Fault information generation method and system suitable for feeder automation in multi-energy scene

Abstract

The invention discloses a fault information generation method and system suitable for feeder automation in a multi-energy scene, and the method comprises the steps: each power distribution terminal collects three-phase current flowing through each switch, judges whether a feeder breaks down or not according to the collected three-phase current, and determines a fault type and a fault loop; each power distribution terminal determines the change quantity of each phase of current flowing through the corresponding switch at the opening moment of the outgoing circuit breaker, so that the change quantity of fault loop current flowing through the switch is determined according to the change quantity of each phase of current; and determining a setting value, determining an overcurrent protection criterion based on the open-circuit additional network according to the setting value and the fault loop current variation, and generating and sending fault information to the master station according to the overcurrent protection criterion, so that the master station performs fault section positioning according to the fault information sent by each power distribution terminal. According to the method, the fault information of the FTU without fault direction judgment can be obtained and used for positioning the fault section, a basis is provided for subsequent fault isolation, and the actual requirement of RCTFA is met.

Description

Technical Field

[0001] This invention relates to the field of power system distribution automation technology, and in particular to a fault information generation method and system applicable to feeder automation in multi-energy scenarios. Background Technology

[0002] In multi-functional scenarios, the location of fault sections in remote control type feeder automation (RCTFA) relies on accurate fault information. When a distributed generation (DG) is connected to the feeder, the fault current at certain fault points will change from being fed by a single power source before the DG connection to being fed by power sources from two or more sides.

[0003] The FTUs (Distribution Terminal Units) without DG (Distribution Generator) integration use overcurrent protection elements set to avoid the maximum load current. DG integration alters the single-source radial structure of the distribution network, potentially leading to incorrect fault segment identification. In DG integration scenarios, the solution in feeder automation is: if the overcurrent protection trips and the fault is in the positive direction (FTU load side), fault information 1 is sent to the master station; otherwise, no information is sent. This means only the FTU upstream of the fault point (near the grid side) sends fault information 1. This solution can correctly identify the fault segment, but it requires fault direction determination at the FTU, and existing directional elements have many shortcomings when applied to feeders. In short, currently, there is no simple and effective method to meet the requirement of generating fault information without needing fault direction in DG-integrated feeder scenarios. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the first objective of this invention is to provide a fault information generation method suitable for feeder automation in multi-energy scenarios. This method, applied to RCTFA, will help the master station obtain FTU fault information without needing fault direction determination, thereby locating the faulty section and providing a basis for subsequent fault isolation, thus meeting the actual needs of RCTFA.

[0005] The second objective of this invention is to provide a fault information generation system suitable for feeder automation in multi-energy scenarios.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: A fault information generation method applicable to feeder automation in multi-energy scenarios includes: Each distribution terminal at each switch on the feeder collects the three-phase current flowing through each switch. Based on the collected three-phase current, it determines whether a fault has occurred in the feeder and identifies the fault type and fault loop. Each distribution terminal determines whether the outgoing circuit breaker has tripped and determines the change in current of each phase flowing through each switch, so as to determine the change in fault loop current flowing through each switch based on the change in current of each phase. A setting value is determined, and an overcurrent protection criterion based on the open-circuit auxiliary network is determined based on the setting value and the change in fault loop current. Fault information is generated and sent to the master station based on the overcurrent protection criterion, so that the master station can locate the fault section based on the fault information sent by each distribution terminal.

[0007] Preferably, the power distribution terminal determines whether the outgoing circuit breaker should trip based on the detected change in current.

[0008] Preferably, the overcurrent protection criterion based on the open-circuit additional network is expressed as follows:

[0009] in, The effective value of the power frequency component of the change in fault loop current flowing through the corresponding switch, as determined by the power distribution terminal. This is the setpoint value.

[0010] Preferably, the setting value is a value related to the calculation error of the current change under the assumption of a grid-side fault, and the setting value is expressed as follows:

[0011] in, The reliability coefficient is set to 1.3. The calculation of current change during a grid-side fault is based on the assumption that there is a large error. It is the current of the two power frequency cycles before the circuit breaker is tripped, and 0.1 is a possible large calculation error coefficient.

[0012] Preferably, fault information is generated and sent to the master station based on overcurrent protection criteria, including: When the effective value of the power frequency component of the change in fault loop current flowing through the corresponding switch, as determined by the distribution terminal, is greater than the set value, the overcurrent protection will activate, indicating a fault on the load side of the distribution terminal, and will send fault information 1 to the master station. If the master station receives the fault information, it will mark fault information 1. Otherwise, the overcurrent protection will not activate, indicating a fault on the grid side of the distribution terminal, and the distribution terminal will not send fault information. If the master station does not receive the fault information, it will mark fault information 0.

[0013] To achieve the above objectives, a second aspect of the present invention provides a fault information generation system suitable for feeder automation in multi-energy scenarios, the system comprising: Multiple distribution terminals are installed at each switch on the feeder. Each distribution terminal is used to collect the three-phase current flowing through each switch, determine whether a fault has occurred in the feeder based on the collected three-phase current, and identify the fault type and fault loop. In addition, it is also used to determine whether the outgoing circuit breaker has tripped and to determine the change in current of each phase flowing through each switch, so as to determine the change in fault loop current flowing through each switch based on the change in current of each phase. Furthermore, it determines a setting value, and determines an overcurrent protection criterion based on the setting value and the change in fault loop current based on the open circuit auxiliary network. Based on the overcurrent protection criterion, it generates and sends fault information to the master station. The main station communicates with multiple power distribution terminals and is used to locate fault sections based on fault information sent by each power distribution terminal.

[0014] Preferably, the distribution terminal is used to determine whether the outgoing circuit breaker has tripped based on the detected change in current.

[0015] Preferably, the overcurrent protection criterion determined by the distribution terminal based on the open-circuit auxiliary network is expressed as follows:

[0016] in, The effective value of the power frequency component of the change in fault loop current flowing through the corresponding switch, as determined by the power distribution terminal. This is the setpoint value.

[0017] Preferably, the setting value determined by the distribution terminal is a value related to the calculation error of the current change when a fault occurs on the grid side, and the setting value is expressed as follows:

[0018] in, The reliability coefficient is set to 1.3. The calculation of current change during a grid-side fault is based on the assumption that there is a large error. It is the current of the two power frequency cycles before the circuit breaker is tripped, and 0.1 is the most likely calculation error coefficient.

[0019] Preferably, when the power distribution terminal generates and sends fault information to the master station based on the overcurrent protection criterion, it is specifically used for: When the effective value of the power frequency component of the change in fault loop current flowing through the corresponding switch, as determined by the distribution terminal, is greater than the set value, the overcurrent protection will activate, indicating a fault on the load side of the distribution terminal. The distribution terminal will then send fault information 1 to the master station. If the master station receives the fault information, it will mark fault information 1. Otherwise, the overcurrent protection will not activate, indicating a fault on the grid side of the distribution terminal. The distribution terminal will not send fault information. If the master station does not receive the fault information, it will mark fault information 0.

[0020] This invention has at least the following technical effects: (1) Since the open circuit additional network only has a current source connected in series at the outgoing circuit breaker position, it is a single-sided power supply for each branch. According to the setting principle of this invention, there is no need to judge the fault direction in the multi-energy scenario.

[0021] (2) The setting value of the overcurrent protection based on the open circuit additional network is a value related to the calculation error of the current change when the grid side is faulted, which is relatively more sensitive than the traditional overcurrent protection.

[0022] (3) Overcurrent protection that does not require direction determination only uses the current quantity, and the calculation is simple.

[0023] (4) All sampling calculations are completed locally in each FTU without the need for cooperation with other agents.

[0024] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0025] Figure 1 This is a flowchart of a fault information generation method for feeder automation in multi-energy scenarios, according to an embodiment of the present invention.

[0026] Figure 2 This is an example diagram of a feeder in a low-current grounding system.

[0027] Figure 3 yes Figure 2 Additional network diagram showing the open circuit at the moment the outgoing circuit breaker trips.

[0028] Figure 4 This is a structural block diagram of a fault information generation system for feeder automation in multi-functional scenarios, according to an embodiment of the present invention. Detailed Implementation

[0029] The following describes this embodiment in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0030] The following description, with reference to the accompanying drawings, describes a fault information generation method and system applicable to feeder automation in multi-functional scenarios.

[0031] Figure 1 This is a flowchart illustrating a fault information generation method for feeder automation in multi-energy scenarios, according to an embodiment of the present invention. Figure 1 As shown, the method includes: Step S1: Each distribution terminal at each switch on the feeder collects the three-phase current flowing through each switch. Based on the collected three-phase current, it is determined whether a fault has occurred in the feeder, and the fault type and fault loop are identified.

[0032] Specifically, each FTU samples the three-phase current measurement data flowing through each switch to obtain the current signal in three-phase coordinates. , , Then, the startup algorithm is applied to determine whether a fault has occurred. Once a fault is confirmed, relevant algorithms are applied to determine the fault type and identify the fault loop. Taking an A / B phase-to-phase short circuit as an example (all faults below refer to A / B phase-to-phase short circuits, which will not be elaborated further), the fault loop consists of phases A and B.

[0033] Step S2: Each distribution terminal determines whether the outgoing circuit breaker has tripped and determines the change in current of each phase flowing through each switch, so as to determine the change in fault loop current flowing through each switch based on the change in current of each phase.

[0034] Figure 2 This is an example diagram of a feeder in a low-current grounding system. (Reference) Figure 2 As shown, CB is the outgoing circuit breaker. The grid side of the busbar connected to CB uses a voltage source of equal value. FS1 (the distribution terminal here is FTU1), FS2 (FTU2), and FS3 (FTU3) are the sectionalizing switches of the main line. FS11 (FTU11) and FS21 (FTU21) are the branch line head switches. LS is the tie switch, and LD is the load ( It is a load branch access point), DG is a distributed power source ( It is a DG branch access point. , This is the point of failure; other system details are briefly described below.

[0035] The FTU can detect changes in current to determine when the outgoing circuit breaker trips after a fault, and then further process the changes in current.

[0036] Specifically, assuming Figure 2 of When a fault occurs at the fault point, the change in current at the instant of tripping phase A at FTU1 is the current after the tripping. Subtract the current from the two power frequency cycles before the circuit breaker trips. The change in current at the moment of tripping phase A at FTU1 is obtained. Similar to the instantaneous current change at the B-phase tripping point of FTU1. ,in, This is the number of sampling points per power frequency cycle. For the first time after the circuit breaker is tripped Each sampling point. The instantaneous current changes of phases A and B at FTU1 during the tripping instant are obtained by Fourier transform to obtain their power frequency variation components, which are represented by phasors. , .

[0037] Furthermore, the fault loop consists of phases A and B, and the change in fault loop current measured at FTU1 in this loop... yes Similarly, the current change obtained at FTU11 is... The change in current at FTU2 is calculated as follows: And so on. The current changes listed below are all power frequency components of the current at the moment the fault loop trips, and will not be elaborated further.

[0038] Step S3: Determine a setting value, determine the overcurrent protection criterion based on the open-circuit supplementary network according to the setting value and the change in fault loop current, generate and send fault information to the master station according to the overcurrent protection criterion, so that the master station can locate the fault section according to the fault information sent by each distribution terminal.

[0039] In one embodiment of the present invention, the overcurrent protection criterion based on the open-circuit supplementary network is expressed as follows: (1) in, This refers to the effective value of the power frequency component of the current change flowing through the corresponding switch at a certain power distribution terminal. The overcurrent protection setting value for this distribution terminal in the open-circuit auxiliary network.

[0040] The setting value is a value related to the calculation error of the current change under the assumption of a grid-side fault, and the setting value is expressed as follows: (2) in, The reliability coefficient is set to 1.3. The calculation of current change during a grid-side fault is based on the assumption that there is a large error. It is the current of the two power frequency cycles before the circuit breaker is tripped, and 0.1 is a possible large calculation error coefficient.

[0041] In one embodiment of the present invention, generating and sending fault information to the master station according to the overcurrent protection criterion of formula (1) includes: when the effective value of the change in current flowing through the corresponding switch determined by the distribution terminal is greater than the setting value, the overcurrent protection is activated, indicating that a fault has occurred on the load side of the distribution terminal, and fault information 1 is sent to the master station, wherein when the master station receives the fault information, it identifies fault information 1; otherwise, the overcurrent protection is not activated, indicating that a fault has occurred on the grid side of the distribution terminal, and the distribution terminal does not send fault information, wherein when the master station does not receive the fault information, it identifies fault information 0.

[0042] Specifically, for traditional overcurrent protection (where the setting value is set to avoid the maximum load current, and there is no need to consider the current change), in Figure 2 If FS21 is disconnected, this feeder is a single-sided power supply system. When a fault occurs, the overcurrent protection at FTU1 will activate and send fault information 1 to the master station. However, the overcurrent protection at FTU11, FTU2, and other FTUs will not activate and will not send fault information to the master station. Based on the received fault information, the master station can locate the fault section between FS1, FS11, and FS2.

[0043] Specifically, regarding traditional overcurrent protection, Figure 2 When FS21 is closed, DG21 is connected to the feeder, and the single-sided power supply system becomes a dual-sided power supply system. In the event of a point fault, the overcurrent protection element of FTU1 will trip. FTU2 and FTU21 may also trip under the action of the DG. In this case, FTU1, FTU2, and FTU21 will all send fault information 1 to the master station. According to the original judgment strategy, the master station will mistakenly locate the fault section on the load side of FS21. To prevent such misjudgment, the sent fault information should also include fault direction information (whether it is a fault on the grid side or the load side of the switch). If the overcurrent protection trips and it is a fault on the load side, then fault information 1 should be sent; otherwise, no information should be sent. In this case, only FTU1 will send 1. However, the existing directional element has many shortcomings when applied to feeders.

[0044] This embodiment proposes overcurrent protection based on an open-circuit supplementary network. Specifically, Figure 2 of The open-circuit auxiliary network after the CB trips due to a fault is as follows: Figure 3 As shown. Since the current after the circuit breaker is used is a sampled value of two power frequency cycles, the sampling instant after the circuit breaker is very short, and there is no need to consider the changes in the large power grid side and the equivalent potential source of DG, their respective internal impedances, and the load at the instant of circuit breaker opening. Figure 3 middle, It is the equivalent impedance on the busbar grid side. It is the equivalent impedance between the busbar and FS1. It is FS1 and point Equivalent impedance between It is a point and Equivalent impedance between yes Equivalent impedance between and FS2, , These are the equivalent impedances on the load sides of FS11 and FS2, respectively. Because a metallic fault is being considered, in... Figure 3 middle The point is directly grounded. Current source. It is the change in current at that point at the instant the CB trips, indicating that the open-circuit auxiliary network is a single-sided power supply network.

[0045] Figure 3 The current at each point can be calculated using step S2. The point is located on the load side of FTU1 and the grid side of other FTUs. The current at FTU1 is relatively large, while the current at other FTUs is zero. Therefore, an overcurrent protection criterion based on the change in fault loop current at the moment of tripping can be applied. (3) From equation (3), when the effective value of the change in current flowing through the corresponding switch is determined by the distribution terminal... When the value is greater than 0, the overcurrent protection based on the change should activate. However, due to... The calculation involves the difference between the phase currents before and after the circuit breaker trips, the difference between the changes in the phase currents of the two phases, and the accumulated calculation errors from other calculation processes. Therefore, the current at other FTUs is not actually zero. Based on the consideration of this calculation error, equation (3) is changed to equation (1).

[0046] In equation (1), FTU1's The setting should be able to identify whether it is on the grid side of FS1 (e.g., Figure 2 of Point) or load side (e.g.) Figure 2 of When a fault occurs at the grid side, the overcurrent protection based on equation (1) reliably does not operate, but it reliably operates when a fault occurs at the load side. Therefore, Specifically determined by equation (2), which does not require setting according to the maximum load current, will greatly improve the sensitivity of overcurrent protection.

[0047] Furthermore, in Figure 3 The criterion (1) is applied at each FTU. Only the overcurrent protection at FTU1 will activate and send fault information 1. This criterion uses the setting value to distinguish between grid-side faults (the fault current flowing through the switch corresponding to the FTU is DG) and load-side faults (the fault current flowing through the FTU is the grid), without needing to determine the fault direction.

[0048] Furthermore, the master station receives fault information 1 from FTU1, while other FTUs do not generate fault information based on equation (1). The master station will correctly locate the fault section between FS1, FS11, and FS2. This method does not require determining the fault direction. It should be noted that there are two reasons why fault information is not generated: one is that the overcurrent protection does not satisfy equation (1), and the other is that the current change cannot determine whether the outgoing circuit breaker has tripped. In this embodiment, the latter is the reason. Although equation (1) is not used for FTUs with grid-side faults, it does not affect the implementation of this method.

[0049] In this embodiment, the open-circuit auxiliary network is a single-sided power supply network. The change in current at the moment of tripping is applied to the overcurrent protection criterion. The setting value is a value related to the calculation error of the current change when assuming a grid-side fault. When this change is greater than the setting value, the system operates, and the fault information is 1. This criterion uses the setting value to distinguish between grid-side faults and load-side faults of the switch corresponding to the FTU, without needing to determine the fault direction.

[0050] The above-described embodiments are merely one implementation of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can apply the method for obtaining fault information according to the present invention to other sectionalizing switches without departing from the concept of the present invention, and these applications all fall within the protection scope of the present invention.

[0051] Figure 4 This is a structural block diagram of a fault information generation system for feeder automation in multi-energy scenarios, according to an embodiment of the present invention. Figure 4 As shown, the fault information generation system 100 for feeder automation in multi-energy scenarios includes multiple power distribution terminals 10 and a master station 20 that is communicatively connected to the multiple power distribution terminals 10.

[0052] Multiple distribution terminals 10 are installed at each switch of the feeder. Each distribution terminal 10 is used to collect the three-phase current flowing through each switch, determine whether a fault has occurred in the feeder based on the collected three-phase current, and determine the fault type and fault loop. In addition, it is also used to determine whether the outgoing circuit breaker has tripped and to determine the change in current of each phase flowing through each switch, so as to determine the change in current of the fault loop flowing through each switch based on the change in current of each phase. Furthermore, it determines a setting value, determines an overcurrent protection criterion based on the setting value and the change in current of the fault loop, generates and sends fault information to the master station 20 based on the overcurrent protection criterion, and the master station 20 is used to locate the fault section based on the fault information sent by each distribution terminal 10.

[0053] In one embodiment of the present invention, the power distribution terminal 10 is used to determine whether the outgoing circuit breaker has tripped based on the detected change in current.

[0054] In one embodiment of the present invention, the overcurrent protection criterion determined by the power distribution terminal 10 based on the open-circuit additional network is as shown in the above formula (1).

[0055] In one embodiment of the present invention, the setting value determined by the distribution terminal 10 is a value related to the calculation error of the current change when the grid side is faulted, and the setting value is expressed as shown in the above formula (2).

[0056] In one embodiment of the present invention, when the distribution terminal 10 generates and sends fault information to the master station according to the overcurrent protection criterion, it is specifically used as follows: when the effective value of the power frequency component of the change in fault loop current flowing through the corresponding switch determined by the distribution terminal 10 is greater than the setting value, the overcurrent protection is activated, indicating that a fault has occurred on the load side of the distribution terminal 10, and the distribution terminal 10 sends fault information 1 to the master station 20, wherein the master station 20 identifies fault information 1 when it receives the fault information; otherwise, the overcurrent protection is not activated, indicating that a fault has occurred on the grid side of the distribution terminal 10, and the distribution terminal 10 does not send fault information, wherein the master station 20 identifies fault information 0 when it does not receive the fault information.

[0057] It should be noted that the specific implementation of the fault information generation system for feeder automation in multi-energy scenarios in this embodiment can be found in the specific implementation of the fault information generation method for feeder automation in multi-energy scenarios described above. To avoid redundancy, it will not be repeated here.

[0058] In summary, this invention discloses a scheme for generating fault information for feeder automation in multi-energy scenarios. When a feeder fault occurs, each FTU determines the fault type and fault loop. Then, when the outgoing circuit breaker trips, the FTU calculates the change in fault loop current at the moment of tripping. This change is the current flowing through each FTU in the open-circuit supplementary network. The open-circuit supplementary network is a single-sided power supply network. When a metallic short-circuit fault occurs on the load side of the FTU (far from the grid side), the overcurrent protection based on the change should operate when the change in fault loop current is greater than 0. However, since the calculation of this change involves the difference between the phase currents before and after tripping, the difference between the changes in phase currents of two phases, and other calculation processing steps, the current at the FTU is not actually 0 when the fault occurs on the grid side of the FTU. Considering this calculation error, this invention proposes an overcurrent protection criterion and setting method based on the open-circuit supplementary network. This method can effectively solve the problem that existing directional elements are insufficient for determining the fault direction in feeder fault direction due to the need to determine the fault direction in existing overcurrent protection in multi-energy scenarios.

[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0060] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for generating fault information suitable for feeder automation in multi-energy scenarios, characterized in that, include: Each distribution terminal at each switch on the feeder collects the three-phase current flowing through each switch. Based on the collected three-phase current, it determines whether a fault has occurred in the feeder and identifies the fault type and fault loop. Each distribution terminal determines whether the outgoing circuit breaker has tripped and determines the change in current of each phase flowing through each switch, so as to determine the change in fault loop current flowing through each switch based on the change in current of each phase. A setting value is determined, and an overcurrent protection criterion based on the open-circuit auxiliary network is determined based on the setting value and the change in fault loop current. Fault information is generated and sent to the master station based on the overcurrent protection criterion, so that the master station can locate the fault section based on the fault information sent by each distribution terminal.

2. The fault information generation method for feeder automation in multi-energy scenarios as described in claim 1, characterized in that, The power distribution terminal determines whether the outgoing circuit breaker should trip based on the detected change in current.

3. The fault information generation method for feeder automation in multi-energy scenarios as described in claim 1, characterized in that, The overcurrent protection criterion based on the open-circuit auxiliary network is expressed as follows: in, The effective value of the power frequency component of the change in fault loop current flowing through the corresponding switch, as determined by the power distribution terminal. This is the setpoint value.

4. The fault information generation method for feeder automation in multi-energy scenarios as described in claim 3, characterized in that, The setting value is a value related to the calculation error of current change assuming a grid-side fault, and the setting value is expressed as follows: in, The reliability coefficient is set to 1.

3. The calculation of current change during a grid-side fault is based on the assumption that there is a large error. It is the current of the two power frequency cycles before the circuit breaker is tripped, and 0.1 is a possible large calculation error coefficient.

5. The fault information generation method for feeder automation in multi-energy scenarios as described in claim 4, characterized in that, Fault information is generated and sent to the master station based on overcurrent protection criteria, including: When the effective value of the power frequency component of the change in fault loop current flowing through the corresponding switch, as determined by the distribution terminal, is greater than the set value, the overcurrent protection will activate, indicating a fault on the load side of the distribution terminal, and will send fault information 1 to the master station. If the master station receives the fault information, it will mark fault information 1. Otherwise, the overcurrent protection will not activate, indicating a fault on the grid side of the distribution terminal, and the distribution terminal will not send fault information. If the master station does not receive the fault information, it will mark fault information 0.

6. A fault information generation system suitable for feeder automation in multi-energy scenarios, characterized in that, include: Multiple distribution terminals are installed at each switch on the feeder. Each distribution terminal is used to collect the three-phase current flowing through each switch, and to determine whether a fault has occurred in the feeder based on the collected three-phase current, and to determine the fault type and fault loop. In addition, it is also used to determine whether the outgoing circuit breaker has tripped, and to determine the change in the current of each phase flowing through each switch, so as to determine the change in the fault loop current flowing through each switch based on the change in the current of each phase. In addition, a setting value is determined, and an overcurrent protection criterion based on the open-circuit supplementary network is determined based on the setting value and the change in fault loop current. Fault information is generated and sent to the master station based on the overcurrent protection criterion. The main station communicates with multiple power distribution terminals and is used to locate fault sections based on fault information sent by each power distribution terminal.

7. The fault information generation system for feeder automation in multi-energy scenarios as described in claim 6, characterized in that, The distribution terminal is used to determine whether the outgoing circuit breaker has tripped based on the detected change in current.

8. The fault information generation system for feeder automation in multi-energy scenarios as described in claim 6, characterized in that, The overcurrent protection criterion determined by the distribution terminal based on the open-circuit auxiliary network is expressed as follows: in, The effective value of the power frequency component of the change in fault loop current flowing through the corresponding switch, as determined by the power distribution terminal. This is the setpoint value.

9. The fault information generation system for feeder automation in multi-energy scenarios as described in claim 8, characterized in that, The setting value determined by the distribution terminal is a value related to the calculation error of the current change under the assumption of a grid-side fault. The setting value is expressed as follows: in, The reliability coefficient is set to 1.

3. The calculation of current change during a grid-side fault is based on the assumption that there is a large error. It is the current of the two power frequency cycles before the circuit breaker is tripped, and 0.1 is a possible large calculation error coefficient.

10. The fault information generation system for feeder automation in multi-energy scenarios as described in claim 9, characterized in that, When the distribution terminal generates and sends fault information to the master station based on the overcurrent protection criteria, it is specifically used for: When the effective value of the power frequency component of the change in fault loop current flowing through the corresponding switch, as determined by the distribution terminal, is greater than the set value, the overcurrent protection will activate, indicating a fault on the load side of the distribution terminal. The distribution terminal will then send fault information 1 to the master station. If the master station receives the fault information, it will mark fault information 1. Otherwise, the overcurrent protection will not activate, indicating a fault on the grid side of the distribution terminal. The distribution terminal will not send fault information. If the master station does not receive the fault information, it will mark fault information 0.

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