CN116299050B - Method, system, equipment and storage medium for detecting faults of protective layer - Google Patents
Method, system, equipment and storage medium for detecting faults of protective layer Download PDFInfo
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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
- G01R31/52—Testing for short-circuits, leakage current or ground faults
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
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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
- G01R31/58—Testing of lines, cables or conductors
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
Abstract
The invention discloses a method, a system, equipment and a storage medium for detecting a sheath fault, wherein the method for detecting the sheath fault comprises the following steps: determining a balance point of the cable line; acquiring a first loop current and a second loop current passing through a balance point, and judging whether the protective layer fails according to the first loop current and the second loop current; determining the balance point of the cabling comprises: constructing a first model equation at least comprising a first loop current parameter, a line parameter and a balance point parameter, and constructing a second model equation at least comprising a second loop current parameter, a line parameter and a balance point parameter; determining a first loop current parameter through a first model equation, and determining a second loop current parameter through a second model equation; and determining a balance point parameter when the first loop current parameter and the second loop current parameter are equal, recording the balance point parameter as a balance point parameter, and determining a balance point according to the balance point parameter.
Description
Technical Field
The present invention relates to power grid technologies, and in particular, to a method, a system, an apparatus, and a storage medium for detecting a sheath fault.
Background
With the advancement of urban modernization, power cables have been widely used in power transmission and distribution systems of various metropolitan areas, becoming an important component of urban power grids. The city has more short cables, the short cables are grounded at two ends of the protective layer, the metal protective layer forms a current path by the connection method, and the load current induces electromotive force in the loop to generate considerable circulation, so that loss can be brought, the protective layer is accelerated to age due to the action of damp and heat, the protective layer of the cable is damaged, and then the protective layer is grounded.
At present, an online fault monitoring method for a cable sheath generally needs to install a related current sensing device at the head end and the tail end of the cable sheath, extract and record a cable sheath current signal in real time, analyze the characteristic quantity of the cable sheath current signal, and judge whether a sheath fault occurs.
The protection layer fault monitoring method in the prior art has the following defects: the method is complex; the equipment cost is high, and equipment needs to run continuously, and the energy loss is big, and economic nature is poor, and it is difficult to use widely.
Disclosure of Invention
The invention provides a method, a system, equipment and a storage medium for detecting a sheath fault, which aim to reduce the system construction cost and the detection (monitoring) complexity of the sheath fault.
In a first aspect, the present invention provides a method for detecting a failure of a protective layer, including:
determining a balance point of the cable line;
acquiring a first loop current and a second loop current passing through the balance point, and judging whether the protection layer fails according to the first loop current and the second loop current;
determining the balance point of the cabling comprises:
constructing a first model equation at least comprising a first loop current parameter, a line parameter and a balance point parameter, and constructing a second model equation at least comprising a second loop current parameter, a line parameter and a balance point parameter;
determining a first loop current parameter through the first model equation, and determining a second loop current parameter through the second model equation;
and determining the balance point parameter when the first loop current parameter and the second loop current parameter are equal, recording the balance point parameter as the balance point parameter, and determining the balance point according to the balance point parameter.
Optionally, the line parameters at least include a first inductive reactance between each two phases of the core of the three-phase cable and a second inductive reactance between each two core protection layers.
Optionally, the first model equation is:
；
the second model equation is:
；
in the method, in the process of the invention,representing balance point parameters->Representing inductive reactance matrix, < >>Comprises the first inductive reactance and the second inductive reactance, and the first inductive reactance and the second inductive reactance are respectively equal to or equal to the first inductive reactance and the second inductive reactance>Representing a first current matrix, ">Comprising a cable current parameter and a first loop current parameter +.>，/>Representing the first ground resistance,/->Represents the unit resistance of the protective layer, ">Represents the unit resistance of the ground loop, < >>Comprising a cable current parameter and a second loop current parameter, < >>Indicating cable length->Represents a second ground resistance, ">Representing the ground plane impedance;
wherein the cable current parameters comprise a first cable current parameter and a second cable current parameterAnd a third cable current parameter.
Optionally, determining whether the protection layer fails according to the first loop current and the second loop current includes:
collecting a first loop current of the cable line from a first end to the balance point, and collecting a second loop current of the cable line from the balance point to a second end of the cable line;
judging whether the first loop current and the second loop current are equal in magnitude and opposite in direction;
if the first loop current and the second loop current are equal in magnitude and opposite in direction, judging that the protective layer has no fault;
and if the first loop current and the second loop current are different in magnitude and/or same in direction, judging that the protective layer is faulty.
Optionally, when the method is applied to the double-end grounding of the cable sheath, whether the cable sheath has a grounding fault or not is judged.
In a second aspect, the present invention further provides a protection layer fault detection system, which includes a detection device, where the detection device stores an executable program, and the executable program implements the protection layer fault detection method described in the embodiment of the present invention when running.
Optionally, the detection device is further configured with an interface, and the interface is used for being electrically connected with the balance point;
the interface comprises an annular copper foil, a woven copper strip and an annular flange, wherein the annular copper foil is wrapped outside the linear protective layer at the balance point position;
the annular flange is arranged outside the annular copper foil;
the annular flange is further provided with an opening, the first end of the braided copper strip is electrically connected with the annular copper foil, and the second end of the braided copper strip penetrates out of the annular flange through the opening and is electrically connected with the fuse.
In a third aspect, the present invention also provides an electronic device comprising at least one processor, and a memory communicatively coupled to the at least one processor;
the memory stores a computer program executable by the at least one processor, the computer program being executable by the at least one processor to enable the at least one processor to perform any one of the sheath fault detection methods described herein.
In a fourth aspect, the present invention further provides a computer readable storage medium, where computer instructions are stored, where the computer instructions are configured to cause a processor to execute any one of the method for detecting a failure of a protective layer described in the present invention.
Compared with the prior art, the invention has the beneficial effects that: the invention provides a protection layer fault detection method, which comprises the steps of determining a balance point through a first model equation and a second model equation, collecting a first loop current and a second loop current passing through the balance point, determining whether the protection layer of a cable has faults or not based on the first loop current and the second loop current, and based on the method, complex characteristics of current in a cable line are not required to be extracted, complex current acquisition equipment is not required, the accuracy of fault judgment of the cable protection layer is ensured, the cost for fault monitoring of the cable protection layer can be reduced, and the popularization and the use are convenient.
Drawings
FIG. 1 is a flow chart of a method of detecting a failure of a protective layer in an embodiment;
FIG. 2 is a flow chart of another method of detecting a sheath failure in an embodiment;
FIG. 3 is a schematic diagram of an interface architecture in an embodiment;
fig. 4 is a schematic diagram of the electronic device structure in the embodiment.
Detailed Description
The invention is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the structures related to the present invention are shown in the drawings.
Example 1
FIG. 1 is a flowchart of a method for detecting a failure of a protective layer in an embodiment, and referring to FIG. 1, the method for detecting a failure of a protective layer includes:
s101, determining the balance point of the cable line.
In this embodiment, the application scenario of the cable line is not limited, and the cable line may be a cable line in an application scenario such as a high-speed cable network, a mine cable network, an urban cable network, and the like.
In this embodiment, the cable is provided with a protective layer, and the protective layer is a sealed metal sheath which is used for preventing moisture from corroding the cable core and is covered on the outer layer of the cable core;
the grounding mode of the protective layer is not particularly limited, and one-end grounding, two-end grounding, cross-connection grounding or other grounding modes can be adopted.
In this embodiment, the balance point of the cable line represents a location point in the cable line, based on which a first end of the cable line (e.g., a head end of the cable line), the location point and the ground may form a current loop, denoted as a first current loop, and a second end of the cable line (e.g., a tail end of the cable line), the location point and the ground may form a current loop, denoted as a second current loop;
if the cable line does not fail, the current in the first current loop and the current in the second current loop are equal in magnitude and opposite in direction.
In this scheme, confirm the equilibrium point of cable line includes:
constructing a first model equation at least comprising a first loop current parameter, a line parameter and a balance point parameter, and constructing a second model equation at least comprising a second loop current parameter, a line parameter and a balance point parameter;
determining a first loop current parameter through a first model equation, and determining a second loop current parameter through a second model equation;
and determining a balance point parameter when the first loop current parameter and the second loop current parameter are equal, recording the balance point parameter as a balance point parameter, and determining a balance point according to the balance point parameter.
In this embodiment, the setting the first loop current parameter includes, at least, in the first loop, a current passing through the cable core and the balance point, where if the cable is a multi-phase cable (e.g., a three-phase cable, a four-phase cable, etc.), the first loop current specifically includes a current passing through each phase core and the balance point in the first loop;
the second loop current parameter at least comprises the current passing through the cable core and the balance point in the second loop, wherein if the cable is a multi-phase cable, the second loop current specifically comprises the current passing through each phase of the cable core and the balance point in the second loop;
the balance point parameters at least comprise the position coordinates of the balance point, and if the cable is a multi-phase cable, the balance point parameters comprise the position coordinates of the balance point corresponding to each phase line core.
In this embodiment, the first loop current parameter and the second loop current parameter respectively correspond to a set of values (numbers) of the first loop current parameter and the second loop current parameter.
In this scheme, when the cable is the heterogeneous cable, the circuit parameter can include, the inductive reactance between the cable core, the inductive reactance between cable core and the sheath, the inductive reactance between the sheath, the length of cable line etc..
Illustratively, in the present solution, the first model equation and the second model equation may be designed based on a circuit principle or empirically, and modeling of the model equations and solving coefficients in the model equations may be implemented by simulation software.
S102, acquiring a first loop current and a second loop current passing through the balance point, and judging whether the protective layer fails or not according to the first loop current and the second loop current.
In this embodiment, after determining the balance point of the cable line, a manual or automatic device is required to draw a grounding point at the balance point of the cable line, so that a first current loop and a second current loop may exist between the cable line and the ground.
In the scheme, a specific mode of judging whether the protection layer fails according to the first loop current and the second loop current is not limited, for example, when the magnitude and the direction of the first loop current meet a first preset condition and the magnitude and the direction of the second loop current meet a second preset condition, the protection layer can be judged to fail, otherwise, the protection layer is judged to fail;
for example, in the present embodiment, the first preset condition and the second preset condition may be set empirically or determined through calibration test.
The embodiment provides a protection layer fault detection method, which comprises the steps of determining a balance point through a first model equation and a second model equation, collecting a first loop current and a second loop current passing through the balance point, determining whether the protection layer of a cable has faults or not based on the first loop current and the second loop current, and based on the method, complex characteristics of current in a cable line are not required to be extracted, complex current collection equipment is not required, the accuracy of fault judgment of the cable protection layer is ensured, and meanwhile, the cost for fault monitoring of the cable protection layer can be reduced, so that the protection layer fault detection method is convenient to popularize and use.
FIG. 2 is a flowchart of another method for detecting a failure of a protective layer according to an embodiment, referring to FIG. 2, the method for detecting a failure of a protective layer includes:
s201, determining a balance point of the cable line.
In this embodiment, the manner of determining the balance point is not limited, for example, for a cable line in an application scenario, the balance point may be solved through a preset function model matched with the application scenario, or the balance point of a specified cable line may be determined through a manual measurement manner;
when the cable line is determined by manual measurement, the balance point and related data (such as the cable line number) are stored, and when the balance point is needed, the related balance point is read from the storage device, so that a subsequent protection layer fault detection method is realized.
S202, collecting first loop current from a first end to a balance point of the cable line, and collecting second loop current from the balance point to a second end of the cable line.
In this embodiment, the first loop current and the second loop current are specifically collected through a balance point, that is, the first loop current and the second loop current are collected through one current sampling point.
S203, judging whether the first loop current and the second loop current are equal in magnitude and opposite in direction.
S204, if the first loop current and the second loop current are equal in magnitude and opposite in direction, judging that the protection layer has no fault.
S205, if the first loop current and the second loop current are different in magnitude and/or same in direction, judging that the protective layer is faulty.
In combination with step S202 to step S205, in this embodiment, the first loop current and the second loop current may be periodically determined, and when the magnitudes of the first loop current and the second loop current are equal and the directions of the first loop current and the second loop current are opposite, it is determined that the cable sheath has no ground fault;
otherwise, the cable sheath is judged to have the ground fault, and at the moment, fault indication information can be further generated to indicate the cable sheath to have the ground fault.
Illustratively, in this embodiment, it may be determined whether the first loop current and the second loop current are equal in magnitude and opposite in direction as follows:
introducing the first loop current and the second loop current into the same current detection device, and if the current detection device detects the current, judging that the first loop current and the second loop current are different in magnitude and/or same in direction;
if it is determined that the current detection device does not detect the current, it is determined that the first loop current and the second loop current are equal in magnitude and opposite in direction.
The embodiment provides a protection layer fault detection method, which comprises the steps of determining a balance point, collecting a first loop current and a second loop current passing through the balance point, judging whether the first loop current and the second loop current are equal in magnitude and opposite in direction to judge whether the protection layer of a cable breaks down, and based on the method, complex characteristics of current in a cable line are not required to be extracted, complex current collection equipment is not required, the accuracy of fault judgment of the cable protection layer is ensured, and meanwhile, the cost for fault monitoring of the cable protection layer can be reduced, so that the protection layer fault detection method is convenient to popularize and use.
Further, when the balance point is solved by setting the first model equation and the second model equation, if the cable is a three-phase cable, the specific set line parameters at least include a first inductive reactance between each two phases of cores of the three-phase cable and a second inductive reactance between each two cores of the protection layer.
Further, when the cable is a three-phase cable, and when the line parameter includes a first inductance between each two phases of cores of the three-phase cable and a second inductance between each two core shields, the line parameter further includes a ground resistance, a sheath unit resistance, and a ground loop unit resistance.
In the scheme, the set line parameters comprise inductive reactance among the wire cores, inductive reactance among the wire core protection layers, grounding resistance, protection layer unit resistance and ground loop unit resistance, and based on the set line parameters, the design of a first model equation and a second model equation can be realized based on a differential flow principle, so that the design difficulty of the model equation is reduced.
Further, when the cable is a three-phase cable, the line parameters include a first inductive reactance between each two phases of cores of the three-phase cable, a second inductive reactance between each two cores of the cable, a ground resistance, a sheath unit resistance and a ground loop unit resistance, and the first model equation is as follows:
；
the second model equation is:
；
in the method, in the process of the invention,representing balance point parameters->Representing inductive reactance matrix, < >>Comprises a first inductive reactance and a second inductive reactance>Representing a first current matrix, ">Comprising a cable current parameter and a first loop current parameter +.>，/>Representing the first ground resistance,/->Represents the unit resistance of the protective layer, ">Represents the unit resistance of the ground loop, < >>Comprising a cable current parameter and a second loop current parameter (">），/>Indicating cable length->Represents a second ground resistance, ">Representing the ground plane impedance;
wherein the cable current parameter comprises a first cable current parameter) Second cable current parameter->And a third cable current parameter (+)>）。
In the scheme, the two ends of the cable sheath are set to be grounded, namely, when the first model equation and the second model equation are used for determining the two ends of the cable sheath to be grounded, the balance point of the cable core is set.
In the scheme, the cable is a three-phase cable, and balance point parameters are setThe method comprises the following steps:
in the above-mentioned method, the step of,、/>、/>the balance point coordinates of the first phase wire core, the balance point coordinates of the second phase wire core and the balance point coordinates of the third phase wire core are respectively from the head end (the coordinate of the head end is recorded as 0) of the cable line.
In this scheme, an inductance matrix is setThe method comprises the following steps:
in the above-mentioned method, the step of,representing first inductive reactance->Representing a second inductive reactance, wherein +.>、/>The method comprises the following steps of:
in the above-mentioned method, the step of,inductive reactance between the protective layer representing the ith phase wire core and the jth phase wire core, +.>Representing the inductive reactance between the sheath of the i-phase core and the sheath of the j-phase core.
In this scheme, the cable length is setThe method comprises the following steps:
in the above-mentioned method, the step of,、/>、/>the length of the first phase wire core, the length of the second phase wire core and the length of the third phase wire core of the cable are respectively represented.
In this scheme, a first current matrixThe method comprises the following steps:
in the above-mentioned method, the step of,representing the cable current parameter, ">The concrete steps are as follows:
first loop current parameterThe concrete steps are as follows:
second current matrixThe method comprises the following steps:
second loop current parameterThe concrete steps are as follows:
in the above-mentioned method, the step of,、/>、/>respectively representing the current passing through the first phase wire core, the current passing through the second phase wire core and the current passing through the third phase wire core in the first loop;
、/>、/>in the second loop, the current through the first phase core, the current through the second phase core, and the current through the third phase core are respectively represented.
In this solution, the cable length (with both ends of the sheath grounded)Inductive reactance matrix->First ground resistance->Second ground resistance->The unit resistance of the protective layer->Ground loop sheetBit resistance->For the measurement value, it can be obtained directly by measurement.
In the scheme, solveWhen the first loop current parameter is set>And a second loop current parameter->Equal, the +.A.can be found by combining the first model equation and the second model equation>。
In the scheme, the calculation of the balance point is realized based on the first model equation and the second model equation, the parameters to be measured are few, the acquisition difficulty is low, the calculation difficulty of determining the balance point is further reduced, and the calculation efficiency can be improved.
Example two
The embodiment provides a protection layer fault detection system, which comprises a detection device, wherein the detection device stores an executable program, and any one of the protection layer fault detection methods described in the first embodiment is implemented when the executable program runs, and the implementation process and the beneficial effects of the protection layer fault detection method are the same as those described in the first embodiment, and are not repeated herein.
FIG. 3 is a schematic diagram of an interface structure in an embodiment, referring to FIG. 3, in this embodiment, the detecting device is further configured with an interface for electrically connecting with a balance point;
the interface comprises an annular copper foil 1, a braided copper strip 3 and an annular flange 2, wherein the annular copper foil 1 is wrapped outside the linear protective layer at the position of the balance point;
the annular flange 2 is arranged outside the annular copper foil 1;
the annular flange 2 is further provided with an opening 21, a first end of the braided copper strip 3 is electrically connected with the annular copper foil 1, and a second end of the braided copper strip penetrates out of the annular flange 2 through the opening 21 and is electrically connected with the fuse.
For example, the cable is set to be a three-phase cable, and an interface is set at the balance point of each phase cable, taking an interface configured for a phase cable as an example, in this scheme, the interface can be manufactured by the following manner:
the nonmetal outer protective layer of the cable is stripped and cut in an annular mode by using a special cable cutter, the stripping and cutting width is 40-50 mm, the stripped and cut section is flat and not inclined, and the fracture is cleaned up, so that the metal protective layer in the cable is completely exposed, and no impurity coverage is ensured;
preparing a roll of copper foil with the thickness of 3mm, cutting the copper foil to the width of 35mm, brushing electrical conductive paste on one surface, winding the parallel section on the metal protective layer, and pressing the extrusion bubble to enable the extrusion bubble to be fully contacted with the metal protective layer;
a braided copper strip is used as a differential current guide wire, the braided copper strip with the width of 4-8 mm is fixed on a copper foil by a PVC adhesive tape or a welding mode, and the other end of the guide wire is grounded after being connected with a fuse;
the annular flange matched with the cable in size is customized, the annular flange is used for being arranged on a fracture of the nonmetal protective layer, the flange is used for recovering the protection effect of the nonmetal protective layer of the cable, and the flange is characterized in that:
the glass fiber reinforced plastic material is made of glass fiber reinforced plastic, and has insulation and protection functions; the flange consists of two symmetrical semicircles, the two semicircles can be spliced into a ring, and the inner diameter of the ring is the same as the outer radius of the cable; the width of the flange is 60-80 mm, and the gap of the cable nonmetal protective layer which is peeled and cut can be completely shielded; an opening is reserved at the die closing position of the annular flange, the diameter of the opening is 10mm, and the opening can just pass through the guide wire.
Illustratively, in this embodiment, the differential current lead from the interface is connected to a fuse, which is grounded and serves as a protection device for the detection device.
Illustratively, in this scenario, the parameters of the fuse are selected according to the following rules:
rated voltage Urn: GB50217-94 specifies: no safety measures are taken which cannot be contacted with the metal protective layer at will, and the voltage is not more than 50V; in other cases, it must not be greater than 100V. Therefore, the rated voltage of the fuse is only required to be selected to be more than 100V;
rated current Irn: under normal working conditions, the current flowing through the fuse is very small, when only the protective layer is broken and grounded, the unbalanced current flowing through the fuse generally does not exceed 100A, the fuse should not be fused, and in addition, the fuse can be fused normally when the wire core is grounded;
maximum breaking current: the fuse should be able to effectively fuse when a single-phase ground short circuit occurs in the wire core, so that the maximum breaking current > single-phase ground short circuit current Ik.
For example, in one possible embodiment, the detecting device may include a sampling unit, a detecting unit, and a signaling unit, where the sampling unit is configured to implement a determination that whether the first loop current and the second loop current are equal in magnitude and opposite in direction;
specifically, the sampling unit may be a rogowski coil with an integrator, the rogowski coil passes through a differential current guide wire from an interface corresponding to a phase cable, when the magnitude of the first loop current is equal to that of the second loop current, the rogowski coil does not output, otherwise, the rogowski coil outputs a signal;
the primary and secondary side output ratios of the Rogowski coil under the power frequency are set to meet the following conditions: the output voltage of the input integrator in the Rogowski coil is 0-3.3V, and the precision is higher than 0.1%.
In the scheme, the detection unit can adopt a singlechip, the singlechip is in a sleep state under normal conditions, and the singlechip maintains the sleep state when the rogowski coil does not output signals;
when the Rogowski coil outputs a signal, the singlechip wakes up, and carries out analog-to-digital conversion on the output signal from the Rogowski coil based on a digital-to-analog conversion function to obtain a voltage value Uani corresponding to a corresponding cable, a starting voltage Ust is set in consideration of the possibility of misoperation, and when the voltage value Uani > Ust exists, the singlechip sends a starting signal to the transmitting unit.
Illustratively, in this solution, the signaling unit may be a wireless bluetooth, antenna, routing, etc. device, where the signaling unit is configured to notify the maintenance personnel that the sheath is malfunctioning when uini > Ust.
In the scheme, an interface is arranged at a balance point of a cable sheath with two grounded ends, the interface comprises a differential current guide wire, the differential current guide wire is grounded after being connected with a fuse to form two differential current loops, a first differential current loop is arranged on the left side, a second differential current loop is arranged on the right side, and a detection device is connected with the differential current guide wire;
during normal operation, because the two differential current loops are balanced in current, currents with the same magnitude and opposite directions are generated in the detection device and are mutually offset, no current flows into the detection device, and no loss is caused; when the protective layer has a ground fault, the two differential current loops are unbalanced, current flows in, and the detection device is started to send a signal to operation and maintenance personnel;
based on the above, the detection device is started only when the protective layer fails, and the device is in a sleep state when the cable line works normally, so that the detection device is more economical and durable and can be used as an alarm device for the failure of the protective layer.
Example III
Fig. 4 shows a schematic diagram of the structure of an electronic device 10 that may be used to implement an embodiment of the invention. Electronic devices are intended to represent various forms of digital computers, such as laptops, desktops, workstations, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. Electronic equipment may also represent various forms of mobile devices, such as personal digital processing, cellular telephones, smartphones, wearable devices (e.g., helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions, are meant to be exemplary only, and are not meant to limit implementations of the inventions described and/or claimed herein.
As shown in fig. 4, the electronic device 10 includes at least one processor 11, and a memory, such as a Read Only Memory (ROM) 12, a Random Access Memory (RAM) 13, etc., communicatively connected to the at least one processor 11, in which the memory stores a computer program executable by the at least one processor, and the processor 11 may perform various appropriate actions and processes according to the computer program stored in the Read Only Memory (ROM) 12 or the computer program loaded from the storage unit 18 into the Random Access Memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 may also be stored. The processor 11, the ROM 12 and the RAM 13 are connected to each other via a bus 14. An input/output (I/O) interface 15 is also connected to bus 14.
Various components in the electronic device 10 are connected to the I/O interface 15, including: an input unit 16 such as a keyboard, a mouse, etc.; an output unit 17 such as various types of displays, speakers, and the like; a storage unit 18 such as a magnetic disk, an optical disk, or the like; and a communication unit 19 such as a network card, modem, wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information/data with other devices via a computer network, such as the internet, and/or various telecommunication networks.
The processor 11 may be a variety of general and/or special purpose processing components having processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), various specialized Artificial Intelligence (AI) computing chips, various processors running machine learning model algorithms, digital Signal Processors (DSPs), and any suitable processor, controller, microcontroller, etc. The processor 11 performs the various methods and processes described above, such as the sheath failure detection method.
In some embodiments, the sheath failure detection method may be implemented as a computer program tangibly embodied on a computer-readable storage medium, such as storage unit 18. In some embodiments, part or all of the computer program may be loaded and/or installed onto the electronic device 10 via the ROM 12 and/or the communication unit 19. When the computer program is loaded into RAM 13 and executed by processor 11, one or more steps of the sheath failure detection method described above may be performed. Alternatively, in other embodiments, processor 11 may be configured to perform the sheath failure detection method by any other suitable means (e.g., by means of firmware).
Various implementations of the systems and techniques described here above may be implemented in digital electronic circuitry, integrated circuit systems, field Programmable Gate Arrays (FPGAs), application Specific Integrated Circuits (ASICs), application Specific Standard Products (ASSPs), systems On Chip (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and/or combinations thereof. These various embodiments may include: implemented in one or more computer programs, the one or more computer programs may be executed and/or interpreted on a programmable system including at least one programmable processor, which may be a special purpose or general-purpose programmable processor, that may receive data and instructions from, and transmit data and instructions to, a storage system, at least one input device, and at least one output device.
A computer program for carrying out methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the computer programs, when executed by the processor, cause the functions/acts specified in the flowchart and/or block diagram block or blocks to be implemented. The computer program may execute entirely on the machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.
In the context of the present invention, a computer-readable storage medium may be a tangible medium that can contain, or store a computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer readable storage medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. Alternatively, the computer readable storage medium may be a machine readable signal medium. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
To provide for interaction with a user, the systems and techniques described here can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to a user; and a keyboard and a pointing device (e.g., a mouse or a trackball) through which a user can provide input to the electronic device. Other kinds of devices may also be used to provide for interaction with a user; for example, feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form, including acoustic input, speech input, or tactile input.
The systems and techniques described here can be implemented in a computing system that includes a background component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front-end component (e.g., a user computer having a graphical user interface or a web browser through which a user can interact with an implementation of the systems and techniques described here), or any combination of such background, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: local Area Networks (LANs), wide Area Networks (WANs), blockchain networks, and the internet.
The computing system may include clients and servers. The client and server are typically remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. The server can be a cloud server, also called a cloud computing server or a cloud host, and is a host product in a cloud computing service system, so that the defects of high management difficulty and weak service expansibility in the traditional physical hosts and VPS service are overcome.
Note that the above is only a preferred embodiment of the present invention and the technical principle applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, while the invention has been described in connection with the above embodiments, the invention is not limited to the embodiments, but may be embodied in many other equivalent forms without departing from the spirit or scope of the invention, which is set forth in the following claims.
Claims (7)
1. A method for detecting a failure of a protective layer, comprising:
determining a balance point of the cable line;
acquiring a first loop current and a second loop current passing through the balance point, and judging whether the protection layer fails according to the first loop current and the second loop current;
determining the balance point of the cabling comprises:
constructing a first model equation at least comprising a first loop current parameter, a line parameter and a balance point parameter, and constructing a second model equation at least comprising a second loop current parameter, a line parameter and a balance point parameter;
determining a first loop current parameter through the first model equation, and determining a second loop current parameter through the second model equation;
determining the balance point parameter when the first loop current parameter and the second loop current parameter are equal, marking the balance point parameter as the balance point parameter, and determining the balance point according to the balance point parameter;
the circuit parameters at least comprise a first inductive reactance between each two phases of wire cores of the three-phase cable and a second inductive reactance between each two wire core protection layers;
the circuit parameters also comprise a grounding resistor, a protective layer unit resistor and a ground loop unit resistor;
the first model equation is:
；
the second model equation is:
；
in the method, in the process of the invention,representing balance point parameters->Representing inductive reactance matrix, < >>Comprises the first inductive reactance and the second inductive reactance, and the first inductive reactance and the second inductive reactance are respectively equal to or equal to the first inductive reactance and the second inductive reactance>Representing a first current matrix, ">Comprising a cable current parameter and a first loop current parameter +.>，/>Representing the first ground resistance,/->Represents the unit resistance of the protective layer, ">Represents the unit resistance of the ground loop, < >>Comprising a cable current parameter and a second loop current parameter, < >>Indicating cable length->Represents a second ground resistance, ">Representing the ground plane impedance;
wherein the cable current parameters comprise a first cable current parameter and a second cable current parameterAnd a third cable current parameter.
2. The sheath failure detection method of claim 1, wherein determining whether a sheath has failed based on the first loop current and the second loop current comprises:
collecting a first loop current of the cable line from a first end to the balance point, and collecting a second loop current of the cable line from the balance point to a second end of the cable line;
judging whether the first loop current and the second loop current are equal in magnitude and opposite in direction;
if the first loop current and the second loop current are equal in magnitude and opposite in direction, judging that the protective layer has no fault;
and if the first loop current and the second loop current are different in magnitude and/or same in direction, judging that the protective layer is faulty.
3. The method for detecting a sheath fault according to any one of claims 1 or 2, wherein when the method is applied to the double-side grounding of a cable sheath, it is determined whether the cable sheath has a grounding fault.
4. A sheath fault detection system comprising detection means storing an executable program that when run implements the sheath fault detection method of any one of claims 1 to 3.
5. The sheath failure detection system of claim 4 wherein the detection device is further configured with an interface for electrical connection with a balance point;
the interface comprises an annular copper foil, a woven copper strip and an annular flange, wherein the annular copper foil is wrapped outside the linear protective layer at the balance point position;
the annular flange is arranged outside the annular copper foil;
the annular flange is further provided with an opening, the first end of the braided copper strip is electrically connected with the annular copper foil, and the second end of the braided copper strip penetrates out of the annular flange through the opening and is electrically connected with the fuse.
6. An electronic device comprising at least one processor, and a memory communicatively coupled to the at least one processor;
the memory stores a computer program executable by the at least one processor to enable the at least one processor to perform the sheath fault detection method of any one of claims 1-3.
7. A computer readable storage medium storing computer instructions for causing a processor to perform the method of sheath failure detection of any one of claims 1-3.
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