A method for early warning of operating overvoltage associated with action of a lightning arrester and a circuit breaker

Abstract

The application provides an operation overvoltage early warning method for associating lightning arresters and circuit breaker action conditions, and belongs to the overvoltage and insulation coordination field of electrical engineering. The early warning method comprises six parts: obtaining action information of an action lightning arrester and classifying, matching and obtaining an action circuit breaker and associated equipment, judging the action type of the action lightning arrester, judging whether the action circuit breaker has abnormal operation information, judging early warning information and issuing overvoltage early warning information. The method associates the action conditions of the lightning arrester and the circuit breaker, is used for verifying the rationality of overvoltage and insulation coordination in the protection range of the action lightning arrester, and provides technical data for equipment selection and configuration; meanwhile, with the help of the protection range of the action lightning arrester, the electrical equipment associated with the action lightning arrester is selected, the safety of the operation of the associated equipment is predicted, and the substation operation and maintenance personnel are reminded to access in advance and pre-control in advance in the form of early warning, so that the reliability of the operation of the electrical equipment is improved.

Description

Technical Field

[0001] This invention belongs to the field of overvoltage and insulation coordination in electrical engineering, and specifically relates to an operational overvoltage early warning method that relates to the operation of surge arresters and circuit breakers. Background Technology

[0002] When power transmission and transformation equipment is struck by lightning or due to faults and operations, the electrical equivalent topology and parameters of the power grid and substation will change. This is then classified into lightning overvoltage, also known as external overvoltage, and internal overvoltage. Internal overvoltage is further divided into temporary overvoltage and operational overvoltage caused by the operation of circuit breakers, etc.

[0003] Surge arresters, as crucial electrical equipment in substations, play a vital role in limiting overvoltage. Their operating threshold is closely related to the overvoltage multiple and the insulation level of the electrical equipment. Monitoring the leakage current of surge arresters is one of the effective means of evaluating their operational health. A discharge counter (or simply counter) is connected in series with the low-voltage end of the surge arrester via a grounding down conductor and then connected to the substation grounding grid. The operation of the surge arrester is recorded by setting its operating point. When the leakage current value exceeds the current value set at the operating point, the number of surge arrester operations recorded by the counter increases. Currently, substations mostly use mechanical counters, with one counter equipped for each surge arrester to complete the corresponding surge arrester leakage current monitoring and operation counting. Even with the adoption of digital devices in the surge arresters, the discharge count of the counter is still manually read on-site by substation technicians.

[0004] Due to climatic differences between the north and south, lightning strikes are more frequent in the south, and surge arrester trips are mostly caused by lightning overvoltage. In the north, statistics show that overvoltage accidents caused by switching overvoltages account for approximately 70%-80% of all overvoltage accidents in the entire power system, and this problem is becoming increasingly urgent. Therefore, after surge arrester trips, it is necessary to distinguish the type of overvoltage in order to propose different technical solutions and preventive measures to address different situations. Furthermore, when analyzing the causes of surge arrester trips, the circuit breaker's disconnection process and electrical equipment such as parallel capacitors and parallel reactors affected by overvoltage should not be overlooked. This issue directly relates to the rationality of overvoltage and insulation coordination and is also a problem that urgently needs to be solved on-site.

[0005] Therefore, it is necessary to explore and develop an overvoltage early warning method or system that relates the operation of surge arresters and circuit breakers. Summary of the Invention

[0006] This invention provides an overvoltage warning method based on the operation status of surge arresters and circuit breakers. The purpose is to verify the rationality of overvoltage and insulation coordination within the protection range of the surge arrester by using the operation status of the surge arrester and circuit breaker, providing technical data for equipment selection and configuration; and to predict the safety of the operation of the associated electrical equipment by selecting the electrical equipment associated with the surge arrester, thereby improving the reliability of the electrical equipment operation.

[0007] To achieve the objectives of this invention, the following technical solution is adopted:

[0008] An operational overvoltage early warning method that correlates the operation of surge arresters and circuit breakers relies on an electrical equipment early warning and protection system based on operational data to realize overvoltage early warning in substations. The electrical equipment early warning and protection system based on operational data is referred to as the protection system. The protection system includes an operational information extraction module, an information classification module, a calculation and judgment module, a storage module, an output module, a defect information recording module, an early warning prompt module, a waveform recorder, and a secondary calculation and judgment module.

[0009] The operational overvoltage early warning method includes the following steps:

[0010] Step 1: Obtain and classify the action information of the surge arrester.

[0011] The surge arrester that has taken action is called the action surge arrester. When the number of discharges recorded by the counter of the action surge arrester increases by one, the local digitization device built into the action surge arrester itself obtains the number of actions of the counter and transmits the number of actions to the operation information extraction module.

[0012] After the operation information extraction module starts and obtains the operation information of the electrical equipment, it transmits the number of actions and the action time T of the counter recorded by the protection system to the information classification module. The information classification module obtains the equipment information related to the operation of the surge arrester from the operation information of the electrical equipment and classifies it.

[0013] Step 2: Match and obtain the operating circuit breakers and associated devices.

[0014] The circuit breaker that is electrically connected to the operating surge arrester is called the associated circuit breaker, and the electrical equipment connected to the end of the associated circuit breaker is called the associated equipment.

[0015] Step 2.1: The calculation and judgment module uses the equipment information classification results transmitted by the information classification module to call the state matching method in the storage module to select the associated circuit breakers and associated equipment. Assume that after this step, N associated circuit breakers are obtained; N≥1.

[0016] Step 2.2: Define a time period T1, T1 = [T - T0, T], where T0 is the buffer time, T0 = 2Y, and Y is the rigid tripping time of the circuit breaker; the judgment module checks whether any of the N associated circuit breakers have an action within the time period T1. If an associated circuit breaker has an action, the associated circuit breaker with the action is recorded as the action circuit breaker, and the action status of the action circuit breaker is recorded as 1; if no action is performed, the action status of the associated circuit breaker is recorded as 0.

[0017] Step 3: Determine the type of operation of the surge arrester.

[0018] If the operating status of all N associated circuit breakers is 0, meaning that no circuit breaker operates in the substation during time period T1, the operation type is defined as "lightning overvoltage" or "temporary overvoltage" and recorded as type I. The calculation and judgment module outputs the judgment result through the output module, and after being recorded by the defect information recording module, the early warning module is triggered to issue an early warning to prompt maintenance personnel to verify the lightning weather, external faults of the substation, and the operation status of the opposite substation. This early warning operation ends.

[0019] If any one of the N associated circuit breakers has an operating status of 1, that is, there is an operating circuit breaker in the substation during time period T1, the operating type is defined as "operating overvoltage" and recorded as type II; the calculation and judgment module transmits the judgment result to the defect information recording module through the output module and proceeds to step 4.

[0020] Step 4: Determine if there is any abnormal operating information from the circuit breaker.

[0021] The abnormal operation information includes historical abnormal operation information of the circuit breaker and current abnormal operation information occurring within time period T1; the historical abnormal operation information is retrieved and extracted by the defect information recording module and sent to the secondary calculation and judgment module.

[0022] The determination of this abnormal operation information is as follows:

[0023] The defect information recording module acquires the three-phase phase voltage waveform signal u of the busbar connected to the circuit breaker that operates within time period T1. a (t), u b (t), u c (t), and the three-phase phase voltage waveform signal u a (t), u b (t), u c (t) is fed back to the secondary calculation and judgment module; where t is any moment in an operation process within the time period T1, and the operation process is a process from the time period T1 until the voltage value drops to zero after the corresponding relay protection device of the electrical equipment issues a circuit breaker trip command.

[0024] The secondary calculation and judgment module retrieves the overvoltage diagnosis method and criterion values ​​based on waveform characteristics from the storage module, and performs calculations and judgments. Specifically, it obtains the total number of high-frequency segments based on the three-phase phase voltage waveform signals ua(t), ub(t), and uc(t), and calculates the phase overvoltage multiple and phase-to-phase overvoltage multiple of the circuit breaker. Then, it compares the above results with the given criterion values. If the above results are not within the reasonable range set by the criterion values, they are recorded as unreasonable information, and the set of all unreasonable information is recorded as the abnormal operation information for this operation. If the above results are within the reasonable range set by the criterion values, that is, there is no abnormal operation information in the judgment and calculation results for this operation.

[0025] Wherein, the total number of high-frequency segments is the total number of frequency segments with a frequency value greater than 5000Hz in the three-phase phase voltage waveform during an operation;

[0026] Step 5, Identify the warning information

[0027] If no abnormal operation information is found for this instance, the surge arrester is deemed to have operated correctly and no warning is required.

[0028] If abnormal operation information exists, determine the type of warning for this operation. Specifically: if the phase overvoltage multiple of the circuit breaker is determined to be unreasonable, the result is that a phase overvoltage warning is required; if the phase-to-phase overvoltage multiple of the circuit breaker is determined to be unreasonable, the result is that a phase-to-phase overvoltage warning is required.

[0029] After the secondary calculation and judgment module obtains the historical abnormal operation information of the action arrester, it judges whether there is a situation where the total number of high-frequency segments of the action circuit breaker is judged as unreasonable information. If so, the judgment result is that a warning of possible reignition / reignition of the action circuit breaker is required.

[0030] Step 6: Issue an overvoltage warning message.

[0031] The secondary calculation and judgment module feeds back the early warning information to the defect information recording module. The defect information recording module obtains the historical abnormal operation information of the associated equipment through the information of the associated equipment, and transmits the historical abnormal operation information of the associated equipment and the early warning information obtained in step 5 to the early warning prompt module. This prompts the operation and maintenance personnel to take measures to prevent the associated equipment from being damaged again, based on the historical operation of the associated equipment and the current early warning situation.

[0032] Preferably, the operation information extraction module is communicatively connected to the substation information operation system and is used to extract operation information of various electrical equipment from the substation operation information system. The operation information extraction module is unidirectionally connected to the information classification module and is used to transmit the acquired operation information to the information classification module.

[0033] The information classification module is unidirectionally connected to the operation information extraction module and the calculation and judgment module, respectively. It is used to receive operation information, classify the operation information according to the type of electrical equipment that needs to be protected by early warning, and transmit the classified operation information to the calculation and judgment module.

[0034] The storage module has built-in pre-stored information, which includes pre-stored data and pre-stored judgment methods; the pre-stored data includes initial values, criterion values, and early warning activation values ​​for various electrical devices.

[0035] The calculation and judgment module is unidirectionally electrically connected to the storage module and is used to extract pre-stored data and pre-stored judgment methods from the storage module; the calculation and judgment module is unidirectionally connected to the output module and is used to perform calculations and judgments based on the operating information extracted by the information classification module, the pre-stored data extracted by the storage module, and the pre-stored judgment methods to obtain abnormal operating information of the electrical equipment and transmit the abnormal operating information to the output module.

[0036] The output module is unidirectionally connected to the calculation and judgment module, the secondary calculation and judgment module, and the defect information recording module, respectively. It receives abnormal operation information transmitted by the calculation and judgment module and the calculation and judgment results of the secondary calculation and judgment module, and transmits the abnormal operation information to the defect information recording module.

[0037] The defect information recording module is bidirectionally connected to the waveform recorder. It triggers the waveform recorder using the currently received abnormal operation information, then receives the abnormal operation information waveform signal returned by the waveform recorder, and extracts and records the waveform information in the abnormal operation information waveform signal. The defect information recording module is unidirectionally connected to the early warning module. It triggers the early warning function of the early warning module using the waveform information in the extracted abnormal operation information waveform signal. The early warning module issues an early warning of electrical equipment defects, reminding the operators to handle them in a timely manner.

[0038] The defect information recording module is also unidirectionally connected to the secondary calculation and judgment module to transmit the waveform signal recorded by the waveform recorder, so that the secondary calculation and judgment module can recalculate and judge the waveform signal obtained by the waveform recorder and feed back the calculation and judgment results to the output module.

[0039] In addition to being connected to the output module and the defect information recording module as described above, the secondary calculation and judgment module is also unidirectionally connected to the information classification module and the storage module. It is used to obtain the types of overvoltage protection measures configured in the information classification module, extract the pre-stored algorithms in the storage module, and transmit the unreasonable information after final calculation and judgment to the output module. The output module outputs the unreasonable information and transmits it to the defect information recording module for recording.

[0040] The warning module is unidirectionally connected to the output module and is used to feed back the warning information to the output module, and display the output result with the help of a visualization device connected to the output module.

[0041] The waveform recorder has no fewer than 8 sampling channels, with multiple channels acquiring data simultaneously, and each channel has an acquisition rate of no less than 10M / s.

[0042] Preferably, the local digitization device mentioned in step 1 is a device that converts the analog signal generated by the surge arrester's counter into a digital signal and transmits it to the substation information operation system via a wireless transceiver.

[0043] Preferably, the action of whether the associated circuit breaker is in operation as described in step 2 refers to the action of the circuit breaker changing from closed to open.

[0044] Preferably, the criterion value in step 4 is:

[0045] If the phase overvoltage multiple is greater than or equal to 4, the overvoltage protection measures are deemed to be improperly configured.

[0046] If the phase-to-phase overvoltage multiple is greater than 5.6, the phase-to-phase overvoltage protection measures are deemed to be improperly configured.

[0047] If the total number of high-frequency segments is greater than 1, it is determined that the circuit breaker will experience reignition or re-ignition.

[0048] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0049] 1. Based on the main wiring configuration of the substation and the protection range of the surge arrester, this invention selects the circuit breaker and the electrical equipment connected to the end of the circuit breaker that are electrically connected to the operating surge arrester. Instead of considering the operation of the surge arrester and its counter in isolation—simply considering the correct operation of the surge arrester and the accuracy of the counter measurement, etc.—this invention places the surge arrester and its counter in the electrical wiring environment to discuss the operation of the surge arrester and its counter. It explores the causes of the surge arrester's operation through the dialectical relationship between the whole and the part, avoiding the situation of surge arrester maloperation. The corresponding results are more specific and comprehensive.

[0050] 2. This invention selects circuit breakers that are electrically connected to the operating surge arrester and the electrical equipment connected to the end of the circuit breaker. It discusses the operation of the surge arrester in conjunction with the overvoltage process during the circuit breaker disconnection process, and examines the rationality of the overvoltage and insulation coordination within the protection range of the surge arrester. In other words, it verifies the rationality of the local wiring and equipment configuration of the existing substation through actual operation, providing first-hand technical data for the subsequent substation equipment selection, configuration and other modifications.

[0051] 3. This invention focuses on the type of operation of surge arresters, rather than simply discussing whether the surge arrester operates or the number of times it operates. Instead, it provides a method for identifying lightning overvoltage, temporary overvoltage, and switching overvoltage, providing technical support for further clarifying the cause of surge arrester operation and investigating the cause of damage to electrical equipment.

[0052] 4. This invention, combined with an overvoltage diagnosis method based on waveform characteristics, addresses practical substation operation issues such as the rationality of surge arrester protection range during operational overvoltages, and whether related equipment such as parallel capacitors and parallel reactors are susceptible to secondary damage from reignition or re-ignition. It can predict the extent of equipment damage in advance and remind substation operation and maintenance personnel to connect and control the equipment in advance in the form of early warnings or alerts, thereby improving the safety of equipment operation. Attached Figure Description

[0053] Figure 1 This is a flowchart of the early warning method of the present invention.

[0054] Figure 2 This is a schematic diagram of the electrical equipment early warning and protection system based on operational data in this invention.

[0055] Figure 3 This is a simplified diagram of the early warning method of the present invention. Specific implementation methods

[0056] Figure 1 This is a flowchart of the early warning method of the present invention. Figure 3 This is a simplified diagram of the early warning method of the present invention. Figure 1 and Figure 3 As can be seen, the present invention provides an operational overvoltage early warning method that correlates the operation of surge arresters and circuit breakers. It relies on an electrical equipment early warning and protection system based on operational data to realize overvoltage early warning in substations. The electrical equipment early warning and protection system based on operational data is referred to as the protection system. The protection system includes an operational information extraction module 1, an information classification module 2, a calculation and judgment module 3, a storage module 4, an output module 5, a defect information recording module 6, an early warning prompt module 7, a waveform recorder 8, and a secondary calculation and judgment module 10.

[0057] The operational overvoltage early warning method includes the following steps:

[0058] Step 1: Obtain and classify the action information of the surge arrester.

[0059] The surge arrester that has taken action is called the action surge arrester. When the number of discharges recorded by the counter of the action surge arrester increases by one, the local digitization device built into the action surge arrester itself obtains the number of actions of the counter and transmits the number of actions to the operation information extraction module 1.

[0060] After the operation information extraction module 1 starts and obtains the operation information of the electrical equipment, it transmits the number of actions and the action time T of the counter recorded by the protection system to the information classification module 2. The information classification module 2 obtains the equipment information related to the operation of the surge arrester from the operation information of the electrical equipment and classifies it.

[0061] In this embodiment, the local digitization device is a device that converts the analog signal generated by the surge arrester's counter into a digital signal and transmits it to the substation information operation system via a wireless transceiver.

[0062] Step 2: Match and obtain the operating circuit breakers and associated devices.

[0063] The circuit breaker that is electrically connected to the operating surge arrester is called the associated circuit breaker, and the electrical equipment connected to the end of the associated circuit breaker is called the associated equipment.

[0064] Step 2.1: The calculation and judgment module 3 uses the equipment information classification results transmitted by the information classification module 2 to call the state matching method in the storage module 4 to select the associated circuit breakers and associated equipment. Assume that after this step, N associated circuit breakers are obtained; N≥1.

[0065] In this embodiment, the state matching method described in step 2.1 includes acquiring phase voltage waveform signals, calculating phase-to-phase voltage waveform signals, extracting and calculating waveform information of voltage waveform signals, determining the rationality of overvoltage protection measures, and outputting diagnostic results.

[0066] Step 2.2, define a time period T1, T1 = [T - T0, T], where T0 is the buffer time, T0 = 2Y, and Y is the rigid tripping time of the circuit breaker; the judgment module 3 judges whether there is an action among the N associated circuit breakers in the time period T1. If the associated circuit breaker has an action, the associated circuit breaker with the action is recorded as the action circuit breaker, and the action status of the action circuit breaker is recorded as 1; if there is no action, the action status of the associated circuit breaker is recorded as 0.

[0067] In this embodiment, whether the associated circuit breaker is in operation refers to the action of the circuit breaker changing from closed to open.

[0068] Step 3: Determine the type of operation of the surge arrester.

[0069] If the operating status of all N associated circuit breakers is 0, meaning that no circuit breaker operates in the substation during time period T1, the operation type is defined as "lightning overvoltage" or "temporary overvoltage" and recorded as type I. The calculation and judgment module 3 outputs the judgment result through the output module 5, and after being recorded by the defect information recording module 6, it triggers the early warning module 7 to issue an early warning, prompting maintenance personnel to verify the lightning weather, external faults of the substation, and the operation status of the opposite substation. This early warning operation ends.

[0070] If any one of the N associated circuit breakers has an operating status of 1, that is, there is an operating circuit breaker in the substation during time period T1, the operating type is defined as "operational overvoltage" and recorded as type II; the calculation and judgment module 3 transmits the judgment result to the defect information recording module 6 through the output module 5 and proceeds to step 4.

[0071] Step 4: Determine if there is any abnormal operating information from the circuit breaker.

[0072] The abnormal operation information includes historical abnormal operation information of the circuit breaker and current abnormal operation information occurring within time period T1; the historical abnormal operation information is retrieved and extracted by the defect information recording module 6 and sent to the secondary calculation and judgment module 10.

[0073] The determination of this abnormal operation information is as follows:

[0074] The defect information recording module 6 acquires the three-phase phase voltage waveform signals ua(t), ub(t), and uc(t) of the bus connected to the circuit breaker within the time period T1, and feeds the three-phase phase voltage waveform signals ua(t), ub(t), and uc(t) back to the secondary calculation and judgment module 10; where t is any moment in an operation process within the time period T1, and the operation process is a process from the time when the corresponding relay protection device of the electrical equipment issues a circuit breaker trip command until its voltage value drops to zero;

[0075] The secondary calculation and judgment module 10 calls the overvoltage diagnosis method and criterion value based on waveform characteristics from the storage module 4, and performs calculation and judgment. Specifically, it obtains the total number of high-frequency segments based on the three-phase phase voltage waveform signals ua(t), ub(t), and uc(t), and calculates the phase overvoltage multiple and phase-to-phase overvoltage multiple of the circuit breaker. Then, it compares the above results with the given criterion value. If the above results are not within the reasonable range set by the criterion value, they are recorded as unreasonable information, and the set of all unreasonable information is recorded as the abnormal operation information for this time. If the above results are within the reasonable range set by the criterion value, that is, there is no abnormal operation information in the judgment and calculation results for this time.

[0076] The total number of high-frequency segments refers to the total number of frequency segments with a frequency value greater than 5000Hz in the three-phase phase voltage waveform during an operation.

[0077] In this embodiment, the criterion value in step 4 is:

[0078] If the phase overvoltage multiple is greater than or equal to 4, the overvoltage protection measures are deemed to be improperly configured.

[0079] If the phase-to-phase overvoltage multiple is greater than 5.6, the phase-to-phase overvoltage protection measures are deemed to be improperly configured.

[0080] If the total number of high-frequency segments is greater than 1, it is determined that the circuit breaker will experience reignition or re-ignition.

[0081] Step 5, Identify the warning information

[0082] If no abnormal operation information is found for this instance, the surge arrester is deemed to have operated correctly and no warning is required.

[0083] If abnormal operation information exists, determine the type of warning for this operation. Specifically: if the phase overvoltage multiple of the circuit breaker is determined to be unreasonable, the result is that a phase overvoltage warning is required; if the phase-to-phase overvoltage multiple of the circuit breaker is determined to be unreasonable, the result is that a phase-to-phase overvoltage warning is required.

[0084] After the secondary calculation and judgment module 10 obtains the historical abnormal operation information of the action arrester, it determines whether there is a situation where the total number of high-frequency segments of the action circuit breaker is judged as unreasonable information. If so, the judgment result is that a warning of possible reignition / reignition of the action circuit breaker is required.

[0085] Step 6: Issue an overvoltage warning message.

[0086] The secondary calculation and judgment module 10 feeds back the early warning information to the defect information recording module 6. The defect information recording module 6 obtains the historical abnormal operation information of the associated equipment through the information of the associated equipment, and transmits the historical abnormal operation information of the associated equipment and the early warning information obtained in step 5 to the early warning prompt module 7, so as to prompt the operation and maintenance personnel to take measures to prevent the associated equipment from being damaged again, based on the historical operation status of the associated equipment and the current early warning situation.

[0087] Figure 2 This is a schematic diagram of the electrical equipment early warning and protection system based on operational data in this invention. Figure 2As can be seen, in this embodiment, the operation information extraction module 1 is communicatively connected to the substation information operation system and is used to extract operation information of various electrical equipment from the substation operation information system. The operation information extraction module 1 is unidirectionally connected to the information classification module 2 and is used to transmit the acquired operation information to the information classification module 2.

[0088] The information classification module 2 is unidirectionally connected to the operation information extraction module 1 and the calculation and judgment module 3, respectively. It is used to receive operation information, classify the operation information according to the type of electrical equipment that needs to be protected by early warning, and transmit the classified operation information to the calculation and judgment module 3.

[0089] The storage module 4 has built-in pre-stored information, which includes pre-stored data and pre-stored judgment methods; the pre-stored data includes initial values, criterion values, and early warning activation values ​​for various electrical devices.

[0090] The calculation and judgment module 3 is unidirectionally electrically connected to the storage module 4 and is used to extract pre-stored data and pre-stored judgment methods from the storage module 4; the calculation and judgment module 3 is unidirectionally connected to the output module 5 and is used to perform calculations and judgments based on the operating information extracted by the information classification module 2, the pre-stored data extracted by the storage module 4, and the pre-stored judgment methods to obtain abnormal operating information of the electrical equipment and transmit the abnormal operating information to the output module 5.

[0091] The output module 5 is unidirectionally connected to the calculation and judgment module 3, the secondary calculation and judgment module 10, and the defect information recording module 6, respectively. It receives the abnormal operation information transmitted by the calculation and judgment module 3 and the calculation and judgment results of the secondary calculation and judgment module 10, and transmits the abnormal operation information to the defect information recording module 6.

[0092] The defect information recording module 6 is bidirectionally connected to the waveform recorder 8. It triggers the waveform recorder 8 using the currently received abnormal operation information, then receives the abnormal operation information waveform signal returned by the waveform recorder 8, and extracts and records the waveform information in the abnormal operation information waveform signal. The defect information recording module 6 is unidirectionally connected to the early warning module 7. It triggers the early warning function of the early warning module 7 using the waveform information in the extracted abnormal operation information waveform signal. The early warning module 7 issues an early warning of electrical equipment defects, reminding the operators to handle them in a timely manner.

[0093] The defect information recording module 6 is also unidirectionally connected to the secondary calculation and judgment module 10, and is used to transmit the waveform signal recorded by the waveform recorder 8, so that the secondary calculation and judgment module 10 can recalculate and judge the waveform signal obtained by the waveform recorder, and feed back the calculation and judgment results to the output module 5.

[0094] In addition to being connected to the output module 5 and the defect information recording module 6 as described above, the secondary calculation and judgment module 10 is also unidirectionally connected to the information classification module 2 and the storage module 4. It is used to obtain the types of overvoltage protection measures configured in the information classification module 2, extract the pre-stored algorithms in the storage module 4, and transmit the unreasonable information after final calculation and judgment to the output module 5. The output module 5 outputs the unreasonable information and transmits it to the defect information recording module 6 for recording.

[0095] The warning module 7 is unidirectionally connected to the output module 5 and is used to feed back the warning information to the output module 5, and display the output result with the help of a visualization device 9 connected to the output module 5.

[0096] The waveform recorder 8 has a sampling channel of no less than 8 channels, with multiple channels acquiring data simultaneously, and the sampling rate of each channel is no less than 10M / s.

Claims

1. An operational overvoltage early warning method that associates the operation status of surge arresters and circuit breakers, relying on an electrical equipment early warning protection system based on operational data to realize the early warning of overvoltage in substations, the electrical equipment early warning protection system based on operational data is referred to as the protection system, the protection system includes an operational information extraction module (1), an information classification module (2), a calculation and judgment module (3), a storage module (4), an output module (5), a defect information recording module (6), an early warning prompt module (7), a waveform recorder (8), and a secondary calculation and judgment module (10); Its features are, The operational overvoltage early warning method includes the following steps: Step 1: Obtain and classify the action information of the surge arrester. The surge arrester that has taken action is called the action surge arrester. When the number of discharges recorded by the counter of the action surge arrester increases by one, the local digitization device built into the action surge arrester itself obtains the number of actions of the counter and transmits the number of actions to the operation information extraction module (1). After the operation information extraction module (1) starts and obtains the operation information of the electrical equipment, it transmits the number of actions and the action time T of the counter recorded by the protection system to the information classification module (2). The information classification module (2) obtains the equipment information related to the operation arrester from the operation information of the electrical equipment and classifies it. Step 2: Match and obtain the operating circuit breakers and associated devices. The circuit breaker that is electrically connected to the operating surge arrester is called the associated circuit breaker, and the electrical equipment connected to the end of the associated circuit breaker is called the associated equipment. Step 2.1, the calculation and judgment module (3) uses the equipment information classification result transmitted by the information classification module (2) to call the state matching method in the storage module (4) to select the associated circuit breaker and associated equipment. Assume that after this step, N associated circuit breakers are obtained; N≥1; Step 2.2, define time period T1, T1 = [T-T0, T], where T0 is the buffer time, T0 = 2Y, and Y is the rigid opening time of the circuit breaker; the judgment module (3) judges whether there is an action in each of the N associated circuit breakers within the time period T1. If the associated circuit breaker has an action, the associated circuit breaker with the action is recorded as the action circuit breaker, and the action status of the action circuit breaker is recorded as 1; if there is no action, the action status of the associated circuit breaker is recorded as 0. Step 3: Determine the type of operation of the surge arrester. If the operating status of N associated circuit breakers is 0, that is, no circuit breaker operates in the substation during time period T1, the operation type is defined as "lightning overvoltage" or "temporary overvoltage" and recorded as type I; the calculation and judgment module (3) outputs the judgment result through the output module (5) and records it through the defect information recording module (6), and then triggers the early warning prompt module (7) to issue an early warning to prompt the operation and maintenance personnel to verify the lightning weather, external faults of the substation and the operation status of the opposite substation; this early warning operation ends; If any one of the N associated circuit breakers has an operating state of 1, that is, there is an operating circuit breaker in the substation during the time period T1, the operating type is defined as "operational overvoltage" and recorded as type II; the calculation and judgment module (3) transmits the judgment result to the defect information recording module (6) through the output module (5) and proceeds to step 4; Step 4: Determine if there is any abnormal operating information from the circuit breaker. The abnormal operation information includes the historical abnormal operation information of the circuit breaker and the current abnormal operation information that occurred within the time period T1; the historical abnormal operation information is retrieved and extracted by the defect information recording module (6) and sent to the secondary calculation and judgment module (10); The determination of this abnormal operation information is as follows: The defect information recording module (6) acquires the three-phase phase voltage waveform signals ua(t), ub(t), and uc(t) of the bus connected to the circuit breaker within the time period T1, and feeds the three-phase phase voltage waveform signals ua(t), ub(t), and uc(t) back to the secondary calculation and judgment module (10); where t is any moment in an operation process within the time period T1, and the operation process is a process from the time period T1 when the corresponding relay protection device of the electrical equipment issues a circuit breaker trip command until its voltage value drops to zero; The secondary calculation and judgment module (10) calls the overvoltage diagnosis method and criterion value based on waveform characteristics from the storage module (4) and performs calculation and judgment. Specifically, it obtains the total number of high-frequency segments based on the three-phase phase voltage waveform signals ua(t), ub(t), and uc(t), and calculates the phase overvoltage multiple and phase-to-phase overvoltage multiple of the circuit breaker. Then, it compares the above results with the given criterion value. If the above results are not within the reasonable range set by the criterion value, they are recorded as unreasonable information, and the set of all unreasonable information is recorded as the abnormal operation information for this operation. If the above results are within the reasonable range set by the criterion value, there is no abnormal operation information in the judgment and calculation results for this operation. Wherein, the total number of high-frequency segments is the total number of frequency segments with a frequency value greater than 5000Hz in the three-phase phase voltage waveform during an operation; Step 5, Identify the warning information If no abnormal operation information is found for this instance, the surge arrester is deemed to have operated correctly and no warning is required. If abnormal operation information exists, determine the type of warning for this operation. Specifically: if the phase overvoltage multiple of the circuit breaker is determined to be unreasonable, the result is that a phase overvoltage warning is required; if the phase-to-phase overvoltage multiple of the circuit breaker is determined to be unreasonable, the result is that a phase-to-phase overvoltage warning is required. After the secondary calculation and judgment module (10) obtains the historical abnormal operation information of the action arrester, it judges whether there is a situation where the total number of high-frequency segments of the action circuit breaker is judged as unreasonable information. If so, the judgment result is that the action circuit breaker may reignite / reignite. Step 6: Issue an overvoltage warning message. The secondary calculation and judgment module (10) feeds back the early warning information to the defect information recording module (6). The defect information recording module (6) obtains the historical abnormal operation information of the associated equipment through the information of the associated equipment, and transmits the historical abnormal operation information of the associated equipment and the early warning information obtained in step 5 to the early warning prompt module (7) together, so as to prompt the operation and maintenance personnel to take timely measures to prevent the associated equipment from being damaged again, based on the historical operation status of the associated equipment and the current early warning information.

2. The method for early warning of operating overvoltage related to the operation of surge arresters and circuit breakers according to claim 1, characterized in that, The operation information extraction module (1) is connected to the substation information operation system and is used to extract operation information of various electrical equipment from the substation operation information system. The operation information extraction module (1) is connected to the information classification module (2) in a one-way manner and is used to transmit the obtained operation information to the information classification module (2). The information classification module (2) is unidirectionally connected to the operation information extraction module (1) and the calculation and judgment module (3) respectively. It is used to receive operation information, classify the operation information according to the type of electrical equipment that needs to be protected by early warning, and transmit the classified operation information to the calculation and judgment module (3). The storage module (4) has built-in pre-stored information, which includes pre-stored data and pre-stored judgment methods; the pre-stored data includes the initial values, judgment values ​​and early warning activation values ​​of various electrical equipment; The calculation and judgment module (3) is unidirectionally electrically connected to the storage module (4) and is used to extract pre-stored data and pre-stored judgment methods from the storage module (4); the calculation and judgment module (3) is unidirectionally connected to the output module (5) and is used to perform calculations and judgments based on the operating information extracted by the information classification module (2), the pre-stored data extracted by the storage module (4), and the pre-stored judgment methods to obtain abnormal operating information of the electrical equipment and transmit the abnormal operating information to the output module (5); The output module (5) is unidirectionally connected to the calculation and judgment module (3), the secondary calculation and judgment module (10), and the defect information recording module (6), respectively, and receives the abnormal operation information transmitted by the calculation and judgment module (3), the calculation and judgment results of the secondary calculation and judgment module (10), and transmits the abnormal operation information to the defect information recording module (6). The defect information recording module (6) is bidirectionally connected to the waveform recorder (8). It triggers the waveform recorder (8) with the currently received abnormal operation information, and then receives the abnormal operation information waveform signal returned by the waveform recorder (8), and extracts and records the waveform information in the abnormal operation information waveform signal. The defect information recording module (6) is unidirectionally connected to the early warning module (7). The early warning module (7) is triggered by the waveform information in the extracted abnormal operation information waveform signal. The early warning module (7) issues an early warning of electrical equipment defects to remind the operators to handle them in a timely manner. The defect information recording module (6) is also unidirectionally connected to the secondary calculation and judgment module (10) to transmit the waveform signal recorded by the waveform recorder (8) so that the secondary calculation and judgment module (10) can recalculate and judge the waveform signal obtained by the waveform recorder and feed back the calculation and judgment results to the output module (5). In addition to being connected to the output module (5) and the defect information recording module (6) as described above, the secondary calculation and judgment module (10) is also unidirectionally connected to the information classification module (2) and the storage module (4). It is used to obtain the types of overvoltage protection measures configured in the information classification module (2), extract the pre-stored algorithms in the storage module (4), and transmit the unreasonable information after final calculation and judgment to the output module (5). The output module (5) outputs and transmits the unreasonable information to the defect information recording module (6) for recording. The warning prompt module (7) is unidirectionally connected to the output module (5) and is used to feed back the warning information to the output module (5) and display the output result through a visualization device (9) connected to the output module (5). The waveform recorder (8) has a sampling channel of no less than 8 channels, with multiple channels acquiring data synchronously, and the sampling rate of each channel is no less than 10M / s.

3. The method for early warning of operating overvoltage related to the operation of surge arresters and circuit breakers according to claim 1, characterized in that, The local digitization device mentioned in step 1 is a device that converts the analog signal generated by the surge arrester counter into a digital signal and transmits it to the substation information operation system via a wireless transceiver.

4. The method for early warning of operational overvoltage related to the operation of surge arresters and circuit breakers according to claim 1, characterized in that, The question of whether the associated circuit breaker is in operation, as mentioned in step 2, refers to the action of the circuit breaker changing from closed to open.

5. The method for early warning of operating overvoltage related to the operation of surge arresters and circuit breakers according to claim 1, characterized in that, The criterion value mentioned in step 4 is: If the phase overvoltage multiple is greater than or equal to 4, the overvoltage protection measures are deemed to be improperly configured. If the phase-to-phase overvoltage multiple is greater than 5.6, the phase-to-phase overvoltage protection measures are deemed to be improperly configured. If the total number of high-frequency segments is greater than 1, it is determined that the circuit breaker will experience reignition or re-ignition.

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