CN108152682A - Electrical power distribution network fault location method and system - Google Patents
Electrical power distribution network fault location method and system Download PDFInfo
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Abstract
The present invention provides a kind of electrical power distribution network fault location method and system, method includes：The voltage data detected and current data are sent to main website, and judge whether that phase voltage, which occurs, to be mutated according to voltage data；When phase voltage mutation occurs, preceding M cycle data when phase voltage is mutated and rear N number of cycle data are obtained, and send preceding M cycle data and rear N number of cycle data to main website, wherein M >=3, N >=4；When receiving the single-phase earthing signal that main website is generated according to voltage data and current data, deflection scale component of a vector data, fundamental wave zero sequence current failure Fexture component data and oscillation peak polarity data are determined according to preceding M cycle data and rear N number of cycle data；Sending direction scaling vector component data, fundamental wave zero sequence current failure Fexture component data and oscillation peak polarity data alleviate the problem of fault location accuracy of the prior art is low, have reached the technique effect for improving fault location accuracy to main website.
Description
Technical Field
The invention relates to the technical field of power distribution network fault positioning, in particular to a power distribution network fault positioning method and system.
Background
According to statistics, more than 95% of power failure accidents suffered by power consumers are caused by the power distribution network, wherein the single-phase earth fault accounts for more than 80% of the total fault frequency of the power distribution network. In addition, most of the phase-to-phase faults are developed from single-phase earth faults, and therefore, research on fault location mainly focuses on solving the problem of locating single-phase earth fault sections.
Many experts and scholars have been dedicated to the study of fault location methods, and various fault location methods have been proposed. The existing fault location technology comprises: matrix algorithm techniques and artificial intelligence techniques. The matrix algorithm technology carries out fault location by establishing a network topology and a characteristic matrix of a measurement information sequence, however, the method has a large dependence on the accuracy of the measurement information, and if the accuracy of the measurement information is reduced, the accuracy of the fault location is also reduced. Most of uploaded information of the artificial intelligence technology is single direction identification, the reliability of signals is not distinguished, and the utilization of characteristic information is not sufficient, so that the accuracy of fault location can be reduced. Therefore, the existing fault location technology has the problem of low fault location accuracy.
Disclosure of Invention
In view of this, the present invention provides a method and a system for locating a fault in a power distribution network, so as to solve the technical problem of low accuracy of fault location in the prior art.
In a first aspect, an embodiment of the present invention provides a power distribution network fault location method, where the method is applied to multiple feeder terminal units in a power distribution network fault location system, where the multiple feeder terminal units communicate with a master station in the power distribution network fault location system, respectively, and the method includes:
sending the detected voltage data and current data to the main station, and judging whether phase voltage mutation occurs according to the voltage data;
when the phase voltage mutation occurs, acquiring first M pieces of periodic wave data and last N pieces of periodic wave data when the phase voltage mutation occurs, and sending the first M pieces of periodic wave data and the last N pieces of periodic wave data to the main station, wherein M is more than or equal to 3, and N is more than or equal to 4;
when a single-phase grounding signal generated by the main station according to the voltage data and the current data is received, determining direction scale vector component data, fundamental wave zero-sequence current fault direction measure component data and oscillation peak value polarity data according to the first M pieces of periodic wave data and the last N pieces of periodic wave data;
and sending the direction scale vector component data, the fundamental zero sequence current fault direction measure component data and the oscillation peak value polarity data to the main station.
With reference to the first aspect, an embodiment of the present invention provides a first possible implementation manner of the first aspect, where determining fundamental zero-sequence current fault direction measure component data according to the first M pieces of cycle data and the last N pieces of cycle data includes:
determining three-phase current data, three-phase voltage data and a system load impedance angle according to the first M pieces of periodic wave data and the last N pieces of periodic wave data;
determining a phase offset according to the three-phase current data and the three-phase voltage data;
substituting the phase offset and the number of sampling points in a preset period into a preset first formula to determine a phase offset adjustment factor;
determining an operation interval adjusting factor according to the system load impedance angle and a preset operation interval;
substituting the sampling point number, the phase deviation adjustment factor and the operation interval adjustment factor in the period into a preset zero-sequence current direction vector component formula to obtain zero-sequence current direction vector component data;
and obtaining fundamental wave zero sequence current fault direction measure component data according to the zero sequence current direction vector component data and a preset zero sequence current fault direction judging method.
With reference to the first aspect, an embodiment of the present invention provides a second possible implementation manner of the first aspect, where the method for determining a zero sequence current fault direction includes:
when d isAk·dBk·dCk>0, determining that the downstream line has forward fault, wherein dAkData representing the A-phase component of the zero-sequence current direction vector, dBkData representing the B-phase component of the zero-sequence current direction vector, dCkRepresenting zero sequence current direction vector C phase component data;
when d isAk·dBk·dCk<When 0, determining that the upstream line has reverse fault;
when d isAk·dBk·dCk>at 0, αkWhen d is equal to 1Ak·dBk·dCk<at 0, αkis-1, wherein αkRepresenting the direction scale vector component data.
With reference to the first aspect, an embodiment of the present invention provides a third possible implementation manner of the first aspect, where determining oscillation peak polarity data according to the first M pieces of cycle data and the last N pieces of cycle data includes:
obtaining a phase current sampling time sequence and a standard sinusoidal signal distance according to the first M pieces of periodic wave data and the last N pieces of periodic wave data;
determining a three-dimensional space phase point according to the phase current sampling time sequence and a preset coordinate delay method;
determining an oscillation starting point according to the three-dimensional space phase point, a preset distance function and a preset oscillation starting point judgment condition;
and determining the oscillation peak polarity data according to the standard sinusoidal signal distance and the oscillation starting point.
With reference to the first aspect, an embodiment of the present invention provides a fourth possible implementation manner of the first aspect, where the determining the oscillation peak polarity data according to the standard sinusoidal signal distance and the oscillation starting point includes:
substituting the oscillation starting point into the distance function to obtain a result, and subtracting the standard sinusoidal signal distance to obtain a first difference value;
respectively substituting phase points arranged behind the oscillation starting point in the phase current sampling time sequence into the distance function to obtain a plurality of distance values;
respectively subtracting the distance values from the standard sinusoidal signal to obtain a plurality of second difference values;
determining the distance value corresponding to the second difference value with the largest absolute value as a target distance value;
if the target distance value is the same as the first difference value in sign, determining a phase point corresponding to the target distance value as an oscillation initial peak point;
substituting the oscillation initial peak point into the distance function, and obtaining the difference between the obtained result and the distance of the standard sinusoidal signal to obtain the oscillation peak polarity data.
In a second aspect, an embodiment of the present invention further provides a power distribution network fault location method, where the method is applied to a master station in a power distribution network fault location system, the power distribution network fault location system further includes a plurality of feeder terminal units, and the plurality of feeder terminal units communicate with the master station respectively, and the method includes:
receiving a plurality of voltage data and a plurality of current data sent by a plurality of feeder terminal units;
generating a single-phase grounding signal according to the voltage data and the current data, and respectively sending the single-phase grounding signal to a plurality of feeder terminal units related to the single-phase grounding signal;
receiving first M pieces of periodic wave data, last N pieces of periodic wave data, direction scale vector component data, fundamental wave zero sequence current fault direction measure component data and a plurality of oscillation peak value polarity data which are sent by a plurality of feeder line terminal units related to the single-phase grounding signal, wherein M is more than or equal to 3, and N is more than or equal to 4;
correspondingly generating fundamental wave zero-sequence current fault direction measure according to a plurality of fundamental wave zero-sequence current fault direction measure component data;
generating a transient phase current fault direction measure from a plurality of said direction scale vector component data and a plurality of said oscillation peak polarity data;
and positioning the power distribution network fault according to the first M pieces of periodic wave data, the last N pieces of periodic wave data, the fundamental wave zero sequence current fault direction measurement, the transient phase current fault direction measurement and a preset multi-index decision model.
In combination with the second aspect, the present invention provides a first possible implementation manner of the second aspect, wherein the generating a transient phase current fault direction measure according to a plurality of direction scale vector component data and a plurality of oscillation peak polarity data includes:
generating intermediate variables by the aid of the polarity data of the oscillation peak values in a preset mode respectively;
multiplying the intermediate variable corresponding to the same feeder terminal unit by the direction scale vector component data to respectively obtain transient phase current fault direction measure component data;
and forming the transient phase current fault direction measure by using a plurality of pieces of the transient phase current fault direction measure component data.
With reference to the second aspect, an embodiment of the present invention provides a second possible implementation manner of the second aspect, where the locating a power distribution network fault according to the fundamental zero-sequence current fault direction measure, the transient phase current fault direction measure, and a preset multi-index decision model includes:
generating a first direction scaling weight, a first sub-targeting function priority value, a second direction scaling weight and a second sub-targeting function priority value according to the fundamental wave zero sequence current fault direction measure, the transient phase current fault direction measure, a preset second credibility factor and a preset first credibility factor;
determining a detection state vector according to the plurality of direction scale vector component data and a preset detection state generation condition;
determining an expected value vector according to the first M pieces of periodic wave data, the last N pieces of periodic wave data and a preset expected value function;
substituting the first direction scale weight, the detection state vector and the expected value vector into a preset first sub-target function to determine a first sub-target;
substituting the second direction scale weight, the detection state vector and the expected value vector into a preset second sub-target function to determine a second sub-target;
substituting the first sub-goal function priority value, the second sub-goal function priority value, the first sub-goal and the second sub-goal into a preset uniform goal function to obtain an optimal solution of the goal function;
and positioning the power distribution network fault according to the optimal solution of the objective function.
In combination with the second aspect, the embodiment of the invention providesIn a third possible implementation manner of the second aspect, the multi-index decision model is:
where n denotes the number of line sections into which the distribution network system is divided, liDenotes the line segment state numbered i, i 1, 2., n, L denotes the n-dimensional line state set, E denotes the feasible domain of the function, ω1Representing the priority value, ω, of the first sub-targeting function2Representing the second sub-targeting function priority value, f1(L) represents the first sub-targeting function, f2(L) represents the second sub-targeting function.
In a third aspect, an embodiment of the present invention further provides a power distribution network fault location system, including: a master station as claimed in any of the second aspects and a plurality of feeder terminal units as claimed in any of the first aspects.
The embodiment of the invention has the following beneficial effects: the power distribution network fault positioning method provided by the embodiment of the invention is applied to a plurality of feeder terminal units in a power distribution network fault positioning system, the feeder terminal units are respectively communicated with a master station in the power distribution network fault positioning system, and the method comprises the following steps: sending the detected voltage data and current data to the main station, and judging whether phase voltage mutation occurs according to the voltage data; when the phase voltage mutation occurs, acquiring first M pieces of periodic wave data and last N pieces of periodic wave data when the phase voltage mutation occurs, and sending the first M pieces of periodic wave data and the last N pieces of periodic wave data to the main station, wherein M is more than or equal to 3, and N is more than or equal to 4; when a single-phase grounding signal generated by the main station according to the voltage data and the current data is received, determining direction scale vector component data, fundamental wave zero-sequence current fault direction measure component data and oscillation peak value polarity data according to the first M pieces of periodic wave data and the last N pieces of periodic wave data; the direction scale vector component data, the fundamental zero sequence current fault direction measure component data and the oscillation peak value polarity data are sent to the master station, the power distribution network fault location method is applied to the master station in a power distribution network fault location system, and the method comprises the following steps: receiving a plurality of voltage data and a plurality of current data sent by a plurality of feeder terminal units; generating a single-phase grounding signal according to the voltage data and the current data, and respectively sending the single-phase grounding signal to a plurality of feeder terminal units related to the single-phase grounding signal; receiving first M pieces of periodic wave data, last N pieces of periodic wave data, direction scale vector component data, fundamental wave zero sequence current fault direction measure component data and a plurality of oscillation peak value polarity data which are sent by a plurality of feeder line terminal units related to the single-phase grounding signal, wherein M is more than or equal to 3, and N is more than or equal to 4; correspondingly generating fundamental wave zero-sequence current fault direction measure according to a plurality of fundamental wave zero-sequence current fault direction measure component data; generating a transient phase current fault direction measure from a plurality of said direction scale vector component data and a plurality of said oscillation peak polarity data; and positioning the power distribution network fault according to the first M pieces of periodic wave data, the last N pieces of periodic wave data, the fundamental wave zero sequence current fault direction measurement, the transient phase current fault direction measurement and a preset multi-index decision model.
Therefore, when the phase voltage sudden change occurs in the feeder terminal unit and a single-phase grounding signal sent by the main station is received, the power distribution network fault location method generates fundamental zero-sequence current fault direction measure and transient phase current fault direction measure according to the acquired frequency data, quantitatively evaluates the obvious degree of fault characteristics, introduces a credibility theory into the multi-index decision model as a decision rule, constructs a power distribution network fault location multi-target function, solves the optimal solution of a target function, and optimally locates the power distribution network fault according to the target function, so that the problem of low fault location accuracy in the prior art is solved, and the technical effect of improving the fault location accuracy is achieved.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
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 will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a first flowchart of a power distribution network fault location method according to an embodiment of the present invention;
fig. 2 is a second flowchart of a power distribution network fault location method according to an embodiment of the present invention;
FIG. 3 is a flowchart of step S205 in FIG. 2;
fig. 4 is a schematic structural diagram of a power distribution network fault location system provided in an embodiment of the present invention.
Detailed Description
To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. 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.
At present, the problem of low fault location accuracy exists in the existing fault location technology, and based on the problem, the fault location method and the system for the power distribution network provided by the embodiment of the invention can relieve the problem of low fault location accuracy in the prior art, and achieve the technical effect of improving the fault location accuracy.
To facilitate understanding of the present embodiment, a detailed description is first given of a power distribution network fault location method disclosed in the present embodiment, where the power distribution network fault location method is applied to a plurality of feeder terminal units in a power distribution network fault location system, and the plurality of feeder terminal units communicate with a master station in the power distribution network fault location system respectively, as shown in fig. 1, the power distribution network fault location method may include the following steps.
And step S101, sending the detected voltage data and current data to the main station, and judging whether phase voltage sudden change occurs according to the voltage data.
Illustratively, the voltage data and the current data are collected in real time, and the voltage data and the current data are dynamically stored and refreshed according to a data window with a first preset length. And judging whether the mutation amount of the voltage data exceeds a set threshold value, determining that the phase voltage mutation occurs when the mutation amount of the voltage data exceeds the set threshold value, and operating a positioning program.
Step S102, when the phase voltage sudden change occurs, obtaining the first M pieces of periodic wave data and the last N pieces of periodic wave data when the phase voltage sudden change occurs, and sending the first M pieces of periodic wave data and the last N pieces of periodic wave data to the main station, wherein M is larger than or equal to 3, and N is larger than or equal to 4.
Illustratively, when the phase voltage sudden change occurs, the current data are collected in real time, and the current data are stored according to a data window with a second preset length, wherein the storage length can be M + N periods, M is more than or equal to 3, and N is more than or equal to 4.
Step S103, when a single-phase grounding signal generated by the main station according to the voltage data and the current data is received, determining direction scale vector component data, fundamental zero-sequence current fault direction measure component data and oscillation peak polarity data according to the first M pieces of cycle data and the last N pieces of cycle data.
For example, if a single-phase grounding signal generated by the master station according to the voltage data and the current data is not received within a preset time, the stored voltage data and the stored current data are automatically deleted, and the device is restarted to enter a device starting judgment state.
For example, determining fundamental zero sequence current fault direction measure component data according to the first M pieces of periodic data and the last N pieces of periodic data may include the following steps.
And step S10311, determining three-phase current data, three-phase voltage data and a system load impedance angle according to the first M pieces of periodic wave data and the last N pieces of periodic wave data.
Illustratively, the number of sampling points n in one period of a known sampling signalsAmplitude of phase current IimWhere I is a, B, C, zero sequence current amplitude I0mSum of grid angular frequency omega and system single-phase to ground capacitance C0∑。
And step S10312, determining a phase offset according to the three-phase current data and the three-phase voltage data.
Illustratively, when there is an excess resistance R at the grounding pointfIn time, the three-phase voltage data may be used as a reference instead of the zero-sequence voltage to determine the phase offset Δ θ. Δ θ ═ arctan (-3 ω R)fC0∑)。
And step S10313, substituting the phase offset and the number of sampling points in a preset period into a preset first formula, and determining a phase offset adjustment factor.
Illustratively, the first formula may beThereby determining the phase offset adjustment factor epsilon.
And step S10314, determining an operation interval adjusting factor according to the system load impedance angle and a preset operation interval.
Illustratively, the operating range is (0 °,60 °) when the system is loaded with an impedance angleWhen the operation interval is exceeded, the system load impedance angle can be adjusted by changing the operation interval adjustment factor sigmaAnd the operation interval is positioned. In order to make the system load impedance angleIn the operating interval, the adjusting factor sigma of the operating interval is changed, and every time the adjusting factor sigma is increased by 1, the interval is rotated by 360 degrees/n anticlockwisesThereby determining the adjustment factor sigma of the operation interval, and the adjusted operation interval is (-360 DEG sigma/n)s,60°-360°σ/ns)。
And step S10315, substituting the sampling point number, the phase offset adjustment factor and the operation interval adjustment factor in the period into a preset zero-sequence current direction vector component formula to obtain zero-sequence current direction vector component data.
Illustratively, the zero sequence current direction vector component formula isWherein ii(s) is the sampled value at the moment of phase current s, i0(s-epsilon) is the sampled value at the time of zero sequence current s-epsilon. dAkIs the zero sequence current direction vector A phase component data of the feeder terminal unit with the sequence number k, dBkIs serial number kZero sequence current direction vector B phase component data, d of the feeder terminal unitCkAnd the zero sequence current direction vector C phase component data of the feeder line terminal unit with the sequence number k.
And step S10316, obtaining the fundamental wave zero sequence current fault direction measure component data according to the zero sequence current direction vector component data and a preset zero sequence current fault direction judging method.
For example, the zero sequence current fault direction determination method may be: when d isAk·dBk·dCk>When 0, determining that the downstream line has a forward fault; when d isAk·dBk·dCk<And 0, determining that the upstream line has reverse fault. When d isAk·dBk·dCk>at 0, αkWhen d is equal to 1Ak·dBk·dCk<at 0, αkis-1, wherein αkRepresenting the direction scale vector component data. The positive direction of each branch line in the system is specified to be from the bus side to the load side, the fault of the downstream line of the feeder line terminal unit is a positive direction fault, and the fault of the upstream line is a reverse direction fault.
Illustratively, when the ground phase is a phase, the system load impedance angle is equal to the feeder terminal unit with the sequence number k and the forward fault occursWhen the load is fixed, the load current can be regarded as a constant quantity, and the phasors of the three-phase current and the zero-sequence current meet the following relation:for the feeder line terminal unit with the reverse fault and the sequence number of k, the phasors of the three-phase current and the zero-sequence current meet the following relation:therefore, when the system is loaded with an impedance angleWhen the feeder terminal unit with the serial number k has a forward fault, dAk·dBk·dCk>0. When the feeder line terminal unit with the sequence number k has reverse fault, dAk·dBk·dCk<0. Therefore, d can be calculated according to the three-phase current and the zero-sequence current at the feeder terminal unit with the sequence number kAk、dBkAnd dCkAnd then determines the direction of the fault.
Illustratively, if the grounding point has a transition resistance Rf，Will followThe offset is shifted. At this time, the offset pair d needs to be taken into accountAk、dBkAnd dCkThe influence of (c). Neutral point potential when single-phase earthedThe offset relationship is:wherein,is the system single-phase equivalent potential. When setting metallic groundingIs an ideal valueThenOffset from the ideal value ofΔθ＝arctan(-3ωRfC0Sigma), wherein,for zero sequence voltage offset, Δ U0Is the amplitude offset, and Δ θ is the phase offset, when RfC0Σ from 0 → ∞ and Δ θ from 0 ° → 90 °. When the grounding phases are A, B, C respectively, takeTaking the voltage per unit of the voltage to ground as a reference value, the voltage per unit of the voltage to ground is respectively as follows: from the above formula, the grounding phase is known to beDelta theta can be uniquely determined, eliminating delta theta from the calculated dAk、dBkAnd dCkThe influence of (c). By combining the deduction, the fault direction judgment can be realized by using the load voltage to replace the zero sequence voltage as a reference standard.
Exemplary, x1kCan represent the fundamental wave zero sequence current fault direction measure component data, x of the feeder terminal unit with the sequence number k1k＝I0mk·αk。
Illustratively, determining oscillation peak polarity data from the first M cycles data and the last N cycles data may comprise the following steps.
Step S10321, obtaining a phase current sampling time sequence and a standard sinusoidal signal distance according to the first M cycle data and the last N cycle data.
For example, the phase current sampling time sequence collected at the feeder terminal unit with the sequence number k may be ikI (1), i (2), i (N), which may be determined for a standard sinusoidal signal x(s) Acos (ω s Δ t + Φ). For the sampling time sequence of the standard sinusoidal signal x(s) ═ Acos (ω s Δ t + Φ), the coordinates of the s-th phase point in the three-dimensional space are composed of:the coordinate composition of the three-dimensional space can be obtained
Illustratively, at the instant of a single-phase ground fault, there is a significant transient process. And supposing that insulation breakdown occurs to the phase A when the power frequency voltage is at the negative maximum value, the non-fault phase charges the ground capacitor, the charging current flows to the fault point f through the power supply, the fault phase discharges the ground capacitor, and the discharging current flows to the fault point f through the bus. For the feeder terminal unit with the forward fault, the A-phase transient current of the feeder terminal unit with the forward fault consists of two currents, namely discharge current and charging current, and for the feeder terminal unit with the reverse fault, the A-phase transient current is only the discharge current. The transient current direction is characterized by the polarity of the initial peak of the current oscillation, and the transient current directions at the two feeder terminal units are always opposite. Therefore, the main station can synthesize the polarity information of the fault phase transient current oscillation initial peak value of each feeder terminal unit at the initial fault moment to accurately judge the fault direction.
Step S10322, determining a three-dimensional space phase point according to the phase current sampling time sequence and a preset coordinate delay method.
Illustratively, the time sequence i is sampled according to the phase currentkThe phase space is reconstructed by adopting a coordinate delay method to obtain N-2 tau f in a three-dimensional space, wherein the phase space is { i (1), i (2) }sPhase points, { h (1), h (2),.., h (N-2 τ f)s) In which fsIn order to be able to sample the frequency,t is a known quantity and the embedding dimension m is 3.
Step S10323, determining an oscillation starting point according to the three-dimensional space phase point, a preset distance function, and a preset oscillation starting point determination condition.
Illustratively, the distance function may beWhere h (x) and h (y) are the components of the s-th phase point in the x-y plane, i (s + τ f)s) Is a time delay point of i(s).
Illustratively, F(s) of the standard sinusoidal signal is A, and after a single-phase ground fault occurs, high-frequency components are superposed on the standard sinusoidal signal, so that F(s) of corresponding phase points of a sampling time sequence deviates from the standard sinusoidal signal by the distance A. Therefore, the oscillation start point determination conditions are set to: and | Δ F(s) | F(s) -F (s-1) | > δ, wherein δ | | F (s-1) -fs | s-2| + | F (s-2) -F (s-3) |, Δ F(s) is the distance function deviation of the current phase point s from the previous phase point s-1, and δ is a judgment threshold. And the phase point meeting the oscillation starting point judgment condition is the oscillation starting point.
Illustratively, the oscillation start point s may affect (s- τ f) after the phase space reconstructionsS) and (s, s + τ fs) Euclidean distance of two phase points, i.e. at point s- τ fsThe generated over-domain phenomenon is actually caused by s, and thus the starting point s beyond the threshold range is mapped to the actual phase current oscillation component starting point. s + τ fs。
Step S10324, determining the oscillation peak polarity data according to the standard sinusoidal signal distance and the oscillation starting point.
Illustratively, the determining the oscillation peak polarity data according to the standard sinusoidal signal distance and the oscillation starting point may include the following steps.
Step S10331, substituting the oscillation starting point into the distance function to obtain a result, and subtracting the standard sinusoidal signal distance to obtain a first difference.
Step S10332, respectively substituting phase points arranged behind the oscillation start point in the phase current sampling time sequence into the distance function to obtain a plurality of distance values.
Step S10333, subtracting the distance values from the standard sinusoidal signal, respectively, to obtain a plurality of second difference values.
In step S10334, the distance value corresponding to the second difference value having the largest absolute value is determined as the target distance value.
Step S10335, if the target distance value and the first difference value have the same sign, determining a phase point corresponding to the target distance value as an oscillation initial peak point.
Illustratively, the oscillation initial peak point is denoted as s'.
Step S10336, substituting the oscillation initial peak point into the distance function, and obtaining a difference between the obtained result and the standard sinusoidal signal distance, thereby obtaining the oscillation peak polarity data.
Illustratively, the oscillation peak polarity data is denoted as mkThen m iskF (s') -a, wherein mkIs the oscillation peak polarity data of the feeder termination unit with sequence number k.
And step S104, sending the direction scale vector component data, the fundamental zero sequence current fault direction measure component data and the oscillation peak value polarity data to the main station.
In the embodiment of the invention, the power distribution network fault positioning method is applied to a plurality of feeder terminal units in a power distribution network fault positioning system, the feeder terminal units are respectively communicated with a master station in the power distribution network fault positioning system, and the method comprises the following steps: sending the detected voltage data and current data to the main station, and judging whether phase voltage mutation occurs according to the voltage data; when the phase voltage mutation occurs, acquiring first M pieces of periodic wave data and last N pieces of periodic wave data when the phase voltage mutation occurs, and sending the first M pieces of periodic wave data and the last N pieces of periodic wave data to the main station, wherein M is more than or equal to 3, and N is more than or equal to 4; when a single-phase grounding signal generated by the main station according to the voltage data and the current data is received, determining direction scale vector component data, fundamental wave zero-sequence current fault direction measure component data and oscillation peak value polarity data according to the first M pieces of periodic wave data and the last N pieces of periodic wave data; the direction scale vector component data, the fundamental wave zero sequence current fault direction measure component data and the oscillation peak value polarity data are sent to the main station, so that when the feeder line terminal unit has the phase voltage sudden change and receives a single-phase grounding signal sent by the main station, the power distribution network fault positioning method generates the fundamental wave zero sequence current fault direction measure and the oscillation peak value polarity data used for generating the transient phase current fault direction measure according to the acquired frequency data, the obvious degree of fault characteristics can be evaluated quantitatively, quantitative data support is provided for the power distribution network fault positioning process, the problem of low fault positioning accuracy in the prior art is solved, and the technical effect of improving the fault positioning accuracy is achieved. .
In another embodiment of the present invention, a detailed description is given of a power distribution network fault location method disclosed in the embodiment of the present invention, where the power distribution network fault location method is applied to a master station in a power distribution network fault location system, the power distribution network fault location system further includes a plurality of feeder terminal units, and the plurality of feeder terminal units are respectively in communication with the master station, as shown in fig. 2, the power distribution network fault location method may include the following steps.
Step S201, receiving a plurality of voltage data and a plurality of current data sent by a plurality of feeder terminal units.
Step S202, generating a single-phase grounding signal according to the plurality of voltage data and the plurality of current data, and respectively sending the single-phase grounding signal to the plurality of feeder terminal units related to the single-phase grounding signal.
Step S203, receiving first M pieces of periodic wave data, last N pieces of periodic wave data, direction scale vector component data, fundamental wave zero sequence current fault direction measure component data and a plurality of oscillation peak value polarity data which are sent by a plurality of feeder terminal units related to the single-phase grounding signal, wherein M is more than or equal to 3, and N is more than or equal to 4.
And step S204, correspondingly generating fundamental zero-sequence current fault direction measure according to the plurality of fundamental zero-sequence current fault direction measure component data.
Illustratively, the fundamental zero-sequence current fault direction measure isWherein x1kIs the fundamental zero sequence current fault direction measure component data of the feeder terminal unit with the sequence number k, npRepresenting the total number of said feeder termination units in the system.
Step S205, generating a transient phase current fault direction measure according to the plurality of direction scale vector component data and the plurality of oscillation peak polarity data.
Illustratively, a plurality of the directional scale vector component data may constitute a directional scale vector, the directional scale vector being represented aswherein alpha iskAnd representing direction scale vector component data of the feeder terminal unit with the sequence number k.
Illustratively, as shown in fig. 3, step S205 may include the following steps.
Step S301, generating intermediate variables from the oscillation peak polarity data in a preset manner.
Illustratively, the intermediate variable may be b ═ abs (m)k)，mkIs the oscillation peak polarity data of the feeder termination unit with sequence number k.
Step S302, multiplying the intermediate variable corresponding to the same feeder terminal unit by the direction scaling vector component data, to obtain transient phase current fault direction measure component data, respectively.
exemplarily, the intermediate variable b and the direction scale vector component data α of the feeder terminal unit with the sequence number k are usedkMultiplying to obtain the transient phase current fault direction measure component data x of the feeder line terminal unit with the sequence number k2kWherein x is2k＝abs(mk)·αk。
Step S303, forming the transient phase current fault direction measure from the plurality of transient phase current fault direction measure component data.
For example, the transient phase current fault direction measure may beWherein x is2kAnd the measurement component data are transient phase current fault direction measurement component data of the feeder line terminal unit with the sequence number k.
And S206, positioning the power distribution network fault according to the first M pieces of periodic wave data, the last N pieces of periodic wave data, the fundamental wave zero sequence current fault direction measure, the transient phase current fault direction measure and a preset multi-index decision model.
For example, the multi-index decision model may be:
where n denotes the number of line sections into which the distribution network system is divided, liDenotes the line segment state with the number i, i 1,2Feasible region, ω1Representing the priority value, ω, of the first sub-targeting function2Representing the second sub-targeting function priority value, f1(L) represents the first sub-targeting function, f2(L) represents the second sub-targeting function.
Illustratively, step S206 may include the following steps.
Step S2061, generating a first direction scale weight, a first sub-target function priority value, a second direction scale weight and a second sub-target function priority value according to the fundamental zero sequence current fault direction measure, the transient phase current fault direction measure, a preset second credibility factor and a preset first credibility factor.
Illustratively, according to the fault direction measure X of the fundamental zero-sequence current1Generating the first direction scale weights and the normalized scalar arrayFault direction measure X of the transient phase current2Generating the second direction-scale weights and the normalized scalar arrayThe first direction scale weight has a component ofThen the first direction scale weight isThe second direction scale weight has a component ofThen the second direction scale weight isThe first sub-targeting function priority value omega1＝CF1(1)+CF2(1)-CF1(1)×CF2(1) Wherein, CF1(1)＝CF(1|e1)×max{0,CF(e1)}，CF2(1)＝CF(1|e2)×max{0,CF(e2)}，CF(e1) And CF (e)2) Is the confidence level of the evidence, indicating the degree to which the evidence is true, CF (e)1) And CF (e)2) The value of (a) will gradually increase with the continuous expansion of the historical information base, CF (e)1)∈[0,1]，CF(e2)∈[0,1]。CF(1|e1) And CF (1| e)2) Is a confidence factor, i.e. e1And e2The influence on the confidence of index 1, here the confidence factor is considered to be constant positive. CF (1| e)1)＝Pt1And (t is 1,2,.. num), wherein num is the number of fault types, t is the current fault type, and P is the current fault typet1For the accuracy, P, of index 1 in the information base for locating t-type faultst1Is known in advance.Wherein, the second sub-targeting function priority value omega2＝CF1(2)+CF2(2)-CF1(2)×CF2(2) Wherein, CF1(2)＝CF(2|e1)×max{0,CF(e1)}，CF2(2)＝CF(2|e2)×max{0,CF(e2)}，CF(e1) And CF (e)2) Is the confidence level of the evidence, indicating the degree to which the evidence is true, CF (e)1) And CF (e)2) The value of (a) will gradually increase with the continuous expansion of the historical information base, CF (e)1)∈[0,1]，CF(e2)∈[0,1]。CF(2|e1) And CF (2| e)2) Is a confidence factor, i.e. e1And e2The influence on the confidence of index 2 is here considered to be that the confidence factor is always positive. CF (2| e)1)＝Pt2And (t is 1,2,.. num), wherein num is the number of fault types, t is the current fault type, and P is the current fault typet2For the accuracy, P, of index 2 in the information base for locating t-type faultst2Is known in advance.Wherein,
in step S2062, a detection state vector is determined according to a plurality of pieces of the direction scale vector component data and a preset detection state generation condition.
Illustratively, the detection state generation condition isWherein r is 1,2, k is 1,2p。
Step S2063, determining an expected value vector according to the first M pieces of periodic wave data, the last N pieces of periodic wave data, and a preset expected value function.
Illustratively, the expectation function isWherein ljIs the state of the j-th line upstream of the feeder termination unit with sequence number k,ljjis the state of the jj-th section of the line downstream of the feeder termination unit with sequence number k,
step S2064, substituting the first direction scale weight, the detected state vector and the expected value vector into a preset first sub-target function, and determining a first sub-target.
Illustratively, the first sub-targeting function isThe smaller the value, the higher the corresponding degree of the feeder terminal unit information in the line state group.
Step S2065, substituting the second direction scale weight, the detected state vector, and the expected value vector into a preset second sub-target function, and determining a second sub-target.
Illustratively, the second sub-targeting function isThe smaller the value, the higher the corresponding degree of the feeder terminal unit information in the line state group.
Step S2066, the first sub-goal function priority value, the second sub-goal function priority value, the first sub-goal and the second sub-goal are substituted into a preset uniform goal function to obtain the optimal solution of the goal function.
Illustratively, the uniform objective function isThe optimal solution of the objective function can be solved through a discrete binary particle swarm optimization algorithm.
And S2067, positioning the power distribution network fault according to the optimal solution of the objective function.
For example, if the form of the objective function optimal solution is L ═ 1,0, it may be determined that a power distribution network fault has occurred at the location of the feeder termination unit with sequence number 1.
In the embodiment of the invention, the power distribution network fault positioning method is applied to a main station in a power distribution network fault positioning system, the power distribution network fault positioning system further comprises a plurality of feeder terminal units, the plurality of feeder terminal units are respectively communicated with the main station, and the method comprises the following steps: receiving a plurality of voltage data and a plurality of current data sent by a plurality of feeder terminal units; generating a single-phase grounding signal according to the voltage data and the current data, and respectively sending the single-phase grounding signal to a plurality of feeder terminal units related to the single-phase grounding signal; receiving first M pieces of periodic wave data, last N pieces of periodic wave data, direction scale vector component data, fundamental wave zero sequence current fault direction measure component data and a plurality of oscillation peak value polarity data which are sent by a plurality of feeder line terminal units related to the single-phase grounding signal, wherein M is more than or equal to 3, and N is more than or equal to 4; correspondingly generating fundamental wave zero-sequence current fault direction measure according to a plurality of fundamental wave zero-sequence current fault direction measure component data; generating a transient phase current fault direction measure from a plurality of said direction scale vector component data and a plurality of said oscillation peak polarity data; positioning the power distribution network fault according to the first M pieces of periodic wave data, the last N pieces of periodic wave data, the fundamental wave zero sequence current fault direction measure, the transient phase current fault direction measure and a preset multi-index decision model, so that the main station generates the transient phase current fault direction measure according to a plurality of oscillation peak value polarity data after receiving the fundamental wave zero sequence current fault direction measure sent by the feeder terminal unit and the plurality of oscillation peak value polarity data used for generating the transient phase current fault direction measure, so that the obvious degree of fault characteristics can be quantitatively evaluated, meanwhile, a credibility theory is introduced into the multi-index decision model as a decision rule, a power distribution network fault positioning multi-target function is constructed, an optimal solution of the target function is solved, and the power distribution network fault is optimally positioned according to the target function, wherein an optimization solution thought is adopted in the embodiment of the invention, the fault-tolerant performance of fault positioning is improved, so that the problem of low fault positioning accuracy in the prior art is solved, and the technical effect of improving the fault positioning accuracy is achieved.
In another embodiment of the present invention, a power distribution network fault location system disclosed in the embodiment of the present invention is described in detail, where the power distribution network fault location system includes: the main station according to any of the above embodiments and a plurality of feeder terminal units according to any of the above embodiments.
Illustratively, as shown in fig. 4, the distribution network fault location system is described by taking the example that the distribution network fault location system includes one main station and two feeder terminal units. The power distribution network fault location system may include: a main station 41, a first feeder termination unit 42 and a second feeder termination unit 43.
Unless specifically stated otherwise, the relative steps, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of the present invention.
The device provided by the embodiment of the present invention has the same implementation principle and technical effect as the method embodiments, and for the sake of brief description, reference may be made to the corresponding contents in the method embodiments without reference to the device embodiments.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the system and the apparatus described above may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In all examples shown and described herein, any particular value should be construed as merely exemplary, and not as a limitation, and thus other examples of example embodiments may have different values.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
In addition, in the description of the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
The computer program product for performing the power distribution network fault location method provided by the embodiment of the present invention includes a computer-readable storage medium storing a nonvolatile program code executable by a processor, where instructions included in the program code may be used to execute the method described in the foregoing method embodiment, and specific implementation may refer to the method embodiment, and is not described herein again.
It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units is only one logical division, and there may be other divisions when actually implemented, and for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of devices or units through some communication interfaces, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a non-volatile computer-readable storage medium executable by a processor. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present invention, which are used for illustrating the technical solutions of the present invention and not for limiting the same, and the protection scope of the present invention is not limited thereto, although the present invention is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. A power distribution network fault positioning method is characterized in that the method is applied to a plurality of feeder terminal units in a power distribution network fault positioning system, the feeder terminal units are respectively communicated with a main station in the power distribution network fault positioning system, and the method comprises the following steps:
sending the detected voltage data and current data to the main station, and judging whether phase voltage mutation occurs according to the voltage data;
when the phase voltage mutation occurs, acquiring first M pieces of periodic wave data and last N pieces of periodic wave data when the phase voltage mutation occurs, and sending the first M pieces of periodic wave data and the last N pieces of periodic wave data to the main station, wherein M is more than or equal to 3, and N is more than or equal to 4;
when a single-phase grounding signal generated by the main station according to the voltage data and the current data is received, determining direction scale vector component data, fundamental wave zero-sequence current fault direction measure component data and oscillation peak value polarity data according to the first M pieces of periodic wave data and the last N pieces of periodic wave data;
and sending the direction scale vector component data, the fundamental zero sequence current fault direction measure component data and the oscillation peak value polarity data to the main station.
2. The method for locating faults in a power distribution network according to claim 1, wherein determining fundamental zero-sequence current fault direction measure component data according to the first M pieces of cycle data and the last N pieces of cycle data comprises:
determining three-phase current data, three-phase voltage data and a system load impedance angle according to the first M pieces of periodic wave data and the last N pieces of periodic wave data;
determining a phase offset according to the three-phase current data and the three-phase voltage data;
substituting the phase offset and the number of sampling points in a preset period into a preset first formula to determine a phase offset adjustment factor;
determining an operation interval adjusting factor according to the system load impedance angle and a preset operation interval;
substituting the sampling point number, the phase deviation adjustment factor and the operation interval adjustment factor in the period into a preset zero-sequence current direction vector component formula to obtain zero-sequence current direction vector component data;
and obtaining fundamental wave zero sequence current fault direction measure component data according to the zero sequence current direction vector component data and a preset zero sequence current fault direction judging method.
3. The power distribution network fault location method according to claim 2, wherein the zero sequence current fault direction determination method comprises:
when d isAk·dBk·dCk>0, determining that the downstream line has forward fault, wherein dAkData representing the A-phase component of the zero-sequence current direction vector, dBkData representing the B-phase component of the zero-sequence current direction vector, dCkRepresenting zero sequence current direction vector C phase component data;
when d isAk·dBk·dCk<When 0, determining that the upstream line has reverse fault;
when d isAk·dBk·dCk>at 0, αkWhen d is equal to 1Ak·dBk·dCk<at 0, αkis-1, wherein αkRepresenting the direction scale vector component data.
4. The method for locating faults in a power distribution network according to claim 3, wherein determining oscillation peak polarity data according to the first M cycles and the last N cycles comprises:
obtaining a phase current sampling time sequence and a standard sinusoidal signal distance according to the first M pieces of periodic wave data and the last N pieces of periodic wave data;
determining a three-dimensional space phase point according to the phase current sampling time sequence and a preset coordinate delay method;
determining an oscillation starting point according to the three-dimensional space phase point, a preset distance function and a preset oscillation starting point judgment condition;
and determining the oscillation peak polarity data according to the standard sinusoidal signal distance and the oscillation starting point.
5. The method of claim 4, wherein the determining the oscillation peak polarity data according to the standard sinusoidal signal distance and the oscillation starting point comprises:
substituting the oscillation starting point into the distance function to obtain a result, and subtracting the standard sinusoidal signal distance to obtain a first difference value;
respectively substituting phase points arranged behind the oscillation starting point in the phase current sampling time sequence into the distance function to obtain a plurality of distance values;
respectively subtracting the distance values from the standard sinusoidal signal to obtain a plurality of second difference values;
determining the distance value corresponding to the second difference value with the largest absolute value as a target distance value;
if the target distance value is the same as the first difference value in sign, determining a phase point corresponding to the target distance value as an oscillation initial peak point;
substituting the oscillation initial peak point into the distance function, and obtaining the difference between the obtained result and the distance of the standard sinusoidal signal to obtain the oscillation peak polarity data.
6. A power distribution network fault positioning method is characterized in that the method is applied to a main station in a power distribution network fault positioning system, the power distribution network fault positioning system further comprises a plurality of feeder terminal units, the plurality of feeder terminal units are respectively communicated with the main station, and the method comprises the following steps:
receiving a plurality of voltage data and a plurality of current data sent by a plurality of feeder terminal units;
generating a single-phase grounding signal according to the voltage data and the current data, and respectively sending the single-phase grounding signal to a plurality of feeder terminal units related to the single-phase grounding signal;
receiving first M pieces of periodic wave data, last N pieces of periodic wave data, direction scale vector component data, fundamental wave zero sequence current fault direction measure component data and a plurality of oscillation peak value polarity data which are sent by a plurality of feeder line terminal units related to the single-phase grounding signal, wherein M is more than or equal to 3, and N is more than or equal to 4;
correspondingly generating fundamental wave zero-sequence current fault direction measure according to a plurality of fundamental wave zero-sequence current fault direction measure component data;
generating a transient phase current fault direction measure from a plurality of said direction scale vector component data and a plurality of said oscillation peak polarity data;
and positioning the power distribution network fault according to the first M pieces of periodic wave data, the last N pieces of periodic wave data, the fundamental wave zero sequence current fault direction measurement, the transient phase current fault direction measurement and a preset multi-index decision model.
7. The method of claim 6, wherein generating a transient phase current fault direction measure from the plurality of direction scale vector component data and the plurality of oscillation peak polarity data comprises:
generating intermediate variables by the aid of the polarity data of the oscillation peak values in a preset mode respectively;
multiplying the intermediate variable corresponding to the same feeder terminal unit by the direction scale vector component data to respectively obtain transient phase current fault direction measure component data;
and forming the transient phase current fault direction measure by using a plurality of pieces of the transient phase current fault direction measure component data.
8. The method for locating faults of the power distribution network according to claim 7, wherein locating faults of the power distribution network according to the fundamental zero sequence current fault direction measure, the transient phase current fault direction measure and a preset multi-index decision model comprises:
generating a first direction scaling weight, a first sub-targeting function priority value, a second direction scaling weight and a second sub-targeting function priority value according to the fundamental wave zero sequence current fault direction measure, the transient phase current fault direction measure, a preset second credibility factor and a preset first credibility factor;
determining a detection state vector according to the plurality of direction scale vector component data and a preset detection state generation condition;
determining an expected value vector according to the first M pieces of periodic wave data, the last N pieces of periodic wave data and a preset expected value function;
substituting the first direction scale weight, the detection state vector and the expected value vector into a preset first sub-target function to determine a first sub-target;
substituting the second direction scale weight, the detection state vector and the expected value vector into a preset second sub-target function to determine a second sub-target;
substituting the first sub-goal function priority value, the second sub-goal function priority value, the first sub-goal and the second sub-goal into a preset uniform goal function to obtain an optimal solution of the goal function;
and positioning the power distribution network fault according to the optimal solution of the objective function.
9. The power distribution network fault location method of claim 8, wherein the multi-index decision model is:
where n denotes the number of line sections into which the distribution network system is divided, liDenotes the line segment state numbered i, i 1, 2., n, L denotes the n-dimensional line state set, E denotes the feasible domain of the function, ω1Representing the priority value, ω, of the first sub-targeting function2Representing the second sub-targeting function priority value, f1(L) represents the first sub-targeting function, f2(L) represents the second sub-targeting function.
10. A power distribution network fault location system, comprising: a master station as claimed in any one of claims 6 to 9 and a plurality of feeder terminal units as claimed in any one of claims 1 to 5.
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| CN111366815A (en) * | 2020-04-24 | 2020-07-03 | 北京东土科技股份有限公司 | Low-current grounding line selection method, device and medium based on power distribution station server |
| CN111366815B (en) * | 2020-04-24 | 2022-09-20 | 北京东土科技股份有限公司 | Low-current grounding line selection method, device and medium based on power distribution station server |
| CN112415330A (en) * | 2020-10-27 | 2021-02-26 | 山东山大电力技术股份有限公司 | Power grid fault intelligent identification method and system based on wide area information |
| CN112578228A (en) * | 2020-12-17 | 2021-03-30 | 米格电气江苏有限公司 | Zero-sequence-independent single-phase earth fault discrimination algorithm for power distribution network |
| CN113092951A (en) * | 2021-06-10 | 2021-07-09 | 沈阳工业大学 | Offshore wind farm complex topology line fault information prediction method and device |
| CN113092951B (en) * | 2021-06-10 | 2021-08-06 | 沈阳工业大学 | Offshore wind farm complex topology line fault information prediction method and device |
| CN114879085A (en) * | 2022-07-12 | 2022-08-09 | 北京智芯半导体科技有限公司 | Single-phase earth fault identification method and device, electronic equipment and medium |
| CN114879085B (en) * | 2022-07-12 | 2022-10-04 | 北京智芯半导体科技有限公司 | Single-phase earth fault identification method and device, electronic equipment and medium |
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