Fault detection method for power distribution network, electronic device, storage medium, and program product

Abstract

The invention discloses a fault detection method of a power distribution network, electronic equipment, a storage medium and a program product. The method comprises the following steps: monitoring electric power parameters of at least one protection section in the power distribution network to obtain monitored electric power parameters; based on the power distribution network identifier of the power distribution network, obtaining a fault setting value corresponding to the at least one protection section; performing fault detection on the at least one protection section based on the monitored electric power parameter and the fault setting value to obtain a fault detection result; and determining that the power distribution network has a fault in response to the fault detection result that any protection section has the fault. According to the invention, the technical problem that the accuracy of detecting the fault in the power distribution network is low in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of data processing, and in particular to a fault detection method, electronic equipment, storage medium and program product for a distribution network. Background Art

[0002] At present, I IDG (Inverter-Interfaced Distributed Generation) is usually configured in the distribution network as a backup power supply used in the event of a fault in the distribution network. However, the output characteristics of I IDG will change with the changes in the operating environment. For example, when a fault occurs in the distribution network, the incorporation of I IDG will change the short-circuit voltage, current and phase of the original network, thereby affecting the accuracy of the results of fault detection on the distribution network.

[0003] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0004] The embodiments of the present invention provide a method for detecting faults in a distribution network, an electronic device, a storage medium and a program product, so as to at least solve the technical problem of low accuracy in detecting faults occurring in a distribution network in the related art.

[0005] According to one aspect of an embodiment of the present invention, there is provided a fault detection method for a distribution network, comprising: monitoring power parameters of at least one protection section in the distribution network to obtain monitored power parameters; acquiring a fault setting value corresponding to at least one protection section based on a distribution network identifier of the distribution network; performing fault detection on at least one protection section based on the monitored power parameters and the fault setting value to obtain a fault detection result; and determining that a fault occurs in the distribution network in response to a fault in any protection section as a result of the fault detection.

[0006] Furthermore, based on the distribution network identifier of the distribution network, a fault setting value corresponding to at least one protection zone is obtained, including: obtaining power parameters output by preset power equipment in the distribution network when the distribution network operates normally; based on the distribution network identifier, determining a fault type corresponding to a fault that will occur in the distribution network; based on the fault type, obtaining a mapping relationship between the power parameters and the fault setting value; and constructing a fault setting value based on the mapping relationship and the power parameters.

[0007] Furthermore, the power parameters include: a first current output by a preset power supply in the distribution network, the preset power supply is used to provide backup power when a fault occurs in the distribution network, the fault type includes: phase-to-phase short circuit, the mapping relationship includes: a first relationship corresponding to the phase-to-phase short circuit, and the fault setting value includes: a short-circuit current setting value corresponding to the phase-to-phase short circuit; based on the mapping relationship and the power parameters, constructing the fault setting value, including: obtaining the grid configuration parameters of the distribution network; based on the first current and the grid configuration parameters, determining according to the first relationship the positive-sequence current flowing through at least one protection section when a fault occurs in at least one protection section; based on the absolute value of the product of the positive-sequence current and the preset coefficient, obtaining the short-circuit current setting value.

[0008] Furthermore, based on the first current and the grid configuration parameters, a positive sequence current flowing through at least one protection section when a fault occurs in at least one protection section is determined, including: based on the grid configuration parameters, determining a composite sequence network corresponding to the distribution network and a first equivalent impedance corresponding to different branches in the composite sequence network when a fault occurs in at least one protection section; based on the first equivalent impedance and the first current, determining a grid connection point voltage corresponding to a preset power source and a second current output by the preset power source when a fault occurs in at least one protection section; and determining the positive sequence current based on the grid connection point voltage and the second current.

[0009] Furthermore, the fault setting value also includes: a short-circuit direction setting value corresponding to a phase-to-phase short circuit; based on the mapping relationship and the power parameters, constructing a fault setting value, including: based on the grid configuration parameters, determining the negative-sequence network corresponding to the distribution network and the second equivalent impedance corresponding to different areas in the negative-sequence network when a fault occurs in at least one protection section; based on the second equivalent impedance, determining the first impedance angle upstream of at least one protection section and the second impedance angle downstream of at least one protection section; based on the first angle bisector of the first impedance angle and the angle bisector of the second impedance angle, constructing a short-circuit direction setting value.

[0010] Furthermore, the fault types include: three-phase short circuit, the mapping relationship includes: a second relationship corresponding to the three-phase short circuit, and the fault setting value includes: a short-circuit current setting value corresponding to the three-phase short circuit; based on the mapping relationship and the power parameters, the fault setting value is constructed, including: based on the grid configuration parameters of the distribution network, determining a third equivalent impedance corresponding to at least one protection section, and a target voltage transmitted in at least one protection section when the distribution network operates normally; obtaining a target current based on a quotient of the target voltage and the third equivalent impedance; obtaining a short-circuit current setting value based on the absolute value of the product of the target current and a preset coefficient.

[0011] Furthermore, the power parameters include: a protection voltage and a protection current output by a protection device in at least one protection section, the protection device is used to protect at least one protection section, and the fault setting value includes: a short-circuit direction setting value corresponding to a three-phase short circuit; based on the mapping relationship and the power parameters, a fault setting value is constructed, including: obtaining a first positive-sequence component of the protection voltage and a second positive-sequence component of the protection current, and a maximum sensitivity angle corresponding to at least one protection section; processing the first positive-sequence component, the second positive-sequence component and the maximum sensitivity angle according to a preset formula to obtain a short-circuit direction setting value.

[0012] According to one aspect of an embodiment of the present invention, there is provided a fault detection device for a distribution network, comprising: a power monitoring module, used to monitor power parameters of at least one protection section in the distribution network to obtain monitored power parameters; a setting value acquisition module, used to obtain a fault setting value corresponding to at least one protection section based on a distribution network identifier of the distribution network; a fault detection module, used to perform fault detection on at least one protection section based on the monitored power parameters and the fault setting value to obtain a fault detection result; and a fault determination module, used to determine that a fault occurs in the distribution network in response to a fault detection result indicating that a fault occurs in any protection section.

[0013] Furthermore, the setting value acquisition module is also used to: obtain the power parameters output by the preset power equipment in the distribution network when the distribution network is operating normally; determine the fault type corresponding to the fault that will occur in the distribution network based on the distribution network identification; obtain the mapping relationship between the power parameters and the fault setting value based on the fault type; and construct the fault setting value based on the mapping relationship and the power parameters.

[0014] Furthermore, the power parameters include: a first current output by a preset power supply in the distribution network, the preset power supply is used to provide backup power when a fault occurs in the distribution network, the fault type includes: phase-to-phase short circuit, the mapping relationship includes: a first relationship corresponding to the phase-to-phase short circuit, and the fault setting value includes: a short-circuit current setting value corresponding to the phase-to-phase short circuit; the setting value acquisition module is also used to: obtain the grid configuration parameters of the distribution network; based on the first current and the grid configuration parameters, determine according to the first relationship the positive-sequence current flowing through at least one protection section when a fault occurs in at least one protection section; based on the absolute value of the product of the positive-sequence current and the preset coefficient, obtain the short-circuit current setting value.

[0015] Furthermore, the set value acquisition module is also used to: determine, based on the grid configuration parameters, the composite sequence network corresponding to the distribution network and the first equivalent impedance corresponding to different branches in the composite sequence network when a fault occurs in at least one protection section; determine, based on the first equivalent impedance and the first current, the grid connection point voltage corresponding to the preset power supply and the second current output by the preset power supply when a fault occurs in at least one protection section; determine the positive sequence current based on the grid connection point voltage and the second current.

[0016] Furthermore, the fault setting value also includes: a short-circuit direction setting value corresponding to a phase-to-phase short circuit; the setting value acquisition module is also used to: determine, based on the grid configuration parameters, a negative-sequence network corresponding to the distribution network and second equivalent impedances corresponding to different areas in the negative-sequence network when a fault occurs in at least one protection section; determine, based on the second equivalent impedance, a first impedance angle upstream of at least one protection section and a second impedance angle downstream of at least one protection section; construct a short-circuit direction setting value based on a first angle bisector of the first impedance angle and an angle bisector of the second impedance angle.

[0017] Furthermore, the fault types include: three-phase short circuit, the mapping relationship includes: a second relationship corresponding to the three-phase short circuit, and the fault setting value includes: a short-circuit current setting value corresponding to the three-phase short circuit; the setting value acquisition module is also used to: determine the third equivalent impedance corresponding to at least one protection section based on the grid configuration parameters of the distribution network, and the target voltage transmitted in at least one protection section when the distribution network operates normally; obtain the target current based on the quotient of the target voltage and the third equivalent impedance; obtain the short-circuit current setting value based on the absolute value of the product of the target current and the preset coefficient.

[0018] Furthermore, the power parameters include: a protection voltage and a protection current output by a protection device in at least one protection section, and the protection device is used to protect at least one protection section; the setting value acquisition module is also used to: obtain a first positive sequence component of the protection voltage and a second positive sequence component of the protection current, and a maximum sensitivity angle corresponding to at least one protection section; and process the first positive sequence component, the second positive sequence component and the maximum sensitivity angle according to a preset formula to obtain a short-circuit direction setting value.

[0019] According to another aspect of an embodiment of the present invention, there is further provided an electronic device, comprising: a memory storing an executable program; and a processor for running the program, wherein the method in each embodiment of the present invention is executed when the program is running.

[0020] According to another aspect of an embodiment of the present invention, a computer-readable storage medium is provided. The computer-readable storage medium includes a stored executable program, wherein when the executable program is running, the device where the computer-readable storage medium is located is controlled to execute the methods in various embodiments of the present invention.

[0021] According to another aspect of an embodiment of the present invention, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the method in each embodiment of the present invention is implemented.

[0022] According to another aspect of an embodiment of the present invention, a computer program product is provided, including a non-volatile computer-readable storage medium, wherein the non-volatile computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method in each embodiment of the present invention is implemented.

[0023] According to another aspect of the embodiments of the present invention, a computer program is provided. When the computer program is executed by a processor, the methods in the embodiments of the present invention are implemented.

[0024] In an embodiment of the present invention, the power parameters of at least one protection section in the distribution network are monitored to obtain the monitored power parameters; based on the distribution network identifier of the distribution network, a fault setting value corresponding to at least one protection section is obtained; based on the monitored power parameters and the fault setting value, fault detection is performed on at least one protection section to obtain a fault detection result; in response to the fault detection result being a fault in any protection section, the mode in which the distribution network fails is determined, and a fault setting value for fault detection is constructed in real time for the power parameters of preset power equipment in the distribution network that may affect the fault detection process. This ensures the accuracy of the fault detection result obtained by using the monitored monitored power parameters and the fault setting value, thereby ensuring the accuracy of fault detection of the distribution network, thereby solving the technical problem of low accuracy in detecting faults occurring in the distribution network in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 is a flow chart of a method for fault detection in a distribution network according to an embodiment of the present invention;

[0027] Figure 2 is a schematic diagram of a distribution network structure according to an embodiment of the present application;

[0028] Figure 3 is a schematic diagram of a composite sequence network of a distribution network according to an embodiment of the present application;

[0029] Figure 4 is a schematic diagram of a negative sequence network of a distribution network according to an embodiment of the present application;

[0030] Figure 5 is a schematic diagram of another negative sequence network of a distribution network according to an embodiment of the present application;

[0031] Figure 6 It is a structural block diagram of a fault detection device for a distribution network according to an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0033] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0034] According to an embodiment of the present invention, an embodiment of a fault detection method for a distribution network is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0035] Figure 1 FIG. 1 is a flow chart of a method for detecting a fault in a distribution network according to an embodiment of the present invention. Figure 1 As shown, the method comprises the following steps:

[0036] Step S102: monitor power parameters of at least one protection section in the distribution network to obtain monitored power parameters.

[0037] The protection zone may refer to an area in the power network that is monitored and protected by a specific protection device. The power parameter may refer to a parameter used to determine whether a fault occurs in the protection zone.

[0038] In an optional solution of this embodiment, in order to quickly identify and isolate the fault area when a distribution network fault occurs, the distribution network detection system (hereinafter referred to as the detection system) can divide the distribution network into multiple areas to construct multiple protection sections. Correspondingly, when performing fault detection on the distribution network, the detection system can first perform fault detection on these protection sections. If these protection sections are normal, the detection system can determine that the distribution network can currently operate normally; if these protection sections are abnormal, it means that there may be potential risks in the distribution network. In order to prevent the fault from spreading to the entire system and reduce the scope and duration of the power outage of the distribution network, the detection system can quickly isolate and handle the fault of the protection section where the abnormality is detected to protect the safety of the entire distribution network. Based on this, in order to accurately perform fault detection on different protection sections in the distribution network, the detection system can monitor the power parameters of at least one protection section in the distribution network in real time to obtain the above-mentioned monitoring power parameters, and quickly determine whether the protection section is normal based on the monitoring power parameters. Among them, the monitoring power parameters can include but are not limited to: impedance parameters, reactance parameters, current, voltage and other parameters, and users can choose according to actual conditions, which is not limited here.

[0039] Step S104: acquiring a fault setting value corresponding to at least one protection zone based on the distribution network identifier of the distribution network.

[0040] The above-mentioned fault setting value may refer to a calibration value used to determine whether a fault occurs in the corresponding protection zone, and the data type of the fault setting value is the same as the data type of the monitored power parameter.

[0041] In an optional scheme of the present embodiment, in order to ensure the efficiency of fault detection for the protection section, the detection system may first determine the distribution network identifier of the distribution network, and then obtain the fault setting value corresponding to the above-mentioned at least one protection section from a pre-constructed data table for storing different fault setting values, so as to ensure that the detection system can quickly perform fault detection on the protection section according to the monitored power parameters and the fault setting values ​​after monitoring the monitored power parameters of the corresponding protection section.

[0042] Step S106, performing fault detection on at least one protection zone based on the monitored power parameters and the fault setting value to obtain a fault detection result.

[0043] In an optional solution of this embodiment, after obtaining the fault setting value corresponding to at least one protection section, the detection system can use the monitoring power parameter and the fault setting value to perform fault detection on the protection section to determine whether there is a fault in the protection section, thereby obtaining the above-mentioned fault detection result. For example, assuming that the acquired monitoring power parameter is the current output by the protection section, and the corresponding fault setting value is the current threshold, if it is greater than the above-mentioned fault setting value, the detection system can determine that there is currently a fault in the protection section; if the acquired monitoring power parameter is less than or equal to the above-mentioned fault setting value, the detection system can determine that the protection section is operating normally.

[0044] Step S108: In response to the fault detection result indicating that a fault occurs in any protection zone, it is determined that a fault occurs in the distribution network.

[0045] In an optional scheme of the present embodiment, after fault detection is performed on different protection sections, if all protection sections are normal, the detection system can determine that the distribution network is currently operating normally; if a fault occurs in any protection section, the detection system can determine that a fault has occurred in the distribution network, and at the same time, start to execute the corresponding fault handling strategy for the fault to avoid the fault affecting the operation of the entire distribution network.

[0046] In an embodiment of the present invention, the power parameters of at least one protection section in the distribution network are monitored to obtain the monitored power parameters; based on the distribution network identifier of the distribution network, a fault setting value corresponding to at least one protection section is obtained; based on the monitored power parameters and the fault setting value, fault detection is performed on at least one protection section to obtain a fault detection result; in response to the fault detection result being a fault in any protection section, the mode in which the distribution network fails is determined, and a fault setting value for fault detection is constructed in real time for the power parameters of preset power equipment in the distribution network that may affect the fault detection process. This ensures the accuracy of the fault detection result obtained by using the monitored monitored power parameters and the fault setting value, thereby ensuring the accuracy of fault detection of the distribution network, thereby solving the technical problem of low accuracy in detecting faults occurring in the distribution network in the related art.

[0047] Furthermore, based on the distribution network identifier of the distribution network, a fault setting value corresponding to at least one protection zone is obtained, including: obtaining power parameters output by preset power equipment in the distribution network when the distribution network operates normally; based on the distribution network identifier, determining a fault type corresponding to a fault that will occur in the distribution network; based on the fault type, obtaining a mapping relationship between the power parameters and the fault setting value; and constructing a fault setting value based on the mapping relationship and the power parameters.

[0048] The above-mentioned preset power equipment may refer to equipment that may affect the fault detection process. The above-mentioned fault type may refer to a fault type corresponding to a fault that may occur in the power distribution network.

[0049] In an optional scheme of the present embodiment, in order to accurately determine the fault setting value corresponding to the protection zone currently being detected, the detection system may first obtain the power parameters output by the preset power equipment in the distribution network when the distribution network is operating normally, and at the same time determine the fault type of the fault that may occur in the distribution network based on the identification information of the distribution network, and then obtain the mapping relationship between the power parameters and the fault setting value based on the determined fault type, and finally construct the fault setting value corresponding to the fault type based on the mapping relationship and the obtained power parameters.

[0050] Furthermore, the power parameters include: a first current output by a preset power supply in the distribution network, the preset power supply is used to provide backup power when a fault occurs in the distribution network, the fault type includes: phase-to-phase short circuit, the mapping relationship includes: a first relationship corresponding to the phase-to-phase short circuit, and the fault setting value includes: a short-circuit current setting value corresponding to the phase-to-phase short circuit; based on the mapping relationship and the power parameters, constructing the fault setting value, including: obtaining the grid configuration parameters of the distribution network; based on the first current and the grid configuration parameters, determining according to the first relationship the positive-sequence current flowing through at least one protection section when a fault occurs in at least one protection section; based on the absolute value of the product of the positive-sequence current and the preset coefficient, obtaining the short-circuit current setting value.

[0051] In an optional scheme of the present embodiment, considering that the I IDG is used as a backup power supply when a distribution network fails, the output characteristics of the corresponding I IDG will change with the changes in the operating environment. For example, when a distribution network fails, the incorporation of the I IDG will change the short-circuit voltage, current and phase of the original network, resulting in an impact on the results of fault detection of the distribution network. Therefore, the above-mentioned acquired power parameters may at least include a preset power supply in the distribution network, that is, a first current output by the IIDG, and the corresponding fault setting value for fault detection of the protection zone based on the first current may include a short-circuit current setting value.

[0052] Considering that phase-to-phase short circuit is a type of fault that is prone to occur in the distribution network, taking the fault type of phase-to-phase short circuit, the mapping relationship is the first relationship corresponding to the phase-to-phase short circuit, and the fault setting value is the short-circuit current setting value of the phase-to-phase short circuit as an example, when constructing the fault setting value according to the mapping relationship and the power parameters, the detection system can first obtain the grid configuration parameters of the distribution network, and then determine the positive sequence current flowing through the corresponding protection section when a fault occurs in the protection section based on the first current and the grid configuration parameters according to the first relationship; according to the absolute value of the positive sequence current and the preset reliability coefficient, the above-mentioned short-circuit current setting value can be obtained.

[0053] Furthermore, based on the first current and the grid configuration parameters, a positive sequence current flowing through at least one protection section when a fault occurs in at least one protection section is determined, including: based on the grid configuration parameters, determining a composite sequence network corresponding to the distribution network and a first equivalent impedance corresponding to different branches in the composite sequence network when a fault occurs in at least one protection section; based on the first equivalent impedance and the first current, determining a grid connection point voltage corresponding to a preset power source and a second current output by the preset power source when a fault occurs in at least one protection section; and determining the positive sequence current based on the grid connection point voltage and the second current.

[0054] In an optional scheme of the present embodiment, when determining the positive sequence current flowing through at least one of the above-mentioned protection sections, the composite sequence network corresponding to the distribution network when a fault occurs in the above-mentioned protection section and the first equivalent impedance corresponding to different paths in the load sequence network can be determined based on the acquired grid configuration parameters. Based on the first equivalent impedance and the first current, the detection system can determine the grid connection point voltage corresponding to the preset power supply when a fault occurs in the above-mentioned protection section, and the second current output by the preset power supply. Finally, based on the grid connection point voltage and the second current, the detection system can determine the corresponding positive sequence current.

[0055] Furthermore, the fault setting value also includes: a short-circuit direction setting value corresponding to a phase-to-phase short circuit; based on the mapping relationship and the power parameters, constructing a fault setting value, including: based on the grid configuration parameters, determining the negative-sequence network corresponding to the distribution network and the second equivalent impedance corresponding to different areas in the negative-sequence network when a fault occurs in at least one protection section; based on the second equivalent impedance, determining the first impedance angle upstream of at least one protection section and the second impedance angle downstream of at least one protection section; based on the first angle bisector of the first impedance angle and the angle bisector of the second impedance angle, constructing a short-circuit direction setting value.

[0056] In an optional solution of this embodiment, considering that current is a vector, the above-mentioned fault setting value may also include a short-circuit direction setting value corresponding to the phase-to-phase short circuit. Correspondingly, when determining the short-circuit direction setting value corresponding to the phase-to-phase short circuit, the detection system may first determine the negative-sequence network corresponding to the distribution network when a fault occurs in the above-mentioned protection section according to the acquired grid configuration parameters, and the second equivalent impedance corresponding to different areas in the negative-sequence network. According to the second equivalent impedance, the detection system may determine the first impedance angle upstream of the corresponding protection section, and the second impedance angle downstream of the protection section. According to the first angle bisector of the first impedance angle and the second angle bisector of the second impedance angle, the detection system may construct the above-mentioned short-circuit direction setting value.

[0057] Furthermore, the fault types include: three-phase short circuit, the mapping relationship includes: a second relationship corresponding to the three-phase short circuit, and the fault setting value includes: a short-circuit current setting value corresponding to the three-phase short circuit; based on the mapping relationship and the power parameters, the fault setting value is constructed, including: based on the grid configuration parameters of the distribution network, determining a third equivalent impedance corresponding to at least one protection section, and a target voltage transmitted in at least one protection section when the distribution network operates normally; obtaining a target current based on a quotient of the target voltage and the third equivalent impedance; obtaining a short-circuit current setting value based on the absolute value of the product of the target current and a preset coefficient.

[0058] In an optional scheme of the present embodiment, considering that among the inter-phase short circuit type faults, the three-phase short circuit type faults can be regarded as serious fault conditions occurring in the distribution network, and it is necessary to use the protection device in the distribution network to handle the fault with the maximum protection capability and response speed, therefore, in the present application, the fault type of the three-phase short circuit can also be considered, and the corresponding second mapping relationship corresponding to the three-phase short circuit can be included in the aforementioned acquired mapping relationship, and the short-circuit current setting value corresponding to the three-phase short circuit can be included in the fault setting value. Based on this, when constructing the short-circuit current setting value corresponding to the three-phase short circuit, the detection system can first determine the third equivalent impedance corresponding to the currently detected protection section according to the grid configuration parameters of the distribution network, and the target voltage transmitted in the protection section when the distribution network is operating normally. According to the quotient of the target voltage and the above-mentioned third equivalent impedance, the above-mentioned target current can be obtained, and according to the absolute value of the product of the target current and the preset reliability coefficient, the detection system can determine the short-circuit current setting value corresponding to the three-phase short circuit.

[0059] Furthermore, the power parameters include: a protection voltage and a protection current output by a protection device in at least one protection section, the protection device is used to protect at least one protection section, and the fault setting value includes: a short-circuit direction setting value corresponding to a three-phase short circuit; based on the mapping relationship and the power parameters, a fault setting value is constructed, including: obtaining a first positive-sequence component of the protection voltage and a second positive-sequence component of the protection current, and a maximum sensitivity angle corresponding to at least one protection section; processing the first positive-sequence component, the second positive-sequence component and the maximum sensitivity angle according to a preset formula to obtain a short-circuit direction setting value.

[0060] In an optional solution of this embodiment, corresponding to the short-circuit current setting value corresponding to the three-phase short circuit, the fault setting value may also include a short-circuit direction setting value corresponding to the three-phase short circuit, and the acquired power parameters may also include a protection voltage and a protection current output by a protection device in the protection section currently undergoing fault detection, wherein the protection device is used to protect the protection section and promptly handle faults occurring in the protection section. Based on this, when constructing the short-circuit direction setting value corresponding to the three-phase short circuit, the detection system may first determine the first positive sequence component of the protection voltage and the second positive sequence component of the protection current, and simultaneously obtain the maximum sensitivity angle corresponding to the protection section, and then process the first positive sequence component, the second positive sequence component and the maximum sensitivity angle according to a preset formula to obtain the short-circuit direction setting value corresponding to the three-phase short circuit.

[0061] For ease of understanding, Figure 2 It is a schematic diagram of a distribution network structure according to an embodiment of the present application, wherein area A may refer to at least one protection section that needs to be protected, ah represents the protection devices configured in different protection sections, I IDG represents the preset power supply, and f1 represents the location where a fault may occur in area A. Figure 3 is a schematic diagram of a composite sequence network of a distribution network according to an embodiment of the present application, such as Figure 3 As shown, when a fault occurs in area A, the detection system can construct a composite sequence network containing different equivalent impedances according to the power configuration parameters of the distribution network. Figure 4 is a schematic diagram of a negative sequence network of a distribution network according to an embodiment of the present application, which may correspond to Figure 2 Negative sequence network of the distribution network when a phase-to-phase short circuit occurs at f1. Figure 5 It is a schematic diagram of another negative-sequence network of a distribution network according to an embodiment of the present application, which can correspond to the negative-sequence network of the distribution network when a fault occurs in the distribution network bus.

[0062] Based on this, when determining the short-circuit current setting value corresponding to the phase-to-phase short circuit, the detection system can obtain the output first current I of the IDG when the distribution network is operating normally. DG , and the protection voltage U output by the protection device corresponding to area A a And protection current I a Based on these parameters, the detection system can calculate the power supply equivalent impedance Z corresponding to the system power supply of the distribution network in real time. s and downstream load equivalent impedance Z a , the calculation formula can be shown as follows:

[0063] Z s =(E s -U a ) / I a ;

[0064]

[0065] Among them, Z A Represents Figure 2 The equivalent impedance corresponding to region A, Z B , Z C , Z D Represents Figure 2 The equivalent impedance of multiple areas downstream of area A, E s Represents the voltage of the system power output. Figure 3 Middle Z M Represents Figure 2 The equivalent impedance corresponding to other protection zones except area A can be regarded as the composite sequence network impedance from protection device 1 to fault point f1, U pccf It represents the grid connection point voltage.

[0066] According to the determined power supply equivalent impedance Z s and downstream load equivalent impedance Z a , the detection system can further determine Figure 3 The equivalent impedance corresponding to different regions in the given composite sequence network is Figure 3 In the above equation, Z1=Z s +Z A , Z2=Z A , Z3=Z C +Z D +Z a , where Z a It represents the A-phase impedance of the distribution network.

[0067] pass Figure 3 It can be seen that the correlation between the currents of different nodes in the above composite sequence network is:

[0068]

[0069] Among them, Z K It represents the fault impedance at the fault point.

[0070] Based on this, the detection system can detect the first current I DG As the initial value of current iteration, input into the above association relationship, the corresponding grid connection point corresponding to the fault in area A can be determined. pccf , and then obtain the corrected IIDG output current, so as to obtain the positive sequence current I corresponding to the phase-to-phase short circuit in area A Af .

[0071] Determine the positive sequence current I Af The formula can be:

[0072]

[0073] U f =U pccf -I DG Z M +I fBZ2 ;

[0074] I Af =(E s -U f ) / Z1.

[0075] The corresponding short-circuit current setting value I ZDZ The determination formula can be:

[0076] I ZDZ =|KI Af |.

[0077] Among them, K represents the reliability coefficient, which can be between 1.1-1.2.

[0078] When determining the short-circuit direction setting value corresponding to the phase-to-phase short circuit, assuming that a phase-to-phase short circuit occurs at f1, the detection system can first be constructed Figure 4 The corresponding negative sequence network, where Z4 = Z S , Z5=Z Af , Z6=Z fB +Z B +Z C +Z D +Z a Based on this, when a phase-to-phase short circuit occurs at f1, the relationship between the negative sequence voltage and negative sequence current of the protection device is:

[0079] Z S =-U a / I a .

[0080] When a forward fault occurs, the ratio of the negative sequence voltage to the reverse negative sequence current at the protection device is equal to the equivalent impedance of the system power supply.

[0081] Based on this, in this application, the reverse angle of the line impedance angle θ upstream of the protection device can be used as the maximum sensitivity angle of the forward fault Right now

[0082] Furthermore, when a phase-to-phase short circuit occurs in the busbar, the sequence diagram of the negative sequence network is as follows: Figure 5 As shown, where Z7 = Z S , Z8=Z A +Z B +Z C +Z D +Za Based on this, the relationship between the negative sequence voltage and negative sequence current of the protection device during bus fault is:

[0083] Z S′ =U a / I a .

[0084] When a reverse fault occurs, the ratio of the negative sequence voltage to the negative sequence current at the protection device is equal to the downstream impedance Z8 of the protection device. The detection system can use the impedance angle of the downstream impedance of the protection device minus the grid-connected line impedance as the maximum sensitivity angle of the protection device for reverse faults.

[0085] To ensure the reliable operation of the directional element, the detection system can select and The angle bisector of is used as the boundary of the action area to obtain the positive action area of ​​the directional element, thereby constructing the short-circuit directional setting value corresponding to the phase-to-phase short circuit.

[0086] When determining the short-circuit current setting value corresponding to a three-phase short circuit, it is assumed that a three-phase short circuit occurs at position fl in area A. At this time, the relationship between the voltage and current at the protection device is:

[0087] U a =I a Z d .

[0088] Among them, Z d It represents the equivalent impedance from the protection device to the fault point f1.

[0089] Correspondingly, the formula for determining the short-circuit current setting value corresponding to a three-phase short circuit can be:

[0090] I ZDZ =|KU1 / Z A |.

[0091] When determining the short-circuit current setting value corresponding to a three-phase short circuit, the detection system can determine the fault direction based on the positive sequence direction element, for example, it can meet the following conditions:

[0092]

[0093] in, It represents the maximum sensitivity angle, that is, the line impedance angle; U f and I f They refer to the positive sequence components of the protection voltage and current respectively.

[0094] According to an embodiment of the present invention, a device embodiment for fault detection in a distribution network is provided. It should be noted that the device can be used to execute the above-mentioned method for fault detection in a distribution network. Figure 6 is a structural block diagram of a fault detection device for a distribution network according to an embodiment of the present application, such as Figure 6 As shown, the device includes: a power monitoring module 602 , a set value acquisition module 604 , a fault detection module 606 and a fault determination module 608 .

[0095] Among them, the power monitoring module 602 is used to monitor the power parameters of at least one protection section in the distribution network to obtain the monitored power parameters; the setting value acquisition module 604 is used to obtain the fault setting value corresponding to at least one protection section based on the distribution network identifier of the distribution network; the fault detection module 606 is used to perform fault detection on at least one protection section based on the monitored power parameters and the fault setting value to obtain a fault detection result; the fault determination module 608 is used to determine that a fault occurs in the distribution network in response to the fault detection result that a fault occurs in any protection section.

[0096] Furthermore, the setting value acquisition module is also used to: obtain the power parameters output by the preset power equipment in the distribution network when the distribution network is operating normally; determine the fault type corresponding to the fault that will occur in the distribution network based on the distribution network identification; obtain the mapping relationship between the power parameters and the fault setting value based on the fault type; and construct the fault setting value based on the mapping relationship and the power parameters.

[0097] Furthermore, the power parameters include: a first current output by a preset power supply in the distribution network, the preset power supply is used to provide backup power when a fault occurs in the distribution network, the fault type includes: phase-to-phase short circuit, the mapping relationship includes: a first relationship corresponding to the phase-to-phase short circuit, and the fault setting value includes: a short-circuit current setting value corresponding to the phase-to-phase short circuit; the setting value acquisition module is also used to: obtain the grid configuration parameters of the distribution network; based on the first current and the grid configuration parameters, determine according to the first relationship the positive-sequence current flowing through at least one protection section when a fault occurs in at least one protection section; based on the absolute value of the product of the positive-sequence current and the preset coefficient, obtain the short-circuit current setting value.

[0098] Furthermore, the set value acquisition module is also used to: determine, based on the grid configuration parameters, the composite sequence network corresponding to the distribution network and the first equivalent impedance corresponding to different branches in the composite sequence network when a fault occurs in at least one protection section; determine, based on the first equivalent impedance and the first current, the grid connection point voltage corresponding to the preset power supply and the second current output by the preset power supply when a fault occurs in at least one protection section; determine the positive sequence current based on the grid connection point voltage and the second current.

[0099] Furthermore, the fault setting value also includes: a short-circuit direction setting value corresponding to a phase-to-phase short circuit; the setting value acquisition module is also used to: determine, based on the grid configuration parameters, a negative-sequence network corresponding to the distribution network and second equivalent impedances corresponding to different areas in the negative-sequence network when a fault occurs in at least one protection section; determine, based on the second equivalent impedance, a first impedance angle upstream of at least one protection section and a second impedance angle downstream of at least one protection section; construct a short-circuit direction setting value based on a first angle bisector of the first impedance angle and an angle bisector of the second impedance angle.

[0100] Furthermore, the fault types include: three-phase short circuit, the mapping relationship includes: a second relationship corresponding to the three-phase short circuit, and the fault setting value includes: a short-circuit current setting value corresponding to the three-phase short circuit; the setting value acquisition module is also used to: determine the third equivalent impedance corresponding to at least one protection section based on the grid configuration parameters of the distribution network, and the target voltage transmitted in at least one protection section when the distribution network operates normally; obtain the target current based on the quotient of the target voltage and the third equivalent impedance; obtain the short-circuit current setting value based on the absolute value of the product of the target current and the preset coefficient.

[0101] Furthermore, the power parameters include: a protection voltage and a protection current output by a protection device in at least one protection section, and the protection device is used to protect at least one protection section; the setting value acquisition module is also used to: obtain a first positive sequence component of the protection voltage and a second positive sequence component of the protection current, and a maximum sensitivity angle corresponding to at least one protection section; and process the first positive sequence component, the second positive sequence component and the maximum sensitivity angle according to a preset formula to obtain a short-circuit direction setting value.

[0102] An embodiment of the present application further provides an electronic device, comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the methods in various embodiments of the present invention when running.

[0103] An embodiment of the present application further provides a computer-readable storage medium, which includes a stored executable program, wherein when the executable program is running, the device where the computer-readable storage medium is located is controlled to execute the methods in various embodiments of the present invention.

[0104] An embodiment of the present application further provides a computer program product, including a computer program, which implements the methods in various embodiments of the present invention when executed by a processor.

[0105] An embodiment of the present application further provides a computer program product, including a non-volatile computer-readable storage medium, wherein the non-volatile computer-readable storage medium is used to store a computer program, and when the computer program is executed by a processor, the method in each embodiment of the present invention is implemented.

[0106] The embodiments of the present application further provide a computer program, which implements the methods in the above-mentioned embodiments of the present invention when executed by a processor.

[0107] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0108] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0109] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed over multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0110] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0111] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0112] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for fault detection of a distribution network, characterized in that: include: Monitoring power parameters of at least one protection section in the distribution network to obtain monitored power parameters; Based on the distribution network identifier of the distribution network, obtaining a fault setting value corresponding to the at least one protection zone; Performing fault detection on the at least one protection zone based on the monitored power parameter and the fault setting value to obtain a fault detection result; In response to the fault detection result indicating that a fault occurs in any one of the protection zones, it is determined that a fault occurs in the power distribution network.

2. The method according to claim 1, characterized in that Acquiring a fault setting value corresponding to the at least one protection zone based on a distribution network identifier of the distribution network includes: Acquiring power parameters output by a preset power device in the distribution network when the distribution network is operating normally; Based on the distribution network identifier, determining a fault type corresponding to a fault that may occur in the distribution network; Based on the fault type, obtaining a mapping relationship between the power parameter and the fault setting value; The fault setting value is constructed based on the mapping relationship and the power parameter.

3. The method according to claim 2, characterized in that The power parameter includes: a first current output by a preset power supply in the distribution network, the preset power supply is used to provide backup power when a fault occurs in the distribution network, the fault type includes: phase-to-phase short circuit, the mapping relationship includes: a first relationship corresponding to the phase-to-phase short circuit, and the fault setting value includes: a short-circuit current setting value corresponding to the phase-to-phase short circuit; constructing the fault setting value based on the mapping relationship and the power parameter includes: Obtaining grid configuration parameters of the distribution network; Based on the first current and the grid configuration parameter, determining, according to the first relationship, a positive sequence current flowing through the at least one protection section when the fault occurs in the at least one protection section; The short-circuit current setting value is obtained based on the absolute value of the product of the positive sequence current and a preset coefficient.

4. The method according to claim 3, characterized in that Determining, based on the first current and the grid configuration parameter, a positive sequence current flowing through the at least one protection section when the fault occurs in the at least one protection section, comprises: Based on the power grid configuration parameters, determining a composite sequence network corresponding to the distribution network and first equivalent impedances corresponding to different branches in the composite sequence network when the fault occurs in the at least one protection section; Based on the first equivalent impedance and the first current, determining the grid connection point voltage corresponding to the preset power supply and the second current output by the preset power supply when the fault occurs in the at least one protection section; The positive sequence current is determined based on the grid connection point voltage and the second current.

5. The method according to claim 3, characterized in that: The fault setting value further includes: a short circuit direction setting value corresponding to the phase-to-phase short circuit; constructing the fault setting value based on the mapping relationship and the power parameter, including: Based on the grid configuration parameters, determining a negative sequence network corresponding to the distribution network and second equivalent impedances corresponding to different areas in the negative sequence network when the fault occurs in the at least one protection section; Based on the second equivalent impedance, determining a first impedance angle upstream of the at least one protection section and a second impedance angle downstream of the at least one protection section; The short-circuit direction setting value is constructed based on a first angular bisector of the first impedance angle and an angular bisector of the second impedance angle.

6. The method according to claim 2, characterized in that The fault type includes: three-phase short circuit, the mapping relationship includes: the second relationship corresponding to the three-phase short circuit, and the fault setting value includes: the short-circuit current setting value corresponding to the three-phase short circuit; based on the mapping relationship and the power parameter, constructing the fault setting value includes: Determining, based on the grid configuration parameters of the distribution network, a third equivalent impedance corresponding to the at least one protection section and a target voltage transmitted in the at least one protection section when the distribution network operates normally; Obtaining a target current based on a quotient of a target voltage transmitted in the at least one protection section and the third equivalent impedance; The short-circuit current setting value is obtained based on the absolute value of the product of the target current and the preset coefficient.

7. The method according to claim 6, characterized in that The power parameters include: the protection voltage and protection current output by the protection device in the at least one protection section, and the protection device is used to protect the at least one protection section. The fault setting value includes: the short-circuit direction setting value corresponding to the three-phase short circuit; based on the mapping relationship and the power parameters, constructing the fault setting value includes: Acquire a first positive sequence component of the protection voltage, a second positive sequence component of the protection current, and a maximum sensitivity angle corresponding to the at least one protection section; The first positive-sequence component, the second positive-sequence component and the maximum sensitivity angle are processed according to a preset formula to obtain the short-circuit direction setting value.

8. An electronic device, characterized in that: include: A memory storing an executable program; A processor, configured to run the program, wherein the program executes the method according to any one of claims 1 to 7 when running.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored executable program, wherein when the executable program is executed, the device where the storage medium is located is controlled to execute the method according to any one of claims 1 to 7.

10. A computer program product, characterized in that The invention comprises a computer program which, when executed by a processor, implements the method according to any one of claims 1 to 7.

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