Forest combustible lightning stratified current characteristic test system and lightning stratified current characteristic test and analysis method

Abstract

The invention discloses a forest combustible lightning stratified current characteristic test system and a lightning stratified current characteristic test and analysis method. The test system comprises a lightning pulse current source, a forest combustible sample, a lightning stratified current characteristic clamping mechanism and a lightning current control and electrical parameter measurement and analysis unit. Through forest combustible stratified current test data under the action of lightning current, a data statistics method is used to finally obtain the stratified characteristics of forest combustible and the correlation between the shunting characteristics of lightning current in different stratification and factors such as forest combustible moisture content, lightning current electrical parameters and the like. A forest combustible lightning stratified current characteristic database simulating different regional characteristics is formed, and a foundation is laid for multi-physical field modeling calculation of smoldering and ignition mechanisms caused by lightning stroke of forest combustible.

Description

Technical Field

[0001] The invention relates to a test method for forest lightning fire characteristics, and in particular to a forest combustible lightning layered current characteristic test system and a lightning layered current characteristic test and analysis method. Background Art

[0002] With global warming and the increase in extreme weather, lightning activities are frequent and the frequency of lightning fires has increased significantly, which not only seriously damages forest resources and the ecological environment, but also poses great harm to people's lives, property and public safety, and poses a huge threat to the sustainable development of the national economy and ecological security. In the past 10 years, the proportion of lightning fires in major forest fires in my country has increased from 5% to more than 60%. The cause mechanism of lightning fires is complex, and it is difficult to monitor and detect, and difficult to extinguish and deal with. The monitoring, early warning and prevention and control of lightning fires have become a global problem.

[0003] According to spatial distribution, combustibles are divided into three categories: forest combustibles, above-ground high-rise forest combustibles and underground forest combustibles. Among them, forest combustibles include dead branches and leaves and undecomposed rough humus in the forest, which have the greatest impact on the fire risk level; according to vitality, forest combustibles are divided into living forest combustibles and dead forest combustibles. For living forest combustibles, moisture content is an important indicator for predicting forest fire occurrence, forest fire behavior, energy release, and estimating forest fire risk; dead forest combustibles are an important cause of forest fires. Studying the distribution of dead forest combustible load on the forest surface is of great significance to fire prevention and forest combustible management.

[0004] Lightning is a multiple continuous time-series discharge process. In the process of multiple lightning strikes, the first lightning component plays a vital role, involving the attachment process of lightning strikes to forest combustibles, directly affecting the lightning stratification current characteristics of lightning current in different stratified structures of forest combustibles, and is of great significance to the theoretical study of forest lightning smoldering or ignition mechanisms. Existing research on lightning fires is mainly based on the establishment of prediction models based on historical lightning fire data, predicting the probability and area of ​​lightning fires based on meteorological conditions and forest conditions, and starting from the physical process or mechanism of lightning attachment to forest combustibles, lightning stratification current, etc., there are very few research literature reports on the generation and development process of lightning fires. Therefore, the accuracy of existing prediction models for lightning warnings is difficult to guarantee. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a lightning stratified current characteristics test system for forest combustibles and a lightning stratified current characteristics test and analysis method, so as to obtain the correlation between the stratified current characteristics of forest combustibles under lightning strikes and the climate environment, the lightning current action mode and the electrical parameters, and lay a foundation for the multi-physical field modeling and calculation of the smoldering and ignition mechanisms caused by lightning strikes on forest combustibles.

[0006] The present invention is achieved through the following technical solutions:

[0007] A forest combustible lightning layered current characteristic test system, comprising a lightning pulse current source, a forest combustible test sample, a lightning layered current characteristic clamping mechanism, a lightning current control and an electrical parameter measurement and analysis unit;

[0008] The lightning pulse current source includes a controllable high-voltage DC charging power supply and a lightning pulse current generating unit. The charging voltage of the lightning pulse current generating unit is monitored by a charging voltage monitoring sensor, and the charging voltage analog value is transmitted to the control unit 31 of the lightning current control and electrical parameter measurement and analysis unit;

[0009] The forest combustible sample is installed through a clamping mechanism of a lightning layered current test and is electrically connected to a lightning pulse current generating unit;

[0010] The clamping mechanism is a mounting fixture having a high-voltage electrode HV and a plurality of low-voltage electrodes LV, the high-voltage electrode is an electrode plate of the same size as one end face of the forest combustible, the plurality of low-voltage electrodes are strip electrodes corresponding to the texture of the other end face of the forest combustible, the high-voltage electrode HV is electrically connected to the output high-voltage port of the lightning pulse current generating unit, and the plurality of low-voltage electrodes LV are respectively electrically connected to the low-voltage ports of the lightning pulse current generating unit;

[0011] The lightning current control and electrical parameter measurement and analysis unit realize the control of forest combustible lightning stratification current test and the measurement and analysis of lightning pulse current electrical parameters, and include a control unit and a lightning pulse current measurement and analysis unit.

[0012] Furthermore, the controllable high-voltage DC charging power supply is mainly composed of an electronically controlled voltage regulator T1, a transformer T2, a voltage-doubling capacitor C B , rectifier silicon stacks D1 and D2 and current limiting resistor Rc. The lightning pulse current generating unit is mainly composed of a pulse energy storage capacitor C, a high-voltage discharge switch G, a waveform forming inductor L and a resistor R, which are electrically connected in series, and the forest combustible sample under test and its connection fixture are connected in series in the loop of the energy storage capacitor, the high-voltage discharge switch G, the waveform forming inductor and the resistor.

[0013] Furthermore, the clamping mechanism includes an insulating box with a four-sided structure for placing the forest combustible sample, and the inner side surfaces of the opposite sides of the insulating box are respectively designed with a high-voltage electrode plate and a plurality of low-voltage electrode plates LV1 to LVN, wherein N is the number of layers of the forest combustible pattern, and electrical connection ends of different layers from the side end surface of the forest combustible are led out through the plurality of low-voltage electrode plates;

[0014] The wires electrically connecting multiple low-voltage electrodes LV1~LVN to the low-voltage output port of the lightning pulse current generating unit are covered with current induction coils L1, L2, ..., LN for measuring the lightning current of each layer of forest combustibles. The lightning current layer current waveforms Im1, Im2, ..., ImN of the forest combustibles are measured respectively, where m in the following table represents the number of data points of the lightning current.

[0015] Furthermore, the charging voltage monitoring circuit receives the signal transmitted by the charging voltage monitoring sensor, and processes it through the programmable controller and its related control circuit, and outputs the control signal to the programmable controller and its related control circuit, thereby controlling the discharge of the discharge switch of the lightning pulse current generating unit; the programmable controller and its related control circuit are also combined with the industrial control computer of the lightning pulse current measurement and analysis unit to control the connection / disconnection, high voltage rise / fall and discharge control of the discharge switch G of the charging process of the forest combustible lightning stratification current characteristic test, so as to realize the automatic control of the forest combustible lightning stratification current characteristic test process.

[0016] Furthermore, the lightning pulse current parameter measurement and analysis unit is mainly composed of pulse current sensors 32-1, 32-2, ..., 32-N, a digital oscilloscope and an industrial control computer 32-4; ​​the pulse current sensors 32-1, 32-2, ..., 32-N are combined with the digital oscilloscope 32-3 to measure the lightning stratification current characteristics of different areas of forest combustibles; the industrial control computer processes and analyzes the lightning stratification current signals of different areas of forest combustibles measured by the digital oscilloscope, so as to obtain the forest combustible lightning stratification including parameters such as forest combustible moisture content, environmental temperature and humidity, and lightning current point electrical parameters, as well as the stratification current characteristics of different strata.

[0017] A method for testing and analyzing the lightning current diversion characteristics of forest standing trees, comprising the following steps:

[0018] (1) Sample selection and processing: Select forest fuel samples from typical forest areas and process the samples to obtain multiple forest fuel samples with different humidity and moisture content;

[0019] (2) Select the first forest combustible sample S1 with the highest moisture content for testing; the electrodes of the clamping mechanism are electrically connected to the lightning pulse current generating unit, the high-voltage electrode HV is in close contact with one end surface of the forest combustible sample, and the multiple low-voltage electrodes LV1 to LVN are in close contact with different textured partitions on the other end surface of the forest combustible sample;

[0020] 1) Lightning current pulses with different peak values ​​are applied to forest combustibles, and the pulse current discharge unit outputs a preset first discharge current point I1, corresponding to which the layered current data I11, I12, ..., I1N of the forest combustibles are obtained;

[0021] 2) changing the output current of the pulse current discharge unit so that the preset discharge current point changes from I1 to Im, and correspondingly obtaining the diversion data Im1, Im2, ..., ImN of the standing trees in the forest;

[0022] 3) Analyze the lightning layered current data I11, I12, ..., I1N to Im1, Im2, ..., ImN of forest combustibles. If the deviation between two adjacent layered current data points of forest combustibles is very small under the action of lightning current pulses of not less than 5 amplitude data points, the two adjacent layers are merged;

[0023] 4) Repeat the test from step 2) to step 3) for the lightning current stratification after the forest combustibles are combined until the lightning current stratification of the forest combustible sample S1 is determined;

[0024] 5) Select the next sample with different moisture content, and repeat steps 1) to 4) until the lightning stratification test of all combustible samples with different moisture content is completed, and the lightning stratification of the forest combustible sample and the stratification current characteristics of each stratification are obtained;

[0025] (3) Repeat the test process of step (2) for forest combustible samples with different temperatures and humidities to obtain lightning current shunt data for each area of ​​the forest combustible samples with different temperatures and humidities;

[0026] (4) Statistical analysis was performed on all forest combustible lightning stratification current test data to obtain the relationship between forest combustible stratification, lightning stratification current intensity, and moisture content, temperature and humidity of forest combustible samples, thus forming a forest combustible lightning stratification current database and characteristic laws.

[0027] The present invention focuses on the lightning stratification current characteristics of forest combustibles struck by lightning, establishes a test system for the lightning stratification current characteristics of forest combustibles, proposes a test method for the lightning stratification current characteristics of forest combustibles, and uses the test data of the stratification current of forest combustibles under the action of lightning current and a data statistical method to finally obtain the stratification characteristics of forest combustibles and the correlation between the shunt characteristics of lightning current in different layers and factors such as the moisture content of forest combustibles and lightning current electrical parameters, thereby forming a database of lightning stratification current characteristics of forest combustibles simulating different regional characteristics, laying a foundation for multi-physical field modeling and calculation of the smoldering and ignition mechanisms caused by lightning strikes on forest combustibles. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural block diagram of the lightning layered current characteristic test system of the present invention;

[0029] Figure 2 It is a circuit principle block diagram of the lightning layered current characteristic test system of the present invention;

[0030] Figure 3 A clamping mechanism for the lightning layered current characteristic test of forest combustibles of the present invention;

[0031] Among them, (a) is a multi-layer structure diagram of forest combustibles clamped by a clamping mechanism; (b) is a schematic diagram of the electrodes in the clamping mechanism Figure 1 ; (c) is a schematic diagram of the electrodes in the clamping mechanism Figure 2 ;

[0032] Figure 4 This is a flow chart of the test and analysis method of lightning stratification current characteristics of forest combustibles. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0034] join Figure 1 , Figure 2 The forest combustible lightning stratified current characteristic test system of the present invention is composed of a lightning pulse current source 1, a forest combustible sample 2, a lightning stratified current characteristic clamping mechanism, a lightning current control and electrical parameter measurement and analysis unit 3.

[0035] The lightning pulse current source 1 is mainly composed of a controllable high-voltage DC charging power supply 1-1 and a lightning pulse current generating unit 1-2. In actual tests, the charging voltage of the controllable high-voltage DC charging power supply 1-1 to the lightning pulse current generating unit 1-2 is monitored online by a charging voltage monitoring sensor 1-3, and the charging voltage analog quantity is transmitted to the control unit 31 of the lightning current control and electrical parameter measurement and analysis unit 3.

[0036] See also Figure 2 The principle circuit of the lightning pulse current source 1 for the forest combustible lightning layered current characteristic test of the present invention mainly contains the circuit principle of the controllable high-voltage DC charging power supply 1-1 and the lightning pulse current generating unit 1-2. In view of the high voltage environment with extremely high amplitude when the actual lightning strike occurs, and the breakdown characteristics of forest combustibles, the working voltage of the lightning pulse power supply in this application cannot be too low, at least 100kV or even higher, so the controllable high-voltage DC charging power supply 1-1 can adopt the usual rectification and filtering charging method, but it is best to adopt the voltage doubling charging method to avoid the occurrence of corona discharge during the experiment, which affects the reliability and stability of the lightning pulse current source.

[0037] The controllable high-voltage DC charging power supply 1-1 is mainly composed of an electronically controlled voltage regulator T1, a transformer T2, and a voltage-doubling capacitor C B, rectifier silicon stacks D1 and D2 and current limiting resistor Rc. The lightning pulse current generating unit 1-2 is mainly composed of a pulse energy storage capacitor C, a high-voltage discharge switch G, a waveform forming inductor L and a resistor R, which are electrically connected in series, and the forest combustible sample under test and its connection fixture are connected in series in the loop of the energy storage capacitor, the high-voltage discharge switch G, the waveform forming inductor and the resistor.

[0038] See also Figure 3 As shown in (a), forest fuel is a multi-layered complex structure with litter layer, humus layer, eluvial layer, sediment layer, parent material layer and parent rock layer, and the materials and properties of each layer are quite different. In laboratory simulation research, theoretical research can construct a multi-layer model for numerical calculation, but the simulation results are difficult to verify. In fact, the thickness of forest fuel samples that can be obtained in experimental research is generally 300-500mm, which can simulate the characteristics of fuel in typical forest areas to a certain extent.

[0039] like Figure 3 In the figure, the clamping mechanism of the lightning stratified current test shown in (b) and (c) is to mount the forest combustible material on a mounting fixture structure having a high-voltage electrode HV and multiple low-voltage electrodes LV, wherein the high-voltage electrode HV is electrically connected to the output high-voltage port of the lightning pulse current generating unit 1-2, and the multiple low-voltage electrodes LV are respectively electrically connected to the low-voltage ports (or called return electrodes) of the lightning pulse current generating unit 1-2.

[0040] The clamping mechanism of forest combustibles is an insulating box with a four-sided structure, which is used to place the forest combustible sample 2. The inner side surfaces of the opposite sides of the insulating box are respectively designed with a high-voltage electrode plate and a plurality of low-voltage electrode plates LV1 to LVN, where N is the number of layers of the forest combustible pattern. The function of the plurality of low-voltage electrode plates is to lead out electrical connection ends of different layers from the side end surface of the forest combustible.

[0041] On the wires electrically connected to the low-voltage output port of the lightning pulse current generating unit, multiple low-voltage electrodes LV1~LVN in close contact with the side end faces of the forest combustibles are mounted. Current induction coils L1, L2, ..., LN for measuring the lightning current of each layer of the forest combustibles are installed. The lightning current layered current waveforms Im1, Im2, ..., ImN of the forest combustibles are measured respectively, where m (≥5) in the following table represents the number of data points of the lightning current.

[0042] The high-voltage electrode is an electrode plate of the same size as the end face of the forest combustible, and the multiple low-voltage electrodes are strip electrodes corresponding to the texture of the end face of the forest combustible. The size of the electrode will change with the change of the lightning stratification of the forest combustible. The high-voltage electrode is connected to the high-voltage end of the lightning pulse current generating unit, and each low-voltage electrode is individually connected to the low-voltage end of the pulse current discharge unit. A current sensing coil is sleeved in the connecting line connecting the multiple low-voltage electrodes to the pulse discharge unit, which is used to measure the lightning current stratification current of the forest combustible. By injecting lightning current pulses with different peak values ​​into the forest combustible, the lightning stratification current data of the forest combustible under the action of lightning current pulses with different peak values ​​can be obtained.

[0043] The function of the lightning current control and electrical parameter measurement and analysis unit 3 is to realize the control of the forest combustible lightning stratification current test and the measurement and analysis of the lightning pulse current electrical parameters. It is mainly composed of a control unit 31 and a lightning pulse current measurement and analysis unit 32. Among them, the control unit 31 is mainly composed of a charging voltage monitoring circuit 31-1, a programmable controller and its related control circuit 31-2. The charging voltage monitoring circuit 31-1 of the control unit 31 receives the signal transmitted by the charging voltage monitoring sensor 1-3, and after being processed by the programmable controller and its related control circuit 31-2, it can output a control signal to the programmable controller and its related control circuit 31-2, so as to control the discharge of the discharge switch of the lightning pulse current generating unit 1-2. In addition, the programmable controller and its related control circuit 31-2 are also combined with the industrial control computer 32-4 of the lightning pulse current measurement and analysis unit 32 to control the connection / disconnection of the charging process of the forest combustible lightning stratification current characteristic test, the high voltage rise / drop and the discharge control of the discharge switch G, so as to realize the automatic control of the forest combustible lightning stratification current characteristic test process.

[0044] The lightning pulse current parameter measurement and analysis unit 32 is mainly composed of pulse current sensors 32-1, 32-2, ..., 32-N, a digital oscilloscope 32-3 and an industrial control computer 32-4. The pulse current sensors 32-1, 32-2, ..., 32-N are combined with the digital oscilloscope 32-3 to measure the lightning stratification current characteristics of different areas of forest combustibles; the industrial control computer 32-4 processes and analyzes the lightning stratification current signals of different areas of forest combustibles measured by the digital oscilloscope 32-3, thereby obtaining the forest combustible lightning stratification including parameters such as forest combustible moisture content, environmental temperature and humidity, and lightning current point electrical parameters, as well as the stratification current characteristics of different strata.

[0045] In order to improve the reliability and credibility of the lightning layered current characteristic data of forest combustibles under repeated lightning discharges, the lightning pulse discharge current source ensures that the pulse current amplitude flowing through the forest combustibles is not too large. It is recommended to be in the order of several kA, otherwise ablation may occur and it is impossible to obtain layered current characteristic data of no less than m (≥5) data points. If the number of layers of forest combustibles is greater than 4, two sets of oscilloscopes or multi-channel data acquisition systems can be used in conjunction with industrial computers for collection, recording and analysis.

[0046] See also Figure 4 , the lightning stratification current characteristic test and analysis method of forest combustibles, the specific test and analysis process is as follows:

[0047] 1) Sample selection and processing: Select forest combustible samples from typical forest areas and process the samples, including humidity and moisture content, to simulate the actual environment of different plants in different seasons and climatic conditions.

[0048] Prepare forest fuel samples with different moisture contents, at least 5 samples with different moisture contents (denoted as S1 to S5). The samples can be selected from typical forests with different climatic and environmental characteristics (such as Daxinganling, Liangzhou, etc.).

[0049] 2) Select / reselect the forest fuel sample S1 with the first moisture content for testing;

[0050] 3) Install the forest combustibles in the clamping mechanism, and connect the low-voltage electrodes, high-voltage electrodes of the clamping mechanism with the output end of the lightning pulse current generating unit.

[0051] 4) Apply lightning current pulses with different peak values ​​to forest combustibles, and measure lightning stratification current data under the action of different peak lightning currents through multiple current sensors.

[0052] m (≥5) discharge current (or discharge voltage) points are selected, and the output of the preset discharge current peak value is realized through the discharge voltage of the pulse current discharge unit 1 - 2 .

[0053] 5) Change the charging voltage of the controllable high-voltage DC charging power supply 1-1 to the energy storage capacitor of the pulse current discharge unit 1-2. When the control unit 31 detects that the charging voltage of the energy storage capacitor is greater than or equal to the preset discharge voltage U1, the control unit 31 outputs a discharge pulse to the controllable high-voltage discharge switch of the pulse current discharge unit 1-2, and the pulse current discharge unit 1-2 outputs the preset first discharge current point I1, corresponding to the stratified current data I11, I12, ..., I1N of the forest combustibles. Similarly, change the charging voltage of the controllable high-voltage DC charging power supply 1-1 to the energy storage capacitor of the pulse current discharge unit 1-2 until the pulse current discharge unit 1-2 outputs the preset first discharge current point Im, corresponding to the stratified current data Im1, Im2, ..., ImN of the forest combustibles.

[0054] 6) Analyze the lightning stratification current data of forest combustibles I11, I12, ..., I1N to Im1, Im2, ..., ImN. If the deviation between two adjacent stratification current data points of forest combustibles is very small (for example, less than 5%) under the action of lightning current pulses with no less than 5 amplitude data points, the two adjacent stratifications can be merged.

[0055] 7) Repeat the tests from step 2) to step 5) on the lightning current stratification after the forest combustibles are combined until the lightning current stratification of the forest combustible sample S1 is determined.

[0056] 8) Select the next sample with different moisture content and repeat steps 3) to 7) until the lightning stratification test of all combustible samples with different moisture content is completed, and the lightning stratification of the forest combustible sample and the stratification current characteristics of each stratification are obtained.

[0057] 9) For the lightning stratification current characteristics of forest combustible samples under different temperature and humidity environments, the test method is the same as the test method for samples with different moisture contents, and the above test process can be repeated to obtain;

[0058] 10) Conduct statistical analysis on all forest combustible lightning stratification current test data to obtain the correlation between forest combustible stratification, lightning stratification current intensity and factors such as forest combustible sample moisture content and climate environment, form a forest combustible lightning stratification current database and characteristic laws, and lay the foundation for the establishment of lightning strikes or models and the prediction of lightning fires.

[0059] 11) Based on the forest combustible lightning stratification current database, multi-factor regression and other methods are used to analyze the combustible lightning stratification current, forming an evaluation method for the forest combustible lightning stratification current characteristics.

Claims

1. A forest combustible lightning layered current characteristics test system, characterized by: It comprises a lightning pulse current source (1), a forest combustible material test piece (2), a lightning layered current characteristic clamping mechanism, a lightning current control unit and an electrical parameter measurement and analysis unit (3); The lightning pulse current source (1) comprises a controllable high-voltage direct current charging power supply (1-1) and a lightning pulse current generating unit (1-2); the charging voltage of the lightning pulse current generating unit (1-2) is monitored by the controllable high-voltage direct current charging power supply (1-1) via a charging voltage monitoring sensor (1-3), and the charging voltage analog quantity is transmitted to a control unit (31) of a lightning current control and electrical parameter measurement and analysis unit (3); The forest combustible material sample (2) is installed through a clamping mechanism for a lightning layered current test and is electrically connected to a lightning pulse current generating unit (1-2); The clamping mechanism is a mounting fixture having a high-voltage electrode HV and a plurality of low-voltage electrodes LV, the high-voltage electrode is an electrode plate of the same size as one end face of the forest combustible, the plurality of low-voltage electrodes are strip electrodes corresponding to the texture of the other end face of the forest combustible, the high-voltage electrode HV is electrically connected to the output high-voltage port of the lightning pulse current generating unit (1-2), and the plurality of low-voltage electrodes LV are respectively electrically connected to the low-voltage ports of the lightning pulse current generating unit (1-2); The lightning current control and electrical parameter measurement and analysis unit (3) realizes the control of the forest combustible lightning layer current test and the measurement and analysis of the electrical parameters of the lightning pulse current, and comprises a control unit (31) and a lightning pulse current measurement and analysis unit (32).

2. The forest combustible lightning layered current characteristic test system according to claim 1 is characterized by: The controllable high-voltage DC charging power supply (1-1) is mainly composed of an electronically controlled voltage regulator T1, a transformer T2, a voltage multiplier capacitor C B , rectifier silicon stacks D1 and D2 and current limiting resistor Rc. The lightning pulse current generating unit (1-2) is mainly composed of a pulse energy storage capacitor C, a high-voltage discharge switch G, a waveform forming inductor L and a resistor R, which are electrically connected in series, and the forest combustible sample to be tested and its connection fixture are connected in series in the loop of the energy storage capacitor, the high-voltage discharge switch G, the waveform forming inductor and the resistor.

3. The forest combustible lightning layered current characteristic test system according to claim 1 is characterized by: The clamping mechanism comprises an insulating box with a four-sided structure for placing the forest combustible material sample (2), and the inner side surfaces of the opposite sides of the insulating box are respectively designed with a high-voltage electrode plate and a plurality of low-voltage electrode plates LV1 to LVN, wherein N is the number of layers of the forest combustible material pattern, and electrical connection ends of different layers from the side end surface of the forest combustible material are led out through the plurality of low-voltage electrode plates; The wires electrically connecting multiple low-voltage electrodes LV1~LVN to the low-voltage output port of the lightning pulse current generating unit are covered with current induction coils L1, L2, ..., LN for measuring the lightning current of each layer of forest combustibles. The lightning current layer current waveforms Im1, Im2, ..., ImN of the forest combustibles are measured respectively, where m in the following table represents the number of data points of the lightning current.

4. The forest combustible lightning layered current characteristic test system according to claim 1 is characterized by: The charging voltage monitoring circuit (31-1) receives the signal transmitted by the charging voltage monitoring sensor (1-3), processes it through the programmable controller and its related control circuit (31-2), and outputs a control signal to the programmable controller and its related control circuit (31-2), thereby controlling the discharge of the discharge switch of the lightning pulse current generating unit (1-2); the programmable controller and its related control circuit (31-2) are also combined with the industrial control computer (32-4) of the lightning pulse current measuring and analyzing unit (32) to control the connection / disconnection, high voltage increase / decrease, and discharge control of the discharge switch G during the charging process of the forest combustible lightning stratification current characteristic test, thereby realizing automatic control of the forest combustible lightning stratification current characteristic test process.

5. The forest combustible lightning layered current characteristic test system according to claim 1 is characterized by: The lightning pulse current parameter measurement and analysis unit (32) is mainly composed of pulse current sensors (32-1), (32-2), ..., (32-N), a digital oscilloscope (32-3) and an industrial control computer (32-4); the pulse current sensors (32-1), (32-2), ..., (32-N) are combined with the digital oscilloscope (32-3) to measure the lightning stratification current characteristics of different areas of forest combustibles; the industrial control computer (32-4) processes and analyzes the lightning stratification current signals of different areas of forest combustibles measured by the digital oscilloscope (32-3), thereby obtaining forest combustible lightning stratification including parameters such as forest combustible moisture content, environmental temperature and humidity, and lightning current point electrical parameters, as well as stratification current characteristics of different strata.

6. A test and analysis method for the lightning shunt characteristics of forest standing trees based on the test system of claim 1, characterized in that The steps include: (1) Sample selection and processing: Select forest fuel samples from typical forest areas and process the samples to obtain multiple forest fuel samples with different humidity and moisture content; (2) Select the first forest combustible sample S1 with the highest moisture content for testing; the electrodes of the clamping mechanism are electrically connected to the lightning pulse current generating unit, the high-voltage electrode HV is in close contact with one end surface of the forest combustible sample, and the multiple low-voltage electrodes LV1 to LVN are in close contact with different textured partitions on the other end surface of the forest combustible sample; 1) applying lightning current pulses with different peak values ​​to forest combustibles, and the pulse current discharge unit (1-2) outputs a preset first discharge current point I1, and correspondingly obtains layered current data I11, I12, ..., I1N of the forest combustibles; 2) changing the output current of the pulse current discharge unit (1-2) so that the preset discharge current point changes from I1 to Im, and correspondingly obtaining the diversion data Im1, Im2, ..., ImN of the standing trees in the forest; 3) Analyze the lightning layered current data I11, I12, ..., I1N to Im1, Im2, ..., ImN of forest combustibles. If the deviation between two adjacent layered current data points of forest combustibles is very small under the action of lightning current pulses of not less than 5 amplitude data points, the two adjacent layers are merged; 4) Repeat the test from step 2) to step 3) for the lightning current stratification after the forest combustibles are combined until the lightning current stratification of the forest combustible sample S1 is determined; 5) Select the next sample with different moisture content, and repeat steps 1) to 4) until the lightning stratification test of all combustible samples with different moisture content is completed, and the lightning stratification of the forest combustible sample and the stratification current characteristics of each stratification are obtained; (3) Repeat the test process of step (2) for forest combustible samples with different temperatures and humidities to obtain lightning current shunt data for each area of ​​the forest combustible samples with different temperatures and humidities; (4) Statistical analysis was performed on all forest combustible lightning stratification current test data to obtain the relationship between forest combustible stratification, lightning stratification current intensity, and moisture content, temperature and humidity of forest combustible samples, thus forming a forest combustible lightning stratification current database and characteristic laws.

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