CN109683063B - Small current ground fault direction detection method using current and voltage derivative - Google Patents
Small current ground fault direction detection method using current and voltage derivative Download PDFInfo
- Publication number
- CN109683063B CN109683063B CN201910133461.9A CN201910133461A CN109683063B CN 109683063 B CN109683063 B CN 109683063B CN 201910133461 A CN201910133461 A CN 201910133461A CN 109683063 B CN109683063 B CN 109683063B
- Authority
- CN
- China
- Prior art keywords
- fault
- zero sequence
- current
- detection point
- zero
- 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
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/086—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution networks, i.e. with interconnected conductors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/088—Aspects of digital computing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
Abstract
A small current grounding system earth fault direction detection method utilizing linearity relation between zero sequence current and voltage derivative of a line belongs to the field of relay protection of a power distribution network. The invention analyzes the linearity relation of the upstream and downstream voltages and currents of a fault point when a single-phase earth fault occurs in an ungrounded and arc-suppression coil grounding system, and provides a method for detecting the fault direction by using the linearity relation between the zero-sequence current and the voltage derivative at the detection point. And acquiring zero sequence voltage and zero sequence current at each detection point, then performing linear fitting on the zero sequence current sampling value sequence and the corresponding zero sequence voltage difference value sequence, and judging that the detection point with the goodness of fit greater than a threshold value and the fitting function slope greater than zero is positioned at the downstream of the fault point, or else, the detection point is positioned at the upstream of the fault point. The invention can be simultaneously applied to low-resistance and high-resistance ground faults of a small-current grounding system, improves the adaptability of a fault direction detection algorithm and has wide practical application value.
Description
Technical Field
The invention provides a method for detecting the direction of a single-phase earth fault of a small-current earthing system by utilizing the linearity relation between zero-sequence current and zero-sequence voltage derivative, which can reliably detect low and high resistance earth faults of an ungrounded system and a resonance earthing system.
Background
China's medium voltage distribution network mostly adopts a small current grounding mode, including that a neutral point is not grounded and the neutral point is grounded through an arc suppression coil (resonance grounding). Due to the reasons of weak fault current, unstable arc and the like, reliable detection of the single-phase earth fault is difficult all the time. In the existing ground fault direction detection methods, the detection method based on the steady state information needs to adopt signals for a long time after the fault, so that the detection speed is low, and the effect is not ideal; while the direction detection method of the high-frequency (hundreds of hertz to thousands of hertz) transient electric quantity based on the ground fault needs to filter power frequency components during detection, which easily causes information leakage, and particularly, when the high-resistance ground is grounded, the direction detection method based on the high-frequency transient electric quantity cannot be applied because the frequency of a fault transient signal is close to the power frequency and the amplitude is small; in addition, the patent "a method for positioning a high-resistance grounding fault of a small-current grounding system based on transient current projection component amplitude comparison" provides a direction detection method based on transient current projection component amplitude comparison, and the method has higher line selection accuracy for the high-resistance grounding fault of a resonance grounding system, but is not suitable for a low-resistance grounding fault.
Therefore, most methods cannot adapt to different fault conditions at the same time, different algorithms need to be selected according to the system grounding mode and the fault type, and the complexity of the algorithms is increased. In addition, for the method of attenuating the transient component by using the fault electrical quantity, because the power frequency component has the same rule at the upstream and downstream of the fault point and cannot be used for positioning, the power frequency component is regarded as an interference quantity in practical application and is often filtered, and a digital filter is generally adopted in the device to filter the power frequency component, so that not only is the calculated quantity increased, but also the filtering effect is not obvious when the transient signal frequency is closer to the power frequency. In fact, the power frequency component of the fault electric quantity also contains abundant fault information, and if the fault information can be utilized, the reliability of line selection can be effectively improved.
The method for detecting the single-phase earth fault direction of the small-current earth system by analyzing the linearity relation between the zero-sequence current and the zero-sequence voltage derivative at the detection point of the line, drawing a zero-sequence current-voltage derivative curve by synthesizing the transient component and the power frequency component of the fault electric quantity, and reflecting the difference of the linearity by using the difference of the properties of the zero-sequence current-voltage derivative curve at each detection point.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the direction detection algorithm is suitable for low and high resistance earth faults of different low current grounding systems, the adaptability of the direction detection algorithm of the low current grounding system is improved, the fault direction can be rapidly determined after a fault occurs, and the fault line can be cut off by further instructing corresponding circuit breakers and switch operation.
The technical solution of the invention is as follows:
a. recording zero sequence current i at each detection point of fault line by using change of bus zero sequence voltage as fault starting condition0Zero sequence voltage u0；
b. Calculating the zero sequence voltage change rate delta u at the detection point0/Δt；
c. Fitting the zero sequence current and zero sequence voltage change rate sequence curve at the detection point;
d. judging the fault direction by using the fitting parameters;
according to the method for detecting the direction of the ground fault of the low-current grounding system, the method is characterized in that:
e. performing least squares linear fitting on the sample sequence to determine a function f (x) ═ bx + c, and calculating coefficients b and c using the following equations:
wherein (the length of the sampling sequence is m):
f. using goodness of fit R2To describe the fitting degree of linear fitting, the calculation method of the goodness of fit of each detection point is as follows:
in the formula:
xk＝Δu0(k)/Δt；
and the zero sequence current mean value at each detection point.
g. Setting a threshold value lambda of goodness-of-fit, and judging goodness-of-fit R at each detection point2And the slope of the fitting function, if the goodness of fit R2>Lambda, and the slope of the fitting function is larger than zero, the fault grounding point is judged to be at the upstream of the detection point, otherwise, the fault grounding point is judged to be at the downstream of the detection point.
In the scheme, the method comprises the following steps:
the threshold λ should be set according to field empirical data, and λ is set to 0.5 under general conditions.
In step d, when the resonant grounding system has a low-resistance grounding fault, the determination process of the curve characteristics of the zero-sequence current and zero-sequence voltage change rate sequence at the detection point is as follows:
because the oscillation frequency of the fault current transient component (transient current) is higher, the equivalent impedance of the arc suppression coil is far larger than the capacitance reactance of the parallel-connected ground distributed capacitor, and the influence of the arc suppression coil on the fault transient can be ignored.
The expression of the total electric quantity (total current) of the zero-sequence current at the detection point downstream of the ground fault point is as follows:
wherein:
i0_d_pis a power frequency component of zero sequence current i0_d_tIs a transient component of the zero-sequence current, u0pIs a power frequency component of zero sequence voltage, u0tIs a zero sequence voltage transient component, C0dThe line is the zero sequence capacitance to the ground at the downstream of the detection point.
It is proportional to the zero sequence voltage full electric quantity (full voltage) derivative and the proportionality coefficient is positive. If the zero sequence current-voltage derivative curve is drawn, the curve is a straight line with positive slope passing through the origin, and the slope of the straight line is equal to the ground zero sequence capacitance value of the line downstream of the detection point.
The expression for the full current at the detection point upstream of the ground fault point is:
wherein:
v is over-compensation detuning degree of the arc suppression coil, C is system zero sequence capacitance to ground, C0uIs the zero sequence capacitance to ground of all lines upstream of the detection point.
It can be seen that the coefficients before the transient voltage derivative and the power frequency voltage derivative are different in size and opposite in polarity, and cannot be combined into a uniform zero sequence full voltage derivative form. In view of the fact that the transient state quantity after the fault is large in amplitude and high in frequency but is fast in attenuation, the transient state voltage derivative and the power frequency voltage derivative are changed alternately, and the transient state quantity and the power frequency quantity in different time periods respectively play a leading role, the ratio of the full current to the full voltage derivative is changed all the time and is not constant.
In step d, when the resonant grounding system has a high-resistance grounding fault, the determination process of the zero-sequence current and zero-sequence voltage change rate sequence curve characteristics at the detection point is as follows:
under the high-resistance grounding fault, the oscillation frequency of the transient current is near the power frequency, and the influence of the arc suppression coil on the transient process can not be ignored at the moment.
The relation between the zero sequence full current and the zero sequence full voltage at the downstream detection point of the ground fault point is the same as that in the low resistance state, so that the relation has the same linearity as that in the low resistance ground fault state.
The full current expression at the detection point upstream of the ground fault point is as follows:
wherein:
ωfis a transient main resonance frequency, I0_Lp_tIs the peak of the sinusoidal component in the transient current, ImThe amplitude of the power frequency current is, gamma is the initial fault phase angle of the sine component, and phi is the initial fault phase angle of the fault phase voltage.
The power frequency component is in direct proportion to the derivative of the zero sequence power frequency voltage, but the transient component and the derivative of the zero sequence transient voltage are not in a linear relation, so that an analytical expression of the zero sequence full current and the zero sequence full voltage derivative cannot be obtained, namely, the zero sequence full current and the zero sequence full voltage derivative do not have a linear relation.
In step d, when the single-phase earth fault occurs in the ungrounded system, the determination process of the curve characteristics of the zero-sequence current and zero-sequence voltage change rate sequence at the detection point is as follows:
the following relation is satisfied between the zero sequence current and the zero sequence voltage derivative at the upstream and downstream detection points of the ground fault point (C is the zero sequence capacitance of the system to the ground):
it can be seen that zero sequence current and zero sequence voltage derivative at the upstream and downstream detection points of the ground fault point are in a positive proportional relationship, and the proportionality coefficient of the downstream detection point is positive and the proportionality coefficient of the upstream detection point is negative. And if the derivative of the zero-sequence voltage is taken as an abscissa and the zero-sequence current at each detection point is taken as an ordinate, drawing a zero-sequence current-voltage derivative curve of each detection point, wherein the downstream detection point is a straight line with a positive slope, and the upstream detection point is a straight line with a negative slope.
In step g, describing the characteristics of the zero sequence current and zero sequence voltage change rate sequence curve at the detection point by using the fitting parameters, and determining the position of the fault point as follows:
under different neutral point grounding modes and fault conditions, a zero sequence current-voltage derivative curve of a downstream detection point of a grounding fault point is always a straight line with a positive slope, while a curve of an upstream detection point is an irregular curve or a straight line with a negative slope, and the curve is obviously different from the downstream detection point. If least squares linear fitting is performed on corresponding sampled data points, fitting parameters can be used to describe the above rule as: the slope of the line fitted with the sampled data from the downstream detection points is positive and the degree of fit is high, while the degree of fit of the line fitted with the sampled data from the upstream detection points is lower or the slope is negative. Therefore, the characteristic can be utilized to formulate a uniform direction detection standard aiming at low-resistance and high-resistance ground faults of different grounding systems, thereby realizing the purpose of improving the adaptability of a direction detection algorithm.
Compared with the prior art, the invention has the beneficial effects that:
in the existing ground fault direction detection methods, the detection method based on steady-state information needs to adopt signals for a long time after fault, so that the detection speed is low, the effect is not ideal, and the reliability of line selection of a resonant grounding system is not high; compared with the former, the direction detection method of the high-frequency (hundreds of hertz to thousands of hertz) transient electric quantity based on the ground fault has higher applicability to a resonance grounding system, but the method needs to filter power frequency components during detection, so that information omission is easily caused, and particularly, when the high-resistance grounding is carried out, the direction detection method based on the high-frequency transient electric quantity cannot be applicable because the frequency of a fault transient signal is close to the power frequency and the amplitude is small; in addition, the patent "a method for positioning a high-resistance grounding fault of a small-current grounding system based on transient current projection component amplitude comparison" provides a direction detection method based on transient current projection component amplitude comparison, and the method has higher line selection accuracy for the high-resistance grounding fault of a resonance grounding system, but is not suitable for a low-resistance grounding fault.
Compared with the method, the method for determining the fault section by utilizing the linearity relation between the zero sequence current and the zero sequence voltage derivative at the detection point has stronger applicability, can still be applicable when the fault grounding resistance is higher and the transient component frequency of the fault is lower, can simultaneously solve the direction detection problem of low-resistance and high-resistance grounding faults of different small current grounding systems, and has unique advantages. The method can be realized only by converting the line selection scheme provided by the invention into an algorithm of a computer and embedding the algorithm into the zero sequence protection of the feeder line, and has very high engineering application value.
Drawings
The invention will be further described with reference to the following detailed description and drawings:
FIG. 1 is a block diagram of a fault direction detection process;
FIG. 2 is a block diagram of a fault line selection process;
FIG. 3 is a simulation model of a typical resonant grounded system;
FIG. 4 is a typical ungrounded system simulation model;
FIG. 5 is a current-voltage derivative simulation curve at different detection points of a resonant grounded system fault line;
FIG. 6 is a simulation curve of current-voltage derivatives at different detection points of a fault line of an ungrounded system;
FIG. 7 is a current-voltage derivative simulation curve for different outgoing lines of a resonant grounded system;
FIG. 8 is a simulation curve of current-voltage derivatives at different outgoing lines of an ungrounded system;
fig. 9 is a current-voltage derivative simulation curve recorded on site at different outgoing lines during a single-phase ground fault of the resonant grounding system;
Detailed Description
The line fault direction detection protection method of the power system can be applied to different low-current grounding systems, can be realized by various methods, can be protection equipment with a specific function, and can also share a software and hardware platform with other functions.
The following are described separately:
1, protection method by using protection equipment
I. The invention is used for determining the fault direction only by detecting the point voltage current signal and does not need the fault information of other lines or detection points, and has the characteristics of self-service. The method comprises the following concrete steps:
a. recording zero sequence current i at each detection point by using the change of bus zero sequence voltage as a fault starting condition0Zero sequence voltage u0；
b. Calculating the zero sequence voltage change rate delta u at the detection point0/Δt；
c. Performing least square linear fitting on the sequence curve of the zero sequence current and the zero sequence voltage change rate at the detection point, determining a function f (x) bx + c, and calculating coefficients b and c by using the following formulas:
wherein (the length of the sampling sequence is m):
d. using goodness of fit R2To describe the fitting degree of linear fitting, the calculation method of goodness of fit of each detection point is as follows:
in the formula:
xk＝Δu0(k)/Δt；
and the zero sequence current mean value at each detection point.
e. Setting a threshold value lambda of goodness-of-fit, and judging goodness-of-fit R at each detection point2And the slope of the fitting function, if the goodness of fit R2>Lambda, and the slope of the fitting function is larger than zero, the fault grounding point is judged to be at the upstream of the detection point, otherwise, the fault grounding point is judged to be at the downstream of the detection point.
For a large current ground fault, if the fault is in a protected zone, a trip command should be immediately output to isolate the faulty line.
For the low-current grounding fault, if the detected line is determined to be the fault line, a tripping instruction can be immediately output to isolate the fault line, or alarm information can be sent out firstly, the operation is continued for a period of time according to regulation, and the tripping instruction is sent out again by manual intervention at a proper time.
II. Based on a hybrid line model of the resonant grounding system shown in fig. 3, a 2000 Ω single-phase grounding fault is set to occur on the line 4 at a distance of 5km from the bus, and the validity of the algorithm is verified.
a. Recording zero sequence current i at each detection point by using the change of bus zero sequence voltage as a fault starting condition0Zero sequence voltage u0；
b. Fitting the curve shown in fig. 5 to determine a least squares linear fit function;
c. goodness of fit at each detection point was calculated as follows:
d. taking the threshold value lambda as 0.5, comparing the goodness of fit at each detection point, and selecting the section two between Q2 and Q3 in the figure 3 as a fault section.
And III, setting a single-phase earth fault at a position 6km away from the bus on the line 2 based on an overhead line model of the ungrounded system shown in the attached drawing 4, and verifying the validity of the algorithm.
a. Recording zero sequence current i at each detection point by using the change of bus zero sequence voltage as a fault starting condition0Zero sequence voltage u0；
b. Fitting the curve shown in fig. 6 to determine a least squares linear fit function;
c. calculating the goodness of fit and the slope of the fitting function at each detection point as follows:
d. and comparing the goodness of fit and the slope of the fitted straight line at each detection point, and selecting a section two between Q2 and Q3 in the figure 4 as a fault section.
2, line single-phase earth fault line selection method
I. A small current grounding system single-phase grounding fault line selection method utilizing linearity relation between zero sequence current of a line and zero sequence voltage derivative of a bus has the following specific working principle:
1) system workflow in normal operation
The line selection device is responsible for monitoring bus zero sequence voltage and zero sequence current signals of each feeder outlet, sampling the monitoring signals during normal work, comparing a sampling value of the bus zero sequence voltage with a device starting threshold value, and judging whether a fault occurs in a line;
2) system workflow during fault
When a single-phase earth fault occurs in a line, the line selection device is started according to the bus zero sequence voltage, when the bus zero sequence voltage value reaches a device starting threshold value, the device is started, fault data such as the bus zero sequence voltage, zero sequence current signals at the outlets of all feeder lines, fault duration, fault occurrence time and the like are recorded, and fault line selection is performed according to the recorded data:
a. calculating the change rate of the zero sequence voltage of the bus;
b. performing least square linear fitting on the zero sequence current of each outgoing line and the bus zero sequence voltage change rate sequence curve to determine a least square linear fitting function;
c. calculating the goodness of fit of each line;
d. setting a threshold value lambda of goodness-of-fit, and judging goodness-of-fit R of each line2And the slope of the fitting function, if the goodness of fit R of the line2>And lambda, and the slope of the fitting function is larger than zero, the line is judged to be a sound line, and otherwise, the line is judged to be a fault line. And if the goodness of fit of all the lines is greater than lambda and the slope of the fitting function is greater than zero, determining that the bus is in ground fault.
II. Based on a hybrid line model of the resonant grounding system shown in fig. 3, a 2000 Ω single-phase grounding fault is set to occur on the line 4 at a distance of 5km from the bus, and the validity of the algorithm is verified.
a. When the amplitude of the bus zero-sequence voltage exceeds a preset threshold, the starting device records the bus zero-sequence voltage and the bus zero-sequence voltage within fault transient time
Zero sequence current at the outlet of each feeder line;
b. fitting the curve shown in fig. 7 to determine a least squares linear fit function;
c. the goodness of fit for each line is calculated as follows:
d. and taking the threshold value as 0.5, comparing the goodness of fit among all lines, and selecting the line 4 with the goodness of fit smaller than 0.5 as a fault line.
And III, setting a single-phase earth fault at a position 6km away from the bus on the line 2 based on an overhead line model of the ungrounded system shown in the attached drawing 4, and verifying the validity of the algorithm.
a. When the zero sequence voltage amplitude of the bus exceeds a preset threshold, the starting device records the zero sequence voltage u of the bus0Zero sequence current i at outlet of each feeder line0；
b. Fitting the curve shown in fig. 8 to determine a least squares linear fit function;
c. calculating the slope of the fitting function and the goodness of fit R of each line2The following were used:
d. and comparing the goodness of fit and the slope of the fitting straight line among all the lines, and selecting the line 2 with the negative slope of the fitting function as a fault line.
The method for detecting the fault direction of the power system judges the fault direction by utilizing the linearity relation between the zero sequence current and the zero sequence voltage derivative, is applicable to both low-resistance and high-resistance ground faults, has a wide application range, fully utilizes the fault power frequency and the transient electric quantity, can be simultaneously applicable to an ungrounded system and a resonance grounding system, can reduce the complexity of a small-current ground fault direction detection algorithm, and improves the adaptability.
Claims (1)
1. A small current grounding system grounding fault direction detection method using linearity relation between zero sequence current and zero sequence voltage derivative is applicable to low-resistance grounding and high-resistance grounding faults of ungrounded systems and resonance grounding systems, and is characterized in that: the method comprises the following steps:
a. recording zero sequence current i at each detection point by using the change of bus zero sequence voltage as a fault starting condition0Zero sequence voltage u0；
b. Calculating the zero sequence voltage change rate delta u at the detection point0/Δt；
c. Performing least square linear fitting on the zero sequence current and zero sequence voltage change rate sequence curve at the detection point, and determining a function f (x) ═ bx + c, wherein the formula of coefficients b and c is calculated as:
in the formula, the length of the sampling sequence is m:
d. using goodness of fit R2To describe the fitting degree of linear fitting, the calculation method of goodness of fit of each detection point is as follows:
in the formula:
xk＝Δu0(k)/Δt；f(xk)to relate to xkA least squares linear fit function of;
the zero sequence current mean value at each detection point is obtained; m is the length of the sampling sequence;
e. setting a threshold value lambda of goodness-of-fit, and judging goodness-of-fit R at each detection point2And the slope of the fitting function, if the goodness of fit R2>Lambda, and the slope of the fitting function is larger than zero, the earth fault point is judged to be at the upstream of the detection point, otherwise, the earth fault point is judged to be at the downstream of the detection point.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910133461.9A CN109683063B (en) | 2019-02-22 | 2019-02-22 | Small current ground fault direction detection method using current and voltage derivative |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910133461.9A CN109683063B (en) | 2019-02-22 | 2019-02-22 | Small current ground fault direction detection method using current and voltage derivative |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109683063A CN109683063A (en) | 2019-04-26 |
| CN109683063B true CN109683063B (en) | 2021-11-12 |
Family
ID=66196001
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910133461.9A Active CN109683063B (en) | 2019-02-22 | 2019-02-22 | Small current ground fault direction detection method using current and voltage derivative |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109683063B (en) |
Families Citing this family (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110361596A (en) * | 2019-06-18 | 2019-10-22 | 上海宝准电源科技有限公司 | A kind of Resonance detector strategy based on zero-crossing examination |
| CN111596164A (en) * | 2019-08-24 | 2020-08-28 | 青岛鼎信通讯股份有限公司 | Single-phase earth fault positioning method based on Pearson correlation coefficient |
| CN110514934B (en) * | 2019-09-10 | 2021-07-30 | 苏州热工研究院有限公司 | Power supply reliability analysis method and system for low-voltage distribution board |
| CN110672927B (en) * | 2019-10-24 | 2022-05-17 | 国家电网有限公司 | Voltage fitting method based on target |
| CN110927516B (en) * | 2019-11-14 | 2022-01-21 | 长沙理工大学 | Power distribution network single-phase earth fault identification method and system based on grounding transformer tap grounding |
| CN110736899B (en) * | 2019-11-25 | 2022-07-12 | 深圳供电局有限公司 | Small current grounding fault positioning method and system, monitoring device, equipment and medium |
| CN110879330B (en) * | 2019-12-02 | 2021-08-10 | 昆明理工大学 | Power distribution network single-phase earth fault development situation discrimination method based on zero sequence volt-ampere curve area |
| CN112162170B (en) * | 2020-06-15 | 2022-05-10 | 国网湖北省电力有限公司黄冈供电公司 | Single-phase earth fault rapid line selection method for small current grounding system |
| CN111830365A (en) * | 2020-06-20 | 2020-10-27 | 青岛鼎信通讯股份有限公司 | Multi-transient statistical fault positioning method applied to power grid fault diagnosis |
| CN111896842A (en) * | 2020-07-27 | 2020-11-06 | 国网上海市电力公司 | Power distribution network arc high-resistance fault section positioning method based on interval slope |
| CN112769129A (en) * | 2020-12-28 | 2021-05-07 | 北京交通大学 | Method for obtaining key parameter relation of power distribution network based on measurement data |
| CN113078611B (en) * | 2021-03-29 | 2023-01-03 | 太原理工大学 | Small-resistance grounding system fault protection method based on zero-sequence current projection component ratio |
| CN113376534B (en) * | 2021-05-12 | 2022-04-05 | 山东大学 | Phase plane diagnosis method for early fault of power battery and advanced early warning system |
| CN113567806A (en) * | 2021-07-02 | 2021-10-29 | 上海思源光电有限公司 | Small current fault line selection method, system, terminal and medium |
| CN113419139B (en) * | 2021-07-30 | 2022-03-01 | 广东电网有限责任公司 | High-resistance grounding fault positioning method and related device for small-resistance grounding system |
| CN113625121B (en) * | 2021-08-19 | 2023-05-05 | 广东电网有限责任公司 | Small-current ground fault positioning method and related device |
| CN113721114B (en) * | 2021-09-13 | 2024-01-19 | 国网湖南省电力有限公司 | High-resistance ground fault line selection method, system and storage medium for resonant ground power distribution network |
| CN116500382B (en) * | 2023-06-26 | 2023-09-19 | 山东大学 | High-resistance fault positioning method and system based on synchronous Lissajous curve characteristics |
| CN117471366B (en) * | 2023-12-27 | 2024-04-09 | 国网福建省电力有限公司 | Metering device neutral line contact failure studying and judging method based on least square method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103760461A (en) * | 2014-01-14 | 2014-04-30 | 昆明理工大学 | Bus protection method based on sudden-change direction of fault current containing power frequency bands |
| CN103795048A (en) * | 2014-03-07 | 2014-05-14 | 福州大学 | Fault current limiting method for short circuit fault early detection |
| CN105955861A (en) * | 2016-05-19 | 2016-09-21 | 努比亚技术有限公司 | Fault detection apparatus and method as well as mobile terminal |
| CN109061393A (en) * | 2018-09-14 | 2018-12-21 | 清华大学 | One kind being suitable for transmission line of electricity arc grounding fault electric arc Precise modeling |
-
2019
- 2019-02-22 CN CN201910133461.9A patent/CN109683063B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103760461A (en) * | 2014-01-14 | 2014-04-30 | 昆明理工大学 | Bus protection method based on sudden-change direction of fault current containing power frequency bands |
| CN103795048A (en) * | 2014-03-07 | 2014-05-14 | 福州大学 | Fault current limiting method for short circuit fault early detection |
| CN105955861A (en) * | 2016-05-19 | 2016-09-21 | 努比亚技术有限公司 | Fault detection apparatus and method as well as mobile terminal |
| CN109061393A (en) * | 2018-09-14 | 2018-12-21 | 清华大学 | One kind being suitable for transmission line of electricity arc grounding fault electric arc Precise modeling |
Non-Patent Citations (1)
| Title |
|---|
| 小电流接地故障选线技术综述;徐丙垠 等;《电力设备》;20050430;第6卷(第4期);第5页第4.1.2节 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109683063A (en) | 2019-04-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109683063B (en) | Small current ground fault direction detection method using current and voltage derivative | |
| CN1180272C (en) | Small-current earth fault switch-selecting and sectioning method for power system | |
| CN100386637C (en) | Fault line selection method for single-phase-to-ground fault in small ground current distribution network | |
| CN109283428B (en) | Zero-sequence component high-order differential transformation-based single-phase grounding transient protection method at feeder outlet | |
| CN109103852B (en) | Single-phase earth fault protection method of small-resistance earth system based on zero-sequence current comparison | |
| CN108957244B (en) | Single-phase earth fault line selection positioning method for distribution network main station | |
| CN104166067A (en) | Single-phase earth fault positioning detection method and device | |
| CN103592571A (en) | Method for achieving single-phase earth fault line selection of small current grounding system | |
| CN111983510B (en) | Single-phase ground fault phase selection method and system based on phase voltage and current abrupt change | |
| CN111426908B (en) | Single-phase earth fault protection method, device and system for small current earthing system | |
| CN112731054B (en) | Power distribution network single-phase earth fault line selection method based on zero sequence residual voltage suppression | |
| CN113078611B (en) | Small-resistance grounding system fault protection method based on zero-sequence current projection component ratio | |
| JP2000503403A (en) | Method for detecting and locating high resistance ground in power network | |
| CN100387999C (en) | Circuit fault directional detecting and protecting method for power supply system | |
| CN110297154A (en) | Earth fault line selection method and device based on zero mould current temporary state energy | |
| CN105914718B (en) | A kind of earth-fault protection method based on difference of phase currents | |
| CN112534280A (en) | System and method for locating faults on a multi-phase electrical network using positive and negative sequence voltage variations | |
| CN112379302B (en) | Small-current ground fault protection method, device and system for integrating time-frequency domain information | |
| CN111900695B (en) | Single-phase earth fault removing method and device | |
| CN106019063A (en) | Fault indicator and fault detecting method | |
| CN112491016B (en) | Selective small-current self-adaptive protection method | |
| Nam et al. | Ground-fault location algorithm for ungrounded radial distribution systems | |
| CN112578228A (en) | Zero-sequence-independent single-phase earth fault discrimination algorithm for power distribution network | |
| CN110568312A (en) | Phase current distortion-based single-phase earth fault line selection method for neutral point ungrounded system | |
| CN110780155A (en) | 10kV power distribution network single-phase grounding positioning method based on zero-sequence active component |
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 |