阅读说明：本技术 山地地区输电线路接地装置瞬态电阻坡度畸变性试验装置 (Mountain region transmission line earthing device transient resistance slope distortion test device ) 是由 李恒真 彭涛 陈斯翔 梁东明 汪进锋 林杰江 刘益军 邹浩 方永锋 易颜波 于 2020-11-30 设计创作，主要内容包括：本发明提供一种山地地区输电线路接地装置瞬态电阻坡度畸变性试验装置,该装置通过山地地形模拟装置设置试验山地的坡度角,并通过坡度传感器进行检测,将坡度传感器所得到数据的数学期望作为实际试验坡度角；之后通过瞬态电压注入装置向山地地区输电线路接地装置注入瞬态电压,测量其瞬态放电电流幅值；通过瞬态放电电流幅值,并结合实际试验坡度角,对山地地区输电线路接地装置瞬态电阻坡度畸变特性进行评估；本发明能较为真实地模拟不同的山地坡度下山地地区输电线路接地装置电阻在瞬态电压下畸变的过程,能够对山地地区输电线路接地装置瞬态电阻坡度畸变特性的准确评估。(The invention provides a transient resistance gradient distortion testing device for a power transmission line grounding device in a mountain area, which is characterized in that a gradient angle of a tested mountain is set through a mountain terrain simulation device and is detected through a gradient sensor, and mathematical expectation of data obtained by the gradient sensor is used as an actual test gradient angle; then injecting transient voltage into the grounding device of the transmission line in the mountain area through the transient voltage injection device, and measuring the transient discharge current amplitude value of the transmission line; evaluating the slope distortion characteristic of the transient resistance of the power transmission line grounding device in the mountain area by the transient discharge current amplitude value and combining with the actual test slope angle; the method can simulate the distortion process of the resistance of the power transmission line grounding device in different mountain slope mountain descending areas under transient voltage relatively truly, and can accurately evaluate the slope distortion characteristic of the transient resistance of the power transmission line grounding device in the mountain slopes.)

1. A transient resistance gradient distortion test device for a grounding device of a power transmission line in a mountain area is characterized by comprising a grounding device (1) of the power transmission line in the mountain area, a mountain terrain simulation device (2), an open-close type injection electrode (3), a copper electrode joint (4), a high-voltage-resistant cable (5), a transient voltage injection device (6), a signal control bus (7), an upper computer (8), a gradient monitoring bus (9), a gradient sensor I (101), a gradient sensor II (102) and a gradient sensor III (103);

a first gradient sensor (101), a second gradient sensor (102) and a third gradient sensor (103) are respectively embedded at different positions in the mountain terrain simulation device (2) and are connected to an upper computer (8) through a gradient monitoring bus (9); mountain region topography analogue means (2), mountain region transmission line earthing device (1), open-close type injection electrode (3), copper electrode joint (4) are connected in order, and copper electrode joint (4) are connected to transient voltage injection device (6) through resistant high tension cable (5), and transient voltage injection device (6) are connected with host computer (8) through signal control bus (7).

2. The device for testing the transient resistance gradient distortion of the grounding device of the power transmission line in the mountainous regions according to claim 1, wherein a first gradient sensor (101), a second gradient sensor (102) and a third gradient sensor (103) are respectively embedded at different positions in the mountainous region terrain simulation device (2) and are connected to an upper computer (8) to measure the gradient angle.

3. The mountain area transmission line grounding device transient resistance slope distortion test device of claim 2, wherein the mountain terrain simulation device (2) sets a test mountain slope angle θ₁(ii) a Before the test, data transmitted by each sensor to the upper computer (8) are recorded, the mathematical expectation of the data is obtained through calculation, the data are recorded as the actual test slope angle theta, and the data of each test are stored and recorded in the upper computer (8).

4. The mountain area power transmission line grounding device transient resistance gradient distortion test device according to claim 3, wherein the transient voltage injection device (6) is composed of an alternating current power supply (11), a transient high voltage module (12), a charging module (13), a protection resistor (14), a grounding module (15), a transient high voltage capacitor (16), a discharging module (17), a discharging loop module (18) and a transient current acquisition module (19); the alternating current power supply (11), the transient high-voltage module (12) and the charging module (13) are connected in sequence and then are connected to the grounding module (15) through the protection resistor (14); the discharging module (17), the discharging loop module (18) and the transient current collecting module (19) are connected in sequence and then are connected to the grounding module (15) through the protection resistor (14); the transient high-voltage capacitor (16) is connected to the two ends of the discharging module (17) after being connected with the discharging loop module (18); the discharge loop module (18) is also connected with the copper electrode joint (4); the transient current acquisition module (19) is also connected with the upper computer (8); the transient high-voltage module (12) is connected with the upper computer (8) through a signal control bus (7); the grounding module (18) and the transient current acquisition module (19) are grounded.

5. The mountain area transmission line grounding device transient resistance gradient distortion test device according to claim 4, wherein the upper computer (8) sets a preset transient voltage through the signal control bus (7) and starts a test discharge instruction to control the charging module (13) to be closed to charge the transient high-voltage capacitor (16), when the voltage reaches a preset value, the discharging module (17) is controlled to be closed to discharge the transient high-voltage capacitor (16), and the transient current collecting module (19) measures the transient discharge current amplitude I and transmits the transient discharge current amplitude I to the upper computer (8) to store a record.

6. The mountain area transmission line grounding device transient resistance slope distortion test device of claim 5, wherein the transient resistance distortion parameter k of the mountain area transmission line grounding device (1) is calculated by the transient discharge current amplitude I measured during the test and the actual test slope angle θ:

calculating distortion influence factor k by formula (1) and formula (2)_T1And distortion influence factor two k_T2：

In the formulas (1) to (2), L is the total length of the transmission line grounding device (1) in the mountain area, and I is the transient discharge current amplitude;

calculating the distortion influence factor three k by the formula (3)_ρ：

k_ρ＝0.67e^-18.28ρ-8.4398ρ·e^-56.21478ρ+ρ^-0.4 (3)

In the formula (3), rho is the resistivity of the soil near the grounding device (1) of the power transmission line in the mountainous region;

calculating mountain slope distortion influence factor k by formula (4)_θ：

In the formula (4), theta is the slope angle of the mountain land;

calculating a global characteristic coefficient k by equation (5)₁：

Combining the above results, the transient resistance distortion parameter of the transmission line grounding device (1) in the mountain area obtained by the formula (6) is:

7. the device for testing transient resistance slope distortion of the grounding device of the transmission line in the mountainous area according to claim 6, wherein the transient resistance slope distortion of the grounding device (1) of the transmission line in the mountainous area under the condition that the amplitude I of the transient discharge current and the actual test slope angle theta are evaluated according to k obtained by calculation:

when k is equal to (0.833,1.2), the transient resistance distortion of the transmission line grounding device (1) in the mountain region is weak; when k is equal to (0.666, 0.833) and U [1.2,1.5), the transient resistance distortion of the power transmission line grounding device (1) in the mountain area is general.

8. The device for testing the slope distortion of the transient resistance of the grounding device of the power transmission line in the mountainous area according to claim 7, wherein when k is (0.4, 0.666) U [1.5,2.5 ], the transient resistance of the grounding device (1) of the power transmission line in the mountainous area has stronger distortion.

9. The device for testing the slope distortion of the transient resistance of the grounding device of the power transmission line in the mountainous area according to claim 8, wherein when k ∈ (0,0.4 ∈ U [2.5 ], + ∞), the transient resistance of the grounding device (1) of the power transmission line in the mountainous area has extremely strong distortion.

10. The device for testing transient resistance slope distortion of the grounding device of the power transmission line in the mountainous region according to claim 9, wherein different test mountainous region slope angles are set through the mountainous region terrain simulation device (2), and the transient resistance slope distortion of the grounding device (1) of the power transmission line in the mountainous region under different actual test slopes is evaluated.

Technical Field

The invention relates to the technical field of power system grounding, in particular to a transient resistance gradient distortion testing device for a power transmission line grounding device in a mountain area.

Background

The transmission line shaft tower generally all erects in remote mountain area, and these positions are struck by lightning very likely, and in case the thunderbolt current earial drainage is obstructed, just can make the lightning current pass through the shaft tower and produce the counterattack to the transmission line, causes transmission line tripping operation accident, influences transmission line's normal operating, reduces power system's stability and reliability, consequently research transmission line earthing device's transient resistance distortion degree has very important meaning.

The expressions of the transient resistance of grounding devices with different shapes are different, but the expressions are derived under the condition that the earth is uniform and semi-space and the surface is flat, and the influence of the gradient on the distortion of the transient resistance is not considered. The grounding device is usually buried in mountain land soil of different terrains, the transient resistance distortion characteristic of the grounding device is closely related to the gradient of the mountain land around the grounding device, and the transient resistance distortion characteristics of the grounding devices under different gradients are not completely the same under the action of lightning stroke transient current. At present, the influence of two factors on the resistance of the grounding device is mainly researched domestically, one is spark effect, namely, due to the fact that the amplitude of lightning transient current is large, partial spark discharge is generated around the grounding device when the lightning transient current flows through the grounding device, the conductivity of soil is increased, and the transient resistance of the grounding device is reduced; the other is an inductance effect, namely, the influence of self inductance and mutual inductance of a conductor on the grounding device is increased due to higher equivalent frequency of lightning current, and the current is blocked from flowing to a far end, so that the transient resistance of the grounding device is increased; and the research on the distortion degree of the transient resistance in different slopes of the mountain area is less, so that a method is urgently needed, the influence of the slope of the mountain area can be considered, the transient resistance distortion characteristic of the power transmission line grounding device in the mountain area is tested and evaluated under different slopes, and reference is provided for the lightning protection design of the power transmission line.

The patent specification with the application number of 201910858674.8 discloses a phase current distortion-based single-phase earth fault line selection method for a neutral point ungrounded system, the line selection algorithm is simple, for the single-phase earth fault of the neutral point ungrounded system, after a voltage dip phase is judged to be a fault phase, only the effective current values of all line fault phases before and after the fault are extracted to carry out simple operation, and the line can be correctly selected; and for intermittent earth faults, the effective value of the phase current is increased after the line fault, and the phase current distortion rate epsilon i is also positive, so that the accuracy of line selection of the method is not influenced. However, the patent cannot test and evaluate the transient resistance distortion characteristic of the transmission line grounding device in the mountain area under different slopes by considering the influence of the mountain slopes.

Disclosure of Invention

The invention provides a device for testing the gradient distortion of a transient resistance of a grounding device of a power transmission line in a mountain area, which can test and evaluate the transient resistance distortion characteristic of the grounding device of the power transmission line in the mountain area under different gradients by considering the influence of the gradient of the mountain area.

In order to achieve the technical effects, the technical scheme of the invention is as follows:

a transient resistance slope distortion testing device for a power transmission line grounding device in a mountain area comprises the power transmission line grounding device in the mountain area, a mountain terrain simulation device, an opening-closing type injection electrode, a copper electrode joint, a high-voltage-resistant cable, a transient voltage injection device, a signal control bus, an upper computer, a slope monitoring bus, a slope sensor I, a slope sensor II and a slope sensor III;

the first slope sensor, the second slope sensor and the third slope sensor are respectively embedded at different positions in the mountain land terrain simulation device and are connected to an upper computer through a slope monitoring bus; the mountain land terrain simulation device, the mountain land area power transmission line grounding device, the open-close type injection electrode and the copper electrode connector are sequentially connected, the copper electrode connector is connected to the transient voltage injection device through a high-voltage-resistant cable, and the transient voltage injection device is connected with the upper computer through a signal control bus;

the first slope sensor, the second slope sensor and the third slope sensor are respectively embedded at different positions in the mountain land terrain simulation device and connected to an upper computer to measure slope angles; mountain land terrain simulation device setting test mountain land slope angle theta₁(ii) a And (3) recording data transmitted by each sensor to the upper computer before the test, calculating to obtain a mathematical expectation, recording as an actual test slope angle theta, and storing and recording data of each test in the upper computer.

Furthermore, the transient voltage injection device is composed of an alternating current power supply, a transient high-voltage module, a charging module, a protection resistor, a grounding module, a transient high-voltage capacitor, a discharging module, a discharging loop module and a transient current acquisition module; the alternating current power supply, the transient high-voltage module and the charging module are connected in sequence and then connected to the grounding module through the protection resistor; the discharging module, the discharging loop module and the transient current collecting module are sequentially connected and then connected to the grounding module through the protection resistor; the transient high-voltage capacitor is connected to the two ends of the discharge module after being connected with the discharge loop module; the discharge loop module is also connected with the copper electrode joint; the transient current acquisition module is also connected with an upper computer; the transient high-voltage module is connected with an upper computer through a signal control bus; the grounding module and the transient current acquisition module are grounded; the upper computer sets up predetermined transient voltage and starts the experimental instruction of discharging through signal control bus, and the control module that charges closes charges, charges transient state high voltage capacitor, and when voltage reached the default, the control module that discharges closes makes transient state high voltage capacitor discharge, and transient state current acquisition module measures transient state discharge current amplitude I to transmit to the upper computer and save the record.

Further, calculating a transient resistance distortion parameter k of the power transmission line grounding device in the mountain area through a transient discharge current amplitude value I measured in the test and an actual test slope angle theta:

calculating distortion influence factor k by formula (1) and formula (2)_T1And distortion influence factor two k_T2：

In the formulas (1) to (2), L is the total length of the grounding device of the transmission line in the mountain area, and I is the transient discharge current amplitude;

calculating the distortion influence factor three k by the formula (3)_ρ：

k_ρ＝0.67e^-18.28ρ-8.4398ρ·e^-56.21478ρ+ρ^-0.4 (3)

In the formula (3), rho is the resistivity of the soil near the grounding device of the power transmission line in the mountainous region;

calculating mountain slope distortion influence factor k by formula (4)_θ：

In the formula (4), theta is the slope angle of the mountain land;

calculating a global characteristic coefficient k by equation (5)₁：

Combining the above results, the equation (6) is carried out to obtain the transient resistance distortion parameter of the transmission line grounding device in the mountain area as follows:

further, evaluating the slope distortion of the transient resistance of the power transmission line grounding device in the mountain area under the transient discharge current amplitude I and the actual test slope angle theta according to the k obtained by calculation:

when k is equal to (0.833,1.2), the transient resistance distortion of the transmission line grounding device in the mountain region is weak; when k belongs to (0.666, 0.833) and U [1.2,1.5 ], the transient resistance distortion of the power transmission line grounding device in the mountain region is general; when k belongs to (0.4, 0.666) U [1.5,2.5), the transient resistance distortion of the power transmission line grounding device in the mountain region is stronger; when k is equal to (0, 0.4) U [2.5, + ∞), the transient resistance distortion of the power transmission line grounding device in the mountain area is extremely strong.

Different test mountain slope angles are set through the mountain land terrain simulation device, and transient resistance slope distortion of the power transmission line grounding device in the mountain land area with different actual test slopes is evaluated.

Compared with the prior art, the technical scheme of the invention has the beneficial effects that:

according to the method, the slope angle of a test mountain can be set through a mountain terrain simulation device by establishing the mountain area power transmission line grounding device transient resistance slope distortion test device, and the slope angle can be detected through a slope sensor to evaluate the mountain area power transmission line grounding device transient resistance slope distortion characteristic; the method can simulate the distortion process of the resistance of the grounding device of the transmission line in the mountainous area under different mountainous slopes under the transient voltage, is convenient and intelligent to operate, safe and reliable, and can accurately evaluate the slope distortion characteristic of the transient resistance of the grounding device of the transmission line in the mountainous area.

Drawings

FIG. 1 is a schematic diagram of the general structure of the present invention;

fig. 2 is an internal schematic view of the transient voltage injection apparatus of the present invention.

Detailed Description

The drawings are for illustrative purposes only and are not to be construed as limiting the patent;

for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product;

it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The technical solution of the present invention is further described below with reference to the accompanying drawings and examples.

Example 1

As shown in fig. 1, the device for testing the slope distortion of the transient resistance of the grounding device of the power transmission line in the mountainous region comprises a grounding device 1 of the power transmission line in the mountainous region, a mountainous region terrain simulation device 2, an open-close type injection electrode 3, a copper electrode joint 4, a high-voltage-resistant cable 5, a transient voltage injection device 6, a signal control bus 7, an upper computer 8, a slope monitoring bus 9, a first slope sensor 101, a second slope sensor 102 and a third slope sensor 103;

the first gradient sensor 101, the second gradient sensor 102 and the third gradient sensor 103 are respectively embedded at different positions in the mountain terrain simulation device 2 and are connected to the upper computer 8 through a gradient monitoring bus 9; mountain region topography analogue means 2, mountain region transmission line earthing device 1, open-close type injection electrode 3, copper electrode joint 4 are connected in order, and copper electrode joint 4 is connected to transient voltage injection device 6 through high voltage resistant cable 5, and transient voltage injection device 6 is connected with host computer 8 through signal control bus 7.

The first gradient sensor 101, the second gradient sensor 102 and the third gradient sensor 103 are respectively embedded at different positions in the mountain terrain simulation device 2 and are connected to the upper computer 8 to measure the gradient angle.

Mountain land terrain simulation device 2 for setting experimental mountain land slope angle theta₁(ii) a Before the test, data transmitted by each sensor to the upper computer 8 are recorded, mathematical expectation of the data is obtained through calculation, the data are recorded as actual test slope angles theta, and data of each test are stored and recorded in the upper computer 8.

As shown in fig. 2, the transient voltage injection device 6 is composed of an ac power supply 11, a transient high voltage module 12, a charging module 13, a protection resistor 14, a grounding module 15, a transient high voltage capacitor 16, a discharging module 17, a discharging loop module 18, and a transient current collecting module 19; the alternating current power supply 11, the transient high voltage module 12 and the charging module 13 are connected in sequence and then connected to the grounding module 15 through the protection resistor 14; the discharging module 17, the discharging loop module 18 and the transient current collecting module 19 are connected in sequence and then connected to the grounding module 15 through the protection resistor 14; the transient high-voltage capacitor 16 is connected to two ends of the discharging module 17 after being connected with the discharging loop module 18; the discharge loop module 18 is also connected with the copper electrode joint 4; the transient current acquisition module 19 is also connected with the upper computer 8; the transient high-voltage module 12 is connected with the upper computer 8 through a signal control bus 7; the grounding module 18 and the transient current collecting module 19 are both grounded.

The upper computer 8 sets a preset transient voltage through the signal control bus 7 and starts a test discharging instruction to control the charging module 13 to be closed to charge the transient high-voltage capacitor 16, when the voltage reaches a preset value, the discharging module 17 is controlled to be closed to discharge the transient high-voltage capacitor 16, the transient current collecting module 19 measures a transient discharging current amplitude value I, and the transient discharging current amplitude value I is transmitted to the upper computer 8 to be stored and recorded.

Example 2

A method for testing the gradient distortion of a transient resistor of a power transmission line grounding device in a mountain area comprises the following steps:

the first step is as follows: the test device for controlling the gradient of the transient resistance distortion characteristic of the grounding device of the power transmission line in the mountainous region is built, and comprises the grounding device 1 of the power transmission line in the mountainous region, a mountainous region terrain simulation device 2, an open-close type injection electrode 3, a copper electrode joint 4, a high-voltage-resistant cable 5, a transient voltage injection device 6, a signal control bus 7, an upper computer 8, a gradient monitoring bus 9, a first gradient sensor 101, a second gradient sensor 102 and a third gradient sensor 103, as shown in figure 1.

The second step is that: setting and controlling the gradient of the mountain land: wherein, the first gradient sensor (101), the second gradient sensor (102) and the third gradient sensor (103) are respectively embedded in the mountain terrain simulator (2)The same position is connected with an upper computer 8 and is used for measuring the slope angle around the mountain land where the grounding device is located; mountain land terrain simulation device 2 can set experimental mountain land slope angle theta by self₁(ii) a Before the test, data transmitted to the upper computer 8 by the first gradient sensor 101, the second gradient sensor 102 and the third gradient sensor 103 are recorded, mathematical expectation of the data is obtained through calculation and recorded as an actual test gradient angle theta, and the data of each test is stored and recorded in the upper computer 8 through a gradient monitoring bus 9.

The third step: injecting transient voltage into the power transmission line grounding device 1 in the mountain area and recording the transient discharge current amplitude I under the actual test slope angle theta; as shown in fig. 2, the transient voltage injection device 6 is composed of an ac power supply 11, a transient high voltage module 12, a charging module 13, a protection resistor 14, a grounding module 15, a transient high voltage capacitor 16, a discharging module 17, a discharging loop module 18, a transient current collecting module 19, and a device housing 20; the upper computer 8 can set a preset transient voltage through the signal control bus 7 and start a test discharging instruction, the charging module 13 is controlled to be closed, the transient high-voltage capacitor 16 is charged, when the voltage reaches a preset value, the discharging module 17 is controlled to be closed, the transient high-voltage capacitor 16 is discharged through the discharging loop module 18, the high-voltage resistant cable 5, the copper electrode joint 4, the open-close type injection electrode 3 and the grounding device 1 of the transmission line in the mountain area, and meanwhile, the transient current amplitude I is measured by the transient current collecting module 19 and is transmitted to the upper computer 8 to be stored and recorded; if the discharge of the test product needs to be stopped after the test is finished, or residual voltage exists on the capacitor after the test is finished, the charge of the transient high-voltage capacitor 16 can be consumed through the protective resistor 14 by closing the grounding module 15, so that the safety of equipment and personnel is ensured.

And fourthly, calculating a transient resistance distortion characteristic parameter k of the power transmission line grounding device in the mountain area through the transient discharge current amplitude I measured during the test and the actual test slope angle theta:

calculating distortion influence factors of one kT1 and two kT2 by using equations (7) and (8):

in the formulas (7) to (8), L is the total length of the power transmission line grounding device 1 in the mountain area, and is represented by m, and I is the transient discharge current amplitude, and is represented by kA.

The distortion influence factor tri k ρ is calculated by equation (9):

k_ρ＝0.67e^-18.28ρ-8.4398ρ·e^-56.21478ρ+ρ^-0.4 (9)

in the formula (9), ρ is the resistivity of the soil near the power transmission line grounding device 1 in the mountain area, and the unit is Ω · m.

Calculating a mountain slope distortion influence factor k θ by equation (10):

in the formula (10), θ is the slope angle of the mountain land and has a unit of °.

The global characteristic coefficient k1 is calculated by equation (11):

combining the above results, the transient resistance distortion characteristic parameter of the grounding device obtained by the equation (12) is:

and fifthly, evaluating the slope distortion characteristic of the transient resistance of the power transmission line grounding device in the mountain area under the transient discharge current amplitude I and the actual test slope angle theta according to the calculated k:

when k is equal to (0.833,1.2), the transient resistance distortion characteristic of the transmission line grounding device 1 in the mountain region is weaker; when k belongs to (0.666, 0.833) and U [1.2,1.5 ], the transient resistance distortion characteristic of the power transmission line grounding device 1 in the mountain region is general; when k belongs to (0.4, 0.666) U [1.5,2.5), the transient resistance distortion characteristic of the power transmission line grounding device 1 in the mountain area is strong, and various conditions are proposed to take resistance distortion influence into account; when k ∈ (0,0.4 [ [2.5 ], + ∞ ]), the transient resistance distortion characteristic of the power transmission line grounding device 1 in the mountain area is extremely strong, and the resistance distortion influence must be considered during design.

And sixthly, testing the transient resistance gradient distortion characteristic of the grounding device 1 of the transmission line in the mountainous region under different gradient angles, setting different testing mountainous region gradient angles through the mountainous region terrain simulation device 2, repeating the third step, the fourth step and the fifth step, and evaluating the transient resistance gradient distortion characteristic of the grounding device 1 of the transmission line in the mountainous region under different actual testing gradients.

The same or similar reference numerals correspond to the same or similar parts;

the positional relationships depicted in the drawings are for illustrative purposes only and are not to be construed as limiting the present patent;

it should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.