CN115308473A - Short-circuit current direct-current component calculation method, device and equipment - Google Patents
Short-circuit current direct-current component calculation method, device and equipment Download PDFInfo
- Publication number
- CN115308473A CN115308473A CN202211024945.8A CN202211024945A CN115308473A CN 115308473 A CN115308473 A CN 115308473A CN 202211024945 A CN202211024945 A CN 202211024945A CN 115308473 A CN115308473 A CN 115308473A
- Authority
- CN
- China
- Prior art keywords
- impedance
- short
- network
- sub
- fault
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/0092—Arrangements for measuring currents or voltages or for indicating presence or sign thereof measuring current only
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Locating Faults (AREA)
Abstract
The application discloses a method, a device and equipment for calculating a direct current component of a short-circuit current, wherein the method comprises the following steps: taking a fault point when the radial network generates an asymmetric short-circuit fault as a splitting point; acquiring positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each sub-network at a fault point; calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network; and calculating the direct-current component of the short-circuit current based on the input impedance and the equivalent impedance of each sub-network. Therefore, the direct-current component of the short-circuit current can be calculated when the radiation-shaped network has the asymmetric short-circuit fault. In addition, the influence of each sub-network on the direct-current component of the short-circuit current can be considered, and compared with the method for calculating the direct-current component of the short-circuit current based on the whole radiation-shaped network, the method for calculating the direct-current component of the short-circuit current can calculate the direct-current component of the short-circuit current more accurately.
Description
Technical Field
The present application relates to the field of power grid technologies, and in particular, to a method, an apparatus, and a device for calculating a short-circuit current dc component.
Background
In order to reduce transmission loss in the power grid, the capacities of the generator and the transformer are gradually increased, and the resistances of a direct current line and an alternating current line in the power grid are gradually reduced. However, when the capacity of the generator and the transformer is increased and the resistance of the transmission line is reduced, the reactance resistance ratio of an equivalent system at a short-circuit fault point is larger and larger when the power grid has a short-circuit fault, and the direct-current component of the short-circuit current is increased, so that the direct-current component of the short-circuit current has increasingly outstanding influence on the power grid.
In the prior art, only a method for calculating a short-circuit current direct-current component when a power grid is in a symmetric short circuit is provided, and a method for calculating a short-circuit current direct-current component when a power grid is in an asymmetric short circuit is not provided.
Disclosure of Invention
In view of this, the present application provides a short-circuit current dc component calculation method, device and apparatus, which are used to calculate a short-circuit current dc component when an asymmetric short circuit occurs in a power grid.
In order to achieve the above object, the following solutions are proposed:
a short-circuit current direct-current component calculation method comprises the following steps:
dividing the radiation-shaped network into a plurality of sub-networks by taking a fault point of the radiation-shaped network when an asymmetric short circuit fault occurs as a dividing point;
acquiring positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each sub-network at the fault point;
calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point;
and calculating the direct-current component of the short-circuit current based on the input impedance and the equivalent impedance of each sub-network.
Optionally, the obtaining the positive sequence equivalent impedance, the negative sequence equivalent impedance, and the zero sequence equivalent impedance of each sub-network at the fault point includes:
determining the fault time when the asymmetric short-circuit fault occurs and the target time after the asymmetric short-circuit fault occurs, wherein the target time is any time in the continuous process of the asymmetric short-circuit fault;
calculating a target time difference between the target time and the fault time;
determining an equivalent frequency corresponding to the target time based on the target time difference;
and calculating the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network corresponding to the target time at the fault point according to the equivalent frequency corresponding to the target time.
Optionally, the calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance, and the zero sequence equivalent impedance of each sub-network at the fault point includes:
determining the fault type of the asymmetric short-circuit fault, wherein the fault type is a single-phase short-circuit fault, a two-phase short-circuit fault or a two-phase short-circuit grounding fault;
calling a preset input impedance analytic expression and an equivalent impedance analytic expression corresponding to the fault type;
calculating to obtain the input impedance of each sub-network by using the positive sequence input impedance, the negative sequence input impedance and the zero sequence input impedance of each sub-network at the fault point and an input impedance analytic expression corresponding to the fault type;
and calculating to obtain the equivalent impedance of each sub-network by using the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point and an equivalent impedance analytic expression corresponding to the fault type.
Optionally, calculating the short-circuit current dc component based on the input impedance and the equivalent impedance of each sub-network includes:
calculating a parallel impedance equal to a ratio between 1 and the sum of the reciprocals of the input impedances of the respective sub-networks;
acquiring a fault point equivalent voltage source;
taking the ratio between the fault point equivalent voltage source and the parallel impedance as an initial value of the short-circuit current;
and calculating to obtain the direct-current component of the short-circuit current by utilizing the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current.
Optionally, the calculating, by using the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network, and the initial value of the short-circuit current, the short-circuit current dc component includes:
and substituting the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current into a preset analytical formula of the direct-current component of the short-circuit current, and calculating to obtain the direct-current component of the short-circuit current.
Optionally, an analytic expression of the short-circuit current dc component is:
wherein, I dc For short-circuit current DC component, N is the total number of each sub-network, I k "is the initial value of the short-circuit current, Z equ For parallel impedance, x is the number of the sub-network, Z xequ Input impedance, T, for sub-network numbered x xa Short-circuit current for sub-network numbered xAnd the attenuation time constant of the direct current component is t, and the time difference between the current time and the fault time is obtained.
Optionally, an analytic expression of the decay time constant of the short-circuit current dc component of the subnet numbered x is:
wherein, Z xCequ Equivalent impedance of the sub-network numbered x, f c The equivalent frequency of the subnet numbered x corresponds to t.
Optionally, the splitting the radiation-shaped network into a plurality of subnets by using a fault point of the radiation-shaped network when the asymmetric short-circuit fault occurs as a split point includes:
judging whether the fault point is on a line of the radial network or not;
if the fault point is on the line of the radial network, taking the fault point when the radial network is in short circuit fault as a splitting point, and splitting the radial network into two sub-networks;
if the fault point is not on the line of the radial network, the fault point is a node of the radial network, and the node with the asymmetric short circuit fault is taken as a splitting point to split the radial network, wherein the number of the sub-networks is equal to the number of branches which are imported into the node, each sub-network comprises a branch which is imported into the node, and the branches which are imported into the node in each sub-network are different.
A short-circuit current direct-current component calculation apparatus comprising:
the splitting unit is used for splitting the radiation-shaped network into a plurality of sub-networks by taking a fault point of the radiation-shaped network when the asymmetric short circuit fault occurs as a splitting point;
the acquisition unit is used for acquiring positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each sub-network at the fault point;
the calculating unit is used for calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point;
and the utilization unit is used for calculating the direct-current component of the short-circuit current based on the input impedance and the equivalent impedance of each sub-network.
A short circuit current direct current component calculation apparatus includes a memory and a processor;
the memory is used for storing programs;
the processor is configured to execute the program to implement the steps of the short-circuit current dc component calculation method.
A readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the short-circuit current dc component calculation method as described above.
According to the technical scheme, the short-circuit current direct-current component calculation method provided by the application can be implemented only when the power grid is subjected to the asymmetric short circuit and the power grid is the radial network, by taking a fault point when the radial network is subjected to the asymmetric short circuit fault as a splitting point and splitting the radial network into a plurality of sub-networks; then, the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point can be obtained; and calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point, and finally calculating the short-circuit current direct-current component based on the input impedance and the equivalent impedance of each sub-network. Therefore, the method and the device can calculate the direct-current component of the short-circuit current when the radiation-shaped network has the asymmetric short-circuit fault.
In addition, the short-circuit current direct-current component can be calculated based on the input impedance and the equivalent impedance of each sub-network, so that the influence of each sub-network on the short-circuit current direct-current component can be considered one by one, and compared with the method of calculating the short-circuit current direct-current component based on the whole radiation-shaped network, the short-circuit current direct-current component can be calculated more accurately.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, it is obvious that the drawings in the following description are only embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
Fig. 1 is a flowchart of a short-circuit current dc component calculation method disclosed in the present application;
fig. 2 is a block diagram of a short-circuit current dc component calculation apparatus disclosed in the present application;
fig. 3 is a block diagram of a hardware structure of a short-circuit current dc component calculation device disclosed in the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The short-circuit current direct-current component calculation method can be applied to a radiation network, belongs to the technical field of power grids, and can be used for calculating the direct-current component of the short-circuit current when the radiation network has an asymmetric short-circuit fault.
Next, referring to fig. 1, a method for calculating a short-circuit current dc component according to the present application is described in detail, which includes the following steps:
s1, taking a fault point when the radiation-shaped network has an asymmetric short-circuit fault as a splitting point, and splitting the radiation-shaped network into a plurality of sub-networks.
Specifically, the radiation network with the asymmetric short circuit fault can be split, in the splitting process, the fault point with the fault can be used as a splitting point, the splitting mode is determined based on the splitting point and the position of the radiation network, and a plurality of sub-networks are obtained after splitting. Each combination of sub-networks can result in a complete radial network.
And S2, acquiring positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each sub-network at the fault point.
Specifically, a positive-sequence node admittance matrix, a negative-sequence node admittance matrix, and a zero-sequence node admittance matrix of each of the subnetworks may be constructed according to the radiometric network. The expression form of each node admittance matrix is as follows:
wherein, diagonal element Y in positive sequence node admittance matrix, negative sequence node admittance matrix and zero sequence node admittance matrix ii Called node i's self-admittance, whose value is equal to the sum of all branch admittances connected to node i; off-diagonal element Y ij Referred to as the admittance between node i and node j, the value of which is equal to the negative of the admittance of the branch connected between node i and node j, Y if no direct branch exists between node i and node j ij And =0. Therefore, any grid topology connection relationship can be described by a node admittance matrix.
Specifically, the admittance analytical formula is:
wherein, Z ij Is the branch impedance between node i and node j, R ij Is a branch resistance, X, between node i and node j ij For branches between node i and node jRoad reactance, imaginary unit denoted by J to avoid symbol collision, w is the angular velocity at which the radial network operates, L ij Is the coil inductance between node i and node j.
Correcting the positive sequence node admittance matrix of each sub-network by adopting an equivalent frequency method to obtain the positive sequence node equivalent admittance matrix of each sub-network under the equivalent frequency; correcting the negative sequence node admittance matrix of each sub-network by adopting an equivalent frequency method to obtain the negative sequence node equivalent admittance matrix of each sub-network under the equivalent frequency; and correcting the zero-sequence node equivalent admittance matrix of each sub-network by adopting an equivalent frequency method to obtain the zero-sequence node admittance matrix of each sub-network under the equivalent frequency.
Specifically, the admittance at the equivalent frequency is given by the following equation:
wherein Y is Cij For admittance at equivalent frequency, Z Cij Is the branch impedance at the equivalent frequency between node i and node j, R Cij Is the branch resistance, X, at the equivalent frequency between node i and node j Cij For branch reactance at equivalent frequency between node i and node J, and for avoiding symbol collision, the imaginary unit is represented by J, w c Is the angular velocity at which the radial network operates.
After the equivalent frequency is determined, each equivalent admittance in the zero-sequence node equivalent admittance matrix, the positive-sequence node equivalent admittance matrix and the negative-sequence node equivalent admittance matrix corresponding to each sub-network can be calculated according to the admittance analytic expression under the equivalent frequency, wherein the equivalent admittance is an admittance under the equivalent frequency.
The zero sequence node admittance matrix, the positive sequence node admittance matrix, the negative sequence node admittance matrix, the zero sequence node equivalent admittance matrix, the positive sequence node equivalent admittance matrix and the negative sequence node equivalent admittance matrix of each sub-network form a radiation-shaped network node admittance matrix set, and each admittance matrix in the radiation-shaped network node admittance matrix set can be processed to obtain a zero sequence node impedance matrix, a positive sequence node impedance matrix, a negative sequence node impedance matrix, a zero sequence node equivalent impedance matrix, a positive sequence node equivalent impedance matrix and a negative sequence node equivalent impedance matrix of each sub-network.
In the processing process, triangular decomposition can be performed on each admittance matrix to obtain each factor matrix, namely Y = LDU, Y is the admittance matrix, U and L are transposed to each other, L is a unit lower triangular matrix, D is a diagonal matrix, and U is a unit upper triangular matrix.
The calculation analytic expressions of the elements U, D, and L are as follows:
d ii is the element of the ith row and the ith column in the D matrix; u. of ij The element of the ith row and the jth column in the U matrix; l ij Is the element in the ith row and the jth column in the L matrix.
The compositional factors of the respective elements of U, D and L are shown below:
after the factor table corresponding to each admittance matrix is obtained in the above manner, each element in the jth column of the impedance matrix corresponding to each admittance matrix can be calculated by the following analytical formula:
based on the above, a zero sequence node impedance matrix, a positive sequence node impedance matrix, a negative sequence node impedance matrix, a zero sequence node equivalent impedance matrix, a positive sequence node equivalent impedance matrix and a negative sequence node equivalent impedance matrix corresponding to each sub-network are obtained through calculation.
And determining the impedance corresponding to the fault point in the zero sequence node impedance matrix, the positive sequence node impedance matrix, the negative sequence node impedance matrix, the zero sequence node equivalent impedance matrix, the positive sequence node equivalent impedance matrix and the negative sequence node equivalent impedance matrix corresponding to each sub-network according to the position of the fault point in the radial network, and obtaining the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance corresponding to the fault point and each sub-network.
And S3, calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point.
Specifically, the input impedance of each sub-network can be obtained by processing the positive sequence input impedance, the negative sequence input impedance and the zero sequence input impedance corresponding to the fault point.
And processing the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network corresponding to the fault point to obtain the equivalent impedance of the sub-network.
And S4, calculating the direct-current component of the short-circuit current based on the input impedance and the equivalent impedance of each sub-network.
Specifically, the input impedance and the equivalent impedance of each sub-network are processed to obtain the contribution value of each sub-network to the short-circuit current direct-current component, the contribution values corresponding to the sub-networks are added, and the result obtained after the addition is the short-circuit current direct-current component.
It can be seen from the foregoing technical solutions that, in the short-circuit current dc component calculation method provided in the embodiments of the present application, a fault point when an asymmetric short-circuit fault occurs in a radial network may be first used as a splitting point, and the radial network is split into multiple subnets, so that the present application is only executed when an asymmetric short-circuit occurs in a power grid and the power grid is a radial network; then, the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point can be obtained; and calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point, and finally calculating the short-circuit current direct-current component based on the input impedance and the equivalent impedance of each sub-network. Therefore, the method and the device can calculate the direct-current component of the short-circuit current when the radiation-shaped network has the asymmetric short-circuit fault.
In addition, the short-circuit current direct-current component can be calculated based on the input impedance and the equivalent impedance of each sub-network, so that the influence of each sub-network on the short-circuit current direct-current component can be considered one by one, and compared with the method of calculating the short-circuit current direct-current component based on the whole radiation-shaped network, the short-circuit current direct-current component can be calculated more accurately.
In some embodiments of the present application, a process of splitting the radial network into a plurality of subnets by using a fault point of the radial network when an asymmetric short-circuit fault occurs as a split point in step S1 is described in detail, which includes the following specific steps:
and S10, judging whether the fault point is on the line of the radial network, if so, executing a step S11, and if not, executing a step S12.
In particular, for a radial network with an asymmetric fault, the fault point may be on the line of the radial network or may be a node of the radial network. When the failure point is at different positions, the way of splitting the radial network will be different.
S11, taking a fault point when the radial network fails as a splitting point, and splitting the radial network into two sub-networks.
When the fault point is a line of the radiation-shaped network, the radiation-shaped network can be directly segmented at the fault point, and the radiation-shaped network is segmented into two sub-networks.
And after the two subnetworks are spliced at the fault point, a complete radiation-shaped network can be obtained.
And S12, taking the node with the asymmetric short circuit fault as a splitting point, splitting the radial network, wherein the number of the sub-networks is equal to the number of branches which are imported into the node, each sub-network comprises a branch which is imported into the node, and the branches which are imported into the node in each sub-network are different.
Specifically, when the fault point is a node of the radial network, the radial network may be directly segmented at the fault point, and the radial network may be segmented into subnets with the same number as the number of branches of the fault point.
Compared with the previous embodiment, the embodiment provides an optional mode for dividing the radial network into a plurality of subnets, and the radial network can be split according to the position of the fault point by the mode, so that the direct-current component of the short-circuit current can be better calculated.
In some embodiments of the present application, a detailed description is given of the process of obtaining the positive sequence equivalent impedance, the negative sequence equivalent impedance, and the zero sequence equivalent impedance of each sub-network at the fault point in step S2, and the steps are as follows:
s20, determining the fault time when the asymmetric short-circuit fault occurs and the target time after the asymmetric short-circuit fault occurs, wherein the target time is any time in the continuous process of the asymmetric short-circuit fault.
Specifically, after the asymmetric short-circuit fault occurs, the corresponding short-circuit current direct-current component at any time can be calculated. Therefore, the time when the short-circuit current dc component needs to be obtained can be determined, and this time can be set as the target time.
And S21, calculating a target time difference between the target time and the fault time.
Specifically, a difference between the target time and the failure time may be calculated, and the difference may be taken as a target time difference indicating the elapsed time length from the failure time to the target time.
And S22, determining the equivalent frequency corresponding to the target time based on the target time difference.
Specifically, there is a correspondence between a product, which is a time difference between the target time and the failure time, and a ratio, which is a ratio between the equivalent frequency and the rated frequency of the radial network.
| f·t | [0，1) | [0，2.5) | [2.5，5) | [5，∞) |
| f c /f | 0.27 | 0.15 | 0.092 | 0.055 |
TABLE 1
The product andthere is a correspondence between the ratios. t is the time difference between the target time and the fault time, f c F is the nominal frequency.
Therefore, after the target time difference is determined, the product between the target time difference and the rated frequency of the radial network can be calculated, the range of the product is determined, the ratio between the equivalent frequency corresponding to the range and the rated frequency is determined, the rated frequency is multiplied by the ratio, and the obtained result is the equivalent frequency.
And S23, calculating the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network corresponding to the target time at the fault point according to the equivalent frequency corresponding to the target time.
Specifically, after the equivalent frequency is determined, each equivalent admittance in the zero-sequence node equivalent admittance matrix, the positive-sequence node equivalent admittance matrix, and the negative-sequence node equivalent admittance matrix of each sub-network corresponding to the target time may be determined according to the admittance analytic expression under the equivalent frequency.
Based on the method for processing each admittance matrix in the set of the radiometric network node admittance matrices to obtain the zero sequence node impedance matrix, the positive sequence node impedance matrix, the negative sequence node impedance matrix, the zero sequence node equivalent impedance matrix, the positive sequence node equivalent impedance matrix and the negative sequence node equivalent impedance matrix of each sub-network, the zero sequence node equivalent impedance matrix, the positive sequence node equivalent impedance matrix and the negative sequence node equivalent impedance matrix corresponding to the target time are obtained.
And selecting equivalent impedances corresponding to the fault points from the zero sequence node equivalent impedance matrix, the positive sequence node equivalent impedance matrix and the negative sequence node equivalent impedance matrix corresponding to the target time to obtain the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network corresponding to the target time at the fault points.
It can be seen from the foregoing technical solutions that, compared to the foregoing embodiments, the present embodiment provides an alternative way of determining the positive-sequence equivalent impedance, the negative-sequence equivalent impedance, and the zero-sequence equivalent impedance of each sub-network at the fault point. By the embodiment, the time after the fault occurs can be segmented, the corresponding equivalent frequency in each time segment is different, the equivalent frequency is different, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point are also changed, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance are different, the equivalent impedance of each sub-network is also different, and the different equivalent impedances finally cause the difference of the short-circuit current direct-current components in different time segments. Based on this, the short-circuit current dc component is different at different time periods. Wherein, the segmentation is determined based on the rated frequency, and is more reliable. Therefore, the method provided by the embodiment improves the reliability of calculating the short-circuit current direct-current component. Through solving equivalent impedance and input impedance under different time periods, the error when the difference of the impedance ratio L/R of each branch circuit is larger can be reduced, and the accuracy of the short-circuit current direct-current component calculated by the method is further improved.
In some embodiments of the present application, the process of calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point in step S3 is described in detail as follows:
s30, determining the fault type of the asymmetric short-circuit fault, wherein the fault type is a single-phase short-circuit fault, a two-phase short-circuit fault or a two-phase short-circuit grounding fault.
Specifically, the fault types of the asymmetric short-circuit fault include three types, i.e., a single-phase short-circuit fault, a two-phase short-circuit fault, and a two-phase short-circuit ground fault.
And determining the fault type to be a single-phase short-circuit fault, a two-phase short-circuit fault or a two-phase short-circuit grounding fault based on the connection mode of each branch circuit of the fault point with the asymmetric short-circuit fault.
And S31, calling a preset input impedance analytic expression and an equivalent impedance analytic expression corresponding to the fault type.
Specifically, for different fault types, different impedance calculation modes exist, and the input impedance and the equivalent impedance corresponding to each sub-network can be calculated through the analytic expression.
Wherein, the analytic formula of the input impedance is:
wherein, Z xequ The input impedance of the subnet numbered x,
the positive sequence input impedance at the point of failure for the subnet numbered x,
the negative sequence input impedance at the point of failure for the subnet numbered x,
zero sequence input impedance at the fault point for the subnet numbered x.
The equivalent impedance analysis formula is:
wherein Z is xCequ The input impedance of the subnet numbered x,
the positive sequence input impedance at the point of failure for subnet number x,
the negative sequence input impedance at the point of failure for the subnet numbered x,
zero sequence input impedance at the fault point for subnet number x.
And S32, calculating to obtain the input impedance of each sub-network by using the positive sequence input impedance, the negative sequence input impedance and the zero sequence input impedance of each sub-network at the fault point and the input impedance analytic expression corresponding to the fault type.
Specifically, the positive sequence input impedance, the negative sequence input impedance, and the zero sequence input impedance of each sub-network at the fault point are substituted into the analytic expression corresponding to the fault type to obtain the input impedance of each sub-network.
The fault types of all sub-networks corresponding to the same fault point in the same radial network are consistent.
And S33, calculating to obtain the equivalent impedance of each sub-network by using the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point and the equivalent impedance analytic expression corresponding to the fault type.
Specifically, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point are substituted into an analytic expression corresponding to the fault type, so as to obtain the input impedance of each sub-network.
It can be seen from the above technical solutions that the present embodiment provides an alternative way of calculating the input impedance and the equivalent impedance of each sub-network. By the method, different calculation modes can be adopted for different fault types. Based on the method, the calculated short-circuit current direct-current component is related to the fault type, and the accuracy of the short-circuit current direct-current component can be improved.
In some embodiments of the present application, a detailed description is given to the step S4 of calculating the short-circuit current dc component based on the input impedance and the equivalent impedance of each sub-network, and the steps are as follows:
s40, calculating parallel impedance, wherein the parallel impedance is equal to the ratio of 1 to the sum of the inverses of the input impedance of each sub-network.
In particular, the parallel impedance of the radiometric network may be calculated by a parallel impedance analytical formula.
The parallel impedance analysis formula is as follows:
wherein, Z equ For shunt impedances, N is the total number of individual subnets.
And S41, acquiring an equivalent voltage source of the fault point.
Specifically, the fault point equivalent voltage source may be calculated by an equivalent voltage source method. Setting each power supply in the radiation network to zero, and adding an ideal voltage source as a unique active voltage V at a fault point f The calculation formula is as follows:
wherein, U n Is the nominal voltage of the radial network, c is the voltage coefficient, and the value range of c is shown in table 2:
TABLE 2
And S42, taking the ratio between the fault point equivalent voltage source and the parallel impedance as an initial value of the short-circuit current.
Specifically, the analytic formula of the initial value of the short-circuit current is as follows:
wherein, V f Is a fault point equivalent voltage source, Z equ Is a parallel impedance of k Is the initial value of the short circuit current.
And S43, calculating to obtain the direct-current component of the short-circuit current by using the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current.
Specifically, the contribution value of each sub-network to the short-circuit current dc component may be calculated by using the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network, and the initial value of the short-circuit current, and the contribution values corresponding to each sub-network are added, and the added value is the short-circuit current dc component.
It can be seen from the above technical solutions that the present embodiment provides an alternative way of calculating the short-circuit current dc component from the input impedance and the equivalent impedance of each sub-network. By the method, the initial value of the short-circuit current can be calculated, and in the fault continuous process, the direct-current component of the short-circuit current is attenuated continuously based on the initial value of the short-circuit current, so that the reliability of the calculated direct-current component of the short-circuit current can be improved by calculating the initial value of the short-circuit current.
In some embodiments of the present application, a detailed description is given of the step S43 of calculating the short-circuit current dc component by using the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network, and the initial value of the short-circuit current, and the steps are as follows:
and S430, substituting the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current into a preset analytical formula of the direct-current component of the short-circuit current, and calculating to obtain the direct-current component of the short-circuit current.
Specifically, an analytical formula for calculating the short-circuit current dc component may be preset, and the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network, and the initial value of the short-circuit current obtained in the above embodiment are substituted into the analytical formula to calculate the short-circuit current dc component.
It can be seen from the above technical solutions that the present embodiment provides an alternative way of calculating the short-circuit current dc component. By the method, after the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current are obtained through calculation, the short-circuit current instruction component can be obtained by directly calling the analytic expression, so that the method is simpler and faster, and the speed of calculating the direct-current component of the short-circuit current is improved.
In some embodiments of the present application, the analytic expression of the short-circuit current dc component is:
wherein, I dc For the short-circuit current DC component, N is the total number of each sub-network, I k "is the initial value of the short-circuit current, Z equ For parallel impedances, x is the subnet number, Z xequ Input impedance, T, for sub-network numbered x xa And t is the time difference between the current time and the fault time.
Specifically, the short-circuit current dc component attenuates with time change on the basis of the short-circuit current initial value, and therefore, when calculating the short-circuit current dc component at each time, the short-circuit current initial value and the short-circuit current dc component attenuation time constant need to be considered.
It can be seen from the above technical solutions that, in the embodiment, each sub-network is considered when calculating the short-circuit current dc component, if only the complete radiation-shaped network is considered and the engineering requirement is satisfied, a part of errors need to be ignored, so that the errors are difficult to avoid.
In some embodiments of the present application, the analytical formula for the decay time constant of the short-circuit current dc component of the subnet numbered x is:
wherein Z is xCequ Equivalent impedance of sub-network numbered x, f c The equivalent frequency of the subnet numbered x corresponds to t.
Specifically, the above analytical formula shows that when the attenuation time constant of the short-circuit current dc component is calculated, the equivalent frequency method is adopted, and the equivalent frequency changes with the change of the time period. Therefore, different attenuation time constants T can be selected at different time periods by applying an equivalent frequency method, so that negative errors can be reduced, and the accuracy and reliability of calculating the direct-current component of the short-circuit current are further improved.
In addition, after the direct-current component of the short-circuit current is calculated more accurately, the short-circuit impact current when the asymmetric short-circuit fault occurs can be calculated more accurately. The performance of the breaker is prepared based on the short-circuit impact current, so that the breaker which is more economical, environment-friendly and timely opened and closed can be prepared by utilizing the more accurate short-circuit impact current.
The short-circuit current dc component calculating device provided in the embodiment of the present application is described below, and the short-circuit current dc component calculating device described below and the short-circuit current dc component calculating method described above may be referred to in correspondence with each other.
As shown in fig. 2, a schematic structural diagram of a short-circuit current dc component calculation apparatus is disclosed, and the short-circuit current dc component calculation apparatus may include:
the splitting unit 1 is configured to split the radial network into a plurality of subnets by using a fault point of the radial network when an asymmetric short-circuit fault occurs as a splitting point;
the obtaining unit 2 is configured to obtain a positive sequence input impedance, a negative sequence input impedance, a zero sequence input impedance, a positive sequence equivalent impedance, a negative sequence equivalent impedance, and a zero sequence equivalent impedance of each sub-network at the fault point;
the calculating unit 3 is used for calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point;
and the utilization unit 4 is used for calculating the short-circuit current direct-current component based on the input impedance and the equivalent impedance of each sub-network.
Further, the obtaining unit may include:
the first acquisition unit is used for determining the fault time when the asymmetric short-circuit fault occurs and the target time after the asymmetric short-circuit fault occurs, wherein the target time is any time in the continuous process of the asymmetric short-circuit fault;
a second acquisition unit configured to calculate a target time difference between the target time and the fault time;
a third obtaining unit, configured to determine, based on the target time difference, an equivalent frequency corresponding to the target time;
and the fourth obtaining unit is used for calculating the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network corresponding to the target time at the fault point according to the equivalent frequency corresponding to the target time.
Further, the calculation unit may include:
the first calculation unit is used for determining the fault type of the asymmetric short-circuit fault, wherein the fault type is a single-phase short-circuit fault, a two-phase short-circuit fault or a two-phase short-circuit grounding fault;
the second calculation unit is used for calling a preset input impedance analytic expression and an equivalent impedance analytic expression corresponding to the fault type;
the third calculating unit is used for calculating the input impedance of each sub-network by utilizing the positive sequence input impedance, the negative sequence input impedance and the zero sequence input impedance of each sub-network at the fault point and the input impedance analytic expression corresponding to the fault type;
and the fourth calculating unit is used for calculating the equivalent impedance of each sub-network by using the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point and the equivalent impedance analytic expression corresponding to the fault type.
Further, the utilization unit may include:
a parallel impedance calculation unit for calculating a parallel impedance equal to a ratio between 1 and a sum of reciprocals of the input impedances of the respective subnets;
the equivalent voltage source acquisition unit is used for acquiring a fault point equivalent voltage source;
the ratio calculation unit is used for taking the ratio between the fault point equivalent voltage source and the parallel impedance as an initial value of the short-circuit current;
and the impedance utilizing unit is used for calculating and obtaining the direct-current component of the short-circuit current by utilizing the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current.
Further, the impedance utilizing unit may include:
and the direct current component calculation unit is used for substituting the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current into a preset analytical formula of the direct current component of the short-circuit current to calculate the direct current component of the short-circuit current.
Further, the dc component calculating unit may include:
a dc component analysis formula storage unit for storing the following analysis formula:
further, the dc component calculating unit may include:
an attenuation constant storage unit for storing the following analytical formula:
the short-circuit current direct-current component calculation device provided by the embodiment of the application can be applied to short-circuit current direct-current component calculation equipment, such as a server, a PC terminal, a calculator and the like. Optionally, fig. 3 shows a block diagram of a hardware structure of the short-circuit current dc component calculation device, and referring to fig. 3, the hardware structure of the short-circuit current dc component calculation device may include: at least one processor 1, at least one communication interface 2, at least one memory 3 and at least one communication bus 4;
in the embodiment of the application, the number of the processor 1, the communication interface 2, the memory 3 and the communication bus 4 is at least one, and the processor 1, the communication interface 2 and the memory 3 complete mutual communication through the communication bus 4;
the processor 1 may be a central processing unit CPU, or an Application Specific Integrated Circuit ASIC (Application Specific Integrated Circuit), or one or more Integrated circuits configured to implement embodiments of the present invention, etc.;
the memory 3 may include a high-speed RAM memory, and may further include a non-volatile memory (non-volatile memory) or the like, such as at least one disk memory;
wherein the memory stores a program and the processor can call the program stored in the memory, the program for:
dividing the radiation-shaped network into a plurality of sub-networks by taking a fault point of the radiation-shaped network when an asymmetric short circuit fault occurs as a dividing point;
acquiring positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each sub-network at the fault point;
calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point;
and calculating the direct-current component of the short-circuit current based on the input impedance and the equivalent impedance of each sub-network.
Alternatively, the detailed function and the extended function of the program may be as described above.
Embodiments of the present application further provide a storage medium, where a program suitable for execution by a processor may be stored, where the program is configured to:
dividing the radiation-shaped network into a plurality of sub-networks by taking a fault point of the radiation-shaped network when an asymmetric short circuit fault occurs as a dividing point;
acquiring positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each sub-network at the fault point;
calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point;
and calculating the direct-current component of the short-circuit current based on the input impedance and the equivalent impedance of each sub-network.
Alternatively, the detailed function and the extended function of the program may be as described above.
Alternatively, the detailed function and the extended function of the program may refer to the above description.
Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a," "8230," "8230," or "comprising" does not exclude the presence of additional like elements in a process, method, article, or apparatus that comprises the element.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. The various embodiments of the present application may be combined with each other. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A short-circuit current direct-current component calculation method is characterized by comprising the following steps:
dividing the radiation-shaped network into a plurality of sub-networks by taking a fault point of the radiation-shaped network when an asymmetric short circuit fault occurs as a dividing point;
acquiring positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each sub-network at the fault point;
calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point;
and calculating the direct-current component of the short-circuit current based on the input impedance and the equivalent impedance of each sub-network.
2. The short-circuit current direct-current component calculation method according to claim 1, wherein the obtaining of the positive-sequence equivalent impedance, the negative-sequence equivalent impedance and the zero-sequence equivalent impedance of each of the sub-networks at the fault point comprises:
determining the fault time when the asymmetric short-circuit fault occurs and the target time after the asymmetric short-circuit fault occurs, wherein the target time is any time in the continuous process of the asymmetric short-circuit fault;
calculating a target time difference between the target time and the fault time;
determining an equivalent frequency corresponding to the target time based on the target time difference;
and calculating the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network corresponding to the target time at the fault point according to the equivalent frequency corresponding to the target time.
3. The method of claim 1, wherein the calculating the input impedance and the equivalent impedance of each of the sub-networks according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each of the sub-networks at the fault point comprises:
determining the fault type of the asymmetric short-circuit fault, wherein the fault type is a single-phase short-circuit fault, a two-phase short-circuit fault or a two-phase short-circuit grounding fault;
calling a preset input impedance analytic expression and an equivalent impedance analytic expression corresponding to the fault type;
calculating the input impedance of each sub-network by using the positive sequence input impedance, the negative sequence input impedance and the zero sequence input impedance of each sub-network at the fault point and the input impedance analytic expression corresponding to the fault type;
and calculating to obtain the equivalent impedance of each sub-network by using the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point and an equivalent impedance analytic expression corresponding to the fault type.
4. The short-circuit current dc component calculation method according to claim 1, wherein calculating the short-circuit current dc component based on the input impedance and the equivalent impedance of each of the sub-networks comprises:
calculating a parallel impedance equal to a ratio between 1 and a sum of reciprocals of the input impedance of each of the subnets;
acquiring a fault point equivalent voltage source;
taking the ratio between the fault point equivalent voltage source and the parallel impedance as an initial value of the short-circuit current;
and calculating to obtain the direct-current component of the short-circuit current by using the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current.
5. The short-circuit current dc component calculation method according to claim 4, wherein the calculating the short-circuit current dc component using the parallel impedance, the input impedance of each of the sub-networks, the equivalent impedance of each of the sub-networks, and the initial value of the short-circuit current includes:
and substituting the parallel impedance, the input impedance of each sub-network, the equivalent impedance of each sub-network and the initial value of the short-circuit current into a preset analytical formula of the direct-current component of the short-circuit current, and calculating to obtain the direct-current component of the short-circuit current.
6. The short-circuit current dc component calculation method according to claim 5, wherein the analytical expression of the short-circuit current dc component is:
wherein, I dc For the short-circuit current DC component, N is the total number of individual subnets, I " k As an initial value of short-circuit current, Z equ For parallel impedance, x is the number of the sub-network, Z xequ Input impedance, T, for the sub-network numbered x xa And t is the time difference between the current time and the fault time.
7. The short-circuit current dc component calculation method according to claim 6, wherein the analytical expression of the decay time constant of the short-circuit current dc component of the subnet with number x is:
wherein Z is xCequ Equivalent resistance for sub-network numbered xAnti, f c The equivalent frequency of the subnet numbered x corresponds to t.
8. The method for calculating the short-circuit current direct-current component according to claim 1, wherein the splitting the radial network into a plurality of subnets by taking a fault point of the radial network when the asymmetric short-circuit fault occurs as a split point comprises:
judging whether the fault point is on a line of the radial network or not;
if the fault point is on the line of the radial network, taking the fault point when the radial network fails as a splitting point, and splitting the radial network into two sub-networks;
if the fault point is not on the line of the radial network, the fault point is a node of the radial network, and the node with the asymmetric short circuit fault is taken as a splitting point to split the radial network, wherein the number of the sub-networks is equal to the number of branches which are imported into the node, each sub-network comprises a branch which is imported into the node, and the branches which are imported into the node in each sub-network are different.
9. A short-circuit current dc component calculation apparatus, comprising:
the splitting unit is used for splitting the radiation-shaped network into a plurality of sub-networks by taking a fault point of the radiation-shaped network when the asymmetric short circuit fault occurs as a splitting point;
the acquisition unit is used for acquiring positive sequence input impedance, negative sequence input impedance, zero sequence input impedance, positive sequence equivalent impedance, negative sequence equivalent impedance and zero sequence equivalent impedance of each sub-network at the fault point;
the calculating unit is used for calculating the input impedance and the equivalent impedance of each sub-network according to the positive sequence input impedance, the negative sequence input impedance, the zero sequence input impedance, the positive sequence equivalent impedance, the negative sequence equivalent impedance and the zero sequence equivalent impedance of each sub-network at the fault point;
and the utilization unit is used for calculating the direct-current component of the short-circuit current based on the input impedance and the equivalent impedance of each sub-network.
10. A short circuit current direct current component calculation apparatus is characterized by comprising a memory and a processor;
the memory is used for storing programs;
the processor, which executes the program, implements the steps of the short-circuit current dc component calculation method according to any one of claims 1 to 8.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211024945.8A CN115308473A (en) | 2022-08-25 | 2022-08-25 | Short-circuit current direct-current component calculation method, device and equipment |
| PCT/CN2022/120777 WO2024040670A1 (en) | 2022-08-25 | 2022-09-23 | Method, apparatus, and device for calculating dc component of short-circuit current |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211024945.8A CN115308473A (en) | 2022-08-25 | 2022-08-25 | Short-circuit current direct-current component calculation method, device and equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115308473A true CN115308473A (en) | 2022-11-08 |
Family
ID=83865188
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211024945.8A Pending CN115308473A (en) | 2022-08-25 | 2022-08-25 | Short-circuit current direct-current component calculation method, device and equipment |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN115308473A (en) |
| WO (1) | WO2024040670A1 (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103852688B (en) * | 2012-11-30 | 2016-11-16 | 施耐德电器工业公司 | For the method and apparatus determining the position of earth fault |
| CN105162099B (en) * | 2015-10-21 | 2018-02-23 | 国家电网公司 | A kind of computing Surface Method for determining distributed power generation access power network unsymmetrical short-circuit electric current |
| CN106990326B (en) * | 2017-05-10 | 2019-05-24 | 上海电力学院 | Power System Shortcuts current dc component calculation method |
| CN109375034B (en) * | 2018-10-10 | 2020-04-17 | 上海大学 | Method for acquiring direct-current component of branch short-circuit current of power system |
| CN110208634B (en) * | 2019-05-08 | 2021-05-04 | 上海电力学院 | Method for acquiring asymmetric short-circuit current direct-current component of complex power system |
-
2022
- 2022-08-25 CN CN202211024945.8A patent/CN115308473A/en active Pending
- 2022-09-23 WO PCT/CN2022/120777 patent/WO2024040670A1/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| WO2024040670A1 (en) | 2024-02-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Yang et al. | Three‐phase harmonic power flow by direct ZBUS method for unbalanced radial distribution systems with passive power filters | |
| CN105680442B (en) | Consider that the expectation of trend and sensitivity consistency equivalence lacks power supply volume appraisal procedure | |
| CN109946561A (en) | A kind of current transformer polarity testing method, apparatus, equipment and storage medium | |
| Doria-Garcia et al. | High impedance fault location: Generalized extension for ground faults | |
| CN109375034B (en) | Method for acquiring direct-current component of branch short-circuit current of power system | |
| Berizzi et al. | A second order method for contingency severity assessment with respect to voltage collapse | |
| Alwash et al. | New impedance‐based fault location method for unbalanced power distribution systems | |
| CN115308473A (en) | Short-circuit current direct-current component calculation method, device and equipment | |
| CN105320810A (en) | Scanning optimization method for short-circuit current | |
| Davydova et al. | Optimization of first zone boundary of adaptive distance protection for flexible transmission lines | |
| Daisy et al. | Single phase fault location in power distribution network using combination of impedance based method and voltage sage matching algorithm | |
| CN113419139B (en) | High-resistance grounding fault positioning method and related device for small-resistance grounding system | |
| Zhang et al. | Kalman filter approach for line parameter estimation for long transmission lines | |
| CN109376392A (en) | A kind of the overvoltage calculation method and system of tandem type compensation device | |
| Vásquez et al. | Fast calculation of Thévenin equivalents for real-time steady state voltage stability estimation | |
| Bernardes et al. | Topological processing of mutually coupled circuits for directional overcurrent protection | |
| Hebling et al. | Sparse and orthogonal method for fast bad data processing in distribution system state estimation | |
| CN113447803A (en) | Short-circuit current calculation voltage coefficient value taking method for checking on-off capacity of circuit breaker | |
| CN112751338A (en) | Reactance arrangement method for limiting short-circuit current of power grid and related device | |
| CN114123164B (en) | Method and device for calculating short-circuit capacity of power system and terminal equipment | |
| CN111681696A (en) | Nonvolatile memory based storage and data processing method, device and equipment | |
| Wang et al. | Robust optimal protection strategy against false data injection attacks in power grids | |
| CN110298766B (en) | Load screening method, device and equipment suitable for relay protection setting calculation | |
| CN115411779A (en) | Short-circuit current calculation method, device and equipment considering double-fed fan crowbar input | |
| CN114725908B (en) | Method for analyzing DC inrush current after single-end locking of DC power distribution network and related device |
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 |