an example, under the condition of normal wiring, the a-frequency band transmission signal is transmitted to the C-phase grounding cable at the second direct grounding side 2 through the first direct grounding box of the first work well, the A phase of the first section of cable, the cross interconnection grounding box of the second work well, the B phase of the second section of cable, the cross interconnection grounding box of the third work well, the C phase of the third section of cable and the second direct grounding box of the fourth work well in sequence to form a grounding circulation. The C-phase grounding cable of the second direct grounding side 2 can receive the a-frequency band transmission signal, and meanwhile, the a-phase and B-phase cables reversely transmit the weak a-frequency band transmission signal.
Referring to fig. 6 in combination, the a-phase grounding cable of the second direct grounding side 2 may receive the B-band transmission signal, and at the same time, the B-phase and C-phase cables reversely transmit the weak B-band transmission signal; the B-phase grounding cable of the second direct grounding side 2 can receive the C-band transmission signal, and meanwhile, the a-phase and C-phase cables reversely transmit the weak C-band transmission signal. Therefore, if the second direct grounding side 2 can detect the received signals of the frequency bands a, b and c, it can be determined that the cross-connection grounding system is in a perfect wiring state and no virtual connection or disconnection fault occurs; if any phase of the second direct grounding side 2 cannot detect the forward harmonic signal, or the frequency band of the detected forward harmonic signal does not belong to the preset frequency band, it can be determined that the cross-connection grounding system has a virtual connection or disconnection fault.
Continuing with fig. 6, taking the a-band transmission signal as an example, under the condition that no phase sequence connection error occurs, the a-band transmission signal is transmitted to the C-phase grounding cable on the second direct grounding side 2 through the first direct grounding box of the first work well, the a-phase of the first section of cable, the cross interconnection grounding box of the second work well, the B-phase of the second section of cable, the cross interconnection grounding box of the third work well, the C-phase of the third section of cable, and the second direct grounding box of the fourth work well in sequence, so as to form a grounding circulation. The C-phase ground cable of the second direct ground side 2 can receive the a-band transmission signal.
Referring to fig. 6 in combination, the a-phase grounding cable of the second direct grounding side 2 may receive the B-band transmission signal, and the B-phase grounding cable of the second direct grounding side 2 may receive the c-band transmission signal. Therefore, if the A phase/B phase/C phase of the second direct grounding side correspondingly receives a B/C/a frequency band transmitting signal, the cross interconnection grounding system can be determined not to have a phase sequence connection error fault; otherwise, if the received signal of the A phase/B phase/C phase of the second direct grounding side does not completely correspond to the B/C/a frequency band transmitted signal, the cross-connection grounding system can be determined to have a phase sequence connection error fault.
In another embodiment, referring to a shown in fig. 2 a, taking a frequency band a as an example, when a phase sequence connection error does not occur, the frequency band a transmission signal is transmitted to the phase B grounding cable on the second direct grounding side 2 through the first direct grounding box of the first work well, the phase a of the first cable, the cross interconnection grounding box of the second work well, the phase C of the second cable, the cross interconnection grounding box of the third work well, the phase B of the third cable, and the second direct grounding box of the fourth work well in sequence, so as to form a grounding loop. The B-phase grounding cable of the second direct grounding side 2 can receive the a-band transmission signal, the a-phase grounding cable of the second direct grounding side 2 can receive the C-band transmission signal, and the C-phase grounding cable of the second direct grounding side 2 can receive the B-band transmission signal. Therefore, if the phase A/phase B/phase C of the second direct grounding side correspondingly receives a C/a/B frequency band transmitting signal, the cross interconnection grounding system can be determined not to have a phase sequence connection error fault; otherwise, if the received signal of the A phase/B phase/C phase of the second direct grounding side does not completely correspond to the transmitted signal of the C/a/B frequency band, the fault of the phase sequence connection of the cross interconnection grounding system can be determined.
It should be noted that, those skilled in the art may set the connection mode of the grounding system according to actual needs, and the detection logic for transmitting and receiving signals corresponds to the connection mode of the grounding system, which is not limited to this.
From this, the technical scheme that this embodiment provided, through the harmonic signal of the one end direct ground side transmission different wave bands at the cross interconnection section, whether the frequency channel according to the received signal lacks discernment broken string trouble to according to the logic corresponding relation discernment phase sequence connection error fault of harmonic receiving and dispatching signal, realize the automatic identification of different fault types, avoid carrying out the wiring detection in cross interconnection intermediate head department simultaneously, can realize the long distance, the electrified detection of the complicated scene of wiring, the efficiency of detecting has been improved greatly, save the labour.
EXAMPLE III
Fig. 7 is a flowchart of a method for detecting a cable sheath cross-connection grounding system according to a third embodiment of the present invention, and this embodiment further adds a step of determining whether a connection fault occurs according to insulation resistance detection or voltage resistance detection after determining that no connection fault occurs in the cross-connection grounding system according to a transmission signal and a reception signal based on the third embodiment. As shown in fig. 7, the method specifically includes:
s410, acquiring a transmitting signal of a first direct grounding side and a receiving signal of a second direct grounding side, wherein the transmitting signal comprises three-phase harmonic signals in different preset frequency bands.
S420, determining whether the cross-connection grounding system has a connection fault according to the transmitting signal and the receiving signal; wherein the connection failure comprises: phase sequence connection error faults and disconnection faults.
And S430, if the cross interconnection grounding system has no connection fault, carrying out cable sheath insulation resistance detection and/or cable sheath voltage withstanding detection on the cross interconnection grounding system.
The detection of the insulation resistance of the cable sheath is generally to measure the leakage current during pressurization, and the insulation resistance value is calculated through the ohm law, so that the detection of the insulation resistance of the cable sheath can avoid secondary damage to equipment due to poor insulation, and the safety of personnel is also ensured. The voltage withstanding detection of the cable sheath refers to the test of the voltage withstanding capability of the cable sheath so as to check the voltage or overvoltage withstanding capability of the cable sheath in insulation, and further check whether the insulation performance of the cable sheath meets the safety standard.
And S440, determining whether a connection fault occurs according to the insulation resistance detection result or the voltage withstanding detection result.
Specifically, if the cross-connection grounding system is determined not to have the connection fault according to the transmitting signal and the receiving signal, cable sheath insulation resistance detection and/or cable sheath voltage withstanding detection can be further performed on the cross-connection grounding system, so that whether the connection fault occurs or not is determined according to an insulation resistance detection result or a voltage withstanding detection result, if the insulation resistance detection result and the voltage withstanding detection result are qualified, the cross-connection grounding system does not have the connection fault, otherwise, if one of the insulation resistance detection result and the voltage withstanding detection result is unqualified or both are unqualified, the cross-connection grounding system can be determined to have the connection fault, at the moment, segmented troubleshooting is performed, the operation efficiency is greatly improved, meanwhile, the cable sheath can be ensured not to be damaged, the cable is prevented from being damaged due to the damage of the cable sheath, and the safety performance is improved.
According to the technical scheme, after the fact that the cross interconnection grounding system is determined not to have the connection fault according to the transmitting signal and the receiving signal is ensured, cable sheath insulation resistance detection and/or cable sheath voltage-withstanding detection are carried out on the cross interconnection grounding system, whether the connection fault occurs or not is determined according to the insulation resistance detection result or voltage-withstanding detection result, if the connection fault occurs, segmentation troubleshooting is carried out, detection efficiency is greatly improved, meanwhile, the fact that the cable is damaged due to the fact that the cable sheath is damaged can be avoided, and safety performance is improved.
Example four
The fourth embodiment of the present invention provides a detection apparatus for a cable sheath cross-connection grounding system, where the cross-connection grounding system is provided with a first direct grounding side, a second direct grounding side, and a cross-connection grounding device, and the detection apparatus may be implemented in a form of hardware and/or software, and is used to execute the detection method for a cable sheath cross-connection grounding system provided in any embodiment of the present invention. Fig. 8 is a schematic structural diagram of a detection apparatus for a cable sheath cross-connection grounding system according to a fourth embodiment of the present invention, and as shown in fig. 8, the detection apparatus includes: a signal transmitting device 510, a signal receiving device 520, and a processing device 530.
The signal transmitting device 510 is disposed on the first direct grounding side, and the signal transmitting device 510 is configured to output a transmitting signal, where the transmitting signal includes three-phase harmonic signals in different preset frequency bands.
The signal receiving device 520 is disposed on the second direct ground side, and the signal receiving device 520 is used for collecting the received signal.
Processing means 530 for determining whether a connection failure occurs in the cross-connect grounding system according to the transmission signal and the reception signal; wherein the connection failure comprises: phase sequence connection error faults and disconnection faults.
Specifically, the signal transmitting device 510 is disposed on the first direct-grounded side, and outputs a transmitting signal including three-phase harmonic signals in different preset frequency bands on the first direct-grounded side, for example, the three-phase harmonic signals may include an a-phase harmonic signal in a frequency band, a B-phase harmonic signal in B frequency band, and a C-phase harmonic signal in C frequency band; the frequencies of the frequency band a, the frequency band b and the frequency band c are not overlapped. The signal receiving device 520 is disposed on the second direct ground side, and collects the received signal on the second direct ground side.
Illustratively, in the process of detecting the cross-connected grounding system, a signal transmitting device 510 disposed on the first direct grounding side outputs a transmitting signal including an a/B/C three-phase harmonic signal, the three-phase harmonic signal is transmitted to the second direct grounding side through a cross-connected three-phase cable, a signal receiving device 520 on the second direct grounding side collects a receiving signal, and a processing device 530 determines whether a connection fault occurs in the cross-connected grounding system according to the transmitting signal and the receiving signal, if the receiving signal includes the a/B/C three-phase harmonic signal, it is determined that the cross-connected grounding system is in good wiring and no virtual connection or disconnection fault occurs, otherwise, if the signal receiving device 520 does not receive at least one phase harmonic signal or the receiving signal does not belong to the three-phase harmonic signal included in the transmitting signal, it is determined that the cross-connected grounding system has the virtual connection or disconnection fault; similarly, if the three-phase receiving phase sequence of the received signal is the same as the preset phase sequence, the cross-connected grounding system has no phase sequence connection error fault, and if the three-phase receiving phase sequence of the received signal is different from the preset phase sequence, the cross-connected grounding system can be determined to have the phase sequence connection error fault.
Optionally, the signal transmitting device 510 includes an a-phase transmitting unit, a B-phase transmitting unit, and a C-phase transmitting unit, where the a-phase transmitting unit, the B-phase transmitting unit, and the C-phase transmitting unit are respectively disposed on a three-phase grounding cable on a first direct grounding side, the a-phase transmitting unit is configured to transmit an a-phase harmonic signal in a frequency band a, the B-phase transmitting unit is configured to transmit a B-phase harmonic signal in a frequency band B, the C-phase transmitting unit is configured to transmit a C-phase harmonic signal in a frequency band C, and frequencies of the frequency band a, the frequency band B, and the frequency band C are not overlapped with each other; the signal receiving device comprises an A-phase receiving unit, a B-phase receiving unit and a C-phase receiving unit, wherein the A-phase receiving unit, the B-phase receiving unit and the C-phase receiving unit are respectively arranged on a three-phase grounding cable on the second direct grounding side.
Specifically, the A-phase transmitting unit, the B-phase transmitting unit and the C-phase transmitting unit are respectively arranged on a three-phase grounding cable on a first direct grounding side, the A-phase transmitting unit transmits an A-phase harmonic signal in an a-frequency band, the B-phase transmitting unit is used for transmitting a B-phase harmonic signal in a B-frequency band, the C-phase transmitting unit is used for transmitting a C-phase harmonic signal in a C-frequency band, the A-phase harmonic signal, the B-phase harmonic signal and the C-phase harmonic signal are respectively transmitted to a second direct grounding side through the three-phase cable, and the A-phase receiving unit, the B-phase receiving unit and the C-phase receiving unit are respectively arranged on the three-phase grounding cable on the second direct grounding side so as to collect receiving signals of the three-phase grounding cable on the second direct grounding side.
Optionally, the signal transmitting device 510 adopts a loop structure; the signal receiving device 520 is in a loop structure.
Specifically, the signal transmitting device may adopt a loop structure, and is sleeved or clamped at a three-phase grounding cable fixed on the first direct grounding side, so as to inject transmitting signals of different preset frequency bands into the three-phase grounding cable respectively. Similarly, the signal receiving device may adopt a loop structure, and the three-phase grounding cable is sleeved or clamped and fixed at the second direct grounding side to detect whether the three-phase grounding cable receives the harmonic signal.
The cable sheath cross-connection grounding system detection device provided by the embodiment comprises a signal transmitting device, a signal receiving device and a processing device, wherein the signal transmitting device is arranged on a first direct grounding side, a transmitting signal comprising a three-phase harmonic signal is output to a three-phase cable, the signal receiving device is arranged on a second direct grounding side and is used for collecting a receiving signal, the processing device determines whether a phase sequence connection error fault and a disconnection fault lamp connection fault occur in the cross-connection grounding system or not according to the transmitting signal and the receiving signal, long-distance and multi-section cross-connection grounding electrified detection is realized, the cross-connection grounding system detection safety is improved, detection can be implemented without disassembling a grounding box, the improvement of detection precision and detection efficiency is facilitated, and the time cost and the labor cost are saved.
EXAMPLE five
The embodiment of the invention provides detection equipment, which comprises the detection device for the cable sheath cross-connection grounding system provided by any embodiment of the invention, so that the beneficial effects of the detection device for the cable sheath cross-connection grounding system provided by any embodiment of the invention can be achieved, and the same points can be referred to the description above.
The above-described embodiments should not be construed as limiting the scope of the invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made in accordance with design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A method for detecting a cross-connection grounding system of a cable sheath, wherein the cross-connection grounding system is provided with a first direct grounding side, a second direct grounding side and a cross-connection grounding device, and is characterized by comprising the following steps:
acquiring a transmitting signal of the first direct grounding side and a receiving signal of the second direct grounding side, wherein the transmitting signal comprises three-phase harmonic signals in different preset frequency bands;
determining whether the cross-interconnected grounding system has a connection fault according to the transmitting signal and the receiving signal;
wherein the connection failure comprises: phase sequence connection error faults and disconnection faults.
2. The method of claim 1, wherein determining whether a connection fault exists in the cross-interconnect grounding system based on the transmit signal and the receive signal comprises:
acquiring a forward receiving frequency band of the received signal;
judging whether the forward receiving frequency band is matched with the preset frequency band or not;
and determining whether the cross-connection grounding system has a disconnection fault according to the judgment result.
3. The method of claim 1, wherein determining whether a connection fault exists in the cross-connect grounding system based on the transmit signal and the receive signal comprises:
acquiring a three-phase receiving phase sequence of the receiving signal;
and comparing the phase sequence of the three-phase receiving phase sequence with a preset phase sequence, and determining whether the cross-connection grounding system has a phase sequence connection error fault according to the phase sequence comparison result.
4. The method of claim 3, wherein the preset phase sequence comprises: the phase A/phase B/phase C of the second direct grounding side correspondingly receives the transmitting signal of the phase C/phase A/phase B;
or the A phase/B phase/C phase of the second direct grounding side correspondingly receives the transmission signal of the B phase/C phase/A phase.
5. The method according to any one of claims 1-4, further comprising, after determining from the transmit signal and the receive signal that the cross-connect grounding system is not faulty,:
carrying out cable sheath insulation resistance detection and/or cable sheath voltage withstanding detection on the cross-connection grounding system;
and determining whether a connection fault occurs according to the insulation resistance detection result or the withstand voltage detection result.
6. The method according to any one of claims 1 to 4, wherein the three-phase harmonic signals include an A-phase harmonic signal in a-band, a B-phase harmonic signal in B-band, and a C-phase harmonic signal in C-band;
the frequencies of the frequency band a, the frequency band b and the frequency band c are not overlapped with each other.
7. A cable sheath cross-connect grounding system detection apparatus, the cross-connect grounding system having a first direct grounding side, a second direct grounding side, and a cross-connect grounding apparatus, for performing the cable sheath cross-connect grounding system detection method of any one of claims 1-6, the apparatus comprising: the device comprises a signal transmitting device, a signal receiving device and a processing device;
the signal transmitting device is arranged on the first direct grounding side and used for outputting transmitting signals, and the transmitting signals comprise three-phase harmonic signals in different preset frequency bands;
the signal receiving device is arranged on the second direct grounding side and used for collecting received signals;
the processing device is used for determining whether the cross-interconnected grounding system has a connection fault according to the transmitting signal and the receiving signal;
wherein the connection failure comprises: phase sequence connection error faults and disconnection faults.
8. The device of claim 7, wherein the signal transmitting device comprises an a-phase transmitting unit, a B-phase transmitting unit, and a C-phase transmitting unit, the a-phase transmitting unit, the B-phase transmitting unit, and the C-phase transmitting unit are respectively disposed on the three-phase grounding cable on the first direct grounding side, the a-phase transmitting unit is configured to transmit an a-phase harmonic signal in a-band, the B-phase transmitting unit is configured to transmit a B-phase harmonic signal in B-band, the C-phase transmitting unit is configured to transmit a C-phase harmonic signal in C-band, and frequencies of the a-band, the B-band, and the C-band are not overlapped with each other;
the signal receiving device comprises an A-phase receiving unit, a B-phase receiving unit and a C-phase receiving unit, wherein the A-phase receiving unit, the B-phase receiving unit and the C-phase receiving unit are respectively arranged on the three-phase grounding cable on the second direct grounding side.
9. The device of claim 7, wherein the signal emitting device is in a loop configuration; the signal receiving device adopts a ring sleeve type structure.
10. A detection apparatus, comprising: the cable jacket cross-connect grounding system test device of any one of claims 7-9.
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| CN202211204021.6A CN115524641A (en) | 2022-09-29 | 2022-09-29 | Detection method, device and detection equipment for cable sheath cross interconnection grounding system |
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| CN202211204021.6A CN115524641A (en) | 2022-09-29 | 2022-09-29 | Detection method, device and detection equipment for cable sheath cross interconnection grounding system |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116577699A (en) * | 2023-07-13 | 2023-08-11 | 三峡集团浙江能源投资有限公司 | Loss-of-ground monitoring device for small-resistance grounding system of pumped storage power station |
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- 2022-09-29 CN CN202211204021.6A patent/CN115524641A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116577699A (en) * | 2023-07-13 | 2023-08-11 | 三峡集团浙江能源投资有限公司 | Loss-of-ground monitoring device for small-resistance grounding system of pumped storage power station |
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