An integrated surge arrester device for a pole-mounted switch

Abstract

The present application relates to power distribution network overvoltage protection technical field, especially to a kind of integrated lightning arrester device for pole-mounted switch, device is determined whether to collect data by early warning module collection atmospheric data;Identification module determines predicted intensity and predicted incident direction by atmospheric data;Data processing module collects and pre-processes data;Bushing prediction module determines target time based on predicted intensity and predicted incident direction;Adjustment determination module determines actual opening time based on pre-tightening force and target opening time;Correction control module determines the remaining duration of adjustment pulse based on ripple frequency, and determines the adjustment amount of pulse remaining duration based on opening speed.The present application solves the problem of lightning stroke opening deviation and opening dynamic parameter misalignment by real-time monitoring of atmospheric electric field and correcting opening time, avoids equipment failure caused by overloading of opening coil and contact opening out of position, significantly improves the operation safety and equipment life of pole-mounted switch.

Description

Technical Field

[0001] This invention relates to the field of overvoltage protection technology for power distribution networks, and in particular to an integrated surge arrester device for pole-mounted switches. Background Technology

[0002] Pole-mounted switches are switching devices used to close, carry, and interrupt normal load currents. To prevent damage to pole-mounted switches from lightning overvoltages or switching overvoltages, surge arresters should be installed. Currently, the configuration of pole-mounted switches and surge arresters mainly adopts a split or external structure, but this has the following technical defects: the conductor between the surge arrester and the pole-mounted switch is too long, and the conductor is prone to additional residual voltage; the surge arrester's volt-ampere characteristics deviate due to long-term exposure to lightning strikes or moisture; the surge arrester and its conductors are exposed outdoors for a long time, resulting in increased surface leakage current and even surface flashover.

[0003] Chinese patent application publication number CN115831512A discloses an integrated multi-functional intelligent surge arrester. The related technical solution includes a shell and a core assembly. The core assembly includes an upper electrode, a resistor, an adjusting aluminum rod, and a lower electrode. Multiple temperature sensing probes and a temperature control data transmission belt are fixed to the core assembly by a winding tape. At the same time, a module mounting cavity is integrated on the shell. The module mounting cavity integrates a data processing center and a power storage device. The data processing center includes temperature collection modules for each area, leakage current detection modules, action count monitoring modules, and data aggregation and transmission modules.

[0004] However, the data processing center in the above technical solutions is susceptible to strong electromagnetic interference caused by lightning strikes, which may lead to data acquisition errors or communication interruptions; all of them adopt a uniform tripping strategy, which results in untimely tripping during strong lightning strikes and excessive action during weak lightning strikes; the mechanical state parameters of the pole-mounted switch are not considered, and the tripping delay caused by switch aging cannot be compensated.

[0005] Therefore, there is an urgent need for an integrated surge arrester device for pole-mounted switches that determines the tripping time based on the predicted lightning strike intensity and direction, and dynamically adjusts and corrects the tripping pulse duration based on the switch's mechanical state and the arc characteristics during the tripping process to obtain the energizing time of the tripping coil. This allows the switch contacts to begin separating before the lightning current peak arrives, thus providing an insulation gap and further protecting the pole-mounted switch. Summary of the Invention

[0006] To address this issue, the present invention provides an integrated surge arrester device for pole-mounted switches, which overcomes the problem in the prior art where the lack of prediction of lightning intensity and direction leads to the inability to adapt the tripping time to different lightning strike conditions, thereby affecting the accuracy of the tripping timing and causing the pole-mounted switch to be easily damaged by lightning strikes and shortening the service life of the tripping mechanism during actual operation.

[0007] To achieve the above objectives, the present invention provides an integrated surge arrester device for pole-mounted switches, comprising: The early warning module is used to collect atmospheric electric field intensity and atmospheric electric field three-dimensional components based on the first preset collection time window, and to determine whether to collect the original data of the pole switch based on the atmospheric electric field intensity and the preset atmospheric electric field intensity. The identification module is used to determine the predicted lightning intensity and the predicted lightning incident direction based on the three-dimensional components of the atmospheric electric field. The data processing module is used to read the raw data based on the second preset acquisition time window and perform preprocessing to obtain a data packet, wherein the data packet includes the contact spring preload, arc voltage ripple frequency and opening speed. The tripping prediction module is used to determine the target tripping time of the pole-mounted switch during a lightning strike based on the lightning strike prediction intensity and the lightning strike prediction incident direction. The adjustment judgment module is used to determine the compensation time of the pole-mounted switch based on the preload of the contact spring, and to determine the actual opening time based on the compensation time and the target opening time. The correction and control module is used to determine whether to adjust the remaining duration of the opening pulse based on the arc voltage ripple frequency and the preset arc voltage ripple frequency during the opening process, and to determine the adjustment amount of the remaining duration of the opening pulse based on the opening speed and the preset opening speed.

[0008] Furthermore, the adjustment determination module includes: The compensation time determination unit is used to collect the current ambient humidity and determine the compensation time amount by combining it with the preload of the contact spring. A time correction unit is used to determine the actual opening time based on the difference between the target opening time and the compensation time.

[0009] Furthermore, the correction and control module includes: An arc comparison unit is used to determine the remaining duration of the tripping pulse based on the fact that the arc voltage ripple frequency is greater than the preset arc voltage ripple frequency. A primary adjustment unit is used to determine to shorten the remaining duration of the tripping pulse based on the tripping speed being greater than or equal to the preset tripping speed, or to determine to extend the remaining duration of the tripping pulse based on the tripping speed being less than the preset tripping speed.

[0010] Furthermore, the primary adjustment unit is also used to determine the extension range of the remaining duration of the tripping pulse based on the tripping speed difference and the preset tripping speed difference, wherein the extension range is positively correlated with the tripping speed difference.

[0011] Furthermore, the primary adjustment unit is also used to determine the reduction range of the remaining duration of the tripping pulse based on the tripping speed offset value and the preset tripping speed offset value, wherein the reduction range is positively correlated with the tripping speed offset value.

[0012] Furthermore, the correction and control module also includes: The energizing duration determination unit is used to determine the energizing duration of the tripping coil based on the actual tripping time and the adjusted tripping pulse duration. A secondary adjustment unit is used to determine the duration of the shortened tripping pulse based on the fact that the energizing duration is greater than the preset energizing duration.

[0013] Furthermore, the secondary adjustment unit is used to determine the reduction range of the adjusted tripping pulse duration based on the difference between the energizing duration and the preset difference between the energizing duration, and the reduction range is positively correlated with the difference between the energizing duration.

[0014] Furthermore, the early warning module includes: An electric field comparison unit is used to determine the acquisition of the original data based on the atmospheric electric field strength being greater than or equal to the preset atmospheric electric field strength. The verification unit is used to collect the space potential and determine to shorten the first preset collection time window based on the space potential being greater than or equal to a preset space potential.

[0015] Furthermore, the tripping prediction module includes: The time window calculation unit is used to determine the predicted arrival time of the lightning strike based on the predicted lightning strike intensity, and to determine the tripping time compensation coefficient based on the predicted incident direction of the lightning strike. The tripping time determination unit is used to determine the target tripping time based on the predicted lightning strike arrival time and the tripping time compensation coefficient.

[0016] Furthermore, the identification module includes: An intensity calculation unit is used to perform inversion calculations based on the three-dimensional components of the atmospheric electric field to obtain the proportion of high charge density regions, so as to determine the lightning strike prediction intensity. The proportion of high charge density regions is positively correlated with the lightning strike prediction intensity. The direction calculation unit is used to establish a spatial rectangular coordinate system, extract the horizontal component of the three-dimensional components of the atmospheric electric field, and calculate the direction angle based on the horizontal component to determine the predicted incident direction of the lightning strike.

[0017] Compared with existing technologies, the beneficial effects of this invention are as follows: It determines whether to collect the original data of the pole-mounted switch based on the atmospheric electric field strength, extracts the three-dimensional components from the original data to determine the predicted lightning strike intensity and predicted incident direction, determines the target opening time of the pole-mounted switch based on the predicted lightning strike intensity and predicted incident direction, determines the compensation time of the pole-mounted switch through the contact spring preload, comprehensively determines the actual opening time, determines whether to adjust the remaining duration of the opening pulse based on the arc voltage ripple frequency, and determines the adjustment amount of the remaining duration of the opening pulse based on the opening speed. This avoids the independent configuration and lack of coordinated control of the surge arrester and pole-mounted switch in traditional solutions, which leads to late switch opening and failure of the contacts to form an effective insulation gap before the peak lightning current during strong lightning strikes, and frequent malfunctions during weak lightning strikes, causing mechanical wear and coil burnout. Therefore, it significantly improves the protection capability and operational reliability of the pole-mounted switch in lightning environments.

[0018] Furthermore, the present invention determines the compensation time based on the current ambient humidity and the preload of the contact spring, and determines the actual opening time based on the difference between the target opening time and the compensation time. The compensation time is determined by the mechanical aging degree and the current operating conditions, and the target opening time is corrected to ensure that the pole-mounted switch can open on time in both the working cycle and extreme environments.

[0019] Furthermore, this invention determines the remaining duration of the tripping pulse based on a comparison of the arc voltage ripple frequency being greater than a preset frequency, and adjusts the remaining duration of the tripping pulse in a timely manner to change the contact separation speed, thereby preventing contact surface ablation or welding. It also avoids frequent pulse adjustments under normal operating conditions, which could affect the stability of the tripping process and reduce unnecessary system intervention. Furthermore, based on a comparison of the tripping speed and the preset tripping speed, the invention determines the adjustment direction corresponding to the remaining duration of the tripping pulse. This shortens the remaining duration of the pulse when the speed is too high to prevent mechanical impact, and extends the remaining duration of the pulse when the speed is too low to ensure proper tripping, further improving the safety and reliability of the tripping process.

[0020] Furthermore, the present invention also determines the shortening range of the remaining duration of the tripping pulse by the tripping speed offset value to reduce the contact collision energy, and determines the extension range of the remaining duration of the tripping pulse based on the tripping speed difference to enhance the driving force of the tripping electromagnet; and through a graded control mechanism, the pulse adjustment amplitude is positively correlated with the speed deviation, realizing fine control of the tripping process, that is, small adjustment when the deviation is small to avoid over-adjustment, and large adjustment when the deviation is large to ensure effectiveness, thereby taking into account both the accuracy and safety of the adjustment process.

[0021] Furthermore, the present invention determines the energizing time of the tripping coil by the actual tripping time and the adjusted tripping pulse duration, and determines to shorten the tripping pulse duration based on the comparison result with the preset energizing time, so as to avoid the coil burning out due to excessive energizing time, which would prevent the pole-mounted switch from disconnecting when lightning strikes, resulting in contact welding; at the same time, the reduction of the adjusted tripping pulse duration is determined based on the difference in energizing time, so as to prevent the coil from overheating and burning out to the greatest extent while ensuring the reliability of tripping.

[0022] Furthermore, this invention also determines the raw data to be collected by comparing the atmospheric electric field strength with or without a preset atmospheric electric field strength, thus avoiding the collection and storage of a large amount of redundant data when there is no lightning strike, thereby reducing the energy consumption of the device. It also avoids the accidental start of data collection due to occasional electric field fluctuations, ensuring that the circuit breaker tripping process is only carried out under lightning strike conditions. Based on the comparison result of the space potential being greater than or equal to a preset space potential, the first preset acquisition time window is dynamically shortened to achieve adaptive adjustment of the acquisition frequency, ensuring that the device can timely obtain the rising rate of the electric field strength, providing sufficient response time for subsequent raw data acquisition and circuit breaker tripping operations.

[0023] Furthermore, this invention determines the predicted arrival time of lightning strikes based on the predicted lightning strike intensity, ensuring a positive correlation between the target tripping time and the predicted lightning strike intensity, thus avoiding tripping too early or too late. It also corrects the tripping time compensation coefficient by adjusting the predicted lightning strike incident direction, avoiding the inability to adapt to different lightning strike directions due to a uniform tripping time compensation coefficient. Finally, it determines the target tripping time based on the predicted lightning strike arrival time and the tripping time compensation coefficient, preventing the target tripping time determined solely by intensity or direction from failing to match strong / weak lightning strikes and positive / lateral lightning conditions, while providing a benchmark for subsequently determining the actual tripping time.

[0024] Furthermore, the present invention determines the predicted lightning intensity and the predicted lightning incident direction based on the three-dimensional components of the atmospheric electric field. By performing different data processing on the same electric field data, the amount of data processing is reduced. At the same time, the data processing processes are independent of each other, and parameter adjustments or error fluctuations in a single data processing process will not affect the processing results of another data, thereby improving the fault tolerance of the device. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the integrated surge arrester device for pole-mounted switches in an embodiment of the present invention; Figure 2 This is a block diagram of the control box in an embodiment of the present invention; Figure 3 This is a flowchart illustrating the logic of determining and adjusting the first preset acquisition time window based on the space potential voltage value in an embodiment of the present invention. Figure 4This is a flowchart illustrating the logic of determining the duration of the tripping pulse based on the tripping speed in an embodiment of the present invention. In the diagram, 1 is a pole-mounted switch, 2 is a surge arrester, and 3 is a control box. Detailed Implementation

[0026] 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.

[0027] 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.

[0028] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0029] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] Specifically, during a severe thunderstorm, the lightning current amplitude may exceed the nominal discharge current of the surge arrester, preventing it from completely diverting the lightning current to the ground. This results in residual lightning voltage being applied to the parallel pole-mounted switch 1, causing insulation damage. To address this scenario, the surge arrester device of this invention predicts lightning strikes in advance and actively controls the pole-mounted switch to trip, utilizing the high insulation strength of the tripping contact to withstand the residual voltage and prevent damage to the pole-mounted switch.

[0031] Please see Figure 1 The diagram shown is a structural schematic of an integrated surge arrester device for a pole-mounted switch in an embodiment of the present invention. Please refer to [link / reference]. Figure 2 As shown, it is a block diagram of the control box in an embodiment of the present invention.

[0032] In this embodiment, the device includes a pole-mounted switch 1, a surge arrester 2, and a control box 3. The control box 3 includes an early warning module, an identification module, a data processing module, a tripping prediction module, an adjustment judgment module, and a correction and control module. These modules are all integrated on the same circuit board within the control box 3, and the modules are electrically connected and interact with each other via printed circuits on the circuit board. The control box 3 is connected to the operating mechanism of the pole-mounted switch 1 via a multi-core shielded cable, used to send tripping commands to the pole-mounted switch 1 and receive real-time monitoring data. In this embodiment, the multi-core shielded cable can be exemplarily set to 4m.

[0033] In this embodiment, the early warning module is used to collect atmospheric electric field intensity and atmospheric electric field three-dimensional components based on a first preset collection time window, and to determine whether to collect the original data of the pole switch based on the atmospheric electric field intensity and the preset atmospheric electric field intensity. The early warning module includes an atmospheric data acquisition unit, an electric field comparison unit, and a verification unit.

[0034] Specifically, the surge arrester 2 has an independent electric field detection electrode on its top, which is fixed to the surge arrester by an insulating bracket. The electrode lead is connected to the input terminal of the warning module circuit board in the control box 3 via a shielded wire.

[0035] When a thundercloud approaches, the charge carried by the thundercloud generates a strong electric field in the surrounding space. When an independent electric field detection electrode is placed in a strong electric field, electrostatic induction occurs, causing induced charges to accumulate on the electrode surface. The induced charges create a potential difference between the independent electric field detection electrode and the ground, which is the space potential.

[0036] The space potential is stepped down by a voltage divider circuit and converted into an analog voltage signal of 0-5V, which is then input to the verification unit. The verification unit reads the space potential voltage value of the analog voltage signal and presets a space potential voltage value. Based on the comparison result with the space potential voltage value, it determines whether to shorten the first preset acquisition time window.

[0037] Please see Figure 3 As shown, it is a flowchart of the logic of determining and adjusting the first preset acquisition time window based on the space potential voltage value in an embodiment of the present invention.

[0038] In one specific embodiment, if the space potential voltage value is greater than or equal to the preset space potential voltage value, it indicates that the current space potential has exceeded the safe level and there is a risk of a rapid increase in the atmospheric electric field strength.

[0039] Therefore, the first preset acquisition time window was shortened to ensure timely capture of changes in electric field characteristics before a lightning strike.

[0040] The verification unit determines the shortened first preset acquisition time window based on the product of the initial first preset acquisition time window and the time reduction coefficient. The time reduction coefficient is the ratio of the preset space potential voltage value to the space potential voltage value; the first preset acquisition time window can be set to 100ms for example.

[0041] It should be noted that the larger the space potential voltage value and the smaller the time reduction coefficient, the greater the degree to which the current space potential exceeds the safety threshold, meaning the thundercloud is closer and the risk of lightning strike is higher. To prevent the pole-mounted switch from being damaged by lightning overvoltage, the tripping action must be completed before the lightning strike occurs. Therefore, it is necessary to collect electric field data at a higher frequency, that is, to further shorten the first preset acquisition time window.

[0042] In one specific embodiment, if the space potential voltage value is less than the preset space potential voltage value, it indicates that the current space potential is at a safe level, the thundercloud is far away, and the probability of a sudden change in the atmospheric electric field intensity is low.

[0043] Therefore, it is determined not to adjust the first preset acquisition time window.

[0044] Specifically, the preset space potential voltage value is determined based on the stability benchmark of space potential under standard thunderstorm activity background when there is no triggering acquisition requirement and the background electric field is undisturbed: under the premise that the environmental electric field conditions and the operating status of the detection electrode remain stable, standard batch samples that have been confirmed to have no nearby ground flashes and normal historical waveforms are collected. The mean value of space potential voltage and the standard deviation of potential fluctuation are continuously calculated by the early warning module, and the sum of the two is taken as the preset space potential voltage value, which can be set to 2.5V for example.

[0045] Furthermore, the atmospheric data acquisition unit acquires the atmospheric electric field intensity and the three-dimensional components (Dx, Dy, Dz) of the atmospheric electric field based on a first preset acquisition time window. In this embodiment, the first preset acquisition time window is determined based on the response timeliness of the lightning warning and can be set to 100ms for example.

[0046] In one specific embodiment, if the atmospheric electric field strength is greater than or equal to the preset atmospheric electric field strength, it indicates that the current atmospheric electric field strength has exceeded the safety threshold and there is a risk of lightning strike. Therefore, it is necessary to implement circuit breaker protection before the lightning strike occurs.

[0047] Therefore, the electric field comparison unit triggers the acquisition of raw data from the pole-mounted switch.

[0048] In one specific embodiment, if the atmospheric electric field strength is less than the preset atmospheric electric field strength, it indicates that the current atmospheric electric field strength is within the safe threshold range, there is no risk of lightning strike, and there is no need to perform trip protection.

[0049] Therefore, it was decided not to collect the raw data from the pole-mounted switch.

[0050] Specifically, the preset atmospheric electric field strength is determined based on the general warning threshold used in the lightning warning engineering application of the power industry, and the preset atmospheric electric field strength can be set to 5kV / m for example.

[0051] In this embodiment, the identification module is connected to the early warning module, and is used to determine the predicted lightning intensity and the predicted lightning incident direction based on the three-dimensional components of the atmospheric electric field; wherein, the identification module includes an intensity calculation unit and a direction calculation unit.

[0052] Furthermore, the intensity calculation unit obtains the three-dimensional components (Dx, Dy, Dz) of the atmospheric electric field through the early warning module. These components represent the atmospheric electric field values ​​in the horizontal X, horizontal Y, and vertical Z directions, respectively, and are used to characterize the electric field intensity and direction generated by the thundercloud charge in space. In this embodiment, the horizontal X direction can be exemplarily set as the east-west direction, the horizontal Y direction can be exemplarily set as the north-south direction, and the vertical Z direction can be exemplarily set as perpendicular to the ground, with upward as the positive direction.

[0053] Furthermore, the intensity calculation unit divides the monitoring space into several grid cells, and calculates the charge density in each grid cell by least squares inversion based on the three-dimensional components (Dx, Dy, Dz) of the atmospheric electric field. A preset charge density is set in advance, and the corresponding grid cell is determined to be a high charge density region based on the comparison result with the charge density.

[0054] In one specific embodiment, if the charge density is greater than or equal to the preset charge density, it indicates that the charge density of the current grid cell has exceeded the normal range that can be reached under the condition of no lightning strike, and there is abnormal charge accumulation caused by the accumulation of thundercloud charge, which meets the charge conditions for forming a lightning discharge.

[0055] Therefore, the corresponding grid cell was identified as a high charge density region, i.e., the core area where charge accumulates in the thundercloud.

[0056] In one specific embodiment, if the charge density is less than the preset charge density, it indicates that the charge density of the current grid cell is within the normal fluctuation range under lightning-free conditions, there is no abnormal accumulation caused by thundercloud charge, and the charge conditions for forming a lightning discharge are not met.

[0057] Therefore, the corresponding grid cell is determined to be a region with low charge density.

[0058] Specifically, the preset charge density is determined based on the maximum absolute error of the inversion algorithm under ideal no-charge conditions: Under zero space charge density, the identification module performs continuous inversion calculations on standard batches of samples with known zero charge density to obtain a sequence of absolute values ​​of the charge density inversion error, and takes the maximum value as the upper limit of the error. Since the inversion result must be greater than zero when the actual charge density is greater than the upper limit of the error, it can be determined that a real charge exists; to eliminate random fluctuations, the upper limit of the error is taken as the preset charge density, which can be set to 0.5 μC / m³ for example.

[0059] The calculation of the proportion of high charge density areas is the ratio of all high charge density areas in the monitoring space to the total number of grid units, in order to reflect the spatial density of the charge accumulation area of ​​thunderclouds.

[0060] Furthermore, the direction calculation unit pre-sets a preset high charge density region proportion and compares it with the high charge density region proportion, and then determines the lightning strike prediction intensity based on the comparison result. The preset high charge density region proportion can be divided into a first preset high charge density region proportion and a second preset high charge density region proportion.

[0061] In one specific embodiment, if the proportion of high charge density region is less than or equal to the first preset high charge density region proportion, the lightning strike prediction intensity is determined to be 10kA; if the proportion of high charge density region is greater than the first preset high charge density region proportion and less than or equal to the second preset high charge density region proportion, the lightning strike prediction intensity is determined to be 30kA; if the proportion of high charge density region is greater than the second preset high charge density region proportion, the lightning strike prediction intensity is determined to be 60kA.

[0062] Specifically, the preset high charge density region proportion is based on statistical calibration of samples of lightning strikes of different intensities during thunderstorms: atmospheric electric field inversion data were collected before 10kA, 30kA, and 60kA lightning strikes occurred, and the high charge density region proportion at the corresponding time of each event was calculated to form a sample set for each intensity level. The 50th percentile of each sample set was taken as the preset value for the corresponding lightning strike prediction intensity. For example, the first preset high charge density region proportion corresponding to 10kA was set to 0.02, and the second preset high charge density region proportion corresponding to 30kA was set to 0.05. If it is greater than 0.05, it is determined to be a 60kA lightning strike prediction intensity.

[0063] It should be noted that high charge density areas correspond to the core areas of charge accumulation in thunderclouds. The larger the proportion of high charge density areas, the denser and wider the charge accumulation area within the monitoring space, and the greater the total charge accumulated in the thundercloud. The total charge of a thundercloud is a key factor determining the amplitude and energy of the lightning current during a lightning discharge. The greater the total charge, the higher the lightning current amplitude and the greater the discharge energy, and the higher the potential risk of damage to pole-mounted switches. Therefore, a greater lightning strike intensity is required for accurate lightning strike prediction.

[0064] Furthermore, the direction calculation unit establishes a spatial rectangular coordinate system and extracts the horizontal components Dx and Dy from the three-dimensional components (Dx, Dy, Dz) of the atmospheric electric field. The horizontal azimuth angle θ is the arctangent of the ratio of Dy to Dx. Quadrant determination and angle correction are performed based on the signs of Dx and Dy. Specifically: if Dx > 0 and Dy ≥ 0, then θ equals the arctangent; if Dx < 0, then θ equals the arctangent plus 180°; if Dx > 0 and Dy < 0, then θ equals the arctangent plus 360°; if Dx = 0 and Dy > 0, then θ is 90°; if Dx = 0 and Dy < 0, then θ is 270°.

[0065] The azimuth angle θ is used to characterize the horizontal direction of the three-dimensional components D(Dx,Dy,Dz) of the atmospheric electric field. Since the horizontal direction of the three-dimensional components (Dx,Dy,Dz) of the atmospheric electric field is the projection position of the thundercloud charge center on the horizontal plane, θ is the predicted incident direction of the lightning strike. In this embodiment, the value range of θ can be set to 0° to 360°, that is, 0° for due east, 90° for due north, 180° for due west, and 270° for due south.

[0066] In this embodiment, the data processing module is connected to the identification module and is used to read the raw data based on the second preset acquisition time window and perform preprocessing to obtain a data packet. The data packet includes the contact spring preload, arc voltage ripple frequency, and tripping speed. The data processing module includes a data acquisition unit, a data cleaning unit, a timing alignment unit, and a data packet encapsulation unit. Specifically, the determination of the second preset acquisition time window is related to the lightning strike prediction intensity, which characterizes the total charge accumulated in the thundercloud. The greater the charge, the stronger the atmospheric electric field generated by the thundercloud, and the shorter the time required for the atmospheric electric field intensity to rise from below the preset atmospheric electric field intensity to reach or exceed the preset atmospheric electric field intensity. In order to ensure that the pole-mounted switch can be tripped before the lightning strike occurs, the original data must be read in a shorter time. Therefore, the greater the lightning strike prediction intensity, the shorter the second preset acquisition time window.

[0067] Furthermore, a preset lightning strike prediction intensity is pre-set through the data processing module and compared with the lightning strike prediction intensity. Based on the comparison result, a second preset acquisition time window is determined. The preset lightning strike prediction intensity can be divided into a first preset lightning strike prediction intensity of 10kA, a second preset lightning strike prediction intensity of 30kA, and a third preset lightning strike prediction intensity of 60kA.

[0068] In this embodiment, if the predicted lightning strike intensity is less than or equal to 10kA, the second preset acquisition time window is set to 50ms; if the predicted lightning strike intensity is greater than 10kA and less than or equal to 30kA, the second preset acquisition time window is set to 40ms; if the predicted lightning strike intensity is greater than 30kA and less than or equal to 60kA, the second preset acquisition time window is set to 35ms; and if the predicted lightning strike intensity is greater than 60kA, the second preset acquisition time window is set to 30ms.

[0069] Specifically, the preset lightning strike prediction intensity is determined based on the rated impulse withstand voltage of the pole-mounted switch and the corresponding critical breakdown lightning current amplitude: the upper limit of the lightning current amplitude that the switch can withstand is obtained through type testing, which is usually no more than 10kA. For example, the upper limit of the lightning current amplitude can be used as the first preset lightning strike prediction intensity, and 3 times the upper limit of the lightning current amplitude and 6 times the upper limit of the lightning current amplitude are used as the corresponding second and third preset lightning strike prediction intensities.

[0070] The lightning current energy is proportional to the square of the upper limit of the lightning current amplitude. Therefore, a lightning strike energy corresponding to 3 times the upper limit of the lightning current amplitude is 9 times the critical energy, and a lightning strike energy corresponding to 6 times the upper limit of the lightning current amplitude is 36 times the critical energy, which can represent significantly enhanced risk levels. For example, the second preset lightning strike prediction intensity is 30kA, and the third preset lightning strike prediction intensity is 60kA.

[0071] Furthermore, the data acquisition unit reads the contact spring preload, arc voltage ripple frequency, and opening speed collected by the corresponding sensor installed at the pole switch 1 based on the second preset acquisition time window, and transmits the above data to the data cleaning unit.

[0072] Furthermore, the data cleaning unit removes abnormal jump values ​​generated during the acquisition process and marks missing data points; the time alignment unit aligns the data from each sensor according to the acquisition time; and the data packet encapsulation unit assembles the cleaned and aligned data into a data packet with a unified format.

[0073] In this embodiment, the trip prediction module is connected to the data processing module, which is used to determine the target tripping time of the pole-mounted switch during a lightning strike based on the predicted lightning intensity and the predicted lightning incident direction. The trip prediction module includes a time window calculation unit and a tripping time determination unit. The trip prediction module circuit board is fixed on the aluminum alloy heat sink at the bottom of the surge arrester, and the identification module circuit board and the data processing module circuit board are connected to the trip prediction module circuit board via ribbon cables.

[0074] In this embodiment, the time window calculation unit determines the predicted arrival time of the lightning strike based on the difference between the preset maximum prediction time and the lightning strike intensity advance. The preset maximum prediction time is determined based on the effective radius of the atmospheric electric field detection and the lower limit of the lightning cloud charge accumulation rate, and is set to 300 ms for example. The lightning strike intensity advance is the product of the time advance coefficient and the predicted lightning strike intensity. The time advance coefficient is obtained by linear regression of historical thunderstorm data, and is set to 0.5 ms / kA for example.

[0075] In this embodiment, the time window calculation unit determines the tripping time compensation coefficient based on the difference between the maximum compensation coefficient and the product of the direction deviation.

[0076] The maximum compensation coefficient is the compensation value for the tripping delay when the pole-mounted switch is directly facing the lightning incident direction and the lightning intensity reaches the design limit, and is set to 0.2 for example. The directional deviation product is the product of the directional sensitivity coefficient and the incident direction deviation angle, where the incident direction deviation angle is the absolute value of the difference between the predicted lightning incident direction and the preset facing direction. The directional sensitivity coefficient is set to 0.003 / °C for example, and the preset facing direction is calibrated according to the installation orientation and is set to 0° for example. The sensitivity coefficient is used to quantify the degree of influence of the lightning incident direction deviating from the preset facing direction on the tripping mechanism's action time.

[0077] Furthermore, the tripping time determination unit determines the target tripping time based on the difference between the predicted lightning strike arrival time and the tripping time compensation amount. The tripping time compensation amount is the product of the tripping time compensation coefficient and the reference compensation time; the reference compensation time is the inherent tripping delay time measured during factory testing of the pole-mounted switch, exemplarily set to 10 ms.

[0078] Furthermore, the adjustment judgment module is connected to the trip prediction module, which is used to determine the compensation time of the pole-mounted switch based on the preload of the contact spring, and to determine the actual trip time based on the compensation time and the target trip time. The adjustment judgment module includes a humidity acquisition unit, a time compensation determination unit, and a time correction unit. The trip prediction module and the adjustment judgment module are soldered onto the same multilayer PCB board, which is fixed to the aluminum alloy heat sink at the bottom of the surge arrester. The waterproof aviation plug is fixed to the side of the bottom of the surge arrester and connected to the corresponding interface on the PCB board via a ribbon cable.

[0079] Specifically, the current ambient humidity is collected by the humidity sensor inside the humidity acquisition unit, and the compensation time of the pole switch is determined based on the preload force of the contact spring of the time compensation determination unit combined with the time compensation determination unit.

[0080] In this embodiment, the compensation time is the sum of the first compensation component and the second compensation component. The first compensation component is the product of the first time coefficient and the spring aging value, and the second compensation component is the product of the second time coefficient and the humidity difference.

[0081] Among them, the spring aging value is the difference between the initial value of the spring preload and the preload of the contact spring; the humidity difference value is the difference between the current ambient humidity and the preset humidity, and the preset humidity can be set to the standard ambient relative humidity of 50%RH for example; the first time coefficient and the second time coefficient are both calibrated by the spring aging test and the humidity effect test, and the first time coefficient can be set to 0.08ms / N and the second time coefficient to 0.12ms / %RH for example.

[0082] Furthermore, the timing correction unit determines the actual tripping time based on the difference between the target tripping time and the compensation time.

[0083] In this embodiment, the correction and control module is connected to the adjustment judgment module and the tripping prediction module respectively. It is used to determine whether to adjust the remaining duration of the tripping pulse based on the arc voltage ripple frequency and the preset arc voltage ripple frequency during the tripping process, and to determine the adjustment amount of the remaining duration of the tripping pulse based on the tripping speed and the preset tripping speed.

[0084] The correction and control module includes an arc comparison unit, a primary adjustment unit, an energizing duration determination unit, and a secondary adjustment unit.

[0085] In this embodiment, during the circuit breaker tripping process, the arc comparison unit pre-sets a preset arc voltage ripple frequency and determines whether to adjust the tripping pulse time based on the comparison result with the arc voltage ripple frequency.

[0086] In one specific embodiment, if the arc voltage ripple frequency is less than or equal to the preset arc voltage ripple frequency, it indicates that the current arc voltage ripple frequency is within the normal range, which means that the arcing is normal during the circuit breaker tripping process and there is no abnormal risk.

[0087] Therefore, it is determined that the remaining duration of the current tripping pulse will not be adjusted, and the current parameters will be maintained to continue tripping.

[0088] In one specific embodiment, if the arc voltage ripple frequency is greater than the preset arc voltage ripple frequency, it indicates that the current arc voltage ripple frequency is higher than the normal range, suggesting abnormal arcing and abnormal arc energy during the tripping process. If not adjusted in time, it may lead to contact erosion and switch damage.

[0089] Therefore, the remaining duration of the current tripping pulse is adjusted to suppress abnormal arcing.

[0090] Specifically, the preset arc voltage ripple frequency is determined based on the measured peak frequency of the typical opening arc: under standard opening conditions, the arc voltage waveform is obtained through multiple opening tests, Fourier analysis is performed, the peak frequency of the ripple spectrum is extracted, and the average value of multiple tests is taken as the preset arc voltage ripple frequency, which can be set to P0=2.5kHz for example.

[0091] Please see Figure 4 As shown, it is a logic flowchart of determining the duration of the tripping pulse based on the tripping speed in an embodiment of the present invention.

[0092] In this embodiment, during the duration of the tripping pulse, the primary adjustment unit continuously monitors the tripping speed of the contacts and presets a tripping speed. Based on the comparison between the tripping speed and the preset tripping speed, the adjustment amount of the remaining duration of the current tripping pulse is determined.

[0093] In one specific embodiment, if the opening speed is greater than or equal to the preset opening speed, it indicates that the current opening speed is too fast. An excessively fast opening speed may cause severe mechanical impact on the contacts at the end of the stroke, resulting in contact deformation and mechanical damage.

[0094] Therefore, it is determined that shortening the remaining duration of the current tripping pulse based on the primary adjustment unit will cause the coil to be de-energized in advance, and the contacts will complete the remaining stroke by relying on inertia, thereby effectively reducing the end collision speed.

[0095] Furthermore, the primary adjustment unit determines the shortened remaining duration of the tripping pulse based on the product of the current remaining duration of the tripping pulse and the shortening time factor.

[0096] Wherein, the shortening time factor is the difference between the initial value and the shortening coefficient; the shortening coefficient is the product of the first preset proportional coefficient and the opening speed offset value; the first preset proportional coefficient is based on the test calibration of the opening speed-time characteristic of the switch operating mechanism, characterizing the pulse time shortening ratio corresponding to the opening speed offset value, and can be set to 0.15 (m / s) for example. -1 The tripping speed offset value is the difference between the tripping speed and the preset tripping speed; the initial value can be 1 for example.

[0097] It should be noted that the higher the opening speed, the greater the mechanical impact energy generated by the contacts at the end of their stroke, and the greater the impact force generated when the contacts collide with the limit device. This may lead to contact deformation, fatigue fracture, or mechanism jamming. Therefore, the remaining duration of the opening pulse increases with the increase of the opening speed. The impact energy is proportional to the square of the speed.

[0098] In one specific embodiment, if the opening speed is less than the preset opening speed, it indicates that the current opening speed is too slow. If the opening speed is too slow, the contact separation speed may be insufficient. When the lightning strike arrives, the contact has not yet reached the safe opening distance and cannot effectively isolate the lightning overvoltage.

[0099] Therefore, it was determined that the remaining duration of the tripping pulse should be extended based on the primary adjustment unit to increase the coil energizing time, provide more driving force to the mechanism, and ensure that the contacts quickly reach the safe opening distance.

[0100] Furthermore, the primary adjustment unit determines the extended remaining duration of the tripping pulse based on the product of the current remaining duration of the tripping pulse and the extension time factor.

[0101] Wherein, the extension time factor is the sum of the initial value and the extension coefficient; the extension coefficient is the product of the second preset proportional coefficient and the difference in opening speed; the second preset proportional coefficient is calibrated based on the opening speed-time characteristic test of the switch operating mechanism to characterize the pulse time extension ratio corresponding to the difference in opening speed; the difference between the preset opening speed and the opening speed is the opening speed difference, which can be set to 0.2 (m / s) for example. -1 .

[0102] It should be noted that the lower the opening speed, the more severe the deviation from the normal range, resulting in slower contact separation, a smaller contact separation distance when lightning strikes, and lower insulation strength between contacts. This can lead to lightning overvoltage breakdown of the contact gap or trigger a secondary arc. Therefore, the remaining duration of the opening pulse increases as the opening speed decreases. The separation distance is directly proportional to the speed.

[0103] Specifically, the preset opening speed is determined based on the rated opening speed calibrated during the factory test of the pole-mounted switch: before the switchgear leaves the factory, the manufacturer measures the rated value of the opening speed under standard operating conditions according to the design specifications, and records it in the product technical specifications as the preset opening speed. For example, the preset opening speed can be set to 1.5 m / s.

[0104] In this embodiment, the secondary adjustment unit determines the energizing start time of the tripping coil based on the actual tripping time, and determines the energizing duration of the tripping coil based on the adjusted tripping pulse duration, i.e., the energizing duration is equal to the adjusted tripping pulse duration. For example, if the actual tripping time is 250ms and the adjusted pulse duration is 19ms, then the tripping coil starts to be energized at 250ms and is de-energized after 19ms.

[0105] Furthermore, a preset power-on duration is pre-set through the secondary adjustment unit module, and the duration of the extended tripping pulse is determined by comparing the result with the power-on duration.

[0106] In one specific embodiment, if the energizing time is longer than the preset energizing time, it indicates that the current energizing time of the tripping coil has exceeded the normal range. The heat accumulated in the coil exceeds the tolerance limit of the insulation material, which can easily lead to the melting and carbonization of the insulation layer, causing short circuits between coil turns or even burnout, ultimately resulting in the failure of the tripping mechanism and the inability of the switch to disconnect during a lightning strike.

[0107] Therefore, it is determined to shorten the duration of the adjusted tripping pulse to reduce the coil energizing time and prevent overheating and burnout.

[0108] Furthermore, the correction and control module determines the corrected opening pulse duration based on the product of the adjusted opening pulse duration and the attenuation factor. Here, the energizing duration difference is the difference between the energizing duration and the preset energizing duration; the attenuation factor is the negative power of λ times the energizing duration difference, where λ is the attenuation coefficient, which can be determined based on coil thermal test data and can be set to 0.15ms for example. -1 .

[0109] It should be noted that if the corrected pulse duration is lower than the minimum safe opening pulse width allowed by the pole-mounted switch, the device will additionally record a serious fault event and simultaneously block the automatic reclosing operation. The minimum safe opening pulse width is determined through factory testing of the pole-mounted switch and can be set to 12ms as an example.

[0110] In one specific embodiment, if the energizing time is less than or equal to the preset energizing time, it indicates that the current energizing time of the trip coil is within the normal range, the heat generated by the coil is within the safety margin, the temperature of the insulation material has not reached the aging threshold, the coil is safe and reliable, and there is no risk of overheating and burning.

[0111] Therefore, the duration of the adjusted tripping pulse is determined, and the tripping is completed while maintaining the current parameters.

[0112] Specifically, the preset energizing time is determined based on the minimum theoretical energizing time required for the trip coil to complete the full stroke of the iron core: after the trip coil is energized, the iron core moves under the action of electromagnetic force, pushing the mechanism to complete the contact separation. Based on the electromagnetic design parameters of the coil, such as inductance, resistance, iron core stroke, and reaction force characteristics, the minimum time required for the iron core to move from the initial position to the end of the stroke is calculated, and the preset energizing time can be set to 20 ms for example.

[0113] All technologies not mentioned in the above embodiments are existing technologies. It should be noted that the specific values ​​of each preset threshold are exemplary settings based on the specific hardware conditions and test scenarios of this embodiment. In specific implementation, those skilled in the art can obtain corresponding empirical values ​​through a limited number of experiments, based on the measurement noise characteristics of the atmospheric electric field sensor, the cost of misjudging lightning strike risk, and the statistical distribution corresponding to different lightning strike prediction intensity levels.

[0114] 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. An integrated surge arrester device for pole-mounted switches, characterized in that, include: The early warning module is used to collect atmospheric electric field intensity and atmospheric electric field three-dimensional components based on the first preset collection time window, and to determine whether to collect the original data of the pole switch based on the atmospheric electric field intensity and the preset atmospheric electric field intensity. The identification module is used to determine the predicted lightning intensity and the predicted lightning incident direction based on the three-dimensional components of the atmospheric electric field. The data processing module is used to read the raw data based on the second preset acquisition time window and preprocess it to obtain a data packet, wherein the data packet includes the contact spring preload, arc voltage ripple frequency and opening speed. The tripping prediction module is used to determine the target tripping time of the pole-mounted switch during a lightning strike based on the lightning strike prediction intensity and the lightning strike prediction incident direction. The adjustment judgment module is used to determine the compensation time of the pole-mounted switch based on the preload of the contact spring, and to determine the actual opening time based on the compensation time and the target opening time. The correction and control module is used to determine whether to adjust the remaining duration of the opening pulse based on the arc voltage ripple frequency and the preset arc voltage ripple frequency during the opening process, and to determine the adjustment amount of the remaining duration of the opening pulse based on the opening speed and the preset opening speed.

2. The integrated surge arrester device for pole-mounted switches according to claim 1, characterized in that, The adjustment determination module includes: The compensation time determination unit is used to collect the current ambient humidity and determine the compensation time amount by combining it with the preload of the contact spring. A time correction unit is used to determine the actual opening time based on the difference between the target opening time and the compensation time.

3. The integrated surge arrester device for pole-mounted switches according to claim 1, characterized in that, The correction and control module includes: An arc comparison unit is used to determine the remaining duration of the tripping pulse based on the fact that the arc voltage ripple frequency is greater than the preset arc voltage ripple frequency. A primary adjustment unit is used to determine to shorten the remaining duration of the tripping pulse based on the tripping speed being greater than or equal to the preset tripping speed, or to determine to extend the remaining duration of the tripping pulse based on the tripping speed being less than the preset tripping speed.

4. The integrated surge arrester device for pole-mounted switches according to claim 3, characterized in that, The primary adjustment unit is also used to determine the extension range of the remaining duration of the tripping pulse based on the tripping speed difference and the preset tripping speed difference, wherein the extension range is positively correlated with the tripping speed difference.

5. The integrated surge arrester device for pole-mounted switches according to claim 4, characterized in that, The primary adjustment unit is also used to determine the reduction range of the remaining duration of the tripping pulse based on the tripping speed offset value and the preset tripping speed offset value, wherein the reduction range is positively correlated with the tripping speed offset value.

6. The integrated surge arrester device for pole-mounted switches according to claim 4 or 5, characterized in that, The correction and control module also includes: The energizing duration determination unit is used to determine the energizing duration of the tripping coil based on the actual tripping time and the adjusted tripping pulse duration. A secondary adjustment unit is used to determine the duration of the shortened tripping pulse based on the fact that the energizing duration is greater than the preset energizing duration.

7. The integrated surge arrester device for pole-mounted switches according to claim 6, characterized in that, The secondary adjustment unit is used to determine the reduction range of the adjusted tripping pulse duration based on the difference between the energizing duration and the preset difference between the energizing duration and the reduction range is positively correlated with the difference between the energizing duration and the preset ...

8. The integrated surge arrester device for pole-mounted switches according to claim 1, characterized in that, The early warning module includes: An electric field comparison unit is used to determine the acquisition of the original data based on the atmospheric electric field strength being greater than or equal to the preset atmospheric electric field strength. The verification unit is used to collect the space potential and determine to shorten the first preset collection time window based on the space potential being greater than or equal to a preset space potential.

9. The integrated surge arrester device for pole-mounted switches according to claim 1, characterized in that, The tripping prediction module includes: The time window calculation unit is used to determine the predicted arrival time of the lightning strike based on the predicted lightning strike intensity, and to determine the tripping time compensation coefficient based on the predicted incident direction of the lightning strike. The tripping time determination unit is used to determine the target tripping time based on the predicted lightning strike arrival time and the tripping time compensation coefficient.

10. The integrated surge arrester device for pole-mounted switches according to claim 1, characterized in that, The identification module includes: An intensity calculation unit is used to perform inversion calculations based on the three-dimensional components of the atmospheric electric field to obtain the proportion of high charge density regions, so as to determine the lightning strike prediction intensity. The proportion of high charge density regions is positively correlated with the lightning strike prediction intensity. The direction calculation unit is used to establish a spatial rectangular coordinate system, extract the horizontal component of the three-dimensional components of the atmospheric electric field, calculate the direction angle based on the horizontal component, and determine the predicted incident direction of the lightning strike.

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