A large-capacity impulse current generating device for tower grounding test

Abstract

The application relates to a large-capacity impulse current generating device for tower grounding test, which comprises a main circuit and a control circuit, the main circuit comprises an AC power supply, a step-up transformer, a rectifier module, a charging module, a discharge sphere gap and a wave modulation resistor, the primary side of the step-up transformer is connected with the AC power supply, the secondary side is connected with the input end of the rectifier module, the output end of the rectifier module is connected with the input side of the charging module, the positive pole of the output side of the charging module is connected with one end of the wave modulation resistor through the discharge sphere gap, the device further comprises a winding coil, the winding coil is wound on a grounding rod of a power transmission line tower, a first end is connected with the other end of the wave modulation resistor, and a second end is connected with the negative pole of the output side of the charging module. Compared with the prior art, the application has larger support current and improves test efficiency.

Description

Technical Field

[0001] This invention relates to impulse current generating devices, and more particularly to a high-capacity impulse current generating device for tower grounding tests. Background Technology

[0002] The impulse current generator is a core device for simulating transient high-current scenarios such as lightning strikes and short circuits, and is widely used for performance testing of power equipment such as surge arresters and grounding devices. For example, Chinese patent CN106526330A discloses a portable impulse current generator for measuring impulse grounding resistance, including a main circuit and a control circuit. The main circuit generates impulse current and is connected to the control circuit, which controls the main circuit to perform pulse discharge. The tail end of the main circuit is connected to the current injection electrode and the return electrode of the grounding electrode, respectively. The injection electrode is connected to a pulse voltage divider, and the measuring end of the pulse voltage divider is connected to an oscilloscope. It also includes a Rogowski coil M connected in series with the return electrode, and the Rogowski coil M is connected to the oscilloscope.

[0003] However, traditional impulse current generators, including the aforementioned portable impulse current generator, rely on the principle of "capacitor energy storage-synchronous discharge," as detailed in Chinese patent CN106526330A. During testing, the four tower legs of the bookstore tower need to be disconnected from the grounding rod, and then the current is injected together as a current injection electrode, which is then connected to the end of the main circuit. After that, a separate return electrode needs to be set up for grounding. However, according to standards such as GB / T 17949.1, in order to meet the requirement of three times the diagonal of the grounding grid, the distance between the return electrode and the current injection electrode needs to be far enough, which results in an excessively large footprint during the overall test.

[0004] In addition, some transmission towers are often built in high mountains to reduce the impact on residential areas. In this case, on the one hand, the grounding of the current injection electrode requires carrying many grounding rods, which is labor-intensive. On the other hand, in order to achieve a sufficiently long distance between the return electrode and the current injection electrode, it is often necessary to cross two mountains. Therefore, going up and down the mountain is both time-consuming and increases fatigue, resulting in only one transmission tower being tested per day, which is inefficient.

[0005] In addition to the problems mentioned above, there is no direct connection between the return electrode and the current injection electrode in the above method. Under the condition that the power of the main circuit remains unchanged, the magnitude of the inrush current that can be achieved is limited. If it is necessary to increase the magnitude of the inrush current, the capacity of the main circuit needs to be increased, which will further increase the size and cost. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art by providing a high-capacity impulse current generating device for tower grounding tests.

[0007] The objective of this invention can be achieved through the following technical solutions: A high-capacity impulse current generating device for tower grounding tests includes a main circuit and a control circuit. The main circuit includes an AC power supply, a step-up transformer, a rectifier module, a charging module, a discharge sphere gap, and a tuning resistor. The primary side of the step-up transformer is connected to the AC power supply, and the secondary side is connected to the input terminal of the rectifier module. The output terminal of the rectifier module is connected to the input terminal of the charging module. The positive terminal of the output terminal of the charging module is connected to one end of the tuning resistor via the discharge sphere gap. The device also includes a wound coil wound around the grounding rod of the transmission line tower, with one end connected to the other end of the tuning resistor and the second end connected to the negative terminal of the output terminal of the charging module.

[0008] The outer side of the wound coil is wrapped with an insulating skin, and the insulating skins of adjacent arc segments in the wound coil are closely attached.

[0009] The number of turns of the winding coil is determined based on the capacity of the main circuit and the magnitude of the target grounding current.

[0010] The wound coil is determined based on the following mathematical expression: y=I 冲 ×[U×(a-bx)-(cU 2 -d)] Where: x is the number of turns of the wound coil, I 冲 U is the target grounding current, U is the test setting voltage, y is the current on the winding coil, and a, b, c, and d are fitting coefficients.

[0011] The discharge sphere is a silicon carbide switch.

[0012] The charging module includes a charging resistor, a DC voltage divider, and a charging capacitor. One end of the charging resistor is connected to the positive terminal of the output terminal of the rectifier module, and the other end is connected to the first terminal of the DC voltage divider and the first terminal of the charging capacitor. The second terminal of the DC voltage divider and the second terminal of the charging capacitor are both connected to the negative terminal of the output terminal of the rectifier module and to the second terminal of the wound coil.

[0013] The DC voltage divider includes two voltage-dividing resistors connected in series.

[0014] The rectifier module is a diode.

[0015] An inductor is also provided between the discharge sphere gap and the tuning current.

[0016] The AC power supply and the step-up transformer are also directly equipped with a voltage regulating transformer.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. By adding a winding coil and winding it around the grounding rod of the transmission tower itself, the test is achieved by inducing a current on the grounding rod of the transmission tower through the short-circuit current of the winding coil itself. On the one hand, since the winding coil is in a short-circuit state, its current is larger, thus increasing the current on the winding coil while maintaining the same capacity of the main circuit. On the other hand, the current on the grounding rod of the transmission tower is generated through induction, thus eliminating the need to remove the connection between the four tower legs and the grounding plate. More importantly, there is no need to set up a separate return electrode, thereby reducing the footprint. When the test is conducted in mountainous areas, there is no need to drive grounding piles on other adjacent mountains, thus greatly improving the test efficiency.

[0018] 2. The insulating skin can effectively prevent inter-turn short circuits or ground discharges when the coil is wound around the grounding rod, ensuring the reliability of the current path. The tight installation of the insulating skin ensures that the coil is tightly wound and the structure is stable. It is not easy to loosen or shift in complex field conditions, which improves the safety and durability of the device. In addition, when the length of the grounding rod exposed above the ground on the transmission tower is limited, the number of turns of the coil can be increased, thereby increasing the magnitude of the induced impulse current on the grounding rod.

[0019] 3. It transforms coil design from an experience-based process into a calculable and predictable engineering process. Its advantage lies in enabling precise parameter calculation and optimized design, allowing technicians to quickly determine the optimal number of turns based on inputs such as target current and test voltage. This ensures the consistency and repeatability of impulse current test results, improving the scientific rigor and reliability of the test.

[0020] 4. Silicon carbide switches offer faster switching speeds, higher withstand voltage, and more stable performance. Their advantages include more precise and faster pulse discharge control, reduced discharge delay and dispersion, thus improving the accuracy and consistency of the inrush current waveform. Additionally, they offer longer equipment lifespan and easier maintenance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Figure 2 The experimental waveform diagram is shown when the number of turns of the wound coil is 10 and the test setting voltage is 3kV. Figure 3 The experimental waveform diagram is shown when the number of turns of the wound coil is 10 and the test setting voltage is 6kV. Figure 4 The experimental waveform diagram is shown when the number of turns of the wound coil is 10 and the test setting voltage is 9kV. Figure 5 The experimental waveform diagram is shown when the number of turns of the wound coil is 5 and the test setting voltage is 3kV. Figure 6 The experimental waveform diagram is shown when the number of turns of the wound coil is 5 and the test setting voltage is 6kV. Figure 7 The experimental waveform diagram is shown when the number of turns of the wound coil is 5 and the test setting voltage is 9kV. Figure 8 The experimental waveform diagram is shown when the number of turns of the wound coil is 3 and the test setting voltage is 3kV. Figure 9 The experimental waveform diagram is shown when the number of turns of the wound coil is 3 and the test setting voltage is 6kV. Figure 10 The experimental waveform diagram is shown when the number of turns of the wound coil is 3 and the test setting voltage is 9kV. Figure 11 This is a schematic diagram of the structure of Embodiment 2 of the present invention; Wherein: T1, voltage regulating transformer; T2, step-up transformer; AC, AC power supply; D, diode; R1, charging resistor; R3, first voltage divider resistor; R4, second voltage divider resistor; C1, charging capacitor; K1, discharge ball gap; R2, tuning resistor; L, capacitor; M, Rogowski coil; Q, wound coil; 1, transmission tower; 2, grounding rod; GND, grounding symbol; VT1, bridge rectifier circuit. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0023] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0024] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "proximal," "distal," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Physical quantities in formulas, unless otherwise specified, should be understood as basic quantities in the International System of Units (SI), or derived quantities derived from basic quantities through mathematical operations such as multiplication, division, differentiation, or integration.

[0025] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0026] In the description of this invention, it should also be noted that, 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 based on the specific circumstances.

[0027] Example 1 A high-capacity impulse current generator for tower grounding tests, such as Figure 1 As shown, the device includes a main circuit and a control circuit. The main circuit includes an AC power supply, a step-up transformer T2, a rectifier module, a charging module, a discharge gap K1, and a tuning resistor R2. The primary side of the step-up transformer T2 is connected to the AC power supply, and the secondary side is connected to the input terminal of the rectifier module. The output terminal of the rectifier module is connected to the input terminal of the charging module. The positive terminal of the output terminal of the charging module is connected to one end of the tuning resistor R2 via the discharge gap K1. The device also includes a winding coil Q, which is wound around the grounding rod 2 of the transmission line tower. The first end of the winding coil Q is connected to the other end of the tuning resistor R2, and the second end is connected to the negative terminal of the output terminal of the charging module.

[0028] The test is achieved by adding a winding coil Q and winding the winding coil Q around the grounding rod 2 of the transmission tower 1 itself. The short-circuit current of the winding coil Q itself induces a current on the grounding rod 2 of the transmission tower 1. On the one hand, since the winding coil Q is in a short-circuit state, its current is larger, which can increase the current on the winding coil Q with the same capacity of the main circuit. On the other hand, the current on the grounding rod 2 of the transmission tower 1 is generated by induction, so there is no need to remove the connection between the four tower feet of the transmission tower 1 and the grounding plate. More importantly, there is no need to set up a separate return electrode, which can reduce the footprint. When the test is carried out in mountainous areas, there is no need to drive grounding piles on other adjacent mountains, which greatly improves the test efficiency.

[0029] In some embodiments, the outer side of the winding coil Q is wrapped with an insulating skin, and the insulating skins of adjacent arc segments in the winding coil Q are tightly attached. The insulating skin can effectively prevent inter-turn short circuits or ground discharges when the coil is wound around the grounding rod 2, ensuring the reliability of the current path. The tight attachment of the insulating skin ensures that the coil is tightly wound and the structure is stable, making it less prone to loosening or displacement under complex field conditions, thus improving the safety and durability of the device. In addition, when the length of the grounding rod 2 exposed above the ground on the transmission tower 1 is limited, the number of turns of the winding coil Q can be increased, thereby increasing the magnitude of the induced impulse current on the grounding rod 2.

[0030] Theoretical derivation shows that the number of turns Q of the wound coil is determined based on the capacity of the main circuit and the target grounding current. Furthermore, in this embodiment, through experimental analysis, the number of turns Q of the wound coil is determined based on the following mathematical expression: y=I 冲 ×[U×(a-bx)-(cU 2 -d)] Where: x is the number of turns of the winding coil Q, I 冲 U is the target grounding current, U is the test setting voltage, y is the current on the winding coil Q, and a, b, c, and d are fitting coefficients.

[0031] The above test settings use the main circuit's supported output voltage, while the target ground current is the required impulse current for the test. This transforms coil design from an experience-based process to a calculable and predictable engineering process. Its advantage lies in enabling precise parameter calculation and optimized design, allowing technicians to quickly determine the optimal number of turns based on inputs such as the target current and test voltage. This ensures the consistency and repeatability of impulse current test results, improving the scientific rigor and reliability of the test.

[0032] Generally, the discharge gap K1 is a silicon carbide switch. Silicon carbide switches have faster switching speeds, higher withstand voltage, and more stable performance. Their advantages include more precise and faster pulse discharge control, reduced discharge delay and dispersion, thereby improving the accuracy and consistency of the inrush current waveform. They also offer longer equipment lifespan and easier maintenance.

[0033] The charging module includes a charging resistor R1, a DC voltage divider, and a charging capacitor LC1. One end of the charging resistor R1 is connected to the positive terminal of the rectifier module's output, and the other end is connected to the first terminal of the DC voltage divider and the first terminal of the charging capacitor LC1. The second terminals of both the DC voltage divider and the charging capacitor LC1 are connected to the negative terminal of the rectifier module's output and the second terminal of the wound coil Q. This structure constitutes a classic and efficient capacitor L charging circuit. Its advantages are: the charging resistor R1 limits the charging current, protecting the rectifier module; the charging capacitor LC1 stores electrical energy and is the energy source for the inrush current; the DC voltage divider monitors the voltage across the charging capacitor LC1 in real time, providing a crucial voltage feedback signal for the control circuit. This modular design makes the charging process controllable and measurable, ensuring the safety and stability of the energy storage stage.

[0034] A DC voltage divider consists of two voltage-dividing resistors connected in series. (See details...) Figure 1 The first voltage divider resistor R3 and the second voltage divider resistor R4 in the circuit have the advantages of simple structure, low cost, and stable and reliable voltage division ratio. By selecting appropriate resistor values, the high-voltage side voltage can be accurately reduced proportionally to the safe input range of low-voltage measuring equipment (such as control circuits), which is the key to achieving safe and accurate high-voltage measurement.

[0035] The rectifier module is a diode D, which has the advantages of extremely simple structure, low manufacturing cost, and reliable unidirectional conductivity. In this device, the rectifier bridge composed of diodes D can efficiently convert the AC power output from the step-up transformer T2 into DC power, providing DC power for charging the subsequent capacitor L, thus ensuring the simplicity and efficiency of the entire system's front-end power supply.

[0036] An inductor is also provided between the discharge sphere gap K1 and the modulation current. The inductor can adjust the waveform parameters of the impulse current, especially slowing down the rise time of the current (i.e. increasing the wavefront time) and helping to suppress high-frequency oscillations that may be generated in the circuit, making the generated impulse current waveform smoother, more standard, and closer to the waveform characteristics of natural lightning current, thereby improving the accuracy and scientific nature of the test.

[0037] The AC power supply and step-up transformer T2 are directly connected to a regulating transformer T1, providing flexible and continuous voltage regulation capabilities. Operators can precisely control the voltage input to the primary side of the step-up transformer T2 by adjusting the regulating transformer T1, thereby achieving stepless and precise control over the charging voltage of the charging module and the amplitude of the output inrush current of the entire device. This avoids the hassle of adjusting the output level by replacing hardware, greatly enhancing the ease of operation and testing flexibility of the device.

[0038] See Figure 1For step-up transformer T2, it includes a closed annular magnetic core of nanocrystalline alloy. Its primary and secondary coils are symmetrically wound on both sides of the magnetic core with a turns ratio of 1:50-1:200. The coil winding spacing is ≤5mm and the magnetic coupling coefficient is ≥0.95.

[0039] The charging circuit has a charging voltage of 100-500V, a peak pulse current of 10-500A, and a rise time of ≤1μs. In this embodiment, the control circuit includes a line connected between the winding coil Q and the second terminal of the charging capacitor LC1. It can collect the short-circuit current on the winding coil Q. If the wavefront time deviates from the set value, the inductance is increased to extend the wavefront time, and the inductance is decreased to shorten the wavefront time to adjust the adjustable inductance value. If the half-peak time is abnormal, the waveform is corrected by adjusting the resistance value of the wave tuning resistor R2.

[0040] In some embodiments, this application also includes a cooling circulation module that removes heat generated by copper loss and eddy current loss in the primary coil, secondary coil, and magnetic core through water cooling pipes, thereby ensuring the stability of continuous equipment operation.

[0041] In some embodiments, the charging capacitor LC1 has a capacitance ≤1000μF and a withstand voltage ≤500V, and the SiC fast switch response time ≤100ns; the grounding rod 2 serves as the magnetic core, with a saturation magnetic induction intensity ≥1.2T and a permeability ≥10. 4 H / m; peak impulse current is 1kA-20kA, wavefront time is 2μs-20μs; half-peak time is 10μs-350μs; charging time is ≤5 seconds / cycle.

[0042] In this embodiment, the key performance indicators of the device are as follows: Peak inrush current: 1kA-20kA (continuously adjustable, adjustment accuracy ±2%). Wavefront time: 2μs-20μs (adjustable, deviation ≤±5%); Half-peak time: 10μs-350μs (adjustable, deviation ≤±5%); Charging time: ≤5 seconds / cycle (more than 90% shorter than traditional capacitor charging). Equipment size: ≤1.5m×0.8m×1.2m (80% smaller than traditional devices with the same parameters); Continuous discharge cycles: ≥200 times / hour (meets batch testing requirements); Impulse impedance test compatibility: It can directly apply high-frequency impulse current above 1MHz to the grounding device with a test error ≤3%.

[0043] like Figure 1As shown, this embodiment constructs a complete and efficient impulse current generation system based on inductive coupling. Its workflow can be decomposed into four stages: energy supply and conversion, energy storage, pulse formation and release, and the core inductive coupling test.

[0044] Energy Supply and Conversion Stage: The mains power (AC) first passes through the voltage regulating transformer T1. The core function of T1 is to provide operators with precise and continuous voltage regulation capabilities, allowing them to steplessly set the initial energy input level of subsequent circuits. This greatly enhances the flexibility and range of device testing. The AC power regulated by T1 is then input to the primary side of the step-up transformer T2. T2 uses a nanocrystalline alloy toroidal closed magnetic core, with its primary and secondary coils tightly wound at a high turns ratio (1:50 to 1:200), ensuring a high magnetic coupling coefficient (≥0.95) and efficient energy transfer, boosting the voltage to the kilovolt level. Subsequently, the high-voltage AC power enters a rectifier module composed of diodes D. D, as a simple, low-cost, and reliable unidirectional conductor, efficiently converts the high-voltage AC power output from T2 into pulsating DC power, preparing for the next stage of energy storage.

[0045] Energy Storage Stage: The rectified DC power enters the charging module. This module is a classic design, containing a charging resistor R1, a DC voltage divider (R3, R4), and a charging capacitor C1. R1 is connected in series in the circuit, its main function being to limit the initial charging current to C1, acting as a buffer and protector against instantaneous high current surges to the rectifier diode D. C1 is the device's energy reservoir; the electrical energy it stores (charging voltage 100-500V) directly determines the amplitude of the final surge current. The DC voltage divider connected in parallel across C1 consists of two precision resistors R3 and R4 connected in series. Its function is to divide the high voltage (e.g., several kilovolts) across C1 by a fixed ratio, obtaining a safe low-voltage sampling signal. This signal is fed back to the control circuit (not fully shown in the diagram), enabling the control system to monitor the charging voltage of C1 in real time and accurately, and prepare for triggering discharge when the voltage reaches a preset value. This design makes the charging process fully controllable and monitorable, ensuring operational safety.

[0046] Pulse Formation and Release Stage: After C1 is charged to the target voltage, the control circuit issues a command to trigger the discharge gap K1 (preferably a silicon carbide switch in this embodiment). Compared with traditional spark gaps, silicon carbide switches have nanosecond-level extremely fast switching speed, high withstand voltage, and excellent stability. This enables precise and rapid discharge control, ensuring the synchronization and consistency of each discharge, thereby generating an impact current with highly repeatable waveform parameters. After passing through K1, the current pulse flows through the tuning resistor R2 and the optional inductor L. R2 and L together constitute a waveform adjustment network: R2 is mainly used to adjust the half-peak time of the current waveform (i.e., the rate of waveform decay), while the inductor L mainly affects the wavefront time of the waveform (i.e., the steepness of the current rise) and can suppress high-frequency oscillations in the circuit. By adjusting these two parameters, the generated impact current waveform (wavefront time 2-20μs, half-peak time 10-350μs) can better meet the requirements of various test standards and more realistically simulate natural lightning current.

[0047] The core inductive coupling test phase: Unlike traditional devices that directly inject current into the grounding electrode, the core innovation of this invention lies in the introduction of a wound coil Q. This coil is directly and tightly wound around the grounding rod 2 of the transmission tower 1 under test. The pulse current flow path is: from the positive terminal of C1 → K1 → R2 / L → the first end of the wound coil Q → flowing back to the negative terminal of C1 from the second end of the wound coil Q. The key point is that the two ends of the wound coil Q are directly short-circuited in the main circuit, forming a short-circuit loop. When a powerful pulse current (peak value reaching 10-500A) flows through this short-circuit loop, it generates a momentary strong magnetic field around it. Because Q is tightly wound around the grounding rod 2, this rapidly changing magnetic field induces a strong eddy current inside the grounding rod 2 (as a conductor), which is the "impulse grounding current" we are testing. This induced current flows into the ground through the grounding rod 2. By measuring the peak value and waveform of this induced current, the performance of the grounding device, such as its impulse grounding resistance, can be evaluated.

[0048] The specific experiments were conducted as follows: After the device is connected, set three different primary charging voltages: 3kV, 6kV, and 9kV. Test each voltage three times and take the average value as the final data. Set the number of turns to 10, 5, and 3.

[0049] The device is started, and after charging is complete, the SiC fast switch is triggered. The peak value of the inrush current (acquired by the Rogowski coil M) and the load voltage (acquired by the voltage divider) are recorded using an oscilloscope, and the current waveform is saved. During the test, observe the data acquisition of the capacitive voltage divider and record the phenomenon of "no or weak current waveform".

[0050] The specific test groups are shown in Table 1. Table 1 The final test results are as follows: Figures 2 to 10 As shown, all of them can achieve the test objectives of the response and meet the requirements.

[0051] Example 2 This embodiment is generally the same as Embodiment 1, so the similarities with Embodiment 1 will not be repeated, and only the differences will be described.

[0052] In this embodiment, as Figure 11 As shown, the device includes a main circuit and a control circuit. The main circuit includes an AC power supply, a step-up transformer, a rectifier module, a charging module, a discharge gap, and a tuning resistor. The primary side of the step-up transformer is connected to the AC power supply, and the secondary side is connected to the input terminal of the rectifier module. The output terminal of the rectifier module is connected to the input terminal of the charging module. The positive terminal of the output terminal of the charging module is connected to one end of the tuning resistor via the discharge gap. The device also includes a winding coil wound around the grounding rod of the transmission line tower, with one end connected to the other end of the tuning resistor and the second end connected to the negative terminal of the output terminal of the charging module. Its distinguishing feature is that the rectifier module uses a bridge rectifier resistor VT1.

[0053] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A high-capacity impulse current generating device for tower grounding tests, comprising a main circuit and a control circuit, wherein the main circuit includes an AC power supply, a step-up transformer, a rectifier module, a charging module, a discharge gap, and a tuning resistor; the primary side of the step-up transformer is connected to the AC power supply, and the secondary side is connected to the input terminal of the rectifier module; the output terminal of the rectifier module is connected to the input side of the charging module; the positive terminal of the output side of the charging module is connected to one end of the tuning resistor via the discharge gap, characterized in that... The device also includes a winding coil wound around a grounding rod on a transmission line tower, with one end connected to the other end of a tuning resistor and the second end connected to the negative terminal of the output side of the charging module.

2. The high-capacity impulse current generating device for tower grounding tests according to claim 1, characterized in that, The outer side of the wound coil is wrapped with an insulating skin, and the insulating skins of adjacent arc segments in the wound coil are closely attached.

3. A high-capacity impulse current generating device for tower grounding tests according to claim 1, characterized in that, The number of turns of the winding coil is determined based on the capacity of the main circuit and the magnitude of the target grounding current.

4. A high-capacity impulse current generating device for tower grounding tests according to claim 3, characterized in that, The wound coil is determined based on the following mathematical expression: y=I 冲 ×[U×(a-bx)-(cU 2 -d)] Where: x is the number of turns of the wound coil, I 冲 U is the target grounding current, U is the test setting voltage, y is the current on the winding coil, and a, b, c, and d are fitting coefficients.

5. A high-capacity impulse current generating device for tower grounding tests according to claim 3, characterized in that, The discharge sphere is a silicon carbide switch.

6. A high-capacity impulse current generating device for tower grounding tests according to claim 1, characterized in that, The charging module includes a charging resistor, a DC voltage divider, and a charging capacitor. One end of the charging resistor is connected to the positive terminal of the output terminal of the rectifier module, and the other end is connected to the first terminal of the DC voltage divider and the first terminal of the charging capacitor. The second terminal of the DC voltage divider and the second terminal of the charging capacitor are both connected to the negative terminal of the output terminal of the rectifier module and to the second terminal of the wound coil.

7. A high-capacity impulse current generating device for tower grounding tests according to claim 6, characterized in that, The DC voltage divider includes two voltage-dividing resistors connected in series.

8. A high-capacity impulse current generating device for tower grounding tests according to claim 6, characterized in that, The rectifier module is a diode.

9. A high-capacity impulse current generating device for tower grounding tests according to claim 1, characterized in that, An inductor is also provided between the discharge sphere gap and the tuning current.

10. A high-capacity impulse current generating device for tower grounding tests according to claim 1, characterized in that, The AC power supply and the step-up transformer are also directly equipped with a voltage regulating transformer.

Images