CN111220884A - Method and system for determining oscillation operation wave loop parameters based on cable closing overvoltage - Google Patents

Method and system for determining oscillation operation wave loop parameters based on cable closing overvoltage Download PDF

Info

Publication number
CN111220884A
CN111220884A CN202010044094.8A CN202010044094A CN111220884A CN 111220884 A CN111220884 A CN 111220884A CN 202010044094 A CN202010044094 A CN 202010044094A CN 111220884 A CN111220884 A CN 111220884A
Authority
CN
China
Prior art keywords
cable
impedance
parameters
formula
calculating
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010044094.8A
Other languages
Chinese (zh)
Inventor
赵学风
林涛
段玮
孙浩飞
蒲路
琚泽立
候喆
王辰曦
李嘉明
邓军波
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
State Grid Corp of China SGCC
Xian Jiaotong University
Electric Power Research Institute of State Grid Shaanxi Electric Power Co Ltd
Original Assignee
State Grid Corp of China SGCC
Xian Jiaotong University
Electric Power Research Institute of State Grid Shaanxi Electric Power Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by State Grid Corp of China SGCC, Xian Jiaotong University, Electric Power Research Institute of State Grid Shaanxi Electric Power Co Ltd filed Critical State Grid Corp of China SGCC
Priority to CN202010044094.8A priority Critical patent/CN111220884A/en
Publication of CN111220884A publication Critical patent/CN111220884A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • 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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • 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
    • G01R31/14—Circuits therefor, e.g. for generating test voltages, sensing circuits

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Resistance Or Impedance (AREA)

Abstract

The invention discloses a method and a system for determining parameters of an oscillating operation wave loop based on cable closing overvoltage, which comprises the following steps: acquiring geometric parameters of a cable to be tested and electrical parameters of a metal conductor, an insulating medium and a laying environment of the cable to be tested; acquiring three-phase short-circuit current at a bus connected with a cable to be tested, and calculating to obtain equivalent impedance of a feed network; calculating to obtain cable impedance and admittance parameters according to the obtained geometric parameters and electrical parameters of the cable to be tested; calculating to obtain the natural resonant frequency and the attenuation constant of the cable according to the obtained equivalent impedance of the feed network, the impedance of the cable and the admittance parameters; and determining parameters of elements in the oscillatory wave loop according to the obtained natural resonant frequency and attenuation constant of the cable. The invention can save time and labor cost; the loop parameters of the oscillatory wave generator required in the test can be determined, and the accuracy of the test result is improved.

Description

Method and system for determining oscillation operation wave loop parameters based on cable closing overvoltage
Technical Field
The invention belongs to the technical field of high voltage and insulation, and particularly relates to a method and a system for determining parameters of an oscillating operating wave loop based on cable closing overvoltage.
Background
The high-voltage power cable transmits and distributes electric energy, and is applied to urban backbone networks, power plant delivery, internal power supply of large industrial and mining enterprises and underwater power transmission lines crossing rivers and sea. In domestic and foreign power transmission systems, the weight average occupied by cables gradually increases. The high-voltage power cable comprises cables of 6-500 kV in various voltage classes. The cable can be divided into oil-impregnated paper, rubber and plastic, crosslinked polyethylene cable, etc. according to the insulating material; it can be classified into ac and dc cables according to the type of transmission current.
The plastic cable has simple structure, convenient manufacture, light weight and convenient laying and installation, is not limited by laying fall, is widely used as a medium-low voltage cable, and can replace a viscous impregnated oilpaper cable in the future, but the cable has the fatal defect of treeing breakdown phenomenon, so that the application of the cable in higher voltage grade is limited.
The polyvinyl chloride cable has low price and wide application range, but has large dielectric loss, and is generally used for systems below 10 kV. The polyethylene cable can be used for a higher voltage system, but the working temperature is too low (only about 70 ℃), the corona resistance is poor, and the working voltage of the international currently-made polyethylene cable is 285kV at most. The crosslinked polyethylene cable is characterized in that an extruded polyethylene insulating layer is subjected to a crosslinking process, polyethylene molecules are changed into molecules with a net structure from linear molecules, the maximum working temperature of a crosslinked polyethylene cable conductor can reach 90 ℃, the voltage reaches 500kV level, the mechanical strength is high, and most of the existing power cables are crosslinked polyethylene cables.
In recent years, when the intermediate joint of the extra-high voltage cable line is subjected to a closing operation, breakdown accidents of the intermediate joint of the cable sometimes occur, and fire accidents of the cable line and a channel are caused, and the cable accidents cause great economic losses and seriously affect the safe and reliable operation of a high-voltage power transmission network. The breakdown event of the intermediate joint of the cable of more than 110kV caused by the overvoltage operation occurs in Beijing, Xian, Chengdu, Zhuhai, Shanghai and other areas, and even some lines still cause the breakdown of the intermediate joint while closing the switch after completion tests are carried out.
Transient voltages in ultra-high voltage cables can reach kilohertz, and one transient process may include thousands of impulse voltages with continuous oscillation attenuation. The voltage acts on the destruction of solid insulation just like cutting wood, if take a big sword to cut wood, even the sword is very sharp, and with very big strength moreover, wood also is hardly cut bad, and take a saw, even the sawtooth is not so big, also can saw the wood very fast.
The traditional voltage withstand test and the damage of transient impact to insulation are the same as the difference between a large knife and a saw, and the voltage withstand test cannot truly reflect the capability of resisting transient overvoltage during operation of the insulation of a cable body and accessories. In general laboratory tests, the cable accessories and the cable body are subjected to pressure-resistant tests by adopting standard operation shock waves. In order to accurately study the operation impact which the cable insulation material bears in actual operation, an oscillatory wave generating device is applied to apply high-frequency oscillatory waves to the cable insulation material or cable accessories, and the insulation tolerance of the cable insulation material or the cable accessories is studied. Therefore, the characteristics of the transient overvoltage waveform that may appear in the cable line and its destructive effect on the cable insulation must be studied to be clear.
The dominant frequency of the transient closing operation overvoltage is directly determined by the natural resonant frequency of the cable line, namely the dominant frequency of the overvoltage is the same as the natural resonant frequency of the line. In studying the effect of the operational shock on the defect development of the cable insulation, the oscillating operating wave applied in the insulating material needs to maintain the frequency characteristic and the voltage attenuation consistent with the actual closing operating voltage. In the oscillatory wave generator, the frequency and attenuation of the generated oscillatory wave are determined by the parameters of resistance, inductance and capacitance in the generating circuit. Therefore, before performing the test, it is first necessary to determine the dominant frequency and voltage attenuation of the transient operating overvoltage, so as to determine the parameters of the components in the oscillatory wave generating device loop.
In summary, a method for determining parameters of an oscillating operating wave loop based on a cable closing overvoltage is needed.
Disclosure of Invention
The invention aims to provide a method and a system for determining parameters of an oscillating operating wave loop based on cable closing overvoltage so as to solve one or more technical problems. The invention can save time and labor cost; the loop parameters of the oscillatory wave generator required in the test can be determined, and the accuracy of the test result is improved.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention discloses a method for determining parameters of an oscillating operation wave loop based on cable closing overvoltage, which comprises the following steps:
step 1, acquiring and obtaining geometric parameters of a cable to be tested, and electrical parameters of a metal conductor, an insulating medium and a laying environment of the cable to be tested;
step 2, acquiring three-phase short-circuit current at a bus connected with a cable to be tested, and calculating to obtain equivalent impedance of a feed network;
step 3, calculating to obtain cable impedance and admittance parameters according to the geometric parameters and the electrical parameters of the cable to be tested obtained in the step 1;
step 4, calculating to obtain the natural resonant frequency and the attenuation constant of the cable according to the equivalent impedance of the feed network obtained in the step 2 and the impedance and the admittance parameters of the cable obtained in the step 3;
step 5, determining parameters of elements in the oscillatory wave loop according to the natural resonant frequency and the attenuation constant of the cable obtained in the step 4;
in step 2, the feed network equivalent impedance calculation formula is as follows:
Figure BDA0002368754760000031
in the formula, ZSIs the equivalent impedance of the feed network; u shapeNRated voltage for the bus; i iskAcquiring three-phase short-circuit current; omega is angular frequency; l isSIs the equivalent inductance parameter of the system.
The invention discloses a system for determining parameters of an oscillating operation wave loop based on cable closing overvoltage, which comprises:
the cable geometric and electrical parameter acquisition module is used for acquiring and acquiring geometric parameters of a cable to be tested and electrical parameters of a metal conductor, an insulating medium and a laying environment of the cable to be tested;
the system equivalent impedance calculation module is used for acquiring and obtaining three-phase short-circuit current at a bus connected with the cable to be tested and calculating to obtain equivalent impedance of the feed network;
the cable distribution line parameter calculation module is used for calculating and obtaining cable impedance and admittance parameters according to the geometric parameters and the electrical parameters of the cable to be tested, which are obtained by the cable geometric and electrical parameter acquisition module;
the cable natural resonant frequency calculation module is used for calculating and obtaining a cable natural resonant frequency and an attenuation constant according to the feed network equivalent impedance obtained by the system equivalent impedance calculation module and the cable impedance and admittance parameters obtained by the cable distribution line parameter calculation module;
the oscillation operation wave generation device loop parameter calculation module is used for determining parameters of elements in the oscillation wave loop according to the natural resonant frequency and the attenuation constant of the cable obtained by the cable natural resonant frequency calculation module;
in the system equivalent impedance calculation module, the feed network equivalent impedance calculation formula is as follows:
Figure BDA0002368754760000041
in the formula, ZSIs the equivalent impedance of the feed network; u shapeNRated voltage for the bus; i iskAcquiring three-phase short-circuit current; omega is angular frequency; l isSIs the equivalent inductance parameter of the system.
Compared with the prior art, the invention has the following beneficial effects:
the method for determining the parameters of the oscillating operation wave loop can determine the element parameters of the oscillating wave loop extremely accurately on the basis of the actual transient voltage frequency and attenuation of a cable line in the closing process, thereby generating a test waveform consistent with the actual transient overvoltage characteristic. When the frequency and the attenuation parameters of the transient closing overvoltage are determined, the calculation steps of the overvoltage frequency are optimized to a great extent only by collecting the self geometric electrical parameters of the cable line and the short-circuit current of the bus, and the calculation accuracy of the dominant overvoltage frequency and the attenuation constant is improved. The oscillation test waveform generated by the oscillation operation loop can effectively research the damage effect of transient overvoltage impact on the insulating material in the operation process of the cable.
The system can obtain the dominant frequency of the transient closing overvoltage of the cable line only through theoretical calculation without field test measurement and computer simulation, and can save time and labor cost; the dominant frequency of the transient overvoltage and the voltage attenuation of the tested cable are obtained through calculation, so that the loop parameters of the oscillatory wave generator required in the test can be determined, and the accuracy of the test result is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below; it is obvious that the drawings in the following description are some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
Fig. 1 is a schematic block diagram of a flow of a method for determining parameters of an oscillating operating wave loop based on a cable closing overvoltage according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a cable impedance loop in a method for determining parameters of an oscillating operating wave loop based on a cable closing overvoltage according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a single-phase single-core cable mode domain current loop in a method for determining parameters of an oscillating operation wave loop based on a cable closing overvoltage according to an embodiment of the present invention;
fig. 4 is a schematic circuit diagram of a circuit with equivalent circuit values considering a distribution parameter of power supply impedance in a method for determining a loop parameter of an oscillating operating wave based on a cable closing overvoltage according to an embodiment of the present invention;
fig. 5 is an equivalent circuit schematic diagram of a loop of a oscillatory wave generator in a method for determining parameters of a loop of an oscillatory operating wave based on a cable closing overvoltage according to an embodiment of the present invention.
Detailed Description
In order to make the purpose, technical effect and technical solution of the embodiments of the present invention clearer, the following clearly and completely describes the technical solution of the embodiments of the present invention with reference to the drawings in the embodiments of the present invention; it is to be understood that the described embodiments are only some of the embodiments of the present invention. Other embodiments, which can be derived by one of ordinary skill in the art from the disclosed embodiments without inventive faculty, are intended to be within the scope of the invention.
Referring to fig. 1, a method for determining a loop parameter of an oscillating operating wave based on a cable closing overvoltage according to an embodiment of the present invention includes the following steps:
step 1, acquiring geometric parameters of a cable, and electrical parameters of a metal conductor, an insulating medium and a laying environment.
Transient voltages in different cable lines have different frequency characteristics, and the difference between different cables is represented by different geometric dimensions and different insulating materials and metal conductor materials. The difference of geometric and electrical characteristics of different lines can be represented at a theoretical level by calculating impedance and admittance parameters in the form of distribution parameters of the cable.
Optionally, for the high-voltage single-core power cable, the first geometric parameters of the cable to be collected include: the cable comprises a cable metal wire core radius, a main insulation outer radius, a metal protection layer outer radius, an outer insulation outer radius and a cable laying depth. Then, the electrical parameters of the metal conductor material, the insulating medium and the laying environment need to be collected, and the method specifically comprises the following steps: resistivity and magnetic permeability of the metal conductor; the dielectric constant and the magnetic permeability of the insulating medium; resistivity of the laying environment.
Optionally, the electrical parameters of the metal conductor, the insulating medium and the laying environment to be collected include: the cable comprises a cable metal core, a main insulation dielectric constant, a metal sheath layer, an external insulation dielectric constant and a laying soil resistivity.
And 2, collecting three-phase short-circuit current at a bus connected with the cable to be researched to obtain the equivalent impedance of the feed network.
The dominant frequency of the transient oscillation voltage is not only influenced by the impedance and admittance parameters of the line, but also influenced by the system impedance. Different feed networks exhibit different equivalent impedances. The equivalent impedance of the system network can be calculated through the short-circuit current at the bus, so that the short-circuit current is necessary to be collected.
According to the three-phase short-circuit current at the bus, the equivalent impedance calculation formula of the feed network is as follows:
Figure BDA0002368754760000061
in the formula, ZSIs the equivalent impedance of the feed system network; u shapeNRated voltage for the bus; i iskThree-phase short-circuit current is acquired; omega is angular frequency; l isSIs the equivalent inductance parameter of the system.
And 3, calculating impedance and admittance parameters of the cable according to the geometric and material electrical parameters of the cable obtained in the step 1.
In step 3, when calculating the impedance parameters of the cable, adopting an accurate surface impedance calculation mode combined with a Bessel function;
the specific steps of the cable impedance calculation comprise:
step 3.1, calculating the internal surface impedance and the external surface impedance of each metal conductor;
step 3.2, calculating the insulation equivalent impedance of the insulation medium;
3.3, calculating equivalent impedance of the laid soil;
and 3.4, calculating the equivalent impedance of the cable based on the surface impedance, the insulation impedance and the soil impedance.
In step 3.1, the calculation formula of the surface impedance of each metal conductor is as follows:
outer surface impedance Z of cable core conductorCouterThe calculation formula is as follows:
Figure BDA0002368754760000071
in the formula, ρcIs the resistivity of the core conductor; r1Is the radius of the cable core; i is0And I1First-class Bessel functions of 0 order and 1 order respectively; m iscThe reciprocal of the penetration depth of the wire core is calculated by the following formula:
Figure BDA0002368754760000072
in the formula, mucThe magnetic conductivity of the core conductor;
the calculation formula of the inner surface impedance and the outer surface impedance of the metal protective layer is as follows:
Figure BDA0002368754760000073
Figure BDA0002368754760000074
in the formula, ρsIs the resistivity of the core conductor; r2The outer radius of the primary insulation; r3The outer radius of the metal protective layer; k0And K1A second class of Bessel functions of order 0 and order 1, respectively; m issThe reciprocal of the skin depth of the metal passivation layer is calculated by the following formula:
Figure BDA0002368754760000075
in the formula, musIs the permeability of the metal cladding.
The calculation formula of the mutual impedance between the inner surface and the outer surface of the metal protective layer is as follows:
Figure BDA0002368754760000076
the further improvement of the invention is that in step 3.2, the calculation formula of the insulation resistance of the insulation medium is as follows:
Figure BDA0002368754760000081
Figure BDA0002368754760000082
in the formula, ZCSinsulThe insulation resistance of the main insulation between the wire core and the metal protective layer; zSGinsulThe external insulation equivalent impedance at the periphery of the metal protective layer; r4An outer radius of the outer insulation; mu.sinsMagnetic permeability of the main insulation; mu.sins2The permeability of the outer insulation.
In step 3.3, the calculation formula of the soil in the laying environment is as follows:
Figure BDA0002368754760000083
in the formula, Z0Equivalent impedance for laying soil; rhoeIs the soil resistivity; r4An outer radius of the outer insulation; h isaThe laying depth of the cable is defined; m iseThe reciprocal of the soil penetration depth is calculated by the formula:
Figure BDA0002368754760000084
in the formula, mueFor the permeability of the soil.
Referring to FIG. 2, for a single-phase cable, the impedance parameters include the core conductor outer surface impedance ZCouterMain insulation medium impedance ZCSinsulThe impedance Z of the inner surface of the metal-clad conductorSinnerImpedance Z with outer surfaceSouterOuter protective layer insulation medium impedance ZSGinsul。ZCouter、ZCSinsulAnd ZSinnerForming a current loop, while ZSouter、ZSGinsulAnd earth soil impedance Z0Forming another current loop with a mutual impedance between the two loops, i.e. ZSmutual。
The self-impedance formula for a core conductor in the impedance of a cable can be characterized as:
Z11＝ZCouter+ZCSinsul+ZSinner+ZSouter+ZSGinsul+Z0-2ZSmutual
the self-impedance calculation formula of the metal sheath conductor is as follows:
Z22＝ZSouter+ZSGinsul+Z0
mutual impedance Z between core conductor and metal12The calculation formula of (2) is as follows:
Z12＝ZSouter+ZSGinsul+Z0-ZSmutual
after obtaining the components in the impedance matrix, the cable impedance [ Z ]cable]The calculation formula of (2) is as follows:
Figure BDA0002368754760000091
the calculation of the admittance matrix needs to be based on the calculation of the potential coefficient, and the potential coefficient matrix of the single-phase power cable is as follows:
Figure BDA0002368754760000092
in the formula, [ P ]cable]Is a potential coefficient matrix of the cable; p11The potential coefficient of the core conductor; p22The potential coefficient of the metal protective layer; p12Is the mutual potential coefficient between the wire core and the metal protection layer.
Potential coefficient P11The calculation formula of (2) is as follows:
Figure BDA0002368754760000093
in the formula, epsilon0Represents the vacuum dielectric constant; epsilon1The dielectric constant of the main insulation of the cable; epsilon2The dielectric constant of the outer insulation.
Potential coefficient P22The calculation formula of (2) is as follows:
Figure BDA0002368754760000094
by solving the potential coefficient matrix, the admittance parameter matrix of the cable can be further calculated, and the calculation formula is as follows:
[Ycable]＝jω·[Pcable]-1
wherein [ Y ] iscable]Representing the admittance matrix of the cable.
And 4, calculating the natural resonant frequency and the attenuation constant of the cable according to the equivalent impedance of the feed network, the impedance of the cable and the admittance parameters obtained in the steps 2 and 3.
In step 4, based on the impedance and admittance parameters of the cable, the dominant frequency of the closing overvoltage and the attenuation constant of the waveform can be calculated.
The basic steps of determining the dominant frequency and attenuation constant of the overvoltage waveform include:
step 4.1, further determining parameters of the coaxial mode loop according to the cable impedance and the admittance formula obtained in the step 3;
and 4.2, calculating the attenuation constant and the natural resonant frequency of the line, namely the dominant frequency of the closing overvoltage based on the coaxial mode loop parameters. The influence of the power supply impedance is also taken into account when calculating the resonance frequency.
In step 4.1, single-phase multi-conductor loops can be transformed into mutually independent loops in the mode domain in combination with phase-to-mode transformation.
As can be taken from fig. 2, the coaxial mode current flows from the cable core back through the metal sheath. Thus, the core current IcContaining only coaxial mode current i1I.e. Ic＝i1. Current in metal protective layer IsWhile containing coaxial mode current i1With soil return mode current i0I.e. Is＝i0-i1。
Referring to fig. 3, the voltage transformation matrix and the current transformation matrix in the phase-to-analog conversion satisfy the following relationship:
Figure BDA0002368754760000101
in the formula, [ T ]v]Is a voltage transformation matrix; [ T ]i]Is a current transformation matrix.
The impedance and admittance matrix parameters of the mode domain loop are calculated by applying the voltage change matrix and the current transformation matrix as follows:
Figure BDA0002368754760000102
Figure BDA0002368754760000103
wherein [ z ] is]Is the impedance parameter of the cable in the mode domain; [ y ]]The admittance parameters of the cable in the mode domain; z is a radical of0And y0Respectively representing the impedance and admittance parameters of the soil return mode loop; z is a radical of1And y1Respectively, the impedance and admittance parameters of the coaxial mode loop.
In step 4.2, based on the parameters of the coaxial mode loop of the line, the attenuation constant of the line can be calculated first. The oscillating voltage has a high frequency characteristic during a transient caused by the switching on. Therefore, the main mode loop of the transient overvoltage is a coaxial mode, so that the parameters of the coaxial mode loop are selected for calculation, and the calculation formula of the line propagation constant is as follows:
Figure BDA0002368754760000104
in the formula, gamma1Is the propagation constant of the line.
Further, the attenuation constant of the line is the real part of the propagation constant, and the calculation result is:
α1＝Re[γ1]
in the formula, α1Is the attenuation constant of the line.
Further, the distributed parameter circuit of the single-phase transmission line is combined, and meanwhile, the influence of system impedance is considered at the head end of the line, and the distributed parameter circuit is shown in fig. 4.
The expression equation of the voltage and the current in the line is as follows:
Figure BDA0002368754760000111
Figure BDA0002368754760000112
in the formula, v and i are respectively the voltage and the current in the line; l and C are respectively a line inductor and a capacitor of a unit length; l is the total length of the line; and x is the distance from the power transmission end of the line.
The boundary conditions of the voltage and the current at the head end and the tail end of the line are as follows:
Figure BDA0002368754760000113
wherein E is a power supply voltage; zSIs the power supply impedance; i issIs the current flowing through the impedance of the power supply.
After substituting the boundary condition into the expression of voltage and current, if the line voltage reaches resonance, the following resonance condition will be satisfied:
Figure BDA0002368754760000114
in the formula, F1S(ω) is the denominator function in the resonance condition; y is0Is the characteristic admittance of the line.
Therefore, when the denominator function F1SWhen (ω) equals 0, the line is in a resonant condition. At this time, the corresponding frequency is the resonant frequency of the line, i.e. the dominant frequency f of the switching-on transient overvoltaged. According to the steps, the natural resonant frequency of the cable line can be obtained through the line distribution parameter impedance, the admittance and the system equivalent impedance.
On the MATLAB calculation platform, the cable impedance admittance parameters can be calculated in a programming mode, and the natural resonant frequency of the line can be calculated. After the program runs, the engineer can input corresponding statistical data information and necessary operation conditions, and then a state evaluation result can be obtained. Meanwhile, the algorithm core can be applied to other computing platforms in an expanded mode, and the practicability and the expansibility of the signal processing capacity are enhanced.
The program contents are as follows:
Figure BDA0002368754760000121
Figure BDA0002368754760000131
Figure BDA0002368754760000141
Figure BDA0002368754760000151
and 5, determining accurate parameters of elements in the oscillatory wave loop through the obtained natural resonant frequency and attenuation constant of the cable.
Referring to FIG. 5, in the equivalent circuit of the oscillatory wave operation wave generating device, CsIs the total charging capacitance, C0The device comprises a voltage divider capacitor and a test article capacitor; l is a wave modulation inductor; r, Rf、RtRespectively a loop damping resistor, a total wave head resistor and a wave tail resistor.
When the voltage reaches the maximum value for the first time, t is pi/ω, so the formula for the wave head time is:
Figure BDA0002368754760000161
in the formula, TfIs the wave head time; wherein
Figure BDA0002368754760000162
ω0＝1/(L·C)1/2α R/2L, wherein R R + Rf；C＝CsC0/(CS+C0)。
The peak voltage of the loop is:
Umax＝U(1+exp(-αTf))
wherein, UmaxIs the voltage peak; u ═ CSU1(CS+C0)。
The natural oscillation frequency f of the loop voltage is:
Figure BDA0002368754760000163
wave tail time TtThe calculation formula of (2) is as follows:
Tt＝0.25(R+Rf)·(Cs+C0)
combining with international standard IEC60060-3 of electric power, and calculating by parameters of the oscillation operating wave generating device, the frequency f of the oscillation voltage wave required is knowndomiantAnd a damping constant α, the parameters of the oscillating operating wave generating device can be obtained, which is suitable for the cable under study and produces voltage wave patterns with high accuracy.
In summary, the present invention provides a method for determining a loop parameter of an oscillating operating wave based on a closing overvoltage, including: acquiring geometric parameters of a cable, electrical parameters of a metal conductor, an insulating medium and a laying environment; collecting three-phase short-circuit current at a bus connected with a cable to be researched to obtain equivalent impedance of a feed network; calculating impedance and admittance parameters of the cable; calculating the natural resonant frequency and the attenuation constant of the cable based on the equivalent impedance of the feed network, the impedance of the cable and the admittance parameters; and determining the accurate parameters of the elements in the oscillatory wave loop through the natural resonant frequency and the attenuation constant of the cable. The method for determining the parameters of the oscillating operation wave loop can determine the element parameters of the oscillating wave loop extremely accurately on the basis of the actual transient voltage frequency and attenuation of a cable line in the closing process, thereby generating a test waveform consistent with the actual transient overvoltage characteristic. Meanwhile, when the frequency and the attenuation parameters of the transient closing overvoltage are determined, the calculation steps of the overvoltage frequency are optimized to a great extent only by collecting the self geometric electrical parameters of the cable line and the short-circuit current of the bus, and the calculation accuracy of the dominant overvoltage frequency and the attenuation constant is improved. The oscillation test waveform generated by the oscillation operation loop can effectively research the damage effect of transient overvoltage impact on the insulating material in the operation process of the cable.
The system for determining the parameters of the oscillating operation wave loop based on the closing overvoltage comprises:
the cable geometric and electrical parameter acquisition module is used for acquiring the geometric radius of each metal conductor and the insulating layer in the cable to be tested and determining electrical parameters such as resistivity, magnetic permeability, dielectric constant and the like of the metal conductor and the insulating medium;
the cable distribution line parameter calculation module is used for calculating impedance parameters and admittance parameters in a cable distribution parameter form;
the system equivalent impedance calculation module is used for calculating the equivalent impedance of the feed network through the short-circuit current of the bus connected with the circuit;
the cable natural resonance frequency calculation module is used for obtaining the natural resonance frequency and the waveform attenuation of the single-phase cable through the impedance and admittance parameter values of the cable and the system equivalent impedance value;
and the oscillation operating wave generating device loop parameter calculating module is used for obtaining the parameters of the oscillation operating wave generating device loop through the dominant frequency and the waveform attenuation of the oscillation wave, so that the operation impact suffered by the cable in practice can be accurately simulated.
To sum up, the embodiment of the present invention discloses a system for determining parameters of an oscillating operating wave loop based on a closing overvoltage, which includes: acquiring geometric parameters of a cable, electrical parameters of a metal conductor, an insulating medium and a laying environment; collecting three-phase short-circuit current at a bus connected with a cable to be researched to obtain equivalent impedance of a feed network; calculating impedance and admittance parameters of the cable; further calculating the natural resonant frequency and the attenuation constant of the cable; and determining the accurate parameters of the elements in the oscillatory wave loop through the natural resonant frequency and the attenuation constant of the cable. The invention can accurately determine the element parameters of the oscillatory wave loop by taking the actual transient voltage frequency and attenuation of the cable line in the closing process as the basis, thereby generating a test waveform consistent with the actual transient overvoltage characteristic. Meanwhile, when the frequency and the attenuation parameters of the transient closing overvoltage are determined, the calculation steps of the overvoltage frequency are optimized to a great extent only by collecting the self geometric electrical parameters of the cable line and the short-circuit current of the bus, and the calculation accuracy of the dominant overvoltage frequency and the attenuation constant is improved. The oscillation test waveform generated by the oscillation operation loop can effectively research the damage effect of transient overvoltage impact on the insulating material in the operation process of the cable.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can make modifications and equivalents to the embodiments of the present invention without departing from the spirit and scope of the present invention, which is set forth in the claims of the present application.

Claims (10)

1. A method for determining parameters of an oscillation operating wave loop based on cable closing overvoltage is characterized by comprising the following steps:
step 1, acquiring and obtaining geometric parameters of a cable to be tested, and electrical parameters of a metal conductor, an insulating medium and a laying environment of the cable to be tested;
step 2, acquiring three-phase short-circuit current at a bus connected with a cable to be tested, and calculating to obtain equivalent impedance of a feed network;
step 3, calculating to obtain cable impedance and admittance parameters according to the geometric parameters and the electrical parameters of the cable to be tested obtained in the step 1;
step 4, calculating to obtain the natural resonant frequency and the attenuation constant of the cable according to the equivalent impedance of the feed network obtained in the step 2 and the impedance and the admittance parameters of the cable obtained in the step 3;
step 5, determining parameters of elements in the oscillatory wave loop according to the natural resonant frequency and the attenuation constant of the cable obtained in the step 4;
in step 2, the feed network equivalent impedance calculation formula is as follows:
Figure FDA0002368754750000011
in the formula, ZSIs the equivalent impedance of the feed network; u shapeNRated voltage for the bus; i iskAcquiring three-phase short-circuit current; omega is angular frequency; l isSIs the equivalent inductance parameter of the system.
2. The method for determining the parameters of the oscillatory operating wave loop based on the cable closing overvoltage according to claim 1, wherein in step 1,
the acquisition of the geometric parameters of the cable to be tested comprises the following steps: the cable comprises a cable metal wire core radius, a main insulation outer radius, a metal protection layer outer radius, an outer insulation outer radius and a cable laying depth;
the method for acquiring the electrical parameters of the metal conductor, the insulating medium and the laying environment of the cable to be tested comprises the following steps: resistivity and magnetic permeability of the metal conductor; the dielectric constant and the magnetic permeability of the insulating medium; resistivity of the laying environment.
3. The method for determining the parameters of the oscillating operating wave loop based on the cable closing overvoltage according to claim 1, wherein in the step 3, the specific steps of calculating the impedance of the cable include:
step 3.1, calculating the internal surface impedance and the external surface impedance of each metal conductor;
step 3.2, calculating the insulation equivalent impedance of the insulation medium;
step 3.3, calculating equivalent impedance of the laid soil;
and 3.4, calculating to obtain the equivalent impedance of the cable based on the inner surface impedance, the outer surface impedance, the insulation impedance and the soil impedance.
4. The method for determining the loop parameter of the oscillatory operation wave based on the cable closing overvoltage according to claim 3,
in step 3.1, the outer surface impedance Z of the cable core conductorCouterThe calculation formula is as follows:
Figure FDA0002368754750000021
in the formula, ρcIs the resistivity of the core conductor; r1Is the radius of the cable core; i is0And I1First-class Bessel functions of 0 order and 1 order respectively; m iscThe reciprocal of the penetration depth of the wire core is calculated by the following formula:
Figure FDA0002368754750000022
in the formula, mucThe magnetic conductivity of the core conductor;
the calculation formula of the inner surface impedance and the outer surface impedance of the metal protective layer is as follows:
Figure FDA0002368754750000023
Figure FDA0002368754750000024
in the formula, ρsIs the resistivity of the core conductor; r2The outer radius of the primary insulation; r3The outer radius of the metal protective layer; k0And K1A second class of Bessel functions of order 0 and order 1, respectively; m issThe reciprocal of the skin depth of the metal passivation layer is calculated by the following formula:
Figure FDA0002368754750000025
in the formula, musThe magnetic conductivity of the metal protective layer;
the calculation formula of the mutual impedance between the inner surface and the outer surface of the metal protective layer is as follows:
Figure FDA0002368754750000031
the calculation formula of the insulation resistance of the insulation medium is as follows:
Figure FDA0002368754750000032
Figure FDA0002368754750000033
in the formula, ZCSinsulIs the insulation of the main insulation between the wire core and the metal sheathA rim impedance; zSGinsulThe external insulation equivalent impedance at the periphery of the metal protective layer; r4An outer radius of the outer insulation; mu.sinsMagnetic permeability of the main insulation; mu.sins2Magnetic permeability of the outer insulation;
in step 3.3, the calculation formula of the soil in the laying environment is as follows:
Figure FDA0002368754750000034
in the formula, Z0Equivalent impedance for laying soil; rhoeIs the soil resistivity; r4An outer radius of the outer insulation; h isaThe laying depth of the cable is defined; m iseThe reciprocal of the soil penetration depth is calculated by the formula:
Figure FDA0002368754750000035
in the formula, mueMagnetic permeability of the laid soil;
in step 3.4, the impedance matrix of the single-phase power cable comprises the self-impedance of the conductor of the cable core, the self-impedance of the conductor of the metal sheath and the mutual impedance between the conductor of the cable core and the metal;
wherein, the conductor of the wire core has a self-impedance Z11The calculation formula of (2) is as follows:
Z11＝ZCouter+ZCSinsul+ZSinner+ZSouter+ZSGinsul+Z0-2ZSmutual；
self-impedance Z of metal sheath22The calculation formula of (2) is as follows:
Z22＝ZSouter+ZSGinsul+Z0；
mutual impedance Z between core conductor and metal12The calculation formula of (2) is as follows:
Z12＝ZSouter+ZSGinsul+Z0-ZSmutual；
after obtaining the components in the impedance matrix, the cable impedance [ Z ]cable]Is calculated by the formula：
Figure FDA0002368754750000041
5. The method for determining the parameters of the oscillating operating wave loop based on the cable closing overvoltage according to claim 1, wherein in the step 3, the calculation of the admittance parameters is premised on the calculation of the potential coefficient; the potential coefficient matrix of the single-phase power cable is as follows:
Figure FDA0002368754750000042
in the formula, [ P ]cable]Is a potential coefficient matrix of the cable; p11The potential coefficient of the core conductor; p22The potential coefficient of the metal protective layer; p12The mutual potential coefficient between the wire core and the metal protection layer is shown;
potential coefficient P11The calculation formula of (2) is as follows:
Figure FDA0002368754750000043
in the formula, epsilon0Represents the vacuum dielectric constant; epsilon1The dielectric constant of the main insulation of the cable; epsilon2Dielectric constant of the outer insulation;
potential coefficient P22The calculation formula of (2) is as follows:
Figure FDA0002368754750000044
the calculation formula of the admittance parameter matrix is as follows:
[Ycable]＝jω·[Pcable]-1，
wherein [ Y ] iscable]A matrix of admittance parameters of the cable is represented.
6. The method for determining the parameters of the oscillating operating wave loop based on the cable closing overvoltage according to claim 1, wherein in the step 4, the step of calculating and obtaining the natural resonant frequency and the attenuation constant of the cable comprises:
step 4.1, determining coaxial mode loop parameters according to the cable impedance and admittance parameters obtained in the step 3;
step 4.2, calculating the attenuation constant and the natural resonant frequency of the circuit based on the coaxial mode loop parameters; the effect of the power supply impedance is taken into account when calculating the natural resonance frequency.
7. The method for determining the loop parameter of the oscillatory operation wave based on the cable closing overvoltage according to claim 6,
step 4.1, combining phase-mode conversion to convert single-phase multi-conductor loops into mutually independent loops in a mode domain;
in phase-to-analog conversion, the voltage conversion matrix and the current conversion matrix satisfy the relationship:
Figure FDA0002368754750000051
in the formula, [ T ]v]Is a voltage transformation matrix; [ T ]i]Is a current transformation matrix;
the calculation formula of the impedance and admittance matrix parameters of the mode domain loop is as follows:
Figure FDA0002368754750000052
Figure FDA0002368754750000053
wherein [ z ] is]Is the impedance parameter of the cable in the mode domain; [ y ]]The admittance parameters of the cable in the mode domain; z is a radical of0And y0Respectively representing the impedance and admittance parameters of the soil return mode loop; z is a radical of1And y1Respectively are impedance and admittance parameters of the coaxial mode loop;
in step 4.2, the primary mode loop of the transient overvoltage is a coaxial mode, the parameters of the coaxial mode loop are selected for calculation, and the calculation formula of the line propagation constant is as follows:
Figure FDA0002368754750000054
in the formula, gamma1Is the propagation constant of the line;
the attenuation constant of the line is the real part of the propagation constant, and the calculation result is as follows:
α1＝Re[γ1]
in the formula, α1Is the attenuation constant of the line;
the expression equation of the voltage and the current in the line is as follows:
Figure FDA0002368754750000061
Figure FDA0002368754750000062
in the formula, v and i are respectively the voltage and the current in the line; l and C are respectively a line inductor and a capacitor of a unit length; l is the total length of the line; x is the distance from the power transmission end of the circuit;
the boundary conditions of the voltage and the current at the head end and the tail end of the line are as follows:
Figure FDA0002368754750000063
wherein E is a power supply voltage; zSIs the power supply impedance; i issIs the current flowing through the power supply impedance;
after substituting the boundary condition into the expression of voltage and current, if the line voltage reaches resonance, the following resonance condition is satisfied:
Figure FDA0002368754750000064
in the formula, F1SIs harmonic toA denominator function in the shake condition; y is0Characteristic admittance of the line;
when denominator function F1SWhen (ω) is equal to 0, the line is in a resonance condition, the corresponding frequency being the resonance frequency of the line.
8. The method for determining the parameters of the oscillating operating wave loop based on the cable closing overvoltage according to claim 1, wherein the step 5 specifically comprises: in an equivalent circuit of the oscillation operation wave generating device, CsIs the total charging capacitance, C0The device comprises a voltage divider capacitor and a test article capacitor; l is a wave modulation inductor; r, Rf、RtRespectively a loop damping resistor, a total wave head resistor and a wave tail resistor;
when the voltage reaches the maximum value for the first time, t ═ pi/ω, the formula for calculating the wave head time:
Figure FDA0002368754750000065
in the formula, TfIs the wave head time; wherein
Figure FDA0002368754750000066
ω0＝1/(L·C)1/2α R/2L, wherein R R + Rf；C＝CsC0/(CS+C0)；
The peak voltage of the loop is:
Umax＝U(1+exp(-αTf))，
wherein, UmaxIs the voltage peak; u ═ CSU1(CS+C0)；
The natural oscillation frequency f of the loop voltage is:
Figure FDA0002368754750000071
wave tail time TtThe calculation formula of (2) is as follows:
Tt＝0.25(R+Rf)·(Cs+C0)；
and calculating parameters of the oscillation operating wave generating device according to the known required oscillation voltage wave frequency and attenuation constant by combining with the international power standard IEC 60060-3.
9. A system for determining parameters of an oscillating operating wave loop based on cable closing overvoltage is characterized by comprising:
the cable geometric and electrical parameter acquisition module is used for acquiring and acquiring geometric parameters of a cable to be tested and electrical parameters of a metal conductor, an insulating medium and a laying environment of the cable to be tested;
the system equivalent impedance calculation module is used for acquiring and obtaining three-phase short-circuit current at a bus connected with the cable to be tested and calculating to obtain equivalent impedance of the feed network;
the cable distribution line parameter calculation module is used for calculating and obtaining cable impedance and admittance parameters according to the geometric parameters and the electrical parameters of the cable to be tested, which are obtained by the cable geometric and electrical parameter acquisition module;
the cable natural resonant frequency calculation module is used for calculating and obtaining a cable natural resonant frequency and an attenuation constant according to the feed network equivalent impedance obtained by the system equivalent impedance calculation module and the cable impedance and admittance parameters obtained by the cable distribution line parameter calculation module;
the oscillation operation wave generation device loop parameter calculation module is used for determining parameters of elements in the oscillation wave loop according to the natural resonant frequency and the attenuation constant of the cable obtained by the cable natural resonant frequency calculation module;
in the system equivalent impedance calculation module, the feed network equivalent impedance calculation formula is as follows:
Figure FDA0002368754750000072
in the formula, ZSIs the equivalent impedance of the feed network; u shapeNRated voltage for the bus; i iskAcquiring three-phase short-circuit current; omega is angular frequency; l isSIs a system ofEquivalent inductance parameters.
10. The system for determining the parameters of the oscillatory operating wave loop based on the cable closing overvoltage according to claim 9, wherein the cable distribution line parameter calculation module comprises:
the first calculation module is used for calculating the internal surface impedance and the external surface impedance of each metal conductor;
the second calculation module is used for calculating the insulation equivalent impedance of the insulation medium;
the third calculation module is used for calculating equivalent impedance of laid soil;
the fourth calculation module is used for calculating and obtaining the equivalent impedance of the cable based on the inner surface impedance, the outer surface impedance, the insulation impedance and the soil impedance;
and the fifth calculation module is used for calculating an admittance parameter matrix of the cable.
CN202010044094.8A 2020-01-15 2020-01-15 Method and system for determining oscillation operation wave loop parameters based on cable closing overvoltage Pending CN111220884A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010044094.8A CN111220884A (en) 2020-01-15 2020-01-15 Method and system for determining oscillation operation wave loop parameters based on cable closing overvoltage

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010044094.8A CN111220884A (en) 2020-01-15 2020-01-15 Method and system for determining oscillation operation wave loop parameters based on cable closing overvoltage

Publications (1)

Publication Number Publication Date
CN111220884A true CN111220884A (en) 2020-06-02

Family

ID=70829552

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010044094.8A Pending CN111220884A (en) 2020-01-15 2020-01-15 Method and system for determining oscillation operation wave loop parameters based on cable closing overvoltage

Country Status (1)

Country Link
CN (1) CN111220884A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112100829A (en) * 2020-08-31 2020-12-18 浙江大学 Sheath induced voltage and circulation calculation method of cable system laid along bridge
CN113281613A (en) * 2021-05-18 2021-08-20 国网江苏省电力有限公司无锡供电分公司 Power cable transmission parameter obtaining method
CN114741899A (en) * 2022-04-29 2022-07-12 西安交通大学 Buried cable high-frequency electrical parameter calculation method based on electromagnetic modal analysis

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3812058A1 (en) * 1988-04-12 1989-10-26 Dehn & Soehne Arrangement for overvoltage protection in low-voltage installations
TW437214B (en) * 1998-09-21 2001-05-28 Maxim Integrated Products Method and circuits for generating a preemphasis waveform
CN102346203A (en) * 2010-07-30 2012-02-08 丁晓东 FM (frequency modulation) series resonance and oscillating wave high-voltage generator
CN109901034A (en) * 2019-04-02 2019-06-18 国网陕西省电力公司电力科学研究院 Power cable local discharge detection device and appraisal procedure based on multi-stag power supply and series resonance
CN110231541A (en) * 2019-06-18 2019-09-13 贵州电网有限责任公司 Method based on the on-line monitoring decaying equivalent electric parameter of Sasser inverse system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3812058A1 (en) * 1988-04-12 1989-10-26 Dehn & Soehne Arrangement for overvoltage protection in low-voltage installations
TW437214B (en) * 1998-09-21 2001-05-28 Maxim Integrated Products Method and circuits for generating a preemphasis waveform
CN102346203A (en) * 2010-07-30 2012-02-08 丁晓东 FM (frequency modulation) series resonance and oscillating wave high-voltage generator
CN109901034A (en) * 2019-04-02 2019-06-18 国网陕西省电力公司电力科学研究院 Power cable local discharge detection device and appraisal procedure based on multi-stag power supply and series resonance
CN110231541A (en) * 2019-06-18 2019-09-13 贵州电网有限责任公司 Method based on the on-line monitoring decaying equivalent electric parameter of Sasser inverse system

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
A. AMETANI 等: "A GENERAL FORMULATION OF IMPEDANCE AND ADMITTANCE OF CABLES", 《IEEE TRANSACTIONS ON POWER APPARATUS AND SYSTEMS》 *
JIAMING LI 等: "Analysis of Statistical and Frequency Characteristics of Transient vervoltage of Hybrid Cable-OHL Lines", 《2018 CHINA INTERNATIONAL CONFERENCE ON ELECTRICITY DISTRIBUTION》 *
TERUO OHNO 等: "Derivation of Theoretical Formulas of the Frequency Component Contained in the Overvoltage Related to Long EHV Cables", 《IEEE TRANSACTIONS ON POWER DELIVERY》 *
李嘉明 等: "电缆线路中操作过电压主导频率的确定方法研究", 《电网技术》 *
赵学风 等: "基于谐振原理由电容器组供电的电缆局部放电振荡波检测与定位技术", 《电气应用》 *
郭治锋 等: "振荡冲击波发生电路的设计及其参数选取", 《变压器》 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112100829A (en) * 2020-08-31 2020-12-18 浙江大学 Sheath induced voltage and circulation calculation method of cable system laid along bridge
CN112100829B (en) * 2020-08-31 2022-04-29 浙江大学 Sheath induced voltage and circulation calculation method of cable system laid along bridge
CN113281613A (en) * 2021-05-18 2021-08-20 国网江苏省电力有限公司无锡供电分公司 Power cable transmission parameter obtaining method
CN114741899A (en) * 2022-04-29 2022-07-12 西安交通大学 Buried cable high-frequency electrical parameter calculation method based on electromagnetic modal analysis
CN114741899B (en) * 2022-04-29 2024-03-19 西安交通大学 Buried cable high-frequency electrical parameter calculation method based on electromagnetic modal analysis

Similar Documents

Publication Publication Date Title
CN111220884A (en) Method and system for determining oscillation operation wave loop parameters based on cable closing overvoltage
CN103728539B (en) Cable electrical fault simulation based on distributed optical fiber temperature measurement analyzes method
Hettiwatte et al. Simulation of a transformer winding for partial discharge propagation studies
CN113484679A (en) High-resistance grounding fault detection method and system for small-resistance grounding system and storage medium
Zhou et al. A study on the propagation characteristics of partial discharge in cable joints based on the FDTD method
Olejnik Adaptive zero-sequence overcurrent criterion for earth fault detection for fault current passage indicators in resistor grounded medium voltage networks
Ghosh et al. The effects of non-standard lightning impulse on electrical insulation: a review
Malekian et al. Frequency dependent model of underground cables for harmonic calculations in frequency domain
CN115313329A (en) Frequency band range selection method for rapid traveling wave protection and related device
Pan et al. Incipient fault location method of cable based on both-end electric quantities
Cortina et al. Telecommunication systems on power distribution networks: High frequency performances of carrier channels
Espín-Delgado et al. Expression for conductor resistance in the frequency range 2-150 kHz
Yu et al. Research on fault diagnosis in the railway power transmission line based on the modern mathematical methods
Li et al. Statistical characteristics of partial discharge caused by typical defects in cable joint under oscillating voltage
Liu et al. Single-ended dc fault location method for mmc-based hvdc power system using adaptive multi-step levenberg-marquardt algorithm
Ala et al. Lightning-current distribution in MV grids interconnected earthing systems
Budi Rahayu Widodo et al. Fault location detection using impedance and impulse injection on 20 kV distribution system wonokromo base on geographic information system
Jensen et al. Fault in transmission cables and current fault location methods
Ashouri et al. Online fault location in monopolar LCC-HVDC links with metallic return using modal transient data
Adjaye et al. Wave propagation characteristics of 3-phase distribution cables
Sukardi et al. Modelling of single power line by ATP-Draw for partial discharge signal measurement
CN116738746B (en) Wind power plant impedance characteristic analysis model construction method, device and equipment
Yang et al. Analysis on capacitance rise of 500kV XLPE submarine cable in AC voltage withstand test
Dán et al. Fault location and compensation of the harmonic content of the residual fault current during single-phase to ground faults in compensated networks
El-Khatib et al. Comparison of cable models for time domain simulations

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20200602