An intelligent early warning system for power grid failure based on big data

Abstract

The present application relates to the technical field of power grid equipment monitoring, in particular to a power grid fault intelligent early warning system based on big data. The present application acquires current waveform and voltage data in real time through the acquisition module and compresses and returns them, and the judgment module judges whether to trigger a fault early warning according to the current wave distortion degree and the harmonic frequency multiple. When early warning, the current wave peak value difference, fault point voltage parameters and voltage timeout time are combined to accurately analyze the fault cause and misjudgment. If misjudgment occurs, the system automatically corrects the data transmission compression rate and the protection device parameters according to the fault point frame protection times, and optimizes the performance of the early warning system. The present application accurately distinguishes between real fault early warning and misjudgment while realizing power grid fault early warning, reduces manual secondary judgment and equipment adjustment, reduces the dependence on manpower in fault early warning, improves the efficiency and accuracy of power grid operation, and provides a strong guarantee for the stable operation of the power system.

Description

Technical Field

[0001] This invention relates to the field of power grid equipment monitoring technology, and specifically to a smart early warning system for power grid faults based on big data. Background Technology

[0002] In current power grid automation monitoring systems, although they can automatically detect potential faults and issue alarms, manual intervention is usually still required for secondary assessment to confirm the authenticity of the fault. This is because while the automation system can quickly detect anomalies, it may fail to accurately determine whether a fault is genuine due to false alarms or the need for more detailed analysis. Once a false alarm is identified, professionals must be dispatched to adjust the relevant equipment to prevent subsequent false alarm reports. This process not only increases workload and response time, but also, in areas with large power grids and numerous automation devices, manual intervention often consumes significant human resources, severely impacting the power grid's operational efficiency. Therefore, how to effectively distinguish between genuine and false faults while achieving automated distribution monitoring, and how to optimize based on the causes of false alarms to reduce the waste and occupation of human resources, has become an urgent problem to be solved.

[0003] Chinese patent CN112994248B discloses a distribution network bus fault early warning device and method, including multiple field detection devices and a server. The field detection devices include voltage transformers, current transformers, a processor, environmental monitoring equipment, and communication equipment. The voltage transformers, current transformers, and environmental monitoring equipment are electrically connected to the processor. The server acquires environmental data, node power, and location data for each node, compares the environmental data and node power of each node with predicted values, and obtains the comparison result. If the comparison result exceeds a set threshold, a fault early warning signal is issued. In addition, a distribution network bus fault early warning method is also provided. Through the aforementioned distribution network bus fault early warning device and method, this invention can predict faults before they occur on the distribution network bus and issue early warning signals in a timely manner, enabling power workers to enter the site in advance for inspection and maintenance, thus preventing further deterioration of the fault and ensuring the normal operation of the power grid system. Although the system can predict power grid faults, it does not consider the phenomenon of false early warnings caused by misjudgment. In actual operation, it still requires manual secondary judgment and adjustment based on the causes of the false judgment, resulting in low efficiency when facing large-scale power grids. How to achieve intelligent early warning of power grid faults, effectively distinguish the possible false judgments of faults in the fault early warning process, and optimize distribution parameters based on the causes of false judgments has become a problem that must be considered in optimizing the distribution automation monitoring system. Summary of the Invention

[0004] To address this issue, the present invention provides a big data-based intelligent early warning system for power grid faults, which overcomes the problem of low monitoring accuracy and low optimization efficiency caused by the need for manual secondary judgment to identify system misjudgments and manual adjustment of monitoring parameters in the existing power network fault early warning process.

[0005] To achieve the above objectives, the present invention provides a big data-based intelligent early warning system for power grid faults, comprising:

[0006] The acquisition module includes several sensors and several oscilloscopes, used to acquire current waveform data and voltage waveform data;

[0007] A transmission module, which is connected to the acquisition module, is used to compress and transmit the processed data;

[0008] A storage module, connected to the transmission module, is used to store the transmitted data, and a recording frame protects the records;

[0009] A data calculation module, which is connected to the storage module, is used to perform calculations on the data;

[0010] The judgment module, which is connected to the data calculation module, is used to determine whether to issue a fault warning based on the current waveform distortion and the current harmonic frequency multiple. When a fault warning is issued, the module determines the cause of the fault warning and whether it is a misjudgment based on the difference between the current peak value and the negative peak value in the current cycle, the effective value of the fault point voltage, and the time when the voltage exceeds the protection voltage. When a misjudgment is determined, the module corrects the protection device operation time, the protection device operation current threshold, the time when the voltage exceeds the protection voltage, and the data transmission compression rate based on the cause of the misjudgment.

[0011] A control module, which is connected to the judgment module and the transmission module, is used to control the response of the corresponding module based on the instructions of the judgment module;

[0012] The notification module, which is connected to the control module, is used to issue warnings and / or misjudgment correction notifications based on the instructions output by the control module.

[0013] Furthermore, the judgment module is used to determine whether it is in the first state based on the current wave distortion, and, when it is determined to be in the first state, to determine whether to issue a fault warning based on the current harmonic frequency multiple, and, when it is determined to issue a fault warning, to determine the reason for issuing the fault warning based on the difference between the current peak value and the negative peak value in this cycle.

[0014] Wherein, the current waveform distortion is the ratio of the harmonic component to the fundamental component within the current cycle, and the current harmonic frequency multiple refers to the multiple of the harmonic frequency relative to the fundamental frequency in the current waveform.

[0015] Furthermore, the judgment module is used to determine the reason for issuing a fault warning based on the peak current amplitude, and when the first reason is determined, output a power grid fault warning as a transformer and incoming line undervoltage warning, or determine the reason for issuing a fault warning based on the effective value of the fault point voltage.

[0016] Wherein, the current peak amplitude is the difference between the peak current and the negative peak current in this cycle, and the effective value of the fault point voltage is the root mean square value of the instantaneous value of the fault point voltage in one cycle.

[0017] Furthermore, the judgment module is used to determine the cause of the fault warning based on the effective value of the fault point voltage, and to output the fault warning as a power grid distribution cable fault warning when the cause is determined to be the second cause, or to determine the cause of the fault warning based on the time when the voltage exceeds the protection voltage.

[0018] Furthermore, the judgment module is used to determine whether a misjudgment or the cause of issuing a fault warning has occurred based on the voltage timeout value, and, when the cause is determined to be a third cause, outputs a fault warning as a protection device fault warning, or determines that a fault warning has been misjudged, and determines the cause of the fault warning misjudgment based on the number of times the frame protection occurs at the fault point.

[0019] The voltage timeout value is the time during which the voltage exceeds the operating current threshold.

[0020] Furthermore, the judgment module is used to determine the cause of the fault misjudgment based on the number of times the fault point is protected, and when the first cause of misjudgment is determined, output the cause of the fault misjudgment as an accidental misjudgment, or, correct the action time based on the difference between the number of times the fault point is protected and the preset number of times the fault point is protected.

[0021] The number of times the fault point is protected refers to the number of times the frame protection occurs at the fault point within N hours, where N is greater than or equal to 48.

[0022] Furthermore, the judgment module is used to increase the action time based on the fault point protection difference, and the increase in action time is proportional to the fault point protection difference;

[0023] The fault point protection difference is the difference between the number of fault point protection attempts and the preset number of fault point protection attempts.

[0024] Furthermore, the judgment module is used to increase the action current threshold based on the action time difference, and the increase in the action current threshold is proportional to the action time difference;

[0025] The action time difference is the difference between the corrected action time and the original action time.

[0026] Furthermore, the judgment module is used to correct the voltage timeout value based on the difference in operating current thresholds, and the increase in the voltage timeout value is proportional to the difference in operating current thresholds;

[0027] The current threshold difference is the difference between the corrected operating current threshold and the original operating current threshold.

[0028] Furthermore, the judgment module is used to increase the data transmission compression rate based on the voltage timeout value difference, and the increase in the data transmission compression rate is proportional to the voltage timeout value difference;

[0029] The voltage timeout difference is the difference between the corrected voltage timeout value and the original voltage timeout value.

[0030] Compared with existing technologies, the advantages of this invention lie in its ability to collect and compress real-time current waveform data and voltage data before transmitting it back. The judgment module determines whether to issue a fault warning based on the degree of current waveform distortion and the multiple of the current harmonic frequency relative to the fundamental frequency. Furthermore, when a fault warning is determined, the system further combines the current waveform peak difference, fault point voltage parameters, and the time the voltage exceeds the protection voltage to determine the cause of the warning and the possibility of misjudgment. In the event of a misjudgment, the system corrects the protection device parameters, voltage timeout value, and data transmission compression rate based on the number of times the fault point frame protection is applied. This system has a clear structure and complete functions, effectively solving the problem in existing power grids where manual secondary judgment is required to identify system misjudgments and adjust parameters accordingly. Through intelligent fault prediction and parameter correction mechanisms, this system can significantly improve the accuracy, efficiency, and reliability of intelligent fault warnings in power grids, reduce reliance on human resources, and enhance the overall performance and stability of power grid operation.

[0031] This monitoring method can effectively distinguish between real faults and false alarms, avoiding the need for manual secondary judgment and equipment adjustment caused by false alarms in traditional monitoring systems. It greatly reduces the reliance on human resources, improves the efficiency of power grid operation and the accuracy of monitoring, realizes the intelligent optimization of the distribution automation monitoring system, and enhances the stability and reliability of the power system.

[0032] Furthermore, by setting preset values ​​for current waveform distortion and current harmonic frequency multiples, the system can accurately determine the presence of potential faults when the current waveform distortion exceeds the preset value, combined with the current harmonic frequency multiples. Simultaneously, the difference between the peak and negative peak values ​​of the current is used to further determine the cause of the fault warning. This method fully utilizes the characteristics of current waveform data, avoiding misjudgments caused by subtle errors between parameters when relying solely on simple parameter combinations such as voltage and current. It significantly improves the accuracy of fault warnings, providing a more reliable basis for subsequent fault handling and system optimization, and further enhancing the intelligence and reliability of the intelligent fault warning system.

[0033] Furthermore, by comparing the peak current amplitude with a preset value and combining it with the effective value of the fault point voltage to further determine the cause of the fault warning, it is possible to effectively distinguish between transformer and incoming line undervoltage faults and other fault types. This judgment method based on peak current amplitude is simple and efficient, and can quickly identify the type of fault warning, providing an important basis for rapid fault diagnosis and handling, thereby shortening fault handling time, improving the operating efficiency of the power grid and the reliability of power supply, and further optimizing the fault warning capability of the intelligent fault warning system.

[0034] Furthermore, by setting a preset range for the effective value of the fault point voltage, it is possible to accurately distinguish between grid cable faults and fault warnings caused by the operation of frame protection. This method utilizes the key parameter of the effective value of the fault point voltage, combined with the law of voltage variation with current, effectively avoiding misjudgments caused by a sharp increase in current, thus further improving the accuracy and reliability of fault warnings. Simultaneously, by accurately determining the type of fault warning, it can provide a clearer direction for subsequent fault handling, reducing unnecessary equipment inspection and maintenance work, and further enhancing the intelligence level of the intelligent fault warning system and the operating efficiency of the power grid.

[0035] Furthermore, by introducing the voltage timeout value parameter, it is possible to effectively distinguish between protection equipment faults and frame protection actions caused by short-term current overload, thereby avoiding unnecessary equipment adjustments and manual interventions due to misjudgments. This method not only improves the accuracy of fault early warning judgment but also reduces the risk of equipment malfunctions and power grid operation interruptions caused by misjudgments, further enhancing the stability of the intelligent fault early warning system and improving the reliability and efficiency of power grid operation.

[0036] Furthermore, by setting a preset value for the number of times a fault point can be protected, it is possible to accurately distinguish between unexpected misjudgments and unreasonable protection device parameter settings, and adjust the action time accordingly. This method can dynamically adjust the parameters of the protection device to better adapt to the actual operating environment, avoid frequent maloperations caused by unreasonable protection device settings, thereby improving the adaptability and reliability of the protection device, further optimizing the performance of the intelligent fault early warning system, and enhancing the stability of the power grid and the reliability of power supply.

[0037] Furthermore, by comparing the fault point protection differential with a preset value and dynamically adjusting the action time based on the magnitude of the difference, the frequency of malfunctions of the protection device can be effectively reduced. This dynamic adjustment mechanism can flexibly adjust the parameters of the protection device according to actual operating conditions, making it more in line with the actual operating needs of the power grid, thereby improving the adaptability and reliability of the protection device, further optimizing the performance of the intelligent fault early warning system, and enhancing the stability of the power grid and the reliability of power supply.

[0038] Furthermore, by comparing the difference in operating time with a preset value and dynamically adjusting the operating current threshold based on the magnitude of the difference, the parameter settings of the protection device can be further optimized. This dynamic adjustment mechanism not only reduces the frequency of maloperation of the protection device but also improves its sensitivity and reliability, ensuring good performance under different power environments and equipment conditions. Simultaneously, by dynamically adjusting the parameters of the protection device, the performance of the intelligent fault early warning system can be further optimized, enhancing the stability of the power grid and the reliability of power supply.

[0039] Furthermore, the mechanism of correcting the voltage timeout value based on the difference in operating current threshold helps to match the voltage timeout value with the corrected operating current threshold, thereby more accurately matching the actual operating characteristics of the power grid and avoiding misjudgment or omission due to parameter mismatch, thus improving the accuracy of fault diagnosis. At the same time, this dynamic adjustment mechanism can automatically optimize parameter settings according to the actual operating status of the power grid, reduce the risk of misjudgment caused by changes in current threshold, and enhance the stability and reliability of the system.

[0040] Furthermore, by comparing the voltage timeout value difference with a preset value and dynamically adjusting the data transmission compression rate based on the magnitude of the voltage timeout value difference, data transmission efficiency can be effectively optimized, avoiding misjudgments of faults caused by data transmission problems. This method not only improves the reliability of data transmission but also reduces signal loss and the risk of misjudgment during data transmission, thereby further optimizing the performance of the intelligent fault early warning system and enhancing the stability of the power grid and the reliability of power supply. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the modules of the intelligent early warning system for power grid faults in an embodiment of the present invention;

[0042] Figure 2 This is a flowchart illustrating the intelligent early warning system for power grid faults in an embodiment of the present invention.

[0043] Figure 3 This is a flowchart illustrating the logic of determining whether a fault misjudgment has occurred based on the voltage timeout value in an embodiment of the present invention.

[0044] Figure 4 This is a logic flowchart of the action time correction based on the fault point protection difference in an embodiment of the present invention. Detailed Implementation

[0045] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0046] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0047] Please see Figure 1 As shown, this is a schematic diagram of the modules of the intelligent early warning system for power grid faults in an embodiment of the present invention. The intelligent early warning system for power grid faults based on big data described in this embodiment includes a data acquisition module, a transmission module, a storage module, a data calculation module, a judgment module, a control module, and a notification module.

[0048] The acquisition module includes several sensors and several oscilloscopes, used to acquire current waveform data and voltage waveform data;

[0049] A transmission module, which is connected to the acquisition module, is used to compress and transmit the processed data;

[0050] A storage module, connected to the transmission module, is used to store the transmitted data, and a recording frame protects the records;

[0051] A data calculation module, which is connected to the storage module, is used to perform calculations on the data;

[0052] The judgment module, which is connected to the data calculation module, is used to determine whether to issue a fault warning based on the current waveform distortion and the current harmonic frequency multiple. When a fault warning is issued, the module determines the cause of the fault warning and whether it is a misjudgment based on the difference between the current peak value and the negative peak value in the current cycle, the effective value of the fault point voltage, and the time when the voltage exceeds the protection voltage. When a misjudgment is determined, the module corrects the protection device operation time, the protection device operation current threshold, the time when the voltage exceeds the protection voltage, and the data transmission compression rate based on the cause of the misjudgment.

[0053] A control module, which is connected to the judgment module and the transmission module, is used to control the response of the corresponding module based on the instructions of the judgment module;

[0054] The notification module, which is connected to the control module, is used to issue warnings and / or misjudgment correction notifications based on the instructions output by the control module.

[0055] Please see Figure 2 As shown, it is a flowchart illustrating the power distribution automation monitoring method in an embodiment of the present invention, including:

[0056] S1: The acquisition module acquires real-time current waveform data and voltage data, compresses and transmits them back through the transmission module, and stores them in the storage module;

[0057] S2: After the data calculation module calculates the data, the judgment module determines whether to issue a fault warning based on the degree of current wave distortion and the multiple of the current harmonic frequency relative to the fundamental frequency.

[0058] S3: When the judgment module determines a fault, it determines the cause of issuing a fault warning and whether a misjudgment has occurred based on the current peak value difference, the fault point voltage parameters, and the time when the voltage exceeds the protection voltage.

[0059] S4: When the judgment module determines a misjudgment, it determines the cause of the misjudgment based on the number of times the frame protection occurs at the fault point;

[0060] S5: The judgment module corrects the protection device parameters, the time when the voltage exceeds the protection voltage, and the data transmission compression rate based on the cause of the fault misjudgment and issues an instruction. Subsequently, the control module corrects the parameters based on the instruction or the control notification module issues a notification.

[0061] The current waveform data refers to a complete record of the current changing over time within a certain period of time. These data can reflect the characteristics of the current, such as amplitude, frequency, phase, and waveform shape, including but not limited to current peak value, current negative peak value, current RMS value, harmonic frequency, fundamental current RMS value, and harmonic current RMS value, which will not be elaborated further.

[0062] The voltage data refers to a complete record of voltage changes over a certain period of time, including but not limited to voltage cycles and real-time voltage, which will not be elaborated further.

[0063] In this solution, the acquisition module uses multiple sensors and an oscilloscope to collect current and voltage waveform data, which are then compressed and transmitted back. Subsequently, the degree of current waveform distortion is used to determine if a fault may occur. Compared to existing technologies that directly detect and coordinate parameters such as voltage, current, and temperature for fault warning, this solution directly utilizes current and voltage waveform data for fault warning, eliminating the need to delve into the complex relationships between these parameters and effectively avoiding misjudgments that can easily occur when relying solely on simple combinations of these parameters. Current waveform data, as a more fundamental parameter, avoids misjudgments caused by subtle errors between multiple parameters when used for fault warning, thus improving accuracy. Furthermore, this solution uses the duration of voltage exceeding the protection voltage and the number of times the fault point triggers frame protection to determine if a fault warning misjudgment has occurred. When a misjudgment occurs, the cause is investigated and corrected accordingly. This improves the accuracy of fault warnings while achieving self-optimization of distribution network parameters, effectively saving manpower and improving grid operation efficiency.

[0064] Furthermore, the judgment module is used to determine whether it is in the first state based on the current wave distortion, and, when it is determined to be in the first state, to determine whether to issue a fault warning based on the current harmonic frequency multiple, and, when it is determined to issue a fault warning, to determine the reason for issuing the fault warning based on the difference between the current peak value and the negative peak value in this cycle.

[0065] Wherein, the current waveform distortion is the ratio of the harmonic component to the fundamental component within the current cycle, and the current harmonic frequency multiple refers to the multiple of the harmonic frequency relative to the fundamental frequency in the current waveform.

[0066] Wherein, the current wave distortion is the ratio of the harmonic component to the fundamental component within the current cycle.

[0067] That is, current wave distortion

[0068] Where I1 is the effective value of the fundamental current;

[0069] I2, I3, I4,······,I i These represent the effective values ​​of the second, third, fourth, and so on up to the i-th harmonic current, where i = 2, 3, 4, ..., n;

[0070] The current harmonic frequency multiple refers to the multiple of the harmonic frequency relative to the fundamental frequency in the current waveform. Where f1 is the standard frequency of the power system, typically 50Hz or 60Hz, f i Let be the frequency of the i-th harmonic, where i = 2, 3, 4, ..., n;

[0071] The current waveform distortion is the ratio of harmonic components to fundamental components within the current cycle. The current waveform distortion reflects the magnitude of harmonic components in the current waveform. The existence of harmonic components in the current is mainly caused by nonlinear loads or faults in the power system. For current, the harmonic amplitude caused by nonlinear loads is related to the operating state of the load and is usually a low-order harmonic, while the harmonics caused by faults are usually high-order harmonics. Therefore, based on the judgment of a relatively serious harmonic phenomenon by the current waveform distortion, the type of harmonic is determined by the multiple of the current harmonic frequency. When the multiple of the current harmonic frequency is greater than the preset multiple of the current harmonic frequency, it indicates that the current harmonic is caused by a fault, and a fault warning needs to be issued at this time.

[0072] Specifically, the process by which the judgment module determines whether it is in the first state based on the current wave distortion, and determines whether to issue a fault warning based on the current harmonic frequency multiple when it is determined to be in the first state, includes:

[0073] The judgment module acquires the current wave distortion (THD) and compares the current wave distortion (THD) with a preset current wave distortion (THD1), wherein the preset current wave distortion (THD1) is greater than 5%.

[0074] If the current wave distortion degree THD is greater than the preset current wave distortion degree THD1, the judgment module determines that the current state is the first state, and the judgment module determines whether to issue a fault warning based on the current harmonic frequency multiple.

[0075] The judgment module obtains the current harmonic frequency multiple XBB and compares the current harmonic frequency multiple XBB with the preset current harmonic frequency multiple XBB1, and sets the preset current harmonic frequency multiple XBB1 to be greater than or equal to 10.

[0076] If the current harmonic frequency multiple XBB is greater than or equal to the preset current harmonic frequency multiple XBB1, the judgment module determines that a fault may occur and issues a fault warning. The judgment module issues the fault warning based on the difference between the current peak value and the negative peak value in this cycle.

[0077] Furthermore, the judgment module is used to determine the reason for issuing a fault warning based on the peak current amplitude, and when the first reason is determined, output a power grid fault warning as a transformer and incoming line undervoltage warning, or determine the reason for issuing a fault warning based on the effective value of the fault point voltage.

[0078] Wherein, the current peak amplitude is the difference between the peak current and the negative peak current in this cycle, and the effective value of the fault point voltage is the root mean square value of the instantaneous value of the fault point voltage in one cycle.

[0079] When a potential fault is detected and a fault warning is issued, the current peak amplitude can be used to determine the type of potential fault. In the current power grid constructed with distribution automation, the causes of potential faults are mainly divided into three categories: transformer and incoming line undervoltage faults, frame protection operation faults, and distribution network cable faults. Among them, transformer and incoming line undervoltage faults refer to the power system going out or operating abnormally due to transformer or incoming line undervoltage, at which time the current will decrease accordingly. Frame protection operation faults are usually caused by abnormal current, such as short circuit faults or short-term current overloads, which will cause the current to increase sharply. Distribution network cable faults will also cause a sharp increase in current. The current peak amplitude refers to the difference between the peak current and the negative peak current in the current cycle, which can intuitively reflect the magnitude of current change. When the current decreases, the current peak amplitude will decrease accordingly; when the current increases, the current peak amplitude will increase accordingly. By using the current peak amplitude, transformer and incoming line undervoltage faults can be effectively distinguished from other fault types, thus providing an important basis for the rapid diagnosis and handling of potential faults.

[0080] Specifically, the process by which the judgment module determines the cause of the fault warning based on the current peak amplitude includes:

[0081] The judgment module acquires the current peak amplitude value A and compares it with a preset current peak amplitude value A1, wherein the preset current peak amplitude value A1 is the effective value of the current. The effective value of the current is the ratio of voltage to the power used;

[0082] If the current peak amplitude A is less than or equal to the preset current peak amplitude A1, the judgment module determines that the fault warning is caused by the first reason and outputs a power grid fault warning as a transformer and incoming line undervoltage warning.

[0083] If the current peak amplitude A is greater than the preset current peak amplitude A1, the judgment module determines the reason for issuing a fault warning based on the effective value of the fault point voltage.

[0084] Furthermore, the judgment module is used to determine the cause of the fault warning based on the effective value of the fault point voltage, and to output the fault warning as a power grid distribution cable fault warning when the cause is determined to be the second cause, or to determine the cause of the fault warning based on the time when the voltage exceeds the protection voltage.

[0085] When a distribution network cable fault occurs or a fault warning is triggered by the operation of the frame protection, the current exhibits a sharp increase. However, for distribution network cable faults, the resistance at the fault location is much smaller than that of the normal path due to the fault, resulting in a sharp increase in current. But because the power supply's output capacity is limited, the output voltage will decrease as the current increases. Therefore, although the current increases, the voltage will decrease. In contrast, the situation caused by the operation of the frame protection still follows Ohm's law, that is, the voltage increases with the increase of the current. The effective value of the fault point voltage is the root mean square value of the instantaneous value of the fault point voltage over one period. In this invention, the effective value of the fault point voltage can effectively measure the true level of the fault point voltage, thereby providing a basis for judging the fault warning type.

[0086] Among them, the effective value of the fault point voltage of the sinusoidal AC voltage , where V peak This is the peak voltage, measured in volts (V).

[0087] Specifically, the process by which the judgment module determines the cause of the fault warning based on the effective value of the fault point voltage includes:

[0088] The judgment module obtains the effective value V of the fault point voltage and compares the effective value V of the fault point voltage with the preset effective value V1 of the fault point voltage, wherein the preset effective value V1 of the fault point voltage is set to [198, 235.4V].

[0089] If the effective value of the fault point voltage V is less than or equal to the preset effective value of the fault point voltage V1, the judgment module determines it as the second cause and outputs a fault warning as a power grid distribution cable fault warning.

[0090] If the effective value V of the voltage at the fault point is greater than the preset effective value V1 of the voltage at the fault point, the judgment module determines the cause of the fault warning based on the time when the voltage exceeds the protection voltage.

[0091] Furthermore, the judgment module is used to determine whether a misjudgment or the cause of issuing a fault warning has occurred based on the voltage timeout value, and, when the cause is determined to be a third cause, outputs a fault warning as a protection device fault warning, or determines that a fault warning has been misjudged, and determines the cause of the fault warning misjudgment based on the number of times the frame protection occurs at the fault point.

[0092] The voltage timeout value is the time during which the voltage exceeds the operating current threshold.

[0093] In power grids, especially those with many automated devices, short-term current overloads or instantaneous voltage spikes are common. Furthermore, malfunctions or poor contact in the protection equipment itself can trigger frame protection and cause fault warnings. However, short-term current overloads or instantaneous voltage spikes are not necessarily genuine faults. Therefore, in practical applications, significant manpower is often required to identify these situations. In this solution, to accurately determine whether a fault truly exists, the voltage timeout value is used to differentiate and identify faults caused by protection equipment operation. The voltage timeout value is the time the voltage exceeds the operating current threshold. When the protection equipment is about to fail, the voltage timeout value will be less than the set operating time. However, for frame protection caused by short-term current overloads, the voltage timeout value will be greater than the operating time. Therefore, the actual situation can be determined using the voltage timeout value.

[0094] Please see Figure 3 As shown, this is a flowchart illustrating the logic of determining whether a fault misjudgment has occurred based on the time the voltage exceeds the protection voltage in an embodiment of the present invention. The process by which the judgment module determines whether a misjudgment has occurred or issues a fault warning based on the voltage timeout value includes:

[0095] The judgment module obtains the voltage timeout value T. 超压 Compare with the action time T, where the specific value of the action time T is not limited in principle and can be derived based on the actual situation and the patterns of historical data.

[0096] If the voltage timeout value T 超压If the time is less than the action time T, the judgment module determines it as a third cause and outputs a fault warning as a protection device fault warning.

[0097] If the voltage timeout value T 超压 If the action time T is greater than or equal to the action time T, the judgment module determines that a fault warning misjudgment has occurred. The judgment module determines the cause of the fault warning misjudgment based on the number of times the frame protection occurs at the fault point.

[0098] Furthermore, the judgment module is used to determine the cause of the fault misjudgment based on the number of times the fault point is protected, and when the first cause of misjudgment is determined, output the cause of the fault misjudgment as an accidental misjudgment, or, correct the action time based on the difference between the number of times the fault point is protected and the preset number of times the fault point is protected.

[0099] During the process of triggering frame protection, two situations may occur. One is that the operating time and operating current thresholds set by the protection device are reasonable, but the frame protection is triggered by a short-term instantaneous high voltage. The other is that the frame protection is triggered because the operating time and operating current thresholds set by the protection device are unreasonable. Therefore, the number of frame protection events at the fault point can be used to distinguish between these situations. The number of frame protection events at the fault point refers to the number of times frame protection occurs at the fault point within N hours. When frame protection occurs frequently in a short period of time, it indicates that the thresholds set by the protection device may not be suitable for the power consumption situation at this location, thus leading to frequent protection behaviors. By analyzing the number of frame protection events at the fault point, this invention can clearly identify whether the thresholds set by the protection device are reasonable, thereby providing strong support for the stable operation of the power system. Here, N is greater than or equal to 48.

[0100] Specifically, the process by which the judgment module determines the cause of a fault misjudgment based on the number of times the fault point has been protected includes:

[0101] The judgment module obtains the number of times the fault point is protected B, and compares the number of times the fault point is protected B with the preset number of times the fault point is protected B1, wherein the preset number of times the fault point is protected B1 is set to be greater than or equal to 3.

[0102] If the number of times the fault point is protected B is less than the preset number of times the fault point is protected B1, then the judgment module determines it as the first cause of misjudgment and outputs the cause of the fault misjudgment as an accidental misjudgment.

[0103] If the number of times the fault point protection is B is greater than or equal to the preset number of times the fault point protection is B1, the judgment module determines that the parameter setting of the protection device is unreasonable, and the judgment module corrects the action time based on the difference between the number of times the fault point protection is B and the preset number of times the fault point protection is B1.

[0104] Furthermore, the judgment module is used to increase the action time based on the fault point protection difference, and the increase in action time is proportional to the fault point protection difference;

[0105] The fault point protection difference is the difference between the number of fault point protections and the preset number of fault point protections. The fault point protection difference reflects the frequency of the protection device's operation exceeding the normal range. If the fault point protection difference is large, it indicates that the protection device is operating too frequently and the operating time needs to be increased significantly to reduce the possibility of triggering. This proportional relationship allows the protection device to be dynamically adjusted according to the actual operating conditions, rather than using a fixed operating time. This can better adapt to different power environments and equipment states, and improve the adaptability and reliability of the protection device.

[0106] Please see Figure 4 As shown, it is a logic flowchart of the fault point protection difference correction action time in an embodiment of the present invention. The process of correcting the action time based on the fault point protection difference includes:

[0107] The judgment module obtains the fault point protection difference G and compares the fault point protection difference G with the set first preset fault point protection difference G1 and the second preset fault point protection difference G2, wherein the first preset fault point protection difference G1 is set to [1, 5] and the second preset fault point protection difference G2 is greater than 5.

[0108] If the fault point protection difference G is less than or equal to the first preset fault point protection difference G1, the judgment module uses the first action time correction threshold α1 to correct the action time T, and the corrected action time T' = T × α1, where the first action time correction threshold α1 is set to 1.05.

[0109] If the fault point protection difference G is greater than the first preset fault point protection difference G1 and less than or equal to the second preset fault point protection difference G2, then the judgment module uses the second action time correction threshold α2 to correct the action time T. The corrected action time T' = T × α2, where the second action time correction threshold α2 is set to 1.11.

[0110] If the fault point protection difference G is greater than the second preset fault point protection difference G2, the judgment module uses the third action time correction threshold α3 to correct the action time T. The corrected action time T' = T × α3, where the third action time correction threshold α3 is set to 1.2.

[0111] Furthermore, the judgment module is used to increase the action current threshold based on the action time difference, and the increase in the action current threshold is proportional to the action time difference;

[0112] The action time difference refers to the difference between the corrected action time and the original action time. It reflects the degree of change in the action time of the protection device after parameter adjustment. Based on the comparison between the action time difference and the preset action time difference, the action current threshold is increased, and the increase in the action current threshold is proportional to the action time difference. This allows for dynamic adjustment of the protection device parameters, ensuring a more reasonable action time and reducing the possibility of malfunction. This dynamic adjustment mechanism can better adapt to different power environments and equipment states, improve the adaptability and reliability of the protection device, and thus improve the overall performance of the power system.

[0113] Specifically, the process by which the judgment module increases the action current threshold based on the action time difference and the preset action time difference includes:

[0114] The judgment module obtains the action time difference value H and compares the action time difference value H with the set first preset action time difference value H1 and the second preset action time difference value H2, wherein the first preset action time difference value H1 is set to [5, 15ms) and the second preset action time difference value H2 is set to [15, 25ms].

[0115] If the action time difference H is less than or equal to the first preset action time difference H1, the judgment module uses the first action current correction threshold β1 to correct the action current threshold K. The corrected action current threshold K' = K × β1, and the first action current correction threshold β1 is set to 1.03.

[0116] If the action time difference H is greater than the first preset action time difference H1 and less than or equal to the second preset action time difference H2, then the judgment module uses the second action current correction threshold β2 to correct the action current threshold K. The corrected action current threshold K' = K × β2, and the second action current correction threshold β2 is set to 1.07.

[0117] If the action time difference H is greater than the second preset action time difference H2, the judgment module uses the third action current correction threshold β3 to correct the action current threshold K. The corrected action current threshold K' = K × β3, and the third action current correction threshold β3 is set to 1.13.

[0118] Furthermore, the judgment module is used to correct the voltage timeout value based on the difference in operating current thresholds, and the increase in the voltage timeout value is proportional to the difference in operating current thresholds;

[0119] After correcting the operating current threshold of the protection device, the voltage timeout value should also be corrected accordingly to ensure that the corrected voltage timeout value can be adapted to the corrected operating current threshold of the protection device. The difference between the operating current thresholds is the difference between the corrected operating current threshold and the operating current threshold before correction. Correcting the voltage timeout value based on the difference between the operating current thresholds helps the system to judge whether the fault warning is reasonable based on more accurate parameters, and avoids misjudgment and missed judgment.

[0120] Specifically, the process by which the judgment module corrects the voltage timeout value based on the difference in operating current thresholds includes:

[0121] The judgment module obtains the action current threshold difference P and compares the action current threshold difference P with the set first preset current threshold difference P1 and second preset current threshold difference P2, wherein the first preset current threshold difference P1∈[5,20mA) and the second preset current threshold difference P2∈[20,40mA] are set.

[0122] If the difference in the action current threshold P is less than or equal to the difference in the first preset current threshold P1, then the judgment module uses the first voltage timeout correction threshold θ1 to correct the voltage timeout value Z. The corrected voltage timeout value Z' = Z × θ1, where the first voltage timeout correction threshold θ1 is set to 1.03.

[0123] If the difference in the action current threshold P is greater than the first preset current threshold difference P1 and less than or equal to the second preset current threshold difference P2, then the judgment module uses the second voltage timeout correction threshold θ2 to correct the voltage timeout value Z. The corrected voltage timeout value Z' = Z × θ2, where the second voltage timeout correction threshold θ2 is set to 1.07.

[0124] If the difference between the action current thresholds P and the second preset current thresholds P2 are greater, the judgment module uses the third voltage timeout correction threshold θ3 to correct the voltage timeout value Z. The corrected voltage timeout value Z' = Z × θ3, where the third voltage timeout correction threshold θ3 is set to 1.12.

[0125] Furthermore, the judgment module is used to increase the data transmission compression rate based on the voltage timeout value difference, and the increase in the data transmission compression rate is proportional to the voltage timeout value difference;

[0126] The voltage timeout difference is the difference between the corrected voltage timeout value and the original voltage timeout value.

[0127] After correcting the protection device parameters, in order to avoid misjudgment of faults caused by poor signal during data transmission, the data transmission compression rate is optimized and adjusted. By correcting the data transmission compression rate based on the voltage timeout value difference, the transmission efficiency can be effectively optimized, fundamentally avoiding misjudgment of faults caused by data transmission problems, and further improving the reliability and accuracy of the intelligent fault early warning system.

[0128] Specifically, the process by which the judgment module increases the data transmission compression rate based on the voltage timeout value difference includes:

[0129] The judgment module obtains the voltage timeout value difference Q and compares the voltage timeout value difference Q with the set first preset voltage timeout value difference Q1 and second preset voltage timeout value difference Q2. In principle, the specific values ​​assigned to the first preset voltage timeout value difference Q1 and the second preset voltage timeout value difference Q2 are not limited and can be derived based on the actual situation and the patterns of historical data.

[0130] If the voltage timeout value difference Q is less than or equal to the first preset voltage timeout value difference Q1, the judgment module uses the first compression correction threshold λ1 to correct the data transmission compression ratio R, and the corrected data transmission compression ratio R' = R × λ1, where the first compression correction threshold λ1 is set to 1.02.

[0131] If the voltage timeout value difference Q is greater than the first preset voltage timeout value difference Q1 and less than or equal to the second preset voltage timeout value difference Q2, then the judgment module uses the second compression correction threshold λ2 to correct the data transmission compression ratio R. The corrected data transmission compression ratio R' = R × λ2, where the second compression correction threshold λ2 is set to 1.05.

[0132] If the voltage timeout value difference Q is greater than the second preset voltage timeout value difference Q2, the judgment module uses the third compression correction threshold λ3 to correct the data transmission compression ratio R. The corrected data transmission compression ratio R' = R × λ3, where the third compression correction threshold λ3 is set to 1.09.

[0133] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A smart early warning system for power grid faults based on big data, characterized in that, include, The acquisition module includes several sensors and several oscilloscopes, used to acquire current waveform data and voltage waveform data; A transmission module, which is connected to the acquisition module, is used to compress and transmit the processed data; A storage module, connected to the transmission module, is used to store the transmitted data, and a recording frame protects the records; A data calculation module, which is connected to the storage module, is used to perform calculations on the data; The judgment module, which is connected to the data calculation module, is used to determine whether to issue a fault warning based on the current waveform distortion and the multiple of the current harmonic frequency, and to determine the reason for issuing the fault warning based on the current peak amplitude. If the current peak amplitude is less than or equal to the preset current peak amplitude, the judgment module determines that the fault warning is caused by the first reason and outputs a power grid fault warning as a transformer and incoming line undervoltage warning. If the current peak amplitude is greater than the preset current peak amplitude, the judgment module determines the reason for issuing the fault warning based on the effective value of the fault point voltage. The judgment module determines the cause of the fault warning based on the effective value of the fault point voltage. If the effective value of the fault point voltage is less than or equal to the preset effective value of the fault point voltage, the judgment module determines it as the second cause and outputs a fault warning as a power grid distribution cable fault warning. If the effective value of the fault point voltage is greater than the preset effective value of the fault point voltage, the judgment module determines the cause of the fault warning based on the time when the voltage exceeds the protection voltage. The judgment module determines the cause of the fault warning based on the time the voltage exceeds the protection voltage. If the voltage timeout value is less than the action time, the judgment module determines it as the third cause and outputs a fault warning as a protection device fault warning. If the voltage timeout value is greater than or equal to the action time, the judgment module determines that the fault warning has been misjudged. The judgment module determines the cause of the fault warning misjudgment based on the number of times the frame protection occurs at the fault point. The judgment module determines the cause of the fault misjudgment based on the number of times the fault point is protected. If the number of times the fault point is protected is less than the preset number of times the fault point is protected, the judgment module determines it as the first cause of misjudgment and outputs the cause of the fault misjudgment as an accidental misjudgment. If the number of times the fault point is protected is greater than or equal to the preset number of times the fault point is protected, the judgment module determines that the parameter setting of the protection device is unreasonable, and the judgment module issues an instruction to correct the action time based on the difference between the number of times the fault point is protected and the preset number of times the fault point is protected. The judgment module is also used to increase the action time based on the fault point protection difference, and the increase in action time is proportional to the fault point protection difference; The judgment module is used to increase the action current threshold based on the action time difference, and the increase in the action current threshold is proportional to the action time difference. The judgment module is also used to correct the time when the voltage exceeds the protection voltage and the data transmission compression rate based on the cause of the abnormality; A control module, which is connected to the judgment module and the transmission module, is used to control the response of the corresponding module based on the instructions of the judgment module; The notification module, which is connected to the control module, is used to issue warnings and / or misjudgment correction notifications based on the instructions output by the control module. Wherein, the current peak amplitude is the difference between the peak current and the negative peak current in this cycle, the effective value of the fault point voltage is the root mean square value of the instantaneous value of the fault point voltage in one cycle, the voltage timeout is the time during which the voltage exceeds the operating current threshold, the number of fault point protections is the number of times the fault point experiences frame protection within N hours, where N is greater than or equal to 48, the fault point protection difference is the difference between the number of fault point protections and the preset number of fault point protections, and the operating time difference is the difference between the corrected operating time and the operating time before correction.

2. The intelligent fault early warning system according to claim 1, characterized in that, The judgment module is used to determine whether it is in the first state based on the current wave distortion, and, when it is determined to be in the first state, to determine whether to issue a fault warning based on the current harmonic frequency multiple, and, when it is determined to issue a fault warning, to determine the reason for issuing the fault warning based on the difference between the current peak value and the complex peak value in this cycle. Wherein, the current waveform distortion is the ratio of the harmonic component to the fundamental component within the current cycle, and the current harmonic frequency multiple refers to the multiple of the harmonic frequency relative to the fundamental frequency in the current waveform.

3. The intelligent fault early warning system according to claim 1, characterized in that, The judgment module is used to correct the voltage timeout value based on the difference in operating current thresholds, and the increase in the voltage timeout value is proportional to the difference in operating current thresholds. The current threshold difference is the difference between the corrected operating current threshold and the original operating current threshold.

4. The intelligent fault early warning system according to claim 2, characterized in that, The judgment module is used to increase the data transmission compression rate based on the voltage timeout value difference, and the increase in the data transmission compression rate is proportional to the current threshold difference. The voltage timeout difference is the difference between the corrected voltage timeout value and the original voltage timeout value.

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