Relay protection detection method for smart power grid

Abstract

The invention provides a relay protection detection method for a smart power grid. The relay protection detection method comprises the following steps: controlling a signal simulator to respectively send a blocking signal and a fault signal to a relay protection device; at the moment, whether the relay protection device has a locking abnormity is judged, when the relay protection device has the locking abnormity, whether the locking signal and the fault signal synchronously arrive at the relay protection device is judged, and when the locking signal and the fault signal synchronously arrive at the relay protection device, it is judged that the relay protection device has a locking logic abnormity; therefore, by adding the logic for judging whether the locking signal and the fault signal synchronously arrive or not, when the locking abnormity occurs and the locking signal and the fault signal are detected not to synchronously arrive, it is indicated that the locking abnormity is not caused by the problem of the locking logic, and at the moment, the locking logic does not need to be adjusted; the problem of abnormal locking can be solved only by adjusting the locking signal and the fault signal to arrive synchronously; therefore, the accuracy of detecting whether the locking logic is abnormal or not is improved.

Description

Technical Field

[0001] The present application relates to the technical field of power grid relay protection detection technology, and specifically to a relay protection detection method for a smart grid. Background Art

[0002] In the test scenario of the relay protection device, the lockout logic will be detected. The lockout logic is to prohibit the protection device from taking unnecessary actions through a lockout signal when a specific situation occurs; for example: when the relay protection device receives most fault signals, it needs to issue protection instructions such as tripping, but when the relay protection device receives a lockout signal, it does not need to issue a protection instruction.

[0003] In the test of relay protection devices in the prior art, the simulator often sends simulated lockout signals and fault signals to the relay protection device to simulate the protection logic under actual working conditions. This test method allows the relay protection device to be evaluated in a controlled environment. When a lockout abnormality occurs in the relay protection device, it is determined that there is a problem with the lockout logic. However, there is a possibility that the fault signal arrives before the lockout signal. Even if the lockout logic is normal at this time, the relay protection device will still follow the normal protection logic, but then receive the belated lockout signal, and cannot suppress the execution of the protection action based on the lockout signal, thereby causing a lockout abnormality. However, the lockout abnormality caused in this way is not caused by a problem with the lockout logic. Therefore, it is impossible to accurately judge the accuracy of whether the detected lockout logic is abnormal. Summary of the invention

[0004] The purpose of this application is to provide a relay protection detection method for a smart grid in order to address the above problems.

[0005] The present application provides a relay protection detection method for a smart grid, comprising the following steps: S1: The control signal simulator sends a blocking signal and a fault signal to the relay protection device simultaneously to perform an initial detection on the relay protection device; S2: Determine whether a locking abnormality occurs in the relay protection device during the first detection; S3: If yes, determine whether the blocking signal and the fault signal arrive at the relay protection device synchronously; S4: If yes, determining through the first detection whether the relay protection device has a blocking logic abnormality; if no, obtaining a synchronization strategy based on the first detection, wherein the synchronization strategy is used to make the blocking signal and the fault signal arrive at the relay protection device synchronously; S5: controlling the signal simulator to send the blocking signal and the fault signal to the relay protection device respectively, and executing the synchronization strategy to perform a secondary detection on the relay protection device; S6: Determine whether a locking abnormality occurs in the relay protection device during the secondary detection; S7: If yes, it is determined through the secondary detection that the relay protection device has a locking logic abnormality.

[0006] According to the technical solution provided by this application, step S3 includes the following steps: S31: When the relay protection device receives the locking signal, generate and record a first timestamp; S32: When the relay protection device receives the fault signal, generate and record a second timestamp; S33: Calculate a first timestamp difference between the first timestamp and the second timestamp, and determine whether the first timestamp difference is less than a first threshold; S341: When the first timestamp difference is less than a first threshold, determine that the lockout signal and the fault signal arrive at the relay protection device synchronously.

[0007] According to the technical solution provided by the present application, after step S33, the following steps are also included: S342: When the first timestamp difference is greater than or equal to the first threshold, determine that the blocking signal and the fault signal do not arrive at the relay protection device synchronously; S35: Retrieve the blocking signal transmission sequence and the fault signal transmission sequence corresponding to the first detection to obtain a plurality of node groups; the node groups include a first node set on the blocking signal transmission path and a third timestamp corresponding thereto, and a second node set on the fault signal transmission path and a fourth timestamp corresponding thereto; wherein the number of all the first nodes on the blocking signal transmission path is equal to the number of all the second nodes on the fault signal transmission path; S36: traverse all the node groups to obtain a deviation starting node group, where the deviation starting node group is a node group corresponding to the first occurrence of a second timestamp difference between the third timestamp and the fourth timestamp greater than a second threshold along the signal transmission direction; In step S4, a synchronization strategy is obtained according to the first detection, which includes the following steps: S41: Obtaining the synchronization strategy executed during the secondary detection according to the deviation starting node group.

[0008] According to the technical solution provided by this application, step S41 includes the following steps: S411: If the absolute value of the difference between the second timestamp difference and the first timestamp difference corresponding to the deviation starting node group is less than a third threshold, adjusting the signal in the transmission path as a first synchronization strategy.

[0009] According to the technical solution provided by this application, step S41 also includes the following steps: S412: If the absolute value of the difference between the second timestamp difference corresponding to the deviation starting node group and the first timestamp difference is greater than or equal to a third threshold, a timestamp difference sequence is obtained, where the timestamp difference sequence includes the second timestamp differences corresponding to a plurality of subsequent node groups and the first timestamp difference; the subsequent node group is a node group in a transmission path between the deviation starting node group and the relay protection device; S413: If the timestamp differences in the timestamp difference sequence have a linear relationship, the signal adjustment in the transmission path is used as the second synchronization strategy; wherein the second synchronization strategy and the first synchronization strategy have different positions for adjusting the signal in the locking signal transmission path and the fault signal transmission path.

[0010] According to the technical solution provided by the present application, after step S412, the following steps are also included: S414: If the timestamp differences in the timestamp difference sequence do not have a linear relationship, signal adjustment at the signal sending end is used as a third synchronization strategy.

[0011] According to the technical solution provided in the present application, the first synchronization strategy is to adjust the transmission signal at the first target node to compensate for the second timestamp difference between the first node and the second node in the deviation starting node group; the first target node is the first node or the second node in the deviation starting node group where the signal arrives anxiously.

[0012] According to the technical solution provided in the present application, the second synchronization strategy is to adjust the transmission signal at the second target node to compensate for the first timestamp difference; the second target node is the first node or the second node in the node group closest to the relay protection device whose signal arrives earlier.

[0013] According to the technical solution provided by the present application, the adjusting of the transmission signal at the second target node comprises the following steps: Using the transmission path corresponding to the second target node as a normal transmission path and using another transmission path as an aged transmission path; Obtaining an aging deviation duration corresponding to a node distance between two adjacent nodes close to the relay protection device in the aging transmission path; A first adjustment duration is obtained according to the second timestamp difference corresponding to the node group closest to the relay protection device and the aging deviation duration, and the transmission signal is adjusted at the second target node with the first adjustment duration.

[0014] According to the technical solution provided by the present application, obtaining the first adjustment duration according to the second timestamp difference corresponding to the node group closest to the relay protection device and the aging deviation duration comprises the following steps: The difference between the second timestamp difference corresponding to the node group closest to the relay protection device and the aging deviation duration is used as the first adjustment duration.

[0015] Compared with the prior art, the present invention has the following advantages: The present application provides a relay protection detection method for a smart grid, comprising the following steps: during the lockout logic detection process of a relay protection device, first, a control signal simulator is used to send a lockout signal and a fault signal to the relay protection device at the same time to perform a first detection on the relay protection device; at this time, it is determined whether a lockout abnormality occurs to the relay protection device during the first detection. When no lockout abnormality occurs, it is determined that the lockout logic of the relay protection device is normal; and when a lockout abnormality occurs, it is determined whether the lockout signal and the fault signal arrive at the relay protection device synchronously; when the lockout signal and the fault signal arrive at the relay protection device synchronously, it is determined through the first detection that the relay protection device has a lockout logic abnormality; and when the lockout signal and the fault signal do not arrive at the relay protection device synchronously, a synchronization strategy is obtained according to the first detection; then the signal simulator is controlled again to send the lockout signal to the relay protection device respectively. signal and fault signal, and execute the synchronization strategy so that the lockout signal and the fault signal arrive at the relay protection device synchronously, so as to perform secondary detection on the relay protection device; at this time, it is judged whether the lockout abnormality occurs in the relay protection device during the secondary detection. When the lockout abnormality occurs, it is determined through the secondary detection that the relay protection device has a lockout logic abnormality; it can be seen from this that the present application adds the judgment logic of whether the lockout signal and the fault signal are reached synchronously. When a lockout abnormality occurs and it is detected that the lockout signal and the fault signal do not arrive synchronously, it means that the lockout abnormality is not caused by a problem with the lockout logic. At this time, there is no need to adjust the lockout logic. It is only necessary to adjust the lockout signal and the fault signal to arrive synchronously according to the synchronization strategy, and then perform secondary detection to determine whether there is still a lockout abnormality, so as to accurately determine whether the lockout abnormality is caused by the lockout logic abnormality; therefore, compared with the prior art, the present application improves the accuracy of detecting whether the lockout logic is abnormal.

[0016] It should be understood that the description of technical features, technical solutions, beneficial effects or similar language in this application does not imply that all features and advantages can be realized in any single embodiment. On the contrary, it is understood that the description of features or beneficial effects means that specific technical features, technical solutions or beneficial effects are included in at least one embodiment. Therefore, the description of technical features, technical solutions or beneficial effects in this specification does not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions and beneficial effects described in the present embodiment can also be combined in any appropriate manner. Those skilled in the art will understand that the embodiment can be realized without one or more specific technical features, technical solutions or beneficial effects of a specific embodiment. In other embodiments, additional technical features and beneficial effects can also be identified in a specific embodiment that does not embody all embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution in this embodiment, the drawings required for use in the description of the embodiment will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A flow chart of a relay protection detection method for a smart grid provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings. The description in this section is only exemplary and explanatory and should not have any limiting effect on the protection scope of the present application. Specifically, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work should fall within the scope of protection of the present application.

[0020] It should be noted that similar reference numerals and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0021] In order to facilitate the understanding of this application, a brief introduction to the related technology is first given: The lockout logic of the relay protection device is a safety mechanism used to prevent the relay protection device from making unnecessary actions under specific conditions. This logic is implemented by identifying and responding to specific signals to ensure the stable operation of the power system. For example, when the relay protection device receives most fault signals, it needs to issue protection instructions such as tripping, but when the relay protection device receives a lockout signal, it does not need to issue a protection instruction. However, in the test of the relay protection device in the prior art, the simulator often simulates the lockout signal and fault signal to the relay protection device to simulate the protection logic under actual working conditions. This test method allows the relay protection device to be evaluated in a controlled environment. When the relay protection device has a lockout abnormality, it is judged that there is a problem with the lockout logic. However, there may be a situation where the fault signal arrives before the lockout signal. Even if the lockout logic is normal at this time, it will still follow the normal protection logic, but then the belated lockout signal is received, and it is impossible to suppress the execution of the protection action based on the lockout signal, thereby causing a lockout abnormality. However, the lockout abnormality caused in this way is not caused by a problem with the lockout logic, so as to cause a misjudgment of the lockout logic.

[0022] In view of this, an embodiment of the present application provides a relay protection detection method for a smart grid. During the lockout logic detection process of the relay protection device, first, the control signal simulator sends a lockout signal and a fault signal to the relay protection device at the same time to perform an initial detection on the relay protection device; at this time, it is determined whether a lockout abnormality occurs in the relay protection device during the initial detection. When no lockout abnormality occurs, it is determined that the lockout logic of the relay protection device is normal; and when a lockout abnormality occurs, it is determined whether the lockout signal and the fault signal arrive at the relay protection device synchronously. When the lockout signal and the fault signal arrive at the relay protection device synchronously, it is determined through the initial detection that there is a lockout logic abnormality in the relay protection device; and when the lockout signal and the fault signal do not arrive at the relay protection device synchronously, a synchronization strategy is obtained according to the initial detection; then the signal simulator is controlled again to send a lockout signal and a fault signal to the relay protection device respectively, and A synchronization strategy is executed so that the lockout signal and the fault signal arrive at the relay protection device synchronously, so as to perform a secondary detection on the relay protection device; at this time, it is determined whether a lockout abnormality occurs in the relay protection device during the secondary detection. When a lockout abnormality occurs, it is determined through the secondary detection that there is a lockout logic abnormality in the relay protection device; thus, it can be seen that the present application adds a judgment logic for whether the lockout signal and the fault signal arrive synchronously. When a lockout abnormality occurs and it is detected that the lockout signal and the fault signal do not arrive synchronously, it means that the lockout abnormality is not caused by a problem with the lockout logic. At this time, there is no need to adjust the lockout logic. It is only necessary to adjust the lockout signal and the fault signal to arrive synchronously according to the synchronization strategy, and then perform a secondary detection to determine whether there is still a lockout abnormality, so as to accurately determine whether the lockout abnormality is caused by the lockout logic abnormality; therefore, compared with the prior art, the present application improves the accuracy of detecting whether the lockout logic is abnormal.

[0023] In order to make the technical solution of the present application clearer and easier to understand, a relay protection detection method for a smart grid provided in an embodiment of the present application is introduced below.

[0024] It should be noted that the method can be executed by a controller. For ease of understanding, the method is introduced below from the perspective of a control device.

[0025] like Figure 1 As shown in FIG. 1 , the figure is a flow chart of a relay protection detection method for a smart grid provided in this embodiment, and the method includes the following steps: S1: The control signal simulator sends a blocking signal and a fault signal to the relay protection device simultaneously to perform the first detection of the relay protection device; S2: Determine whether a locking abnormality occurs in the relay protection device during the first detection; S3: If yes, determine whether the blocking signal and the fault signal arrive at the relay protection device synchronously; S4: If yes, determine through the first detection whether the relay protection device has a blocking logic abnormality; if not, obtain a synchronization strategy based on the first detection, and the synchronization strategy is used to make the blocking signal and the fault signal arrive at the relay protection device synchronously; S5: controlling the signal simulator again to send a blocking signal and a fault signal to the relay protection device respectively, and executing a synchronization strategy to perform a secondary detection on the relay protection device; S6: Determine whether a locking abnormality occurs in the relay protection device during secondary detection; S7: If yes, secondary detection is performed to determine whether there is a locking logic abnormality in the relay protection device.

[0026] Specifically, the relay protection device is an important device in the power system. Its main function is to detect faults or abnormal conditions in the power system and automatically issue a trip command when necessary to isolate the faulty part, prevent the fault from expanding, and protect the safe and stable operation of the power system; Specifically, the signal simulator is a professional device that is used to simulate the operating status and fault status of the power system in the test scenario of the relay protection device; at the same time, it can also monitor and analyze the signal in real time through the data acquisition and processing system to discover and diagnose various problems; In relay protection testing, the signal simulator sends simulated blocking signals and fault signals to the relay protection device to detect whether the blocking logic is working properly. If the relay protection device has a blocking abnormality, that is, it immediately issues a trip protection command after receiving the fault signal, this may indicate that there is a problem with the blocking logic. However, if the blocking signal and the fault signal do not arrive at the relay protection device synchronously, even if the blocking logic is normal, it may cause a blocking abnormality. During the test, the signal simulator can simulate the sending of these signals and the time difference between them, thereby helping technicians evaluate the performance of the relay protection device and the accuracy of the blocking logic. Specifically, during the first detection, when the signal simulator simultaneously sends a locking signal and a fault signal to the relay protection device, and the relay protection device does not have a locking abnormality, it means that the current locking logic is normal; Working principle: The present application adds a judgment logic for whether the lockout signal and the fault signal arrive synchronously. When a lockout abnormality occurs and it is detected that the lockout signal and the fault signal do not arrive synchronously, it means that the lockout abnormality may not be caused by a problem with the lockout logic. At this time, there is no need to adjust the lockout logic. It is only necessary to adjust the lockout signal and the fault signal to arrive synchronously according to the synchronization strategy, and then perform a secondary detection to determine whether the lockout abnormality still exists. In this way, it can be accurately determined whether the lockout abnormality is caused by the lockout logic abnormality. Therefore, compared with the prior art, the present application improves the accuracy of detecting whether the lockout logic is normal.

[0027] In some embodiments, step S3 comprises the following steps: S31: When the relay protection device receives a blocking signal, generate and record a first timestamp; S32: When the relay protection device receives a fault signal, generate and record a second timestamp; S33: Calculate a first timestamp difference between the first timestamp and the second timestamp, and determine whether the first timestamp difference is less than a first threshold; S341: When the first timestamp difference is less than the first threshold, it is determined that the blocking signal and the fault signal arrive at the relay protection device synchronously.

[0028] Specifically, in some embodiments, the relay protection device can be used to determine whether the lockout signal and the fault signal arrive synchronously; the relay protection device is provided with a time synchronization system, a signal identification module and a timestamp recording module to accurately detect and record the arrival time of the lockout signal and the fault signal, thereby realizing accurate judgment of the lockout logic; Among them, the time synchronization system can provide precise time information to ensure the accuracy of timestamps; The relay protection device uses a signal recognition module to distinguish between fault signals and blocking signals. The signal characteristics need to be predefined so that the device can correctly identify different types of signals and record the corresponding timestamps. The signal characteristics include frequency, amplitude, encoding format, etc. When the relay protection device receives a fault signal or a blocking signal, a timestamp is immediately generated. At this time, the timestamp recording module records the exact moment when the signal arrives. This timestamp can be used for subsequent analysis to determine whether the signal arrives synchronously. Specifically, in this embodiment, when the relay protection device receives a lockout signal, it generates and records the current first timestamp; at the same time, when the relay protection device receives a fault protection signal, it generates and records the current second timestamp; and calculates the first timestamp difference between the first timestamp and the second timestamp, and compares the first timestamp difference with the first threshold. In this embodiment, the first threshold is 0.1ms; when the first timestamp difference is less than the first threshold, it means that the first timestamp and the second timestamp arrive within an acceptable time window, and it is determined that the lockout signal and the fault signal arrive at the relay protection device synchronously; at this time, it indicates that the lockout abnormality is caused by a problem with the lockout logic, and it is determined that the relay protection device has a lockout logic abnormality.

[0029] In some embodiments, after step S33, the following steps are also included: S342: When the first timestamp difference is greater than or equal to the first threshold, it is determined that the blocking signal and the fault signal do not arrive at the relay protection device synchronously; S35: Retrieve the blocking signal transmission sequence and the fault signal transmission sequence corresponding to the first detection, and obtain multiple node groups; the node group includes a first node set on the blocking signal transmission path and its corresponding third timestamp, and a second node set on the fault signal transmission path and its corresponding fourth timestamp; wherein the number of all first nodes on the blocking signal transmission path is equal to the number of all second nodes on the fault signal transmission path; S36: traverse all node groups to obtain a deviation starting node group, where the deviation starting node group is a node group corresponding to the first occurrence of a second timestamp difference between the third timestamp and the fourth timestamp greater than a second threshold along the signal transmission direction; In step S4, a synchronization strategy is obtained according to the first detection, which specifically includes the following steps: S41: Obtaining a synchronization strategy to be executed during secondary detection according to the deviation starting node group.

[0030] Specifically, when the first timestamp difference is greater than or equal to the first threshold, it indicates that the lockout signal and the fault signal do not arrive at the relay protection device synchronously; at this time, the corresponding synchronization strategy can be executed through the corresponding lockout signal transmission sequence and fault signal transmission sequence during the first detection to adjust the lockout signal and the fault signal to arrive at the relay protection device synchronously; Specifically, there are a blocking signal transmission path and a fault signal transmission path between the signal simulator and the relay protection device. At this time, a number of smart sensors are distributedly deployed on the blocking signal transmission path, and each smart sensor is a first node; at the same time, a number of smart sensors are distributedly deployed on the fault signal transmission path, and each smart sensor is a second node; wherein the number of all first nodes is the same as the number of all second nodes; when the signal passes through the corresponding smart sensor, the smart sensor will record the timestamp of the signal passing moment; During the signal transmission process of the first detection, a fault signal transmission sequence and a lockout signal transmission sequence are pre-stored and generated. When it is determined that the lockout signal and the fault signal do not arrive at the relay protection device synchronously, the fault signal transmission sequence and the lockout signal transmission sequence corresponding to the first detection are retrieved to obtain multiple node groups, each node group includes a first node set on the lockout signal transmission path and its corresponding third timestamp, and a second node corresponding to the fault signal transmission path and its corresponding fourth timestamp; the second timestamp difference between the third timestamp and the fourth timestamp in each node group is calculated, and the second timestamp difference is compared with the second threshold value. In this embodiment, the second threshold value is 0.05ms; all node groups are traversed to obtain the deviation starting point group, which is the node group corresponding to the first time the second timestamp difference greater than the second threshold value appears along the signal transmission direction; and according to the deviation starting node group, the synchronization strategy that needs to be executed during the secondary detection is obtained to adjust the transmission speed of the lockout signal or the fault signal so that the lockout signal and the fault signal arrive at the relay protection device synchronously.

[0031] In some embodiments, step S41 includes the following steps: S411: If the absolute value of the difference between the second timestamp difference and the first timestamp difference corresponding to the deviation start node group is less than a third threshold, adjusting the signal in the transmission path as the first synchronization strategy.

[0032] The first synchronization strategy is to adjust the transmission signal at the first target node to compensate for the second timestamp difference between the first node and the second node in the deviation start node group; the first target node is the first node or the second node in the deviation start node group where the signal arrives earlier.

[0033] Specifically, if the absolute value of the difference between the second timestamp difference corresponding to the deviation starting node group and the first timestamp is less than the third threshold value, it indicates that the transmission time difference only occurs in the deviation starting node group within the transmission path, and the post-node group does not extend the transmission timestamp difference; therefore, it is only necessary to adjust the transmission signal at the first target node of the deviation starting node group to compensate for the second timestamp difference between the first node and the second node in the deviation starting node group, thereby making the locking signal and the fault signal arrive at the relay protection device synchronously; Specifically, in some embodiments, the slow arrival of the signal indicates that there are some unknown problems in the transmission path. If the signal that has already arrived slowly is adjusted, it may cause correction failure. Therefore, in order to ensure the accuracy of signal adjustment, the first node or the second node where the signal arrives earlier in the deviation starting node group is selected as the first target node, and the signal transmission speed at the node is slowed down, thereby improving the success rate of correction. Specifically, in some embodiments, the transmission speed of the blocking signal or the fault signal is adjusted by controlling the electrical parameters at the deviation starting node group on the transmission path; for example, the fault signal is controlled to decelerate to make up for the time difference between the two, so as to ensure that the blocking signal and the fault signal arrive at the relay protection device synchronously in the secondary detection, thereby improving the accuracy of the blocking logic detection; Specifically, an electrical element is connected in series or in parallel at the first node or the second node where the signal arrives earlier in the deviation starting node group, and the transmission speed of the lockout signal or the fault signal is adjusted by changing the parameters of the electrical element; in this embodiment, the electrical element is a capacitor or an inductor; the capacitor and the inductor affect the propagation speed of the signal in the transmission path by affecting the phase and amplitude of the signal, as well as the interaction with the signal frequency.

[0034] In some embodiments, step S41 further includes the following steps: S412: If the absolute value of the difference between the second timestamp difference corresponding to the deviation starting node group and the first timestamp difference is greater than or equal to a third threshold, a timestamp difference sequence is obtained, where the timestamp difference sequence includes second timestamp differences corresponding to a plurality of subsequent node groups and the first timestamp difference; the subsequent node group is a node group in a transmission path between the deviation starting node group and the relay protection device; S413: If the timestamp differences in the timestamp difference sequence have a linear relationship, adjusting the signal in the transmission path is used as a second synchronization strategy; wherein the second synchronization strategy and the first synchronization strategy have different positions for adjusting the signal in the transmission path.

[0035] Specifically, if the absolute value of the difference between the second timestamp difference corresponding to the deviation starting node group and the first timestamp difference is greater than or equal to the third threshold, it indicates that a transmission time difference between the lockout signal and the fault signal also appears in the subsequent node group starting from the deviation starting node group in the transmission path; at this time, a timestamp difference sequence is obtained, and the timestamp difference sequence includes second timestamp differences corresponding to multiple subsequent node groups, and the first timestamp difference; when the timestamp differences in the timestamp difference sequence have a linear relationship, it indicates that the slow signal transmission in a certain transmission path is caused by aging factors, and at this time, the second synchronization strategy is used to adjust the signal in the transmission path.

[0036] In some embodiments, the second synchronization strategy is to adjust the transmission signal at the second target node to compensate for the first timestamp difference; the second target node is the first node or the second node in the node group closest to the relay protection device where the signal arrives earlier.

[0037] The step of adjusting the transmission signal at the second target node specifically includes the following steps: Using the transmission path corresponding to the second target node as a normal transmission path and using another transmission path as an aged transmission path; Obtaining the aging deviation duration corresponding to the node distance between two adjacent nodes close to the relay protection device in the aging transmission path; A first adjustment duration is obtained according to a second timestamp difference corresponding to a node group closest to the relay protection device and an aging deviation duration, and a transmission signal is adjusted at a second target node with the first adjustment duration.

[0038] The first adjustment duration is obtained according to the second timestamp difference corresponding to the node group closest to the relay protection device and the aging deviation duration, which specifically includes the following steps: The difference between the second timestamp difference corresponding to the node group closest to the relay protection device and the aging deviation duration is used as the first adjustment duration.

[0039] Specifically, in some embodiments, the fault signal and the lockout signal cannot arrive synchronously because of the aging of a certain transmission path, and in order to prevent the adjustment of the signal in the aged path, the arrival time of the signal cannot be accurately adjusted, which will still cause signal transmission deviation; therefore, in this application, the transmission path corresponding to the second target node is used as the normal transmission path, and the other transmission path is used as the aged transmission path; at this time, the aging deviation duration corresponding to the node spacing between two adjacent nodes close to the relay protection device in the aged transmission path is obtained; then the second timestamp difference corresponding to the node group closest to the relay protection device is subtracted from the aging deviation time to obtain the first adjustment duration, and the transmission signal is adjusted at the second target node with the first adjustment duration to compensate for the time difference between the fault signal and the fault signal, thereby ensuring that the lockout signal and the fault signal arrive at the relay protection device synchronously.

[0040] Specifically, an electrical element is connected in series or in parallel at a first node or a second node where the signal arrives earlier in the node group closest to the relay protection device, and the transmission speed of the lockout signal or the fault signal is adjusted by changing the parameters of the electrical element; in this embodiment, the electrical element is a capacitor or an inductor; capacitors and inductors affect the propagation speed of the signal in the transmission path by affecting the phase and amplitude of the signal, as well as the interaction with the signal frequency.

[0041] In some embodiments, after step S412, the following steps are also included: S414: If the timestamp differences in the timestamp difference sequence do not have a linear relationship, signal adjustment at the signal sending end is used as a third synchronization strategy.

[0042] Specifically, if the timestamp differences in the timestamp difference sequence do not have a linear relationship, it indicates that the situation in the current transmission path is complicated. In order to improve the accuracy of signal adjustment, the parameters of the signal sending end are adjusted according to the first timestamp difference, that is, the locking signal is sent first, and then the locking signal is sent after the first timestamp difference, to ensure that the locking signal and the fault signal arrive at the relay protection device synchronously.

[0043] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and its core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the invention to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. A relay protection detection method for a smart grid, characterized in that: The steps include: S1: The control signal simulator sends a blocking signal and a fault signal to the relay protection device simultaneously to perform an initial detection on the relay protection device; S2: Determine whether a locking abnormality occurs in the relay protection device during the first detection; S3: If yes, determine whether the blocking signal and the fault signal arrive at the relay protection device synchronously; S4: If yes, determining through the first detection whether the relay protection device has a blocking logic abnormality; if no, obtaining a synchronization strategy based on the first detection, wherein the synchronization strategy is used to make the blocking signal and the fault signal arrive at the relay protection device synchronously; S5: controlling the signal simulator to send the blocking signal and the fault signal to the relay protection device respectively, and executing the synchronization strategy to perform secondary detection on the relay protection device; S6: Determine whether a locking abnormality occurs in the relay protection device during the secondary detection; S7: If yes, it is determined through the secondary detection that the relay protection device has a locking logic abnormality.

2. A relay protection detection method for a smart grid according to claim 1, characterized in that: Step S3 includes the following steps: S31: When the relay protection device receives the locking signal, generate and record a first timestamp; S32: When the relay protection device receives the fault signal, generate and record a second timestamp; S33: Calculate a first timestamp difference between the first timestamp and the second timestamp, and determine whether the first timestamp difference is less than a first threshold; S341: When the first timestamp difference is less than a first threshold, determine that the lockout signal and the fault signal arrive at the relay protection device synchronously.

3. A relay protection detection method for a smart grid according to claim 2, characterized in that: After step S33, the following steps are also included: S342: When the first timestamp difference is greater than or equal to the first threshold, determine that the blocking signal and the fault signal do not arrive at the relay protection device synchronously; S35: Retrieve the blocking signal transmission sequence and the fault signal transmission sequence corresponding to the first detection to obtain a plurality of node groups; the node groups include a first node set on the blocking signal transmission path and a third timestamp corresponding thereto, and a second node set on the fault signal transmission path and a fourth timestamp corresponding thereto; wherein the number of all the first nodes on the blocking signal transmission path is equal to the number of all the second nodes on the fault signal transmission path; S36: traverse all the node groups to obtain a deviation starting node group, where the deviation starting node group is a node group corresponding to the first occurrence of a second timestamp difference between the third timestamp and the fourth timestamp greater than a second threshold along the signal transmission direction; The step S4, according to the first detection, obtains the synchronization strategy, which specifically includes the following steps: S41: Obtaining the synchronization strategy executed during the secondary detection according to the deviation starting node group.

4. A relay protection detection method for a smart grid according to claim 3, characterized in that: Step S41 includes the following steps: S411: If the absolute value of the difference between the second timestamp difference and the first timestamp difference corresponding to the deviation starting node group is less than a third threshold, adjusting the signal in the transmission path as a first synchronization strategy.

5. A relay protection detection method for a smart grid according to claim 4, characterized in that: Step S41 also includes the following steps: S412: If the absolute value of the difference between the second timestamp difference corresponding to the deviation starting node group and the first timestamp difference is greater than or equal to a third threshold, a timestamp difference sequence is obtained, where the timestamp difference sequence includes the second timestamp differences corresponding to a plurality of subsequent node groups and the first timestamp difference; the subsequent node group is a node group in a transmission path between the deviation starting node group and the relay protection device; S413: If the timestamp differences in the timestamp difference sequence have a linear relationship, adjusting the signal in the transmission path is used as a second synchronization strategy; wherein the second synchronization strategy and the first synchronization strategy have different positions for adjusting the signal in the transmission path.

6. A relay protection detection method for a smart grid according to claim 4, characterized in that: After step S412, the following steps are also included: S414: If the timestamp differences in the timestamp difference sequence do not have a linear relationship, signal adjustment at the signal sending end is used as a third synchronization strategy.

7. A relay protection detection method for a smart grid according to claim 4, characterized in that: The first synchronization strategy is to adjust the transmission signal at the first target node to compensate for the second timestamp difference between the first node and the second node in the deviation starting node group; the first target node is the first node or the second node in the deviation starting node group where the signal arrives earlier.

8. The relay protection detection method for smart grid according to claim 5, characterized in that: The second synchronization strategy is to adjust the transmission signal at the second target node to compensate for the first timestamp difference; the second target node is the first node or the second node whose signal arrives earlier in the node group closest to the relay protection device.

9. A relay protection detection method for a smart grid according to claim 8, characterized in that: The step of adjusting the transmission signal at the second target node specifically comprises the following steps: Using the transmission path corresponding to the second target node as a normal transmission path and using another transmission path as an aged transmission path; Obtaining an aging deviation duration corresponding to a node distance between two adjacent nodes close to the relay protection device in the aging transmission path; A first adjustment duration is obtained according to the second timestamp difference corresponding to the node group closest to the relay protection device and the aging deviation duration, and the transmission signal is adjusted at the second target node with the first adjustment duration.

10. A relay protection detection method for a smart grid according to claim 9, characterized in that: The obtaining of the first adjustment duration according to the second timestamp difference corresponding to the node group closest to the relay protection device and the aging deviation duration specifically includes the following steps: The difference between the second timestamp difference corresponding to the node group closest to the relay protection device and the aging deviation duration is used as the first adjustment duration.

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