CN112398104A - Insulation, arc light, route selection integrated monitoring protection system of distribution network - Google Patents
Insulation, arc light, route selection integrated monitoring protection system of distribution network Download PDFInfo
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- CN112398104A CN112398104A CN202011379048.XA CN202011379048A CN112398104A CN 112398104 A CN112398104 A CN 112398104A CN 202011379048 A CN202011379048 A CN 202011379048A CN 112398104 A CN112398104 A CN 112398104A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/28—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for meshed systems
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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
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
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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
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
- G01R31/1272—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of cable, line or wire insulation, e.g. using partial discharge measurements
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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
- 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
- G01R31/60—Identification of wires in a multicore cable
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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
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- 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
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Testing Relating To Insulation (AREA)
Abstract
The application provides a pair of distribution network insulation, arc light, route selection integrated monitoring protection system, the system includes impulse voltage acquisition device, wide band electric current acquisition device and power frequency voltage acquisition device, and connects impulse voltage acquisition device wide band electric current acquisition device with power frequency voltage acquisition device's integrated control ware. The integrated controller is configured to monitor the insulation fault of the switch cabinet and determine the type of the insulation fault according to the acquired operation parameters of the switch cabinet; the integrated controller can also monitor the switch cabinet isolated light fault and realize the line selection and phase selection of the power distribution network ground fault. This application has combined insulation fault, solitary light protection and line selection to detect the function, and the function is comprehensive in the time, and the degree of accuracy of judgement is also high.
Description
Technical Field
The application relates to the technical field of power system monitoring protection, in particular to a comprehensive monitoring protection system for insulation, arc light and line selection of a power distribution network.
Background
On the one hand, distribution network electrical equipment is the important infrastructure of guarantee reliable power supply, and the operation maintenance of other auxiliary equipment such as cubical switchboard/looped netowrk cabinet switch is mainly based on regularly carrying out insulation test detection or adopts the maintenance replacement mode after the trouble, and regular check out test set need have a power failure or the maintenance replacement mode after the trouble causes suddenly having a power failure, influences the power supply reliability, and distribution equipment is numerous, if adopt regular maintenance mode work load huge. On the other hand, the single-phase earth fault of the power distribution network frequently accounts for more than 80% of the total number of faults, the earth fault is mostly arc light fault, the arc light fault can occur on a bus and on a line, the current technology on the bus is arc light protection technology adopting detection light, the line selection protection and the tripping isolation fault occur on the line, high-resistance earth in the overhead network accounts for the majority, and the fault characteristic of the high-resistance earth fault is not obvious, so that the accuracy rate of the current comprehensive line selection is lower than 90%.
However, the insulation monitoring, arc protection and line selection protection technologies of the existing power distribution network are three technologies with different technical ideas, and the three different technical means correspond to three sets of equipment, so that the problems of inconvenient management, high cost, complex implementation, low detection sensitivity, small coverage and the like exist in the application of the three sets of equipment.
In order to solve the problems, the application provides a comprehensive monitoring and protecting system for insulation, arc light and line selection of a power distribution network.
Disclosure of Invention
The application provides a distribution network insulation, arc light, route selection integrated monitoring protection system to solve when carrying out insulation monitoring, arc light protection and trouble route selection to the distribution network, use three sets of equipment, the management is inconvenient, three sets of equipment cost are high, implement complicacy, and detectivity is low and cover face little scheduling problem.
The application provides a distribution network insulation, arc light, route selection integrated monitoring protection system, the system includes: the device comprises a pulse voltage acquisition device, a broadband current acquisition device, a power frequency voltage acquisition device and a comprehensive controller connected with the pulse voltage acquisition device, the broadband current acquisition device and the power frequency voltage acquisition device;
the pulse voltage acquisition device is arranged on the outgoing line side of each monitored switch cabinet and used for acquiring high-frequency pulse voltage signals of the switch cabinet and sending the high-frequency pulse voltage signals to the integrated controller;
the broadband current acquisition device is arranged on the outgoing line side of each monitored switch cabinet and used for acquiring a broadband zero-sequence current signal of the switch cabinet and sending the broadband zero-sequence current signal to the integrated controller;
the power frequency voltage acquisition device is connected with a switch cabinet bus and used for acquiring a power frequency voltage signal of the switch cabinet and sending the power frequency voltage signal to the integrated controller;
the integrated controller is configured to perform the steps of:
determining a high-frequency pulse voltage amplitude and a high-frequency pulse voltage phase according to the high-frequency pulse voltage signal;
carrying out filter decomposition processing on the broadband zero-sequence current signal, and determining a power frequency zero-sequence current signal and a high-frequency pulse current signal contained in the broadband zero-sequence current signal;
determining whether the switch cabinet has an insulation fault according to the high-frequency pulse voltage amplitude and the power frequency zero sequence current signal, or according to the high-frequency pulse voltage amplitude, the high-frequency pulse current signal and the power frequency zero sequence current signal, or according to the high-frequency pulse voltage amplitude, the high-frequency pulse voltage phase and the power frequency voltage signal; if yes, further judging the type of the insulation fault;
determining whether an arc fault exists on the bus equipment or not according to the high-frequency pulse voltage amplitude and the high-frequency pulse current signal; if yes, giving an arc protection early warning, and taking arc protection measures;
determining whether a line has a ground fault according to the high-frequency pulse voltage amplitude and the high-frequency pulse current signal; if yes, sending out an earth fault early warning, and taking earth fault protection measures.
Optionally, determining whether an insulation fault exists in the switch cabinet according to the high-frequency pulse voltage amplitude and the power frequency zero sequence current signal, or according to the high-frequency pulse voltage amplitude, the high-frequency pulse current signal and the power frequency zero sequence current signal, or according to the high-frequency pulse voltage amplitude, the high-frequency pulse voltage phase and the power frequency voltage signal; if yes, further judging the type of the insulation fault, including:
acquiring the maximum high-frequency pulse voltage amplitude;
when the maximum high-frequency pulse voltage amplitude is greater than or equal to a preset starting fixed value for more than two times continuously, if so, judging that the switch cabinet has an insulation fault; further judging whether the power frequency zero sequence current signal has a zero-break characteristic, if so, judging that the insulation fault type is a single-phase earth fault; if not, judging that the insulation fault type is point discharge or creeping discharge;
or, when the maximum high-frequency pulse voltage amplitude is greater than or equal to the starting fixed value for more than two times continuously, if so, judging that the switch cabinet has an insulation fault; further judging that the high-frequency pulse current signal has phase characteristics according to the power frequency zero sequence current signal, and if so, judging that the insulation fault type is a single-phase earth fault; if not, judging that the insulation fault type is point discharge or creeping discharge;
or, when the maximum high-frequency pulse voltage amplitude is greater than a preset ground fault setting value for more than two times continuously, if so, judging that the switch cabinet has an insulation fault; further judging whether the high-frequency pulse voltage phase has phase characteristics or not according to the power frequency voltage signal, and if so, judging that the insulation fault type is a single-phase earth fault; and if not, judging that the insulation fault type is point discharge or creeping discharge.
Optionally, the starting fixed value and the ground fault setting value are determined by the following method:
under the fault-free state of the system, determining the amplitude of the noise pulse voltage according to the amplitude of the high-frequency pulse voltage of each phase of each line;
determining the starting fixed value according to the noise pulse voltage amplitude;
and determining the ground fault setting value according to the starting fixed value.
Optionally, the determining whether an arc fault exists on the bus device according to the high-frequency pulse voltage amplitude, the high-frequency pulse current signal, and the power frequency voltage signal includes:
and when the maximum high-frequency pulse voltage amplitude is greater than or equal to the starting fixed value for more than two times continuously and all the high-frequency pulse current phases are in the same phase, judging that the arc fault occurs on the bus equipment.
Optionally, the determining whether a ground fault exists in the line according to the high-frequency pulse voltage amplitude, the high-frequency pulse current signal, and the power frequency voltage signal includes:
and when the maximum high-frequency pulse voltage amplitude is greater than or equal to the starting fixed value for more than two times continuously, if the phase of the high-frequency pulse current of a certain line is opposite to that of other lines, judging that the line has a ground fault.
Optionally, the determining, according to the power frequency zero sequence current signal, that the high-frequency pulse current signal has a phase characteristic includes:
obtaining phases corresponding to the maximum values of the high-frequency pulse current in two adjacent periods;
judging whether the phase corresponding to the maximum value of the high-frequency pulse current in two adjacent periods occurs in the working circuitWhen the frequency zero sequence current flows through zero, the frequency zero sequence current respectively is positioned at a preset current position, the preset current position comprises a first position and a second position relative to the power frequency zero sequence current synchronous phase, wherein: the first position is
The second position is
Optionally, the determining whether the high-frequency pulse voltage phase has a phase characteristic according to the power frequency voltage signal includes:
obtaining phases corresponding to the maximum values of the high-frequency pulse voltage in two adjacent periods;
judging whether phases corresponding to the maximum values of the high-frequency pulse voltage in two adjacent periods are respectively located at a preset voltage position, wherein the preset voltage position comprises a third position and a fourth position relative to the power frequency voltage synchronous phase, and the method comprises the following steps of: the third position is
The fourth position is as
Optionally, the pulse voltage acquiring device is a three-phase sensor, and each phase includes a coupling capacitance sensor and a detection impedance.
Optionally, the broadband current obtaining device is an electromagnetic zero-sequence current transformer, a hall current sensor or a rogowski coil.
Optionally, the power frequency voltage obtaining device is an electromagnetic voltage transformer, a photoelectric voltage transformer or a capacitor voltage transformer.
The application provides a pair of distribution network insulation, arc light, route selection integrated monitoring protection system, the system includes impulse voltage acquisition device, wide band electric current acquisition device and power frequency voltage acquisition device, and connects impulse voltage acquisition device wide band electric current acquisition device with power frequency voltage acquisition device's integrated control ware. The integrated controller is configured to monitor the insulation fault of the switch cabinet and determine the type of the insulation fault according to the acquired operation parameters of the switch cabinet; the integrated controller can also monitor the switch cabinet isolated light fault and realize the line selection and phase selection of the power distribution network ground fault. The device has the advantages that (1) the device can monitor insulation faults of the distribution equipment, including point discharge, surface discharge and earth faults, particularly high-resistance earth faults; (2) the device can monitor arc protection of the power distribution equipment; (3) the device can realize the line selection and the phase selection of the ground fault of the power distribution network. The invention integrates the functions of insulation fault, arc protection and line selection detection. Compared with the prior art and equipment, the technical method and the device of the method have the advantages of comprehensive functions, quick response, accurate judgment, high detection sensitivity and the like.
Drawings
In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an insulation, arc light and route selection comprehensive monitoring protection system of a power distribution network according to an embodiment of the present application;
fig. 2 is a schematic structural diagram of a pulse voltage acquisition device according to an embodiment of the present application;
fig. 3 is a flowchart illustrating an execution step of an integrated controller in an insulation, arc light and route selection integrated monitoring and protection system of a power distribution network according to an embodiment of the present application;
fig. 4 is a waveform diagram of a high-frequency pulse voltage detection result provided in the embodiment of the present application;
fig. 5 is a waveform diagram of a fault power frequency zero-sequence current component detection result provided in the embodiment of the present application;
fig. 6 is a waveform diagram of a fault high-frequency zero-sequence current component detection result provided in the embodiment of the present application;
fig. 7 is a phase distribution diagram of the high-frequency pulse voltage provided by the embodiment of the present application.
Illustration of the drawings: 11-a coupled capacitive sensor; 12-detect impedance.
Detailed Description
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 some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.
The embodiment of the application provides a distribution network insulation, arc light, selection line integrated monitoring protection system, specifically refer to the structural schematic diagram of a distribution network insulation, arc light, selection line integrated monitoring protection system of fig. 1.
The power distribution network insulation, arc light and line selection comprehensive monitoring and protection system comprises a pulse voltage acquisition device, a broadband current acquisition device, a power frequency voltage acquisition device, a display module and a comprehensive controller connected with the pulse voltage acquisition device, the broadband current acquisition device, the power frequency voltage acquisition device and the display module. And the display module is used for displaying the data on a screen after receiving the data acquired by the controller and providing the data for field workers.
The pulse voltage acquisition device is arranged on the outgoing line side of each monitored switch cabinet and used for acquiring high-frequency pulse voltage signals of the switch cabinet and sending the high-frequency pulse voltage signals to the integrated controller.
Further, referring specifically to fig. 2, the pulse voltage acquisition device is a three-phase sensor, and each phase of the three-phase sensor includes a coupling capacitance sensor 11 and a detection impedance 12. The coupling capacitance sensor 11 can be any type of capacitor with a capacitance value in the range of 10pF to 1 nF. The detection impedance 12 is a capacitor, an inductor, a resistor or any combination of the three, and the working frequency range is as follows: 10 kHz-20 MHz.
The broadband current acquisition device is arranged on the outgoing line side of each monitored switch cabinet and used for acquiring broadband zero-sequence current signals of the switch cabinet and sending the broadband zero-sequence current signals to the integrated controller.
Further, the broadband current acquisition device is an electromagnetic zero-sequence current transformer, a hall current sensor, a rogowski coil or any other sensor capable of detecting the zero-sequence current of the line. The working frequency band is as follows: 20Hz to 20 MHz.
And the power frequency voltage acquisition device is connected with a switch cabinet bus and used for acquiring a switch cabinet power frequency voltage signal and sending the power frequency voltage signal to the integrated controller.
Further, the power frequency voltage acquisition device is an electromagnetic voltage transformer, a photoelectric voltage transformer, a capacitor voltage transformer or any other sensor capable of detecting the power frequency voltage of the line.
Referring to fig. 3, a flowchart of the execution steps of the integrated controller provided in this embodiment is shown.
And step S101, determining the amplitude and the phase of the high-frequency pulse voltage according to the high-frequency pulse voltage signal.
And S102, performing filter decomposition processing on the broadband zero-sequence current signal, and determining a power frequency zero-sequence current signal and a high-frequency pulse current signal which are contained in the broadband zero-sequence current signal.
And S103, determining whether the switch cabinet has an insulation fault according to the high-frequency pulse voltage amplitude and the power frequency zero sequence current signal, or according to the high-frequency pulse voltage amplitude, the high-frequency pulse current signal and the power frequency zero sequence current signal, or according to the high-frequency pulse voltage amplitude, the high-frequency pulse voltage phase and the power frequency voltage signal. If yes, further judging the type of the insulation fault.
In some embodiments of the present application, in a state where a system is not in fault, recording each phase of high-frequency pulse voltage signal of each line as a noise pulse voltage amplitude Uc, where the noise pulse voltage amplitude Uc is a background noise signal. The start-up constant Uq was further determined to be 1.5 Uc. And further determining that the ground fault setting value Ud of the high-frequency pulse voltage is 2Uq, or setting the ground fault setting value Ud according to a pulse voltage amplitude generated by the ground fault during the test.
And acquiring the maximum high-frequency pulse voltage amplitude.
And when the maximum high-frequency pulse voltage amplitude is greater than or equal to a preset starting fixed value for more than two times continuously, if so, judging that the switch cabinet has an insulation fault. And further judging whether the power frequency zero sequence current signal has a zero-break characteristic, and if so, judging that the insulation fault type is a single-phase earth fault. And if not, judging that the insulation fault type is point discharge or creeping discharge.
Referring to fig. 4 and 5 in particular, as can be seen from the waveform diagrams of the detection results of the high-frequency pulse voltage in fig. 4, at least 5 high-frequency voltage signals are detected by the A, B, C three phases at 4.5ms, 5.5ms, 14.5ms, 15.5ms and 17ms of a power frequency period, wherein the amplitudes of the two pulse signals at 5.5ms and 15.5ms are maximum, the amplitude of the a-phase is about 5V, the amplitude of the B-phase is about 3V, and the amplitude of the C-phase is about 5V. The requirement that the amplitude of 2 or more maximum pulse voltages is larger than the starting constant value of the pulse voltage amplitude by 0.5V in the insulation fault monitoring method is met, and whether the power frequency current zero-break characteristic exists or not is further judged.
In fig. 5, the horizontal axis represents time/s and the vertical axis represents amplitude/a. As can be seen from the waveform diagram of the detection result of the power frequency zero-sequence current component of the fault shown in fig. 5, the fault current has a zero-rest characteristic at the zero-crossing point, and the zero-rest time is about 1 ms.
And in conclusion, the system is judged to have the single-phase earth fault.
Or, when the maximum high-frequency pulse voltage amplitude is greater than or equal to the starting fixed value for more than two times continuously, if so, the switch cabinet is judged to have an insulation fault. And further judging that the high-frequency pulse current signal has phase characteristics according to the power frequency zero sequence current signal, and if so, judging that the insulation fault type is a single-phase earth fault. And if not, judging that the insulation fault type is point discharge or creeping discharge.
Further, the determining that the high-frequency pulse current signal has a phase characteristic according to the power frequency zero sequence current signal includes:
firstly, the phase corresponding to the maximum value of the high-frequency pulse current in two adjacent periods is obtained.
Judging whether the phase corresponding to the maximum value of the high-frequency pulse current in two adjacent periods occurs when the power frequency zero sequence current passes through zero, and respectively locating at a preset current position, wherein the preset current position comprises a first position and a second position relative to the power frequency zero sequence current synchronous phase, and the method comprises the following steps: the phase value of the first position is
The phase value of the second position is
Referring to fig. 4 and 6 in particular, as can be seen from the waveform diagrams of the detection results of the high-frequency pulse voltages in fig. 4, at least 5 high-frequency voltage signals are detected by the A, B, C three phases at 4.5ms, 5.5ms, 14.5ms, 15.5ms and 17ms of a power frequency period, wherein the amplitudes of the two pulse signals at 5.5ms and 15.5ms are maximum, the amplitude of the a-phase is about 5V, the amplitude of the B-phase is about 3V, and the amplitude of the C-phase is about 5V. The requirement that the amplitude of 2 or more maximum pulse voltages is larger than the starting constant value of the pulse voltage amplitude by 0.5V in the insulation fault monitoring method is met, and the phase characteristics of the high-frequency pulse current are further judged.
In fig. 6, the horizontal axis represents time/s and the vertical axis represents amplitude/a. As can be seen from the waveform diagram of the detection result of the high-frequency zero-sequence current component of the fault shown in FIG. 6, the arc reignition generates high-frequency pulse current, the maximum value of which occurs when the power frequency current passes through zero, and the phase is distributed at
And
within the range.
In conclusion, the system is judged to have the single-phase earth fault.
Or, when the maximum high-frequency pulse voltage amplitude is greater than a preset ground fault setting value for more than two times continuously, if so, judging that the switch cabinet has an insulation fault. And further judging whether the high-frequency pulse voltage phase has phase characteristics or not according to the power frequency voltage signal, and if so, judging that the insulation fault type is a single-phase earth fault. And if not, judging that the insulation fault type is point discharge or creeping discharge.
Further, the determining whether the high-frequency pulse voltage phase has a phase characteristic according to the power frequency voltage signal includes:
firstly, the phase corresponding to the maximum value of the high-frequency pulse voltage in two adjacent periods is obtained.
Judging whether phases corresponding to the maximum values of the high-frequency pulse voltage in two adjacent periods are respectively located at a preset voltage position, wherein the preset voltage position comprises a third position and a fourth position relative to the power frequency voltage synchronous phase, and the method comprises the following steps of: the phase value of the third position is
The phase value of the fourth position is
Referring to fig. 4 and 7 in particular, as can be seen from the waveform diagrams of the detection results of the high-frequency pulse voltage in fig. 4, at least 5 high-frequency voltage signals are detected at 4.5ms, 5.5ms, 14.5ms, 15.5ms and 17ms of a power frequency period, wherein the amplitudes of the two pulse signals at 5.5ms and 15.5ms are maximum, the amplitude of the a-phase is about 5V, the amplitude of the B-phase is about 3V, and the amplitude of the C-phase is about 5V. The requirement that 2 or more maximum pulse voltage signal amplitudes are larger than the ground fault setting value by 1V in the insulation fault monitoring method is met, and the phase characteristics of the high-frequency pulse voltage are further judged.
In fig. 7, the horizontal axis represents time/ms and the vertical axis represents voltage/V. As can be seen from the phase distribution diagram of the high-frequency pulse voltage in fig. 7, the maximum values of the high-frequency pulse voltage are respectively distributed at the positions of 5.5ms and 15.5ms in the power frequency cycle, and the relative power frequency voltage phases are 99 ° and 279 °, which satisfy the phase characteristics of 90 ° ± 10 ° and 270 ° ± 10 °.
In conclusion, the system is judged to have a ground fault.
And step S104, determining whether an arc fault exists on the bus equipment or not according to the high-frequency pulse voltage amplitude and the high-frequency pulse current signal. If yes, an arc protection early warning is sent out, and arc protection measures are taken.
Further, when the maximum high-frequency pulse voltage amplitude is greater than or equal to the starting fixed value for more than two times continuously, and all the high-frequency pulse current phases are in the same phase, it is determined that an arc fault occurs on the bus equipment, an arc protection early warning is sent, and an arc extinction technology is adopted or a power side switch is tripped.
And step S105, determining whether the line has a ground fault according to the high-frequency pulse voltage amplitude and the high-frequency pulse current signal. If yes, sending out an earth fault early warning, and taking earth fault protection measures.
Further, when the maximum high-frequency pulse voltage amplitude is greater than or equal to the starting fixed value for more than two times continuously, if the phase of the high-frequency pulse current of a certain line is opposite to that of other lines, the line is judged to have a ground fault, and early warning of the ground fault of the line is sent out, and an arc extinction technology is adopted or the line switch is tripped.
According to the technical scheme, the utility model provides a pair of distribution network insulation, arc light, selection line integrated monitoring protection system, the system includes impulse voltage acquisition device, wide band electric current acquisition device and power frequency voltage acquisition device, and connects impulse voltage acquisition device wide band electric current acquisition device with power frequency voltage acquisition device's comprehensive control ware.
In practical application, the integrated controller is configured to monitor insulation faults of the switch cabinet and determine the types of the insulation faults according to the acquired operation parameters of the switch cabinet; the integrated controller can also monitor the switch cabinet isolated light fault and realize the line selection and phase selection of the power distribution network ground fault. The device has the advantages that (1) the device can monitor insulation faults of the distribution equipment, including point discharge, surface discharge and earth faults, particularly high-resistance earth faults; (2) the device can monitor arc protection of the power distribution equipment; (3) the device can realize the line selection and the phase selection of the ground fault of the power distribution network. The invention integrates the functions of insulation fault, arc protection and line selection detection. Compared with the prior art and equipment, the technical method and the device of the method have the advantages of comprehensive functions, quick response, accurate judgment, high detection sensitivity and the like.
The present application has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to limit the application. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the presently disclosed embodiments and implementations thereof without departing from the spirit and scope of the present disclosure, and these fall within the scope of the present disclosure. The protection scope of this application is subject to the appended claims.
Claims (10)
1. The utility model provides a distribution network insulation, arc light, line selection integrated monitoring protection system which characterized in that, the system includes: the device comprises a pulse voltage acquisition device, a broadband current acquisition device, a power frequency voltage acquisition device and a comprehensive controller connected with the pulse voltage acquisition device, the broadband current acquisition device and the power frequency voltage acquisition device;
the pulse voltage acquisition device is arranged on the outgoing line side of each monitored switch cabinet and used for acquiring high-frequency pulse voltage signals of the switch cabinet and sending the high-frequency pulse voltage signals to the integrated controller;
the broadband current acquisition device is arranged on the outgoing line side of each monitored switch cabinet and used for acquiring a broadband zero-sequence current signal of the switch cabinet and sending the broadband zero-sequence current signal to the integrated controller;
the power frequency voltage acquisition device is connected with a switch cabinet bus and used for acquiring a power frequency voltage signal of the switch cabinet and sending the power frequency voltage signal to the integrated controller;
the integrated controller is configured to perform the steps of:
determining a high-frequency pulse voltage amplitude and a high-frequency pulse voltage phase according to the high-frequency pulse voltage signal;
carrying out filter decomposition processing on the broadband zero-sequence current signal, and determining a power frequency zero-sequence current signal and a high-frequency pulse current signal contained in the broadband zero-sequence current signal;
determining whether the switch cabinet has an insulation fault according to the high-frequency pulse voltage amplitude and the power frequency zero sequence current signal, or according to the high-frequency pulse voltage amplitude, the high-frequency pulse current signal and the power frequency zero sequence current signal, or according to the high-frequency pulse voltage amplitude, the high-frequency pulse voltage phase and the power frequency voltage signal; if yes, further judging the type of the insulation fault;
determining whether an arc fault exists on the bus equipment or not according to the high-frequency pulse voltage amplitude and the high-frequency pulse current signal; if yes, giving an arc protection early warning, and taking arc protection measures;
determining whether a line has a ground fault according to the high-frequency pulse voltage amplitude and the high-frequency pulse current signal; if yes, sending out an earth fault early warning, and taking earth fault protection measures.
2. The comprehensive insulation, arc light and route selection monitoring and protecting system for the power distribution network according to claim 1, wherein whether insulation faults exist in a switch cabinet is determined according to the high-frequency pulse voltage amplitude and the power frequency zero sequence current signal, or according to the high-frequency pulse voltage amplitude, the high-frequency pulse current signal and the power frequency zero sequence current signal, or according to the high-frequency pulse voltage amplitude, the high-frequency pulse voltage phase and the power frequency voltage signal; if yes, further judging the type of the insulation fault, including:
acquiring the maximum high-frequency pulse voltage amplitude;
when the maximum high-frequency pulse voltage amplitude is greater than or equal to a preset starting fixed value for more than two times continuously, if so, judging that the switch cabinet has an insulation fault; further judging whether the power frequency zero sequence current signal has a zero-break characteristic, if so, judging that the insulation fault type is a single-phase earth fault; if not, judging that the insulation fault type is point discharge or creeping discharge;
or, when the maximum high-frequency pulse voltage amplitude is greater than or equal to the starting fixed value for more than two times continuously, if so, judging that the switch cabinet has an insulation fault; further judging that the high-frequency pulse current signal has phase characteristics according to the power frequency zero sequence current signal, and if so, judging that the insulation fault type is a single-phase earth fault; if not, judging that the insulation fault type is point discharge or creeping discharge;
or, when the maximum high-frequency pulse voltage amplitude is greater than a preset ground fault setting value for more than two times continuously, if so, judging that the switch cabinet has an insulation fault; further judging whether the high-frequency pulse voltage phase has phase characteristics or not according to the power frequency voltage signal, and if so, judging that the insulation fault type is a single-phase earth fault; and if not, judging that the insulation fault type is point discharge or creeping discharge.
3. The integrated insulation, arc light, route selection monitoring and protection system for a power distribution network of claim 2, wherein the starting constant and the ground fault setting are determined by:
under the fault-free state of the system, determining the amplitude of the noise pulse voltage according to the amplitude of the high-frequency pulse voltage of each phase of each line;
determining the starting fixed value according to the noise pulse voltage amplitude;
and determining the ground fault setting value according to the starting fixed value.
4. The integrated monitoring and protection system for insulation, arc light and route selection of a power distribution network according to claim 2, wherein the determining whether an arc light fault exists on the bus equipment according to the high-frequency pulse voltage amplitude, the high-frequency pulse current signal and the power frequency voltage signal comprises:
and when the maximum high-frequency pulse voltage amplitude is greater than or equal to the starting fixed value for more than two times continuously and all the high-frequency pulse current phases are in the same phase, judging that the arc fault occurs on the bus equipment.
5. The integrated monitoring and protection system for insulation, arc light and route selection of a power distribution network of claim 2, wherein the determining whether the line has the ground fault according to the high-frequency pulse voltage amplitude, the high-frequency pulse current signal and the power frequency voltage signal comprises:
and when the maximum high-frequency pulse voltage amplitude is greater than or equal to the starting fixed value for more than two times continuously, if the phase of the high-frequency pulse current of a certain line is opposite to that of other lines, judging that the line has a ground fault.
6. The comprehensive insulation, arc light and route selection monitoring and protecting system for the power distribution network according to claim 2, wherein the step of judging that the high-frequency pulse current signal has the phase characteristic according to the power frequency zero-sequence current signal comprises the steps of:
obtaining phases corresponding to the maximum values of the high-frequency pulse current in two adjacent periods;
judging whether the phase corresponding to the maximum value of the high-frequency pulse current in two adjacent periods occurs when the power frequency zero sequence current passes through zero, and respectively locating at a preset current position, wherein the preset current position comprises a first position and a second position relative to the power frequency zero sequence current synchronous phase, and the method comprises the following steps: the first position is
The second position is
7. The integrated monitoring and protection system for insulation, arc light and wire selection of the power distribution network of claim 2, wherein the determining whether the phase of the high-frequency pulse voltage has the phase characteristic according to the power frequency voltage signal comprises:
obtaining phases corresponding to the maximum values of the high-frequency pulse voltage in two adjacent periods;
judging whether phases corresponding to the maximum values of the high-frequency pulse voltage in two adjacent periods are respectively located at a preset voltage position, wherein the preset voltage position comprises a third position and a fourth position relative to the power frequency voltage synchronous phase, and the method comprises the following steps of: the third position is
The fourth position is as
8. The comprehensive insulation, arc light and route selection monitoring and protecting system for the power distribution network as claimed in claim 1, wherein the pulse voltage acquisition device is a three-phase sensor, and each phase comprises a coupling capacitance sensor and a detection impedance.
9. The comprehensive insulation, arc light and route selection monitoring and protecting system for the power distribution network according to claim 1, wherein the broadband current obtaining device is an electromagnetic zero-sequence current transformer, a hall current sensor or a rogowski coil.
10. The comprehensive insulation, arc light and route selection monitoring and protecting system for the power distribution network according to claim 1, wherein the power frequency voltage acquisition device is an electromagnetic voltage transformer, a photoelectric voltage transformer or a capacitor voltage transformer.
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