CN108845176B - Calculation method for voltage distribution of resistance-type voltage transformer considering stray capacitance - Google Patents
Calculation method for voltage distribution of resistance-type voltage transformer considering stray capacitance Download PDFInfo
- Publication number
- CN108845176B CN108845176B CN201811046252.2A CN201811046252A CN108845176B CN 108845176 B CN108845176 B CN 108845176B CN 201811046252 A CN201811046252 A CN 201811046252A CN 108845176 B CN108845176 B CN 108845176B
- Authority
- CN
- China
- Prior art keywords
- voltage
- unit
- node
- stray capacitance
- 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.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
Abstract
The invention provides a method for calculating voltage distribution of a resistance-type voltage transformer considering stray capacitance. Dividing a resistance voltage divider into n tiny units, calculating the surface charge of each unit of the resistance voltage divider by a boundary element method, and further calculating a capacitance coefficient matrix of the resistance voltage divider, thereby obtaining the ground stray capacitance and the high-voltage end stray capacitance of each unit of the resistance voltage divider; according to the obtained stray capacitance to the ground and the stray capacitance to the high-voltage end of each unit, the voltage distribution of the resistance voltage divider is obtained by using a node voltage method; and according to the obtained voltage distribution, further obtaining the influence of the stray capacitance on the voltage division ratio and the phase deviation of the resistance-type voltage transformer. The method can realize rapid solution by means of computer software, and has high application value.
Description
Technical Field
The invention relates to the technical field of power equipment running state detection, in particular to a method for calculating voltage distribution of a resistance-type voltage transformer considering stray capacitance.
Background
Electronic voltage transformers can be classified into resistive voltage transformers, resistive-capacitive voltage transformers, and capacitive voltage transformers according to the measurement principle of the transformers. Compared with other types of transformers, the resistance type voltage transformer has the following advantages:
(1) the divider resistor is reasonably selected, and the resistance type voltage transformer can obtain a size smaller than that of a capacitance type or resistance-capacitance type transformer;
(2) because of adopting a pure resistance voltage division structure, the resistance voltage transformer has no ferromagnetic resonance phenomenon and has large dynamic and linear measurement intervals;
(3) the resistance type voltage transformer can realize high-precision voltage measurement by adopting a specially designed small-size resistor.
The main body of the resistance voltage transformer is a resistance voltage divider, and the measurement precision of the resistance voltage divider directly influences the working performance of the resistance voltage transformer. For an ideal resistive divider, the division ratio k isN=1+R1/R2Wherein R is1Is a high-voltage arm resistor, R2Is a low voltage arm resistor. The difference between the input voltage of the primary high-voltage end and the output voltage of the secondary low-voltage end is k times in amplitude, and no phase difference exists. However, in the existing resistive voltage divider, stray capacitance caused by an inherent electric field exists between the existing resistive voltage divider and the surrounding earth and high-voltage end, which not only changes the voltage dividing ratio of the voltage divider, but also causes phase deviation between the measurement output and the input.
Disclosure of Invention
According to the above proposal, for the existing resistive voltage divider, stray capacitance caused by the inherent electric field exists between the existing resistive voltage divider and the surrounding earth and high-voltage end, which not only changes the voltage dividing ratio of the voltage divider, but also causes the technical problem of phase deviation between the measurement output and the measurement input, thereby providing a method for calculating the voltage distribution of the resistive voltage transformer considering the stray capacitance.
The technical means adopted by the invention are as follows:
a method of calculating a voltage distribution of a resistive voltage transformer that accounts for stray capacitance, comprising:
s1: dividing the resistance voltage divider into n tiny units, and calculating the stray capacitance of each unit of the resistance voltage divider;
s2: according to the obtained stray capacitance of each unit, obtaining the voltage distribution of the resistance voltage divider by using a node voltage method;
s3: and further solving the voltage division ratio and the phase deviation of the stray capacitor to the resistance-type voltage transformer according to the solved voltage distribution.
Further, the step S1 is to divide the resistor voltage divider into n tiny units along the axial direction, and the calculation process of the stray capacitance of each unit of the resistor voltage divider further includes:
s101: calculating the surface charge of each unit;
s102: calculating the stray capacitance of each unit to the ground end;
s103: and calculating the stray capacitance of each unit to the high-voltage end.
Further, the process of finding the voltage distribution of the resistor voltage divider in step S2 is as follows:
s201: in step S1, the resistive divider is divided into n tiny units, and when n is large enough, each tiny unit is regarded as a node, the ground is regarded as a reference node, and the voltage of the high-voltage end node is set asCalculating a node voltage equation;
s202: rewriting and sorting the node voltage equation to obtain n equation sets;
s203: and calculating the n equations to obtain the voltage distribution of the resistor divider.
Further, the calculation process of the voltage division ratio and the phase deviation of the resistive voltage transformer in the step S3 is as follows:
obtaining the voltage division ratio deviation caused by the stray capacitance of the resistance voltage divider body:
k in the formulaN=1+R1/R2The voltage division ratio of an ideal resistance voltage divider;
obtaining voltage phase deviation caused by stray capacitance of a resistor voltage divider body:
compared with the prior art, the method can realize quick solution by means of computer software, and has higher application value. In summary, the technical scheme of the invention is applied to divide the resistive voltage divider into a plurality of units, obtain the surface charge of each unit of the resistive voltage divider by a boundary element method, and further calculate the capacitance coefficient matrix of the resistive voltage divider, thereby obtaining the ground stray capacitance and the high-voltage end stray capacitance of each unit of the resistive voltage divider; according to the obtained stray capacitance to the ground and the stray capacitance to the high-voltage end of each unit, the voltage distribution of the resistance voltage divider is obtained by using a node voltage method; and further solving the voltage division ratio and the phase deviation of the stray capacitor to the resistance-type voltage transformer according to the solved voltage distribution.
For the reasons, the method can be widely popularized in the fields of power equipment operation state detection and the like.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a flow chart of the method of the present invention.
Fig. 2 is a flowchart of the calculation process of step S1 of the method of the present invention.
FIG. 3 is a flowchart of the method of step S2 of the present invention for determining the voltage distribution of the resistor divider.
Detailed Description
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Examples
As shown in fig. 1,2 and 3, the present invention provides a method for calculating voltage distribution of a resistance voltage transformer with stray capacitance, including:
s1: dividing the resistance voltage divider into n tiny units, and calculating the stray capacitance of each unit of the resistance voltage divider;
the vector formed by each unit potential is expressed as U epsilon RnAnd the vector formed by the surface charges of each unit is expressed as Q epsilon RnAnd then:
CU=Q (1)
wherein C is a capacitance coefficient matrix
S101: calculating the surface charge of each unit;
setting the potential of the ith unit as 1V and the potentials of other units as 0V, and calculating the surface total charge of each unit to obtain the ith row parameter of the C matrix; wherein the capacitance coefficient of the jth row and ith column is the charge Q on the jth unitj:
Cji=Qj,j=1,2,…,n (2)
Dividing all unit surfaces into m surface elements, and assuming that the charge on each surface element is uniformly distributed, then the center point x of any surface element kkThe potential of (A) is:
in the formulaFor bin l at point xkThe resulting potential;is bin k at xkPotential generated by a dot
In the formula of0Is a vacuum dielectric constant; a. thekIs the area of bin k; sigmakIs the charge density of bin k; q. q.skSurface charge of bin k
In the formula rklIs the distance, s, from the center of bin l to the center of any bin klIs the area of the first surface element, AlIs the l bin, σlThe charge density of the bin l, and m is the number of bins after all cells are divided;
the formula for all bins is calculated as:
wherein p is an m-order parameter matrix; q is an m-dimensional column vector consisting of the charge amount of each bin;an m-dimensional column vector composed for each bin potential.
Similarly, setting the potentials of all surface elements on the unit i to be 1V, and the potentials of the other surface elements to be 0V, and calculating the formula (6) to obtain the surface charges of all the surface elements; calculated by substituting equation (2):
sequentially calculating to obtain the ith row element of the capacitance coefficient matrix C;
the whole capacitance coefficient matrix C can be obtained by a method of sequentially applying potentials to the units for solving;
s102: calculating the stray capacitance of each unit to the ground end;
the stray capacitance of the ith unit to the ground is:
calculating in sequence to obtain stray capacitance of all units to the ground end;
s103: and calculating the stray capacitance of each unit to the high-voltage end.
The stray capacitance of the ith unit to the high-voltage end is as follows:
Cih=-Ci1 (9)
and calculating in sequence to obtain the stray capacitance of all the units to the high-voltage end.
S2: according to the obtained stray capacitance of each unit, the voltage distribution of the resistance voltage divider is obtained by using a node voltage method;
s201: in step S1, the resistive divider is divided into n tiny units, and when n is large enough, each tiny unit is regarded as a node, the ground is regarded as a reference node, and the voltage of the high-voltage end node is set asThe node voltage equation is:
matrix YBIn the form of a node admittance matrix,is a vector of node voltages,Injecting current into the nodeQuantity, expanded in matrix form:
in the matrixA current is injected for the node i and,is the voltage to ground for node i, i ═ 1,2 … n;
Yiiis a self-admittance, whose value is equal to the current injected into the network via node i when a unit voltage is applied to node i and all other nodes are grounded;
Yijis a mutual admittance, whose value is equal to the current injected into the network via node j when a unit voltage is applied to node i and all other nodes are grounded;
when i is 1
② when i > 1 and j > i
the node I injection current I is obtained from the equations (15) and (16)iThe expression is as follows:
the node voltage equation is:
s202: rewriting and sorting the node voltage equation to obtain n equation sets;
rewriting the above equation (18) as:
the left and right sides of the equal sign of the above formula (19) are respectively rewritten as:
Let YB″=P-1YB'
The above equations (20) and (21) are rewritten as:
the form of the expansion equation is
Wherein the content of the first and second substances,in order to know the voltage at the high voltage terminal,andn quantities to be calculated;
s203: and calculating the n equations to obtain the voltage distribution of the resistor divider.
S3: and further solving the voltage division ratio and the phase deviation of the stray capacitor to the resistance-type voltage transformer according to the solved voltage distribution. The calculation process of the voltage division ratio and the phase deviation of the resistive voltage transformer in the step S3 is as follows:
calculating the voltage division ratio deviation caused by stray capacitance of the resistance voltage divider body:
k in the formulaN=1+R1/R2The voltage division ratio of an ideal resistance voltage divider;
calculating voltage phase deviation caused by stray capacitance of a resistor voltage divider body:
in the above embodiments of the present invention, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (2)
1. A method for calculating voltage distribution of a resistance-type voltage transformer considering stray capacitance is characterized by comprising the following steps:
s1: dividing the resistance voltage divider into n tiny units, and calculating the stray capacitance of each unit of the resistance voltage divider; the vector formed by each unit potential is expressed as U epsilon RnAnd the vector formed by the surface charges of each unit is expressed as Q epsilon RnAnd then:
CU=Q (1)
wherein C is a capacitance coefficient matrix;
s101: calculating the surface charge of each unit;
let the ith unit potential be 1V and other unit potentials be 0VCalculating the surface total charge of each unit to obtain the ith row parameter of the C matrix; wherein the capacitance coefficient of the jth row and ith column is the charge Q on the jth unitj:
Cji=Qj,j=1,2,…,n (2)
Dividing all unit surfaces into m surface elements, and assuming that the charge on each surface element is uniformly distributed, then the center point x of any surface element kkThe potential of (A) is:
in the formulaFor bin l at point xkThe resulting potential;is bin k at xkPotential generated by a dot
In the formula of0Is a vacuum dielectric constant; a. thekIs the area of bin k; sigmakIs the charge density of bin k; q. q.skSurface charge of bin k
In the formula rklIs the distance, s, from the center of bin l to the center of any bin klIs the area of the first surface element, AlIs the l bin, σlThe charge density of the bin l, and m is the number of bins after all cells are divided;
the formula for all bins is calculated as:
wherein p is an m-order parameter matrix; q is an m-dimensional column vector consisting of the charge amount of each bin;an m-dimensional column vector composed of the potentials of each bin;
similarly, setting the potentials of all surface elements on the unit i to be 1V, and the potentials of the other surface elements to be 0V, and calculating the formula (6) to obtain the surface charges of all the surface elements; calculated by substituting equation (2):
sequentially calculating to obtain the ith row element of the capacitance coefficient matrix C;
the whole capacitance coefficient matrix C can be obtained by a method of sequentially applying potentials to the units for solving;
s102: calculating the stray capacitance of each unit to the ground end;
the stray capacitance of the ith unit to the ground is:
calculating in sequence to obtain stray capacitance of all units to the ground end;
s103: calculating the stray capacitance of each unit to the high-voltage end;
the stray capacitance of the ith unit to the high-voltage end is as follows:
Cih=-Ci1 (9)
calculating in sequence to obtain stray capacitance of all units to the high-voltage end;
s2: according to the obtained stray capacitance of each unit, obtaining the voltage distribution of the resistance voltage divider by using a node voltage method;
s201: in step S1, the resistive divider is divided into n tiny units, and when n is large enough, each tiny unit is regarded as a node, the ground is regarded as a reference node, and the voltage of the high-voltage end node is set asThe node voltage equation is:
matrix YBIn the form of a node admittance matrix,is a vector of node voltages,Injecting current vectors for nodes, and expanding the current vectors into a matrix form:
in the matrixA current is injected for the node i and,is the voltage to ground for node i, i ═ 1,2 … n;
Yiiis a self-admittance, whose value is equal to the current injected into the network via node i when a unit voltage is applied to node i and all other nodes are grounded;
Yijis a mutual admittance of a value equal to the unit voltage applied at node i, otherwiseWhen all the nodes are grounded, current is injected into the network through the node j;
when i is 1
② when i > 1 and j > i
the node I injection current I is obtained from the equations (15) and (16)iThe expression is as follows:
the node voltage equation is:
s202: rewriting and sorting the node voltage equation to obtain n equation sets;
rewriting the above equation (18) as:
the left and right sides of the equal sign of the above formula (19) are respectively rewritten as:
Let YB″=P-1YB'
The above equations (20) and (21) are rewritten as:
the form of the expansion equation is
Wherein the content of the first and second substances,in order to know the voltage at the high voltage terminal,andn quantities to be calculated;
s203: obtaining voltage distribution of the resistor divider by operating the n equations;
s3: and further solving the voltage division ratio and the phase deviation of the stray capacitor to the resistance-type voltage transformer according to the solved voltage distribution.
2. The method of claim 1, wherein the resistive voltage transformer voltage division ratio and the phase deviation in step S3 are calculated as follows:
calculating the voltage division ratio deviation caused by stray capacitance of the resistance voltage divider body:
k in the formulaN=1+R1/R2The voltage division ratio of an ideal resistance voltage divider;
calculating voltage phase deviation caused by stray capacitance of a resistor voltage divider body:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201811046252.2A CN108845176B (en) | 2018-09-07 | 2018-09-07 | Calculation method for voltage distribution of resistance-type voltage transformer considering stray capacitance |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201811046252.2A CN108845176B (en) | 2018-09-07 | 2018-09-07 | Calculation method for voltage distribution of resistance-type voltage transformer considering stray capacitance |
Publications (2)
Publication Number | Publication Date |
---|---|
CN108845176A CN108845176A (en) | 2018-11-20 |
CN108845176B true CN108845176B (en) | 2021-01-15 |
Family
ID=64189108
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201811046252.2A Active CN108845176B (en) | 2018-09-07 | 2018-09-07 | Calculation method for voltage distribution of resistance-type voltage transformer considering stray capacitance |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN108845176B (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112072687B (en) * | 2020-08-24 | 2022-01-18 | 华南理工大学 | Method for determining stray capacitance value of alternating current filter |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4422034A (en) * | 1980-01-22 | 1983-12-20 | Toyo Sushinki Kabushiki Kaisha | Method for measuring insulation resistance and device therefor |
CN106249052A (en) * | 2016-07-15 | 2016-12-21 | 国网四川省电力公司电力科学研究院 | A kind of capacitance type potential transformer stray capacitance computational methods |
CN106610482A (en) * | 2015-10-27 | 2017-05-03 | 国网智能电网研究院 | Method for analyzing impact on accuracy of capacitive-type voltage transformer from stray capacitance |
-
2018
- 2018-09-07 CN CN201811046252.2A patent/CN108845176B/en active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4422034A (en) * | 1980-01-22 | 1983-12-20 | Toyo Sushinki Kabushiki Kaisha | Method for measuring insulation resistance and device therefor |
CN106610482A (en) * | 2015-10-27 | 2017-05-03 | 国网智能电网研究院 | Method for analyzing impact on accuracy of capacitive-type voltage transformer from stray capacitance |
CN106249052A (en) * | 2016-07-15 | 2016-12-21 | 国网四川省电力公司电力科学研究院 | A kind of capacitance type potential transformer stray capacitance computational methods |
Non-Patent Citations (2)
Title |
---|
外电场对电容式电压互感器误差特性影响研究;周凯;《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》;20170315(第03期);正文第27-34页 * |
用表面电荷法计算高压设备的杂散电容;姚为正、陈彩屏;《高压电器》;19971231(第2期);第45-48页 * |
Also Published As
Publication number | Publication date |
---|---|
CN108845176A (en) | 2018-11-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US10521533B2 (en) | Inductor simulation method and inductor nonlinear equivalent circuit model | |
El-Kishky et al. | Electric potential and field computation along AC HV insulators | |
CN106610482B (en) | Method for analyzing influence of stray capacitance on accuracy of capacitor voltage transformer | |
Abdel-Salam et al. | Analysis of monopolar ionized field as influenced by ion diffusion | |
CN112260273B (en) | Electric power system weak node visual identification method based on all-pure embedding method | |
CN108845176B (en) | Calculation method for voltage distribution of resistance-type voltage transformer considering stray capacitance | |
Csendes et al. | Surge arrester voltage distribution analysis by the finite element method | |
CN102609588B (en) | Method for calculating ion flow field | |
Christodoulou et al. | Application of Powell’s optimization method to surge arrester circuit models’ parameters | |
Tausch et al. | Capacitance extraction of 3-D conductor systems in dielectric media with high-permittivity ratios | |
CN109541518A (en) | A kind of additive error analysis method and system based on voltage transformer | |
DE102015119969B4 (en) | Arrangement for operating and / or measuring the output of a capacitive energy harvester | |
Techaumnat et al. | Calculation of the electric field for lined-up spherical dielectric particles | |
Harimurugan et al. | A comparative study of field computation methods: Charge simulation method and method of moments | |
Maccarrone et al. | Capacitance and forces for thick circular electrodes | |
CN105453088A (en) | Method for determining capacitance value of capacitor with consideration for applied ac voltage, and program | |
Vlach | Tableau and modified nodal formulations | |
Frei et al. | Calculation of low frequency EMC problems in large systems with a quasi-static approach | |
Dular et al. | Floating potentials in various electromagnetic problems using the finite element method | |
Ghoneim | Charge and current simulation method with boundary element method for grounding system calculations in case of multi-layer soil | |
Paffuti | Results for Capacitances and Forces in cylindrical systems | |
Turki et al. | Transmission lines modeling based on vector fitting algorithm and rlc active/passive filter design | |
Barić et al. | An analytical approximation of the transient response of a voltage dependent supercapacitor model | |
Manfredi | Uncertainty quantification of cable inductances and capacitances via mixed-fidelity models | |
Creosteanu et al. | Comparison between an analytical method and two numerical methods on a given electrostatic potential determination problem |
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 | ||
GR01 | Patent grant | ||
GR01 | Patent grant |