A method for analyzing line faults in distribution network

Abstract

The present invention relates to the technical field of cable fault analysis, and specifically discloses a distribution network line fault analysis method. The method is based on a line fault location area, collects fault state information of a line fault location area in a distribution network, and analyzes to obtain the fault loss degree of the line fault location area, so as to understand in real time the loss degree of the distribution network when a fault occurs, thereby matching the fault type of the line fault location area, and by collecting equipment protection information of the line fault location area, it is possible to determine the paths of occurrence of each fault in the line fault location area, and finally match each fault repair plan of the line fault location area, so as to reduce the fault maintenance cost of the distribution network, complete the line fault repair process of the distribution network, improve the power supply reliability of the distribution network, and improve the normal operation efficiency of the power system.

Description

Technical Field

[0001] The present invention relates to the technical field of cable fault analysis, and in particular to a method for analyzing faults in a distribution network line. Background Art

[0002] Nowadays, with the continuous increase in electricity demand, the corresponding distribution network needs to operate uninterruptedly, which will cause frequent failures in the lines in the distribution network. Frequent failures will cause serious damage to power equipment, requiring larger-scale repairs or replacement conditions, increasing the maintenance cost of the distribution network. At the same time, when a line failure occurs in the distribution network, if it is not resolved in time, it will cause power outages and affect the normal operation of the power system. Therefore, timely and accurate fault analysis of the distribution network lines can improve the power supply reliability of the distribution network, thereby improving the normal operation efficiency of the power system.

[0003] For example, the invention patent with the announcement number CN113533900B announces a fault section determination system and method for a hybrid cable line of a distribution network. The determination system includes a data acquisition module and a data analysis module, and the data acquisition module is connected to the data analysis module. The determination method specifically includes first collecting voltage signals and current signals at both ends of the hybrid cable line of the distribution network, and then obtaining the corresponding power frequency voltage and power frequency current according to the collected voltage signal data and current signal data, and then obtaining the forward current traveling wave differential momentum and the reverse current traveling wave differential momentum according to the power frequency voltage and the power frequency current, and then determining the fault section determination function according to the forward current traveling wave differential momentum and the reverse current traveling wave differential momentum, and then calculating the fault section judgment value, and finally comparing it with the preset threshold to obtain the specific fault section. It is suitable for the fault section determination of multi-section cable hybrid lines, and can avoid the error caused by directly measuring the traveling wave, and improve the accuracy of fault section determination.

[0004] For example, the invention patent with announcement number CN105699856B announces a cable fault location system and method based on intelligent collection and analysis. The cable is composed of multiple cables of different lengths and cross-sectional areas connected by insulating joints. The cable fault location system includes a fault cable, a reference cable, a short-circuit wire, a grounding switch, a data acquisition unit, a cable resistance detection unit and a processor unit. One end of the fault cable and the reference cable is a reference end, and the other end is a test end. The reference ends of the fault cable and the reference cable are connected by a short-circuit wire, and the reference end of the fault cable is also grounded through a grounding switch. The cable resistance detection unit is connected to the test ends of the fault cable and the reference cable respectively, and the data acquisition unit and the cable resistance detection unit are both connected to the processor unit. Compared with the prior art, this solution has the advantages of convenient testing, high degree of automation, and high accuracy of fault location results.

[0005] Combining the above technical solutions, it is found that the current technical solutions for power line fault determination usually perform targeted analysis through single data, while power line failure is a widespread and real-time technical problem. Therefore, the above targeted analysis will make the power line fault determination result inaccurate, which will largely cause the power system to still not operate normally, reducing the fault resolution efficiency of the power system. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a method for analyzing line faults in a distribution network, which can effectively solve the problems involved in the above-mentioned background technology.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a distribution network line fault analysis method, comprising: based on the line fault location area, collecting fault status information of the line fault location area in the distribution network, and analyzing to obtain the fault loss degree of the line fault location area, thereby matching the fault type of the line fault location area; collecting equipment protection information of the line fault location area, and comprehensively considering the fault type of the line fault location area, determining the fault occurrence paths of the line fault location area, and finally matching the fault repair plans of the line fault location area to complete the line fault repair process of the distribution network.

[0008] As a further method, the fault type of the line fault location area is matched, and the specific matching process is:

[0009] The fault loss degree of the line fault locating area is matched with the fault types corresponding to the fault loss degree intervals preset in the line fault information database, thereby matching the fault type of the line fault locating area.

[0010] As a further method, the fault loss degree of the line fault location area is specifically analyzed as follows:

[0011] Evaluate the current and voltage abnormal area of ​​each fault monitoring point in the line fault location area during the fault occurrence cycle, the number of current and voltage peaks of each fault monitoring point in the line fault location area during the fault occurrence cycle, and the number of current and voltage valleys of each fault monitoring point in the line fault location area during the fault occurrence cycle, and comprehensively process to obtain the fault loss degree of the line fault location area. The specific processing formula is:

[0012]

[0013] In the formula, is the fault loss degree of the line fault location area, is the current and voltage abnormal area of ​​the fth fault monitoring point in the line fault location area during the fault occurrence cycle, is the influencing factor of the unit value of the current and voltage abnormal area preset in the line fault information database, is the number of current and voltage peaks at the fth fault monitoring location point in the line fault location area during the fault occurrence cycle, is the number of current and voltage valleys at the fth fault monitoring location point in the line fault location area during the fault occurrence cycle, is the correction factor for the number of current and voltage anomalies preset in the line fault information database, is the number of current and voltage anomaly definitions preset in the line fault information database, f represents the number of each fault monitoring location point, ...,d, d represents the total number of fault monitoring location points.

[0014] As a further method, the matching of each fault repair plan in the line fault location area completes the line fault repair process of the distribution network. The specific process is:

[0015] Each fault occurrence path in the line fault location area is matched with the fault repair plan corresponding to each fault occurrence path preset in the line fault information library, and finally each fault repair plan in the line fault location area is obtained, so as to complete the line fault repair process of the distribution network through each fault repair plan.

[0016] As a further method, the specific determination process of determining each fault occurrence path in the line fault location area is as follows:

[0017] Determine the protection influence of each relay protection device, and compare it with the protection influence limit value preset in the line fault information database. If the protection influence of a certain relay protection device is greater than the preset protection influence limit value, locate the fault path corresponding to the relay protection device, thereby counting the relay protection devices corresponding to the protection influence greater than the preset protection influence limit value, and finally locate the fault paths corresponding to the relay protection devices, perform path overlap comparison on the fault paths, screen out the overlapped fault paths, and thus obtain the fault paths in the line fault location area, which are recorded as the fault occurrence paths in the line fault location area.

[0018] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0019] (1) The present invention provides a method for analyzing line faults in a distribution network. First, based on the line fault location area, the fault status information of the line fault location area in the distribution network is collected, and the fault loss degree of the line fault location area is obtained by analysis, thereby matching the fault type of the line fault location area. The fault type of the distribution network fault area can be widely analyzed, and by collecting the equipment protection information of the line fault location area, the fault occurrence paths of the line fault location area can be determined. Finally, the fault repair plans of the line fault location area are matched to complete the line fault repair process of the distribution network. The above-mentioned timely and accurate fault analysis of the distribution network line can improve the power supply reliability of the distribution network, thereby improving the normal operation efficiency of the power system.

[0020] (2) Based on the line fault location area, the present invention collects the fault status information of the line fault location area in the distribution network, and analyzes the fault loss degree of the line fault location area, so as to understand the loss degree of the distribution network in real time when a fault occurs, thereby matching the fault type of the line fault location area, and providing reference data support for subsequent fault repair.

[0021] (3) The present invention collects equipment protection information in the line fault location area, and comprehensively considers the fault type in the line fault location area, determines the paths of each fault in the line fault location area, and finally matches each fault repair plan in the line fault location area, thereby reducing the fault maintenance cost of the distribution network, completing the line fault repair process of the distribution network, and finally ensuring the normal operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the present invention. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0023] Figure 1 It is a schematic diagram of the method flow of the present invention.

[0024] Figure 2 It is a comprehensive schematic diagram of the current and voltage waveform curves corresponding to the fault occurrence cycle involved in the present invention and the current and voltage waveform curves corresponding to the historical fault cycle.

[0025] Figure numerals: 1. Current and voltage waveform curve within the fault occurrence cycle, 2. Current and voltage waveform curve within the historical fault cycle, 3. Current and voltage abnormal area, 4. Fault occurrence time point corresponding to the current and voltage peak, 5. Fault occurrence time point corresponding to the current and voltage valley. DETAILED DESCRIPTION

[0026] The technical solutions 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, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] Reference Figure 1 As shown, the present invention provides a distribution network line fault analysis method, including: based on the line fault location area, collecting fault status information of the line fault location area in the distribution network, and analyzing to obtain the fault loss degree of the line fault location area, thereby matching the fault type of the line fault location area.

[0028] In a specific embodiment, the present invention collects fault status information of the line fault location area in the distribution network based on the line fault location area, and analyzes the fault loss degree of the line fault location area, so as to understand the loss degree of the distribution network in real time when a fault occurs, thereby matching the fault type of the line fault location area and providing reference data support for subsequent fault repair.

[0029] It should be explained that the above-mentioned line fault location area utilizes the communication network in the distribution automation system built into the distribution network to quickly locate the geographical location of the fault through the transmitted line fault information, that is, the fault occurrence area preliminarily set in the distribution network, providing a regional reference basis for the subsequent accurate determination of the line faults in the distribution network.

[0030] Specifically, the fault status information of the line fault locating area includes the current value and voltage value of each fault monitoring position point in the line fault locating area at each fault occurrence time point, and the current value and voltage value of each fault monitoring position point in the line fault locating area at each historical fault time point.

[0031] It should be explained that the above-mentioned fault occurrence time points are obtained by dividing the fault occurrence cycle according to preset equal time intervals, wherein the fault occurrence cycle refers to the time period for monitoring the fault status of the line fault location area, and is obtained by timing monitoring the fault status of the line fault location area through the SCADA (data acquisition and monitoring control) system in the distribution network, and its value will be adjusted with the area of ​​the line fault location area and the severity of the fault status of the line fault location area. The specific duration is not specially limited in this example; each historical fault time point is obtained by dividing the historical fault cycle according to preset equal time intervals, wherein the historical fault cycle refers to a time period before the fault occurs in the line fault location area, that is, an adjacent time length of the distribution network line before the fault occurs, and the duration of the historical fault cycle is equal to the duration of the fault occurrence cycle. At the same time, the method for obtaining the historical fault cycle is the same as the method for obtaining the fault occurrence cycle, that is, the SCADA (data acquisition and monitoring control) system in the distribution network is used to locate the time period of the line fault location area before the fault occurs.

[0032] It should be explained that the current values ​​and voltage values ​​at the above-mentioned fault occurrence time points and the current values ​​and voltage values ​​at the historical fault time points are all obtained in real time through current sensors and voltage sensors installed in the line fault location area in the distribution network.

[0033] In this example, the above-mentioned fault monitoring location points are randomly arranged according to the line fault location area. The purpose is to monitor the line status in real time. Once a fault occurs, the specific location of the fault can be quickly located to shorten the fault finding time; at the same time, it helps to analyze the fault mode and understand the root cause of the fault, so as to take targeted improvement measures and improve the stability of the entire distribution network.

[0034] Furthermore, the specific analysis process of the fault status information of the line fault location area is as follows:

[0035] The current value and voltage value of each fault monitoring location point in the line fault locating area at each fault occurrence time point are constructed as a current and voltage waveform curve of each fault monitoring location point in the line fault locating area within the fault occurrence cycle. At the same time, the current value and voltage value of each fault monitoring location point in the line fault locating area at each historical fault time point are constructed as a current and voltage waveform curve of each fault monitoring location point in the line fault locating area within the historical fault cycle.

[0036] It should be explained that the current and voltage waveform curves of each fault monitoring position point in the line fault location area in the fault occurrence cycle and the current and voltage waveform curves of each fault monitoring position point in the line fault location area in the historical fault cycle are only taken out of a group of curve graphs of the fault monitoring position points in this example, and the curve schematic diagram is as follows Figure 2 As shown, it is a comprehensive schematic diagram of the current and voltage waveform curves corresponding to the fault occurrence cycle and the current and voltage waveform curves corresponding to the historical fault cycle. 1 is the current and voltage waveform curve of the line fault location area in the fault occurrence cycle, and 2 is the current and voltage waveform curve of the line fault location area in the historical fault cycle. The horizontal axis is the current value in amperes, and the vertical axis is the voltage value in volts. Figure 2 It can be found that the current and voltage conditions corresponding to the line fault location area monitored this time are more obvious than the historical current and voltage fault conditions, indicating that the fault in the line fault location area this time is more serious. Therefore, it is necessary to comprehensively consider various influencing factors to comprehensively obtain the specific fault information of the line fault location area.

[0037] Specifically, the current and voltage abnormal areas of each fault monitoring location point in the line fault location area during the fault occurrence cycle, the number of current and voltage peaks of each fault monitoring location point in the line fault location area during the fault occurrence cycle, and the number of current and voltage valleys of each fault monitoring location point in the line fault location area during the fault occurrence cycle are evaluated. The specific evaluation process is:

[0038] The current and voltage waveform curves of each fault monitoring position point in the line fault locating area within the fault occurrence cycle are overlapped and compared with the current and voltage waveform curves of each fault monitoring position point in the line fault locating area within the historical fault cycle, thereby obtaining the current and voltage abnormal area of ​​each fault monitoring position point in the line fault locating area within the fault occurrence cycle.

[0039] It should be explained that the current and voltage abnormal areas of each fault monitoring location point in the above-mentioned line fault location area within the fault occurrence cycle are as follows: Figure 2 As shown, the shaded part is the current and voltage abnormal area 3 of a certain fault monitoring position point in the line fault location area during the fault occurrence cycle, and the device for coincidence comparison is an extended toolbox in MATLAB. By transmitting the above two curves to an extended toolbox in MATLAB through wireless communication technology, the built-in waveform analysis technology will be used to obtain the current and voltage abnormal area required by the present invention.

[0040] From the current and voltage waveform curves of each fault monitoring position point in the line fault location area within the fault occurrence cycle, the number of fault occurrence time points corresponding to the current and voltage peaks and the number of fault occurrence time points corresponding to the current and voltage valleys are extracted, and recorded as the number of current and voltage peaks at each fault monitoring position point in the line fault location area within the fault occurrence cycle and the number of current and voltage valleys at each fault monitoring position point in the line fault location area within the fault occurrence cycle, respectively.

[0041] It should be explained that the number of current and voltage peaks and the number of current and voltage valleys are as follows: Figure 2 As shown, 4 is the fault occurrence time point corresponding to the current and voltage peak, 5 is the fault occurrence time point corresponding to the current and voltage valley, the number of current and voltage peaks is 4, and the number of current and voltage valleys is 3.

[0042] Furthermore, the fault loss degree of the line fault location area is specifically analyzed as follows:

[0043] Evaluate the current and voltage abnormal area of ​​each fault monitoring point in the line fault location area during the fault occurrence cycle, the number of current and voltage peaks of each fault monitoring point in the line fault location area during the fault occurrence cycle, and the number of current and voltage valleys of each fault monitoring point in the line fault location area during the fault occurrence cycle, and comprehensively process to obtain the fault loss degree of the line fault location area. The specific processing formula is:

[0044]

[0045] In the formula, is the fault loss degree of the line fault positioning area. In this example, when the current distribution network line fails, the current and voltage at the time of the fault will fluctuate more than the current and voltage during normal operation. If you want to accurately locate the location of the fault in the distribution network, you need to conduct a comprehensive analysis based on historical fault conditions. Therefore, by constructing the current and voltage fluctuation curves of the current fault and historical faults, you can compare the specific conditions of the current and voltage fluctuations of this fault to make a better fault judgment. In the current and voltage curve diagram, you can obviously find extremely high and extremely low waveforms, which are the places where the distribution network in this example is very likely to fail. Therefore, through the current and voltage abnormal area, the number of current and voltage peaks, and the number of current and voltage valleys in this example, you can comprehensively determine the fault loss of the distribution network, and provide a location reference basis for subsequent repairs to the fault location of the distribution network.

[0046] It is the abnormal current and voltage area of ​​the fth fault monitoring position point in the line fault location area within the fault occurrence cycle, indicating the impact of a fault at a certain position point in the line fault location area. The larger the area, the wider the fault range.

[0047] It is the influencing factor of the unit value of the current and voltage abnormal area preset in the line fault information library. It is obtained by fitting the corresponding relationship between the historical current value, the historical voltage value and the current and voltage abnormal area in the line fault location area, and the fitting curve corresponding to the current and voltage abnormal area is obtained. The current value and voltage value in the real-time line fault location area are brought into the fitting curve corresponding to the current and voltage abnormal area to obtain the influencing factor of the unit value of the current and voltage abnormal area in this example. At the same time, the value range in this example is (0,1).

[0048] It is the number of current and voltage peaks at the fth fault monitoring position point in the line fault location area within the fault occurrence cycle, indicating the position with the maximum value in the current and voltage waveform curve of a certain position point in the line fault location area within the fault occurrence cycle.

[0049] It is the number of current and voltage valleys at the fth fault monitoring position point in the line fault location area within the fault occurrence cycle, indicating the position where the value of the curve is extremely small in the current and voltage waveform curve of a certain position point in the line fault location area within the fault occurrence cycle.

[0050] It is the correction factor of the number of current and voltage anomalies preset in the line fault information library. It is obtained by fitting the fitting curve corresponding to the number of current and voltage anomalies through the correspondence between the historical number of current and voltage peaks, the historical number of current and voltage valleys and the number of current and voltage anomalies in the line fault location area, and the real-time number of current and voltage peaks and the number of current and voltage valleys are brought into the fitting curve corresponding to the number of current and voltage anomalies to obtain the correction factor of the number of current and voltage anomalies in this example. At the same time, the value range in this example is (0,1).

[0051] The number of current and voltage anomaly limits preset in the line fault information library represents the maximum permissible number of the current and voltage peak numbers and the current and voltage valley numbers set in this example.

[0052] f represents the number of each fault monitoring location point, ...,d, d represents the total number of fault monitoring location points

[0053] Specifically, the fault type of the line fault location area is matched, and the specific matching process is:

[0054] The fault loss degree of the line fault locating area is matched with the fault types corresponding to the fault loss degree intervals preset in the line fault information database, thereby matching the fault type of the line fault locating area.

[0055] In this exemplary embodiment, the specific matching process of the fault type in the above line fault location area is as follows:

[0056] Each fault loss degree interval corresponds to a fault type. The fault loss degree interval corresponding to the fault loss degree of the line fault location area is queried from the line fault information database, and the fault type corresponding to the fault loss degree interval is the fault type of the line fault location area.

[0057] Collect equipment protection information in the line fault location area, and comprehensively analyze the fault types in the line fault location area to determine the fault occurrence paths in the line fault location area. Finally, match the fault repair plans in the line fault location area to complete the line fault repair process of the distribution network.

[0058] In a specific embodiment, the present invention collects equipment protection information in a line fault location area, and comprehensively considers the fault type in the line fault location area, determines the paths of each fault in the line fault location area, and finally matches each fault repair plan in the line fault location area, thereby reducing the fault maintenance cost of the distribution network, completing the line fault repair process of the distribution network, and ultimately ensuring the normal operation of the power system.

[0059] Specifically, the equipment protection information of the line fault location area includes the time point corresponding to the reception of the fault signal of each relay protection device and the start time point corresponding to the protection action. The detailed information of the protection action is recorded in real time according to the built-in fault data recorder of the relay protection device, including the time point corresponding to the reception of the fault signal and the start time point corresponding to the protection action.

[0060] It should be explained that the types of the above-mentioned relay protection devices include but are not limited to current protection devices, voltage protection devices, distance protection devices, and busbar protection devices, and a distribution network line may have more than one relay protection device.

[0061] Furthermore, the protection impact of each relay protection device is specifically analyzed as follows:

[0062] The time point corresponding to the reception of the fault signal of each relay protection device and the start time point corresponding to the protection action are subjected to difference processing to obtain the protection response time length of each relay protection device.

[0063] Obtain the historical maintenance information corresponding to each relay protection device, wherein the historical maintenance information includes each historical protection response duration of each relay protection device and the number of faulty devices of each relay protection device within the historical maintenance cycle. The method for obtaining each historical protection response duration is that the relay protection device itself usually records the detailed information of each protection action, and thus the protection response duration can be extracted through the protection record of the relay protection device itself. The method for obtaining the number of faulty devices is to query the number of devices that the relay protection device in the relay protection device control system fails to protect at the moment of a fault. The relay protection device control system refers to the system that performs overall control over the relay protection devices.

[0064] It should be explained that the above-mentioned historical maintenance cycle is the time period when a relay protection device is set to perform protection in this example. Its length is equal to the length of the above-mentioned historical fault cycle and the length of the fault occurrence cycle, and is extracted through the SCADA (Supervisory Control and Data Acquisition) system in the distribution network.

[0065] Based on the protection response time of each relay protection device, the historical protection response time of each relay protection device, the number of faulty devices of each relay protection device within the historical maintenance cycle, and the number of faulty devices defined corresponding to the fault type of the line fault location area preset in the line fault information database.

[0066] It needs to be explained that the number of faulty devices corresponding to the above-mentioned fault types indicates the maximum number of relay protection devices that do not provide protection after the fault type is determined. For example, if the fault type is a short circuit fault, the current quick-break protection device, time-limited current quick-break protection device, overcurrent protection device, etc. should be used for fault protection. However, due to factors such as equipment performance and functional problems, some devices do not participate in the fault protection action, so this device is a faulty device.

[0067] The protection influence of each relay protection device is obtained through comprehensive processing. The specific analysis formula is:

[0068]

[0069] In the formula, Indicates the protection influence of the bth relay protection device. In this example, if a distribution network fails, a large part of the reason is that the relay protection device does not perform effective protection. When the relay protection device does not work effectively, its response time accounts for a large proportion. For example, if the protection response time of the relay protection device is long, the fault condition of the distribution network will be expanded, resulting in the relay protection device being unable to respond to the fault scope in time and unable to effectively perform fault protection. At the same time, it will also cause over-protection of the relay protection device, causing equipment failure, which is not conducive to subsequent protection work. In summary, when a distribution network fails, if the relay protection device fails to effectively perform protection work, the fault scope of the distribution network will be expanded, which is not conducive to the subsequent precise positioning of the fault location and prolonging the maintenance time. Therefore, analyzing multiple parameters of the relay protection device can timely and accurately query the fault location of the distribution network, which is conducive to the rapid and stable operation of the distribution network.

[0070] It represents the correction factor corresponding to the protection impact preset in the line fault information database. The fitting curve corresponding to the protection impact is obtained by fitting the corresponding relationship between the historical protection response time of the relay protection device and the protection impact, and the real-time protection response time is brought into the fitting curve corresponding to the protection impact to obtain the correction factor corresponding to the protection impact in this example. At the same time, the value range in this example is (0,1).

[0071] It indicates the protection response time of the bth relay protection device, which refers to the response time period of the relay protection device when performing fault protection.

[0072] It represents the hth historical protection response duration of the bth relay protection device, which refers to the response time period of the relay protection device under historical fault protection.

[0073] It represents the number of faulty devices of the bth relay protection device in the historical maintenance cycle, which refers to the number of faults of the relay protection device in the historical maintenance cycle.

[0074] The fault device boundary number corresponding to the fault type in the line fault location area refers to the maximum number of faults in the relay protection devices corresponding to the fault type.

[0075] b represents the number of each relay protection device, , u represents the total number of relay protection devices, h represents the number of each historical protection, , p represents the total number of historical protections.

[0076] Specifically, the specific determination process of determining each fault occurrence path in the line fault location area is as follows:

[0077] Determine the protection impact of each relay protection device and compare it with the protection impact limit value preset in the line fault information database, where the protection impact limit value represents the maximum value of the protection impact within a reasonable range.

[0078] If the protection impact of a certain relay protection device is greater than the preset protection impact limit value, it means that the protection impact of the relay protection device exceeds the reasonable range of the protection impact. The fault path corresponding to the relay protection device is located through the distributed fault indicator installed in the distribution network, thereby counting the relay protection devices corresponding to the protection impact greater than the preset protection impact limit value, and finally locating the fault paths corresponding to the relay protection devices, and performing path coincidence comparison on the fault paths, wherein the path coincidence comparison is to query the independent position information about the fault path through the distributed fault indicators installed in the distribution network. If the information given by multiple distributed fault indicators is consistent, the fault path may be confirmed multiple times, that is, it is a repeated fault path. Screening out the overlapping fault paths is helpful to reasonably allocate fault repair resources and reduce the operation and maintenance costs of the distribution network. Thus, the fault paths in the line fault location area are obtained, which are recorded as the fault occurrence paths in the line fault location area.

[0079] Furthermore, the matching of each fault repair plan in the line fault location area completes the line fault repair process of the distribution network. The specific process is:

[0080] Each fault occurrence path in the line fault location area is matched with the fault repair plan corresponding to each fault occurrence path preset in the line fault information library, and finally each fault repair plan in the line fault location area is obtained, so as to complete the line fault repair process of the distribution network through each fault repair plan.

[0081] It should be explained that the specific matching process of each fault repair plan in the above line fault location area is as follows:

[0082] Each fault path corresponds to a fault repair plan. The fault repair plan corresponding to a fault path in the line fault location area is queried from the line fault information database. The fault path corresponding to the fault path is the fault repair plan corresponding to the fault path in the line fault location area.

[0083] It is further necessary to explain that the above-mentioned line fault repair process of the distribution network is completed through various fault repair plans. Specifically, the fault maintenance system in the line fault location area repairs the fault path in the distribution network according to each fault repair plan; for example, in this example, the fault type is set to an overcurrent fault. Then, through the protection information of the relay protection device corresponding to the overcurrent fault, the various fault paths corresponding to the overcurrent fault can be located. Due to the differences in the protection information, environmental factors, etc. of the relay protection device in each fault path, the repair plans matched thereby are different; for example, for each fault path corresponding to the overcurrent fault in this example, if only one relay protection device of a certain fault path is performing protection normally, the corresponding repair plan is as follows:

[0084] After receiving the protection action signal from the relay protection device, the distribution network's automated repair and processing system will quickly determine whether it is an overcurrent fault and confirm whether the fault is serious. Based on the protection information, the automated repair and processing system automatically operates the circuit breaker to isolate the faulty section from the power grid to prevent the fault from further expanding. The fault recorder installed in the distribution network is used to analyze the current and voltage waveforms during the fault, as well as the time of protection action, to assist in determining the specific location of the fault. The automated repair and processing system analyzes the cause of the fault based on the determined fault location. If it is caused by external factors such as overload, it may be necessary to adjust the load distribution or increase the equipment capacity. If it is determined that the fault has been repaired and meets the reclosing conditions, the automated repair and processing system will attempt to reclose to restore power supply. If the reclosing is successful, the distribution network continues to operate. If the reclosing fails, further investigation may be required. After the fault is repaired and the automated repair and processing system has performed necessary tests on it, the power supply to the affected users will be gradually restored, while the power grid operation status will be monitored to ensure stability.

[0085] In a specific embodiment, the present invention provides a distribution network line fault analysis method. First, based on the line fault location area, the fault state information of the line fault location area in the distribution network is collected, and the fault loss degree of the line fault location area is obtained by analysis, thereby matching the fault type of the line fault location area, and the fault type of the distribution network fault area can be widely analyzed. By collecting the equipment protection information of the line fault location area, the fault occurrence path of each fault in the line fault location area can be determined, and finally the fault repair plans of the line fault location area are matched to complete the line fault repair process of the distribution network. The above-mentioned timely and accurate fault analysis of the distribution network line can improve the power supply reliability of the distribution network, thereby improving the normal operation efficiency of the power system.

[0086] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A method for analyzing a distribution network line fault, characterized in that: include: Based on the line fault location area, the fault state information of the line fault location area in the distribution network is collected, and the fault loss degree of the line fault location area is obtained by analysis, thereby matching the fault type of the line fault location area; Collect equipment protection information in the line fault location area, and comprehensively analyze the fault types in the line fault location area to determine the fault occurrence paths in the line fault location area, and finally match the fault repair plans in the line fault location area to complete the line fault repair process of the distribution network; The specific analysis process of the fault loss degree of the line fault location area is as follows: Evaluate the current and voltage abnormal area of ​​each fault monitoring point in the line fault location area during the fault occurrence cycle, the number of current and voltage peaks of each fault monitoring point in the line fault location area during the fault occurrence cycle, and the number of current and voltage valleys of each fault monitoring point in the line fault location area during the fault occurrence cycle, and comprehensively process to obtain the fault loss degree of the line fault location area. The specific processing formula is: In the formula, is the fault loss degree of the line fault location area, is the current and voltage abnormal area of ​​the fth fault monitoring point in the line fault location area during the fault occurrence cycle, is the influencing factor of the unit value of the current and voltage abnormal area preset in the line fault information database, is the number of current and voltage peaks at the fth fault monitoring location point in the line fault location area during the fault occurrence cycle, is the number of current and voltage valleys at the fth fault monitoring location point in the line fault location area during the fault occurrence cycle, is the correction factor for the number of current and voltage anomalies preset in the line fault information database, is the number of current and voltage anomaly definitions preset in the line fault information database, f represents the number of each fault monitoring location point, ...,d, d represents the total number of fault monitoring location points.

2. A distribution network line fault analysis method according to claim 1, characterized in that: The specific matching process of matching the fault type of the line fault location area is as follows: The fault loss degree of the line fault locating area is matched with the fault types corresponding to the fault loss degree intervals preset in the line fault information database, thereby matching the fault type of the line fault locating area.

3. A method for analyzing a distribution network line fault according to claim 1, characterized in that: The fault status information of the line fault locating area specifically includes the current value and voltage value of each fault monitoring position point in the line fault locating area at each fault occurrence time point, and the current value and voltage value of each fault monitoring position point in the line fault locating area at each historical fault time point.

4. A method for analyzing a distribution network line fault according to claim 3, characterized in that: The specific analysis process of the fault status information of the line fault location area is as follows: The current value and voltage value of each fault monitoring location point in the line fault locating area at each fault occurrence time point are constructed as a current and voltage waveform curve of each fault monitoring location point in the line fault locating area within the fault occurrence cycle. At the same time, the current value and voltage value of each fault monitoring location point in the line fault locating area at each historical fault time point are constructed as a current and voltage waveform curve of each fault monitoring location point in the line fault locating area within the historical fault cycle.

5. A distribution network line fault analysis method according to claim 1, characterized in that: The evaluation process of evaluating the abnormal current and voltage area of ​​each fault monitoring location point in the line fault location area during the fault occurrence cycle, the number of current and voltage peaks of each fault monitoring location point in the line fault location area during the fault occurrence cycle, and the number of current and voltage valleys of each fault monitoring location point in the line fault location area during the fault occurrence cycle is as follows: Compare the current and voltage waveform curves of each fault monitoring position point in the line fault location area within the fault occurrence cycle with the current and voltage waveform curves of each fault monitoring position point in the line fault location area within the historical fault cycle, thereby obtaining the current and voltage abnormal area of ​​each fault monitoring position point in the line fault location area within the fault occurrence cycle; From the current and voltage waveform curves of each fault monitoring position point in the line fault location area within the fault occurrence cycle, the number of fault occurrence time points corresponding to the current and voltage peaks and the number of fault occurrence time points corresponding to the current and voltage valleys are extracted, and recorded as the number of current and voltage peaks at each fault monitoring position point in the line fault location area within the fault occurrence cycle and the number of current and voltage valleys at each fault monitoring position point in the line fault location area within the fault occurrence cycle, respectively.

6. A distribution network line fault analysis method according to claim 1, characterized in that: The matching of each fault repair plan in the line fault location area completes the line fault repair process of the distribution network. The specific process is as follows: Each fault occurrence path in the line fault location area is matched with the fault repair plan corresponding to each fault occurrence path preset in the line fault information library, and finally each fault repair plan in the line fault location area is obtained, so as to complete the line fault repair process of the distribution network through each fault repair plan.

7. A method for analyzing a distribution network line fault according to claim 1, characterized in that: The specific determination process of determining each fault occurrence path in the line fault location area is as follows: Determine the protection influence of each relay protection device, and compare it with the protection influence limit value preset in the line fault information database. If the protection influence of a certain relay protection device is greater than the preset protection influence limit value, locate the fault path corresponding to the relay protection device, thereby counting the relay protection devices corresponding to the protection influence greater than the preset protection influence limit value, and finally locate the fault paths corresponding to the relay protection devices, perform path overlap comparison on the fault paths, screen out the overlapped fault paths, and thus obtain the fault paths in the line fault location area, which are recorded as the fault occurrence paths in the line fault location area.

8. A method for analyzing a distribution network line fault according to claim 1, characterized in that: The equipment protection information of the line fault location area specifically includes the time point corresponding to the reception of the fault signal of each relay protection device and the start time point corresponding to the protection action.

9. A method for analyzing distribution network line faults according to claim 7, characterized in that: The specific analysis process of the protection influence of each relay protection device is as follows: Perform difference processing on the time point corresponding to the reception of the fault signal of each relay protection device and the start time point corresponding to the protection action to obtain the protection response time of each relay protection device; Obtaining historical maintenance information corresponding to each relay protection device, wherein the historical maintenance information includes each historical protection response duration of each relay protection device and the number of faulty devices of each relay protection device within a historical maintenance cycle; Based on the protection response time of each relay protection device, the historical protection response time of each relay protection device, the number of faulty devices of each relay protection device within the historical maintenance cycle, and the number of faulty devices defined corresponding to the fault type of the line fault location area preset in the line fault information database, the protection impact of each relay protection device is obtained through comprehensive processing.

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