CN106886841B - Circuit mountain fire Disaster Assessment method and system without real-time collection site information - Google Patents
Circuit mountain fire Disaster Assessment method and system without real-time collection site information Download PDFInfo
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Abstract
The invention discloses a kind of circuit mountain fire Disaster Assessment method without real-time collection site information, including：Determine vegetation pattern and vegetation height；Judge scene of a fire fire behavior type；Obtain alarm transmission line information；Obtain mountain fire and opening position meteorological data occurs；Calculate mountain fire flame zone, ion area and smog area height；Calculate flame zone breakdown voltage；Calculate ion area breakdown voltage；Calculate smog area breakdown voltage；Computing electric power line tripping operation probability；Assess mountain fire grade.The present invention also provides a kind of circuit mountain fire Disaster Assessment system without real-time collection site information.Beneficial effects of the present invention：Consider that supporting body transmission line parameter, mountain fire are interior in fire behavior feature, external environment condition, establish accurate line fault probabilistic model, Forest database is based on using data and meteorological data numerical result obtains, without arriving collection in worksite, realize that mountain fire causes transmission line of electricity tripping operation probability quantitatively to calculate, there is very strong adaptability, improve power network and resist mountain fire disaster ability.
Description
Technical Field
The invention relates to the technical field of electrical engineering, in particular to a line forest fire disaster assessment method and system without acquiring field information in real time.
Background
In recent years, fuels such as coal, liquefied gas and the like gradually replace firewood as main fuels, and the corridor of the power transmission line is dense in vegetation. Due to the influence of burning wasteland of villagers and ancestor worship of people, a large-range mountain fire often occurs in power transmission line corridors, and due to the fact that the duration of the mountain fire is long, reclosing is difficult to succeed, tripping and power failure of multiple lines are prone to occurring, and even grid collapse is caused. Mountain fire has become a new hotspot problem which seriously threatens the safe operation of a large power grid and the normal power supply of the society.
At present, beneficial research and application work is carried out in the aspects of power transmission line forest fire prediction, monitoring, fire extinguishing and the like in China, the capability of a power grid for resisting forest fire disasters is improved, and the positive effect of guaranteeing the safe and stable operation of the power grid is achieved. However, an accurate and actually operable power transmission line forest fire tripping risk assessment method does not exist, and the power grid forest fire risk cannot be known in advance, so that measures cannot be taken in a targeted manner, the smooth implementation of power transmission line forest fire prevention and control work is influenced, and the efficiency of power grid forest fire prevention and control is reduced.
At present, the power transmission line forest fire trip risk assessment method proposed by scholars cannot meet the requirements of practical engineering application. In the patent CN201410737586, the fire risk level of a power transmission line corridor is used as an index, a mountain fire risk assessment model is established by inputting parameters such as daily precipitation, temperature, wind speed, gradient, slope direction, road network density, vegetation water content and the like, the method has many input parameters, the parameters need to be measured in real time and are difficult to realize, the trip risk level prediction assessment is not combined with a mountain fire trip mechanism of the power transmission line, the conduction action of high-temperature ionization and a smoke dust chain is not considered, the obtained results are four qualitative risk levels I, II, III and IV, the refinement and accurate assessment is not realized, and the effect of guiding the power transmission line to prevent mountain fire is limited. Patent CN103472326A proposes a method for evaluating the probability of power transmission line fault caused by forest fire, which is based on collecting the scene information of forest fire, and under the assumption condition of uniform temperature and smoke concentration, calculates the breakdown probability under the minimum gap length. Patent CN201510305595 intensively solves the problem of emergency evaluation decision of the forest fire of the power transmission line based on the importance degree of the line, and the influence of the external environment of the line on the forest fire trip cannot be fully considered.
In summary, the power transmission line forest fire trip probability model applicable in the field has the following disadvantages:
1. the method comprises the steps that on-site meteorological information and vegetation information are temporarily and manually acquired on a forest fire site, and calculation of the forest fire trip probability of the power transmission line with multiple points, wide occurrence positions and uncertainty cannot be practically applied;
2. the existing method does not fully consider the influence of factors such as vegetation, wind and the like on the height and temperature of flame and the effect of particle size and concentration of smoke dust on mountain fire trip, so that the calculation conclusion of mountain fire trip probability is inaccurate;
3. the existing method takes the whole gap of the mountain fire as a uniform medium affected by temperature and smoke dust, is not in accordance with the reality, and does not combine the actual characteristics of each voltage grade for analysis.
Therefore, accurate field evaluation of mountain fire trip risk of the power transmission line is a premise and a basis for carrying out prevention and control work of mountain fire of the power transmission line, and a calculation method of mountain fire trip probability of the power transmission line, which does not need to collect mountain fire field information in real time, is urgently needed, so that theoretical basis and guidance are provided for scientific and efficient mountain fire disposal.
Disclosure of Invention
In order to solve the above problems, an object of the present invention is to provide a method and a system for evaluating a risk level of a forest fire disaster in a power transmission line without acquiring information of a forest fire site in real time.
The invention provides a line forest fire disaster assessment method without acquiring field information in real time, which comprises the following steps:
step 1, determining vegetation type S1 and vegetation height z between mountain fire occurrence position and power transmission line d Wherein the vegetation types are coniferous forest, broad-leaved forest, coniferous and broad-leaved mixed forest, shrub, couch grass, or a mixture of the above vegetation; the vegetation information between the mountain fire occurrence position and the power transmission line can be obtained by inquiring a Chinese forestry vegetation distribution database;
step 2, judging the fire behavior type of the fire scene, wherein the fire behavior type is the surface fire if the vegetation is shrubs and thatch, and the fire behavior type is the crown fire if coniferous forests, broad-leaved forests or coniferous and broad mixed forests exist and the continuity of combustible materials in the vertical direction is good;
step 3, obtaining information of the alarm power transmission line, including the voltage grade U of the power transmission line and the ground distance H of the lead tl The splitting number N of the power transmission line; the information of the alarm power transmission line can be obtained by inquiring an existing power transmission and transformation equipment information management system of a power grid company;
step 4, acquiring meteorological data including real-time wind speed V at the position where the forest fire occurs w And temperature; wherein the real time at the position where the mountain fire occursThe wind speed and the temperature are obtained by a meteorological numerical forecasting system, the calculation precision is 2.5km x 2.5km, and the fire point data information is obtained by online collection according to a power transmission line mountain fire monitoring system;
step 5, dividing the mountain fire near the power transmission line into a flame area, a departure area and a smoke area according to the height, and calculating the heights of the three areas, wherein the heights are respectively D 1 、D 2 And D 3 The method comprises the following steps:
step 501, calculating the mountain fire spreading speed R according to the formulas (1) to (2);
R＝R 0 ·K s ·exp(0.1783·V w ·cosθ)·exp(3.533tanφ) 1.2 (2)
in the formula, R 0 The initial propagation speed of volcano; v w Is the wind speed; k s Correcting the coefficient for the hill fire spreading combustible; phi is the slope angle of the mountain fire spreading area and is obtained by inquiring a high-precision terrain database; theta is an included angle between the wind speed and the gradient and is obtained by inquiring a high-precision terrain database;
step 502, calculating the intensity I of the fire wire according to the formula (3);
I＝0.000049HWR (3)
in the formula, H is the effective combustible heat value of the combustible, the China forestry bureau carries out field investigation on the biomass of various vegetations, and the biomass of various vegetations is calculated according to the vegetation composition and the density of various areas, so that the biomass of various vegetations can be inquired in a China forestry vegetation distribution database; w is effective combustible capacity, the China forestry bureau carries out field investigation on the biomass of various vegetations, calculates according to the vegetation composition and the density of each area, and can inquire in a China forestry vegetation distribution database;
step 503, calculating the height D of the flame zone of the surface fire or the crown fire according to the formula (4) or (5) 1 ；
Step 504, calculating the height D of the ion area according to the formula (6) 2 ；
D 2 ＝0.1D 1 (6)
Step 505, calculating the height D of the smoke zone according to equation (7) 3 ；
D 3 ＝H tl -D 1 -D 2 -z d (7)
Step 6, the reduction of air insulation in the mountain fire flame area is mainly influenced by two factors: 1) The air density of the gap between the conducting wire and the ground is reduced by the high temperature generated by the sufficient combustion of the combustion substances in the mountain fire flame area, so that the insulating strength of the air gap is reduced; 2) The high temperature of the mountain fire flame area causes air ionization, and the alkali metal salt can inject a large amount of electrons and ions into the gap under the flame condition, so that the transition from the streamer channel to the electric arc channel is promoted, and streamer discharge is more easily caused; the high temperature is the leading factor among the two main factors, the ionization is the secondary factor, the main factor is influenced by the vegetation type, the breakdown voltage of the flame zone is lowered comprehensively, and the breakdown voltage U of the flame zone under the flame condition is calculated according to the formulas (8) to (11) f ；
U f ＝K j1 ·U f ′ (11)
Wherein T is the temperature at which the height of the flame body to the ground is z, wherein z d ≤z≤D 1 +z d ；T a Is ambient temperature; i is the intensity of mountain fire; u shape f ' is the breakdown voltage of the flame zone under the action of temperature only; k is j1 A vegetation correction factor for flame zone combustion; e 0 Gap length of H for standard atmospheric conditions tl Power frequency breakdown field strength;
step 7, accumulating a large amount of charges in the ion region, easily generating discharge streams near the circuit due to the charges, easily generating electric field distortion near the circuit due to a large amount of particles, reducing the insulating property, and calculating the breakdown voltage U of the ion region under the flame condition according to the formula (12) z ；
In the formula of U z Is the breakdown voltage of the ion zone under flame conditions; c is a vegetation correction factor of the breakdown field strength of the ion region;
step 8, smoke dust and ash generated by burning the mountain fire in the mountain fire smog area contain a large amount of carbon particles, particle chains are gradually formed due to the adsorption effect of the charged particles, and the particle chains are easy to form bridging under the effect of an electric field, so that the insulating property of the air gap is greatly reduced; meanwhile, the flame body heats the temperature of the smoke area through radiation, and the gap insulation level is reduced; calculating the breakdown voltage U of the smoke region under flame conditions according to the formula (13) s ；
U s ＝K j2 ·K T3 ·E 0 ·D 3 (13)
Wherein the radiant heat temperature influence factor K T3 Calculated by the formulas (14) and (15);
in the formula, T s The temperature of the smoke zone caused by heating the air above by means of radiation generated by the flame; z is a radical of s For calculating the height of the point to the ground, the value range is as follows: z is a radical of formula d +D 1 +D 2 ≤z s ≤H tl ；
In the formula, K j2 A smoke volume fraction correction factor for the smoke region; k is T3 Is a radiant heat temperature influence factor;
step 9, calculating the tripping probability of the power transmission line under the condition of the forest fire, comprising the following steps:
step 901, the split number adopted by the power transmission line influences the uniformity degree of the electric field near the line, the larger the split number is, the more uniform the electric field distribution is, the larger the breakdown field intensity is, and the split number correction factor K of the power transmission line is determined according to the formula (16) j3 ；
Step 902, combining equations (11) to (13) and (16), calculating breakdown voltage U under flame conditions according to equation (17) jc ；
U jc ＝K j3 (U f +U z +U s ) (17)
Step 903, when the mountain fire occurs, the air gap is not uniform due to the particles, the dispersity is large, and 99% of breakdown voltage is endured when the coefficient of variation is 4% when the mountain fire breaks down according to the calculation in step (18);
U 99 ＝0.756U jc (18)
step 904, calculating the probability P (U) of the mountain fire tripping of the power transmission line at the mountain fire occurrence position according to the formula (19);
step 10, dividing the mountain fire trip danger level of the power transmission line according to the calculated mountain fire trip probability P (U) of the power transmission line:
for the transmission line with the voltage class of 500kV and above, when P (U) is more than 70%, serious danger is caused; when P (U) is more than or equal to 30% and less than or equal to 70%, the danger is generally high; when P (U) < 30%, the danger is slight;
for the transmission line with the voltage class of 220kV and below, when P (U) is more than 80%, serious danger exists; when P (U) is more than or equal to 50 percent and less than or equal to 80 percent, the danger is generally high; when P (U) < 50%, the danger is slight.
As a further improvement of the invention, in step 5, the correction coefficient K of the forest fire spreading combustible substance s The values are shown in table 1.
TABLE 1
| Type of combustible | Flat needle leaf | Dry branches and fallen leaves | Cogongrass grass weed | Bush for medical use | Pasture grassland | Arbor |
| K s | 0.8 | 1.2 | 1.6 | 1.8 | 2.0 | 1.0 |
As a further improvement of the invention, in step 6, K j1 Correction factor for vegetation burned in flame zone, obtained for the ratio of the salt content of the burning of different vegetation and the temperature of the burning j1 The values of (a) are shown in table 2.
TABLE 2
| Type of vegetation | Coniferous forest | Broad leaf forest | Needle-broad mixed forest | Bush | All-grass of Japanese Galangal |
| K j1 | 0.8 | 0.9 | 0.85 | 0.7 | 1 |
As a further improvement of the invention, in step 7, the vegetation correction factor C of the ion region breakdown field strength is related to the type and concentration of ions generated by vegetation combustion, is mainly influenced by the vegetation type, ranges from 2 to 4, and specifically takes the values as shown in Table 3.
TABLE 3
| Type of vegetation | Coniferous forest | Broad leaf forest | Taiwan mixed forest | Bush | All-grass of Japanese Galangal |
| C | 4 | 3 | 3.5 | 4 | 2 |
As a further improvement of the invention, in step 8, the smoke volume fraction correction factor K in the smoke area j2 The method is related to factors of vegetation type, vegetation water content, wind speed and landform type, specific values of the factors are shown in table 4, and products are carried out according to the values of the factors, wherein the vegetation water content is obtained from satellite inversion data, and the landform type is obtained from 30m DEM digital elevation. The water content of the vegetation is more than 40 percent, the forest fire is not generated by default, and the coefficient value is empty.
TABLE 4
The invention also provides a power transmission line forest fire disaster risk grade evaluation system, which comprises:
a vegetation type determination module for determining vegetation type S1 and vegetation height z between the mountain fire occurrence position and the power transmission line d Wherein the vegetation types are coniferous forest, broad-leaved forest, coniferous and broad-leaved mixed forest, shrubs, couch grass or a mixture of the above vegetation;
the fire scene fire behavior type judging module is used for judging the fire scene fire behavior type, if vegetation is shrubs and thatch, the vegetation is surface fire, and if coniferous forests, broad-leaved forests or coniferous and broad-leaved mixed forests exist and the continuity of combustible materials in the vertical direction is good, the vegetation is crown fire;
the warning power transmission line information module is used for acquiring the information of the warning power transmission line, including the voltage grade U of the power transmission line and the ground distance H of the lead tl The splitting number N of the power transmission line;
a meteorological data module for acquiring meteorological data including real-time wind speed V at the position of mountain fire w And temperature;
the mountain fire height calculation module is used for calculating the mountain fire heights of the flame area, the departure area and the smoke area, and the heights are respectively D 1 、D 2 And D 3 The method comprises the following steps:
the mountain fire spreading speed calculation module is used for calculating the mountain fire spreading speed R according to the formulas (20) to (21);
R＝R 0 ·K s ·exp(0.1783·V w ·cosθ)·exp(3.533tanφ) 1.2 (21)
in the formula, R 0 The initial propagation speed of volcano; v w Is the wind speed; k s Correcting the coefficient for the hill fire spreading combustible; phi is the slope angle of the mountain fire spreading area; theta is an included angle between the wind speed and the slope;
the fire wire intensity calculating module is used for calculating the fire wire intensity I according to the formula (22);
I＝0.000049HWR (22)
in the formula, H is the effective combustible calorific value of the combustible; w is effective combustible loading;
a flame zone height calculating module for calculating the flame zone height D of the surface fire or the crown fire according to the formula (23) or (24) 1 ；
An ion zone height calculation module for calculating an ion zone height D according to equation (25) 2 ；
D 2 ＝0.1D 1 (25)
A smoke zone height calculating module for calculating the smoke zone height D according to the formula (26) 3 ；
D 3 ＝H tl -D 1 -D 2 -z d (26)
A flame zone breakdown voltage calculation module for calculating the flame zone breakdown voltage U under flame conditions according to the formulas (27) to (30) f ；
U f ＝K j1 ·U f ′ (30)
Wherein T is the temperature at which the height of the flame body to the ground is z, wherein z d ≤z≤D 1 +z d ；T a Is ambient temperature; i is the intensity of mountain fire; u shape f ' is the breakdown voltage of the flame zone under the action of temperature only; k is j1 The vegetation combustion correction factor is obtained for the salt proportion contained in the combustion of different vegetation and the temperature generated by the combustion; e 0 Gap length of H for standard atmospheric conditions tl The power frequency breakdown field strength of time;
an ion region breakdown voltage calculation module for calculating the ion region breakdown voltage U under flame conditions according to the formula (31) z ；
In the formula of U z Is the breakdown voltage of the ion zone under flame conditions; c is a vegetation correction factor of the breakdown field strength of the ion region;
a smoke region breakdown voltage calculation module for calculating the smoke region breakdown voltage U under flame conditions according to formula (32) s ；
U s ＝K j2 ·K T3 ·E 0 ·D 3 (32)
Wherein the radiant heat temperature influence factor K T3 Calculated by the formulas (33) and (34);
in the formula, T s The temperature of the smoke zone caused by heating the air above by means of radiation generated by the flame; z is a radical of formula s For calculating the height of the point to the ground, the value range is as follows: z is a radical of formula d +D 1 +D 2 ≤z s ≤H tl ；
In the formula, K j2 A smoke volume fraction correction factor for the smoke region; k T3 Is a radiant heat temperature influence factor;
the forest fire tripping probability calculation module is used for calculating the tripping probability of the power transmission line under the forest fire condition, and comprises the following steps:
a division number correction factor calculation module for determining the transmission line division number correction factor K according to the formula (35) j3 ；
A breakdown voltage calculation module for calculating a breakdown voltage U under flame conditions according to the formula (36) in combination with the formulas (30) to (32) and (35) jc ；
U jc ＝K j3 (U f +U z +U s ) (36)
A breakdown voltage tolerance calculation module for calculating a breakdown voltage tolerance of 99% when the coefficient of variation is 4% at the time of breakdown of the mountain fire according to (37);
U 99 ＝0.756U jc (37)
the tripping probability calculation module is used for calculating the tripping probability P (U) of the mountain fire of the power transmission line at the mountain fire occurrence position according to the formula (38);
and the danger level evaluation module is used for dividing the mountain fire tripping danger level of the power transmission line according to the calculated mountain fire tripping probability P (U) of the power transmission line:
for the transmission line with the voltage class of 500kV and above, when P (U) is more than 70%, serious danger is caused; when P (U) is more than or equal to 30% and less than or equal to 70%, the danger is generally high; when P (U) < 30%, the danger is slight;
for the transmission line with the voltage class of 220kV and below, when P (U) is more than 80%, serious danger is caused; when P (U) is more than or equal to 50 percent and less than or equal to 80 percent, the danger is generally high; when P (U) < 50%, the danger is slight.
As a further improvement of the invention, in the mountain fire height calculation module, the mountain fire spreading combustible substance correction coefficient K s The values are shown in Table 5.
TABLE 5
| Combustible material type | Flat needle leaf | Dry branches and fallen leaves | All-grass of Japanese Stichopus | Bush for medical use | Pasture grassland | Arbor |
| K s | 0.8 | 1.2 | 1.6 | 1.8 | 2.0 | 1.0 |
As a further improvement of the invention, in a flame zone breakdown voltage calculation module, the proportion of salt contained in the combustion of different vegetation and the temperature generated by the combustion are used to obtain a flame zone combustion vegetation correction factor K j1 The values of (A) are shown in Table 6.
TABLE 6
| Type of vegetation | Coniferous forest | Broad leaf forest | Needle-broad mixed forest | Bush | All-grass of Japanese Galangal |
| K j1 | 0.8 | 0.9 | 0.85 | 0.7 | 1 |
As a further improvement of the invention, in the ion region breakdown voltage calculation module, a vegetation correction factor C of the ion region breakdown field strength is related to the type and concentration of ions generated by vegetation combustion, is influenced by the vegetation type, ranges from 2 to 4, and the value of C is shown in Table 7.
TABLE 7
| Type of vegetation | Coniferous forest | Broad leaf forest | Taiwan mixed forest | Bush for medical use | All-grass of Japanese Galangal |
| C | 4 | 3 | 3.5 | 4 | 2 |
As a further improvement of the invention, in the smoke area breakdown voltage calculation module, the smoke volume fraction correction factor K of the smoke area j2 The method is related to factors of vegetation type, vegetation water content, wind speed and landform type, and the product is carried out according to the value of each factor, and the specific coefficient value of each factor is shown in the table 8. Defaults to no forest fire when the water content of vegetation is more than 40%, and the coefficient value isAnd (4) being empty.
TABLE 8
The beneficial effects of the invention are as follows:
the method is combined with a line tripping mechanism under the condition of the forest fire, multiple factors such as parameters (line height and wire splitting number) of a power transmission line of a supporting body, internal fire behavior characteristics (flame height, flame temperature and smoke dust) of the forest fire, external environment conditions (wind speed, humidity and temperature) and the like are fully considered, an accurate line fault probability model is established, data used in the calculation process can be obtained based on a forestry database and a meteorological data numerical calculation result, data such as wind speed, wind direction, humidity and temperature and the like do not need to be acquired on site, application can be carried out based on the forest fire prediction and monitoring result of the power transmission line, the quantitative calculation of the tripping probability of the power transmission line caused by the forest fire is realized, the adaptability is high, the risk management of the power transmission line is greatly promoted, and the capability of a power grid for resisting the forest fire disaster is improved.
Drawings
Fig. 1 is a schematic flow chart of a method for assessing a fire disaster in a line without acquiring field information in real time according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of influence factors and zones of power transmission line tripping caused by a mountain fire in the embodiment of the invention;
fig. 3 is a schematic diagram of a typical topography of a field line in an embodiment of the present invention.
Detailed Description
The invention is described in further detail below by means of specific embodiments and with reference to the attached drawings.
Embodiment 1, as shown in fig. 1 to 3, a method for assessing a fire disaster in a line without acquiring field information in real time according to a first embodiment of the present invention includes:
step 1, longitude and latitude of a forest fire occurrence position are obtained through monitoring and are 111.7538 and 26.3875, a line tower coordinate in a power transmission line forest fire monitoring and early warning system is combined, a 500kV purple I line of an electric power company of Hunan province of the national grid is obtained as an alarm line, the corresponding tower number is #294, vegetation types between the forest fire occurrence position and the power transmission line are obtained through inquiring from a Chinese forest vegetation distribution database, and vegetation height z is found d Is 1.8m;
step 2, judging the fire behavior type of the fire scene as surface fire;
step 3, obtaining information of the alarm transmission line from an existing power transmission and transformation equipment information management system (PMS) of a power grid company, wherein the voltage level U of the transmission line is 500kV, and the ground distance H of a lead at the tower tl 27 meters, the number of splits N of the transmission line is 4; breakdown voltage E of air gap under atmospheric pressure condition when taking 27 m gap 0 Is 100kV/m;
step 4, calculating to obtain meteorological data of the mountain fire occurrence position through a meteorological numerical forecasting system, wherein the real-time wind speed V is w At a temperature of 27 ℃ and at 3.8 m/s;
step 5, dividing the mountain fire near the power transmission line into a flame area, a departure area and a smoke area according to the height, and calculating the heights of the three areas, wherein the heights are respectively D 1 、D 2 And D 3 The method comprises the following steps:
501, the combustible substance is shrub, and the heat H of the combustible substance per unit area is 19600kJ/m through inquiring from a Chinese forestry vegetation distribution database 2 The effective combustible heat value W of the combustible is 10400kJ/kg; obtaining a slope angle phi of the mountain fire spreading area to be 25 degrees and an included angle theta between the wind speed and the slope to be 30 degrees by inquiring a high-precision terrain database; vegetation water content M obtained by satellite vegetation data inversion f Is 10.85 percent；
Calculating the initial propagation velocity of volcano according to the formula (1):
wherein the combustible is shrub, and the correction coefficient K of the forest fire spreading combustible is obtained according to Table 1 s ＝1.8；
Volcanic propagation velocity according to equation (2):
R＝R 0 ·K s ·exp(0.1783·V w ·cosθ)·exp(3.533tanφ) 1.2
＝1.47×1.8×exp(0.1783×3.8×cos30°)×exp(3.533×tan30°) 1.2
＝45.28m/min
step 502, calculating the fire wire strength I according to the formula (3);
I＝0.000049HWR
＝0.000049×19600×10400×45.28
＝7538kW/m
step 503, calculating the height D of the flame zone of the surface fire according to the formula (4) 1 ；
Step 504, calculating the height D of the ion region according to the formula (6) 2 ；
D 2 ＝0.1D 1 ＝0.50m
Step 505, calculating the height D of the smoke area according to the formula (7) 3 ；
D 3 ＝H tl -D 1 -D 2 -z d ＝27-5.01-0.5-1.8＝19.69m
Step 6, calculating the breakdown voltage U of the flame region under the flame condition according to the formulas (8) to (11) f ；
The flame zone temperature calculation formula is simplified as follows:
obtaining a flame zone combustion vegetation correction factor K according to the table 2 j1 Is 0.7, further calculated to yield:
U f ＝K j1 ·U f ′＝0.7*129＝90.3kV
step 7, according to the table 3, the shrub combustion ionization degree is large, the vegetation correction factor C =4 of the ion region breakdown field strength is known, and the ion region breakdown voltage U under the flame condition is calculated according to the formula (12) z ；
Step 8, obtaining smoke layer smoke volume fraction correction factor K according to table 4 j2 ：
K j2 ＝0.5*0.7*1*0.6＝0.252
The temperature T at z of the height of the soot region is calculated by equation (14) s ：
Calculating the radiant heat temperature influence factor K by the formula (15) T3 ：
Calculation of Smoke under flame conditions according to equation (13)Breakdown voltage U in fog region s ：
U s ＝K j2 ·K T3 ·E 0 ·D 3 ＝285kV
Step 9, calculating the tripping probability of the power transmission line under the condition of the forest fire, comprising the following steps:
step 901, calculating a power transmission line split number correction factor K according to formula (16) j3 ：
The number of divisions used for the transmission line is 4, so K j3 ＝1.25；
Step 902, combining equations (11) to (13) and (16), calculating breakdown voltage U under flame conditions according to equation (17) jc ；
U jc ＝K j3 (U f +U z +U s )＝482kV
Step 903, considering that when the mountain fire occurs, air gaps are not uniform due to particles, the dispersity is large, and when the coefficient of variation is 4% when the mountain fire breaks down, the breakdown withstand voltage is 99% according to the calculation in step (18);
U 99 ＝0.756U jc ＝364kV
step 904, calculating the probability P (U) of the mountain fire tripping of the power transmission line at the mountain fire occurrence position according to the formula (19): p (U) =1.
Therefore, the probability of the mountain fire trip of the line under the condition of the mountain fire point is 100%.
And step 10, dividing the grade of the mountain fire trip danger of the power transmission line according to the calculated mountain fire trip probability P (U) of the power transmission line. For the transmission line with the voltage class of 500kV and above, when P (U) is more than 70%, serious danger is caused; and the proposal is to immediately take the measures of stopping operation or extinguishing fire and quit the function of reclosing, thereby avoiding the impact of mountain fire tripping on the power grid.
Embodiment 2, a system for assessing a fire disaster in a line without acquiring field information in real time according to a second embodiment of the present invention includes:
a vegetation type determination module for determining vegetation type S1 and vegetation height z between the mountain fire occurrence position and the power transmission line d Wherein the vegetation types are coniferous forest, broad-leaved forest, coniferous and broad-leaved mixed forest, shrub, couch grass, or a mixture of the above vegetation;
the fire scene fire behavior type judging module is used for judging the fire scene fire behavior type, if vegetation is shrubs and thatch, the vegetation is surface fire, and if coniferous forests, broad-leaved forests or coniferous and broad-leaved mixed forests exist and the continuity of combustible materials in the vertical direction is good, the vegetation is crown fire;
and the warning power transmission line information module is used for acquiring the information of the warning power transmission line, including the voltage grade U of the power transmission line and the ground distance H of the lead tl The splitting number N of the power transmission line;
a meteorological data module for acquiring meteorological data including real-time wind speed V at the position of mountain fire w And a temperature;
a mountain fire height calculation module for calculating the height of mountain fire in three areas, namely a flame area, a departure area and a smoke area, D 1 、D 2 And D 3 The method comprises the following steps:
the mountain fire spreading speed calculation module is used for calculating the mountain fire spreading speed R according to the formulas (20) to (21);
R＝R 0 ·K s ·exp(0.1783·V w ·cosθ)·exp(3.533tanφ) 1.2 (21)
in the formula, R 0 The initial propagation speed of volcano; v w Is the wind speed; k s Correcting the coefficient for the hill fire spreading combustible; phi is the slope angle of the mountain fire spreading area; theta is an included angle between the wind speed and the slope;
correction coefficient K of forest fire spreading combustible substance s Values are shown in table 5;
TABLE 5
| Type of combustible | Flat needle leaf | Dry branches and fallen leaves | Cogongrass grass weed | Bush | Pasture grassland | Arbor |
| K s | 0.8 | 1.2 | 1.6 | 1.8 | 2.0 | 1.0 |
The fire wire intensity calculating module is used for calculating the fire wire intensity I according to the formula (22);
I＝0.000049HWR (22)
in the formula, H is the effective combustible calorific value of the combustible; w is effective combustible loading;
a flame zone height calculating module for calculating the flame zone height D of the surface fire or the crown fire according to the formula (23) or (24) 1 ；
An ion zone height calculation module for calculating an ion zone height D according to equation (25) 2 ；
D 2 ＝0.1D 1 (25)
A smoke zone height calculating module for calculating the smoke zone height D according to the formula (26) 3 ；
D 3 ＝H tl -D 1 -D 2 -z d (26)
A flame zone breakdown voltage calculation module for calculating the flame zone breakdown voltage U under flame conditions according to the formulas (27) to (30) f ；
U f ＝K j1 ·U f ′ (30)
Wherein T is the temperature at which the height of the flame body to the ground is z, wherein z d ≤z≤D 1 +z d ；T a Is ambient temperature; i is the intensity of mountain fire; u shape f ' is the breakdown voltage of the flame zone under the action of temperature only; k j1 The vegetation combustion correction factor is obtained for the salt proportion contained in the combustion of different vegetation and the temperature generated by the combustion; e 0 Gap length of H for standard atmospheric conditions tl The power frequency breakdown field strength of time;
flame zone combustion vegetation correction factor K j1 Is shown in the tableAnd 6, respectively.
TABLE 6
| Type of vegetation | Coniferous forest | Broad leaf forest | Needle-broad mixed forest | Bush | All-grass of Japanese Galangal |
| K j1 | 0.8 | 0.9 | 0.85 | 0.7 | 1 |
An ion region breakdown voltage calculation module for calculating the ion region breakdown voltage U under flame conditions according to equation (31) z ；
In the formula of U z Is the breakdown voltage of the ion zone under flame conditions; c is a vegetation correction factor of the breakdown field strength of the ion region;
the values of C are shown in Table 7;
TABLE 7
| Type of vegetation | Coniferous forest | Broad leaf forest | Needle-broad mixed forest | Bush | All-grass of Japanese Galangal |
| C | 4 | 3 | 3.5 | 4 | 2 |
A smoke region breakdown voltage calculation module for calculating the smoke region breakdown voltage U under flame conditions according to the formula (32) s ；
U s ＝K j2 ·K T3 ·E 0 ·D 3 (32)
Wherein the radiant heat temperature influence factor K T3 Calculated by the formulas (33) and (34);
in the formula, T s The temperature of the smoke zone caused by heating the air above by means of radiation generated by the flame; z is a radical of formula s For calculating the height of the point to the ground, the value range is as follows: z is a radical of formula d +D 1 +D 2 ≤z s ≤H tl ；
In the formula, K j2 A smoke volume fraction correction factor for the smoke region; k is T3 Is a radiant heat temperature influence factor;
influence K j2 The values of the coefficient values of the respective factors are shown in table 8;
TABLE 8
The mountain fire tripping probability calculation module is used for calculating the tripping probability of the power transmission line under the mountain fire condition, and comprises the following steps:
a division number correction factor calculation module for determining the transmission line division number correction factor K according to the formula (35) j3 ；
A breakdown voltage calculation module for calculating a breakdown voltage U under flame conditions according to the formula (36) in combination with the formulas (30) to (32) and (35) jc ；
U jc ＝K j3 (U f +U z +U s ) (36)
A breakdown voltage tolerance calculation module for calculating a breakdown voltage tolerance of 99% when the coefficient of variation is 4% at the time of breakdown of the mountain fire according to (37);
U 99 ＝0.756U jc (37)
the tripping probability calculation module is used for calculating the tripping probability P (U) of the mountain fire of the power transmission line at the mountain fire occurrence position according to the formula (38);
and the danger grade evaluation module is used for dividing the danger grade of the mountain fire trip of the power transmission line according to the calculated mountain fire trip probability P (U) of the power transmission line:
for the transmission line with the voltage class of 500kV and above, when P (U) is more than 70%, serious danger is caused; when P (U) is more than or equal to 30% and less than or equal to 70%, the danger is generally high; when P (U) < 30%, the risk is slight;
for the transmission line with the voltage class of 220kV and below, when P (U) is more than 80%, serious danger is caused; when P (U) is more than or equal to 50 percent and less than or equal to 80 percent, the danger is generally high; when P (U) < 50%, the danger is slight.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A line forest fire disaster assessment method without acquiring field information in real time is characterized by comprising the following steps:
step 1, determining vegetation type S1 and vegetation height z between mountain fire occurrence position and power transmission line d Wherein the vegetation types are coniferous forest, broad-leaved forest, coniferous and broad-leaved mixed forest, shrub, couch grass, or a mixture of the above vegetation;
step 2, judging the fire behavior type of the fire scene, wherein the fire behavior type is the surface fire if the vegetation is shrubs and thatch, and the fire behavior type is the crown fire if coniferous forests, broad-leaved forests or coniferous and broadleaf mixed forests exist and the continuity of combustible materials in the vertical direction is good;
step 3, obtaining information of the alarm power transmission line, including the voltage grade U of the power transmission line and the ground distance H of the lead tl Power transmission lineThe number of splits N;
step 4, acquiring meteorological data including real-time wind speed V at the position where the mountain fire occurs w And temperature;
step 5, dividing the mountain fire near the power transmission line into a flame area, a departure area and a smoke area according to the height, and calculating the heights of the three areas, wherein the heights are respectively D 1 、D 2 And D 3 The method comprises the following steps:
step 501, calculating the mountain fire spreading speed R according to formulas (1) to (2);
R＝R 0 ·K s ·exp(0.1783·V w ·cosθ)·exp(3.533tanφ) 1.2 (2)
in the formula, R 0 The initial propagation speed of volcano; v w Is the wind speed; k s Correcting the coefficient for the hill fire spreading combustible; phi is the slope angle of the mountain fire spreading area; theta is an included angle between the wind speed and the slope;
step 502, calculating the intensity I of the fire wire according to the formula (3);
I＝0.000049HWR (3)
in the formula, H is the effective combustible calorific value of the combustible; w is effective combustible loading;
step 503, calculating the height D of the flame zone of the surface fire or the crown fire according to the formula (4) or (5) 1 ；
Step 504, calculating the height D of the ion region according to the formula (6) 2 ；
D 2 ＝0.1D 1 (6)
Step 505, calculating smoke according to equation (7)Zone height D 3 ；
D 3 ＝H tl -D 1 -D 2 -z d (7)
Step 6, calculating the breakdown voltage U of the flame zone under the flame condition according to the formulas (8) to (11) f ；
U f ＝K j1 ·U f ′ (11)
Wherein T is the temperature at which the height of the flame body to the ground is z, wherein z d ≤z≤D 1 +z d ；T a Is ambient temperature; i is the intensity of mountain fire; u shape f ' is the breakdown voltage of the flame zone under the action of temperature only; k j1 The vegetation combustion correction factor of the flame zone is obtained for the salt proportion contained in the combustion of different vegetation and the temperature generated by the combustion; e 0 Gap length of H for standard atmospheric conditions tl The power frequency breakdown field strength of time;
step 7, calculating the breakdown voltage U of the ion region under the flame condition according to the formula (12) z ；
In the formula of U z Is the breakdown voltage of the ion zone under flame conditions; c is a vegetation correction factor of the breakdown field strength of the ion region;
step 8, calculating the breakdown voltage U of the smoke area under the flame condition according to the formula (13) s ；
U s ＝K j2 ·K T3 ·E 0 ·D 3 (13)
Wherein the radiant heat temperature influence factor K T3 Calculated by the formulas (14) and (15);
in the formula, T s The temperature of the smoke zone caused by heating the air above by means of the radiation generated by the flame; z is a radical of s For calculating the height of the point to the ground, the value range is as follows: z is a radical of d +D 1 +D 2 ≤z s ≤H tl ；
In the formula, K j2 A smoke volume fraction correction factor for the smoke region; k T3 Is a radiant heat temperature influence factor;
step 9, calculating the tripping probability of the power transmission line under the condition of the forest fire, comprising the following steps:
step 901, determining a power transmission line split number correction factor K according to formula (16) j3 ；
Step 902, combining equations (11) to (13) and (16), calculating the breakdown voltage U under flame conditions according to equation (17) jc ；
U jc ＝K j3 (U f +U z +U s ) (17)
Step 903, calculating the 99% breakdown withstanding voltage when the coefficient of variation is 4% when the mountain fire breaks down according to the step (18);
U 99 ＝0.756U jc (18)
step 904, calculating the probability P (U) of the mountain fire tripping of the power transmission line at the mountain fire occurrence position according to the formula (19);
step 10, dividing the power transmission line forest fire tripping danger grade according to the calculated power transmission line forest fire tripping probability P (U):
for the transmission line with the voltage class of 500kV and above, when P (U) is more than 70%, serious danger is caused; when P (U) is more than or equal to 30% and less than or equal to 70%, the danger is generally high; when P (U) < 30%, the risk is slight;
for the transmission line with the voltage class of 220kV and below, when P (U) is more than 80%, serious danger is caused; when P (U) is more than or equal to 50 percent and less than or equal to 80 percent, the danger is generally high; when P (U) < 50%, the danger is slight.
2. The method for assessing a mountain fire disaster according to claim 1, wherein in step 5, the mountain fire spreading combustible substance correction coefficient K is set to s The values are as follows:
when the combustible is flat needles, K s The value is 0.8;
when the combustible is dry branches and fallen leaves, K s The value is 1.2;
when the combustible is thatch, K s The value is 1.6;
when the combustible is shrub, K s The value is 1.8;
when the combustible is pasture grassland, K s The value is 2.0;
when the combustible is arbor, K s The value is 1.0.
3. The method for evaluating a fire disaster in a street and mountain according to claim 1, wherein in step 6, the vegetation-in-fire correction factor K for vegetation burning in a flame zone is obtained by a ratio of salt content in burning of different vegetation and a temperature of burning of different vegetation j1 The values of (a) are as follows:
when the vegetation type is conifer forest, K j1 The value is 0.8;
when the vegetation type is broad-leaved forest, K j1 The value is 0.9;
when the vegetation type is coniferous or broadIn mixed forests, K j1 The value is 0.85;
when the vegetation type is shrub, K j1 The value is 0.7;
when the vegetation type is thatch, K j1 The value is 1.
4. The method for evaluating the mountain fire disaster according to claim 1, wherein in the step 7, a vegetation correction factor C of the breakdown field strength of the ionic zone is related to the type and concentration of ions generated by vegetation combustion, is influenced by the vegetation type, ranges from 2 to 4, and has the following values:
when the vegetation type is conifer forest, the value of C is 4;
when the vegetation type is broad-leaved forest, the value of C is 3;
when the vegetation type is a pin-wide mixed forest, the value of C is 3.5;
when the vegetation type is shrub, the value of C is 4;
when the vegetation type is thatch, the value of C is 2.
5. The method for assessing a fire disaster in a line mountain according to claim 1, wherein in step 8, the smoke volume fraction correction factor K in the smoke area is determined j2 The method is related to factors such as vegetation type, vegetation water content, wind speed and landform type, and the product is carried out according to the values of the factors, wherein the coefficient values of the factors are as follows:
when the vegetation type is conifer, the coefficient value is 0.5;
when the vegetation type is broadleaf forest, the coefficient value is 0.6;
when the vegetation type is pin-wide mixed forest, the coefficient value is 0.55;
when the vegetation type is shrub, the coefficient value is 0.6;
when the vegetation type is thatch, the coefficient value is 0.75;
when the water content of the vegetation is more than or equal to 40% and more than or equal to 25%, the coefficient value is 0.6;
when the water content of the vegetation is more than or equal to 25%, the coefficient value is 0.7;
when the water content of the vegetation is less than 10%, the coefficient value is 0.8;
when the wind speed grade is 0-2, the coefficient value is 1;
when the wind speed grade is 3-5, the coefficient value is 1.1;
when the wind speed grade is 6-8, the coefficient value is 1.2;
when the landform type is flat ground or mountain top, the coefficient value is 1;
when the landform type is valley, the coefficient value is 0.8;
when the landform type is climbing, the coefficient value is 0.6;
when the landform type is along a slope, the coefficient value is 0.85;
when the landscape type is valley crossing, the coefficient value is 1.05.
6. A line forest fire disaster assessment system without collecting field information in real time is characterized by comprising:
a vegetation type determination module for determining vegetation type S1 and vegetation height z between the mountain fire occurrence position and the power transmission line d Wherein the vegetation types are coniferous forest, broad-leaved forest, coniferous and broad-leaved mixed forest, shrub, couch grass, or a mixture of the above vegetation;
the fire scene fire behavior type judging module is used for judging the fire scene fire behavior type, if vegetation is shrubs and thatch, the vegetation is surface fire, and if coniferous forests, broad-leaved forests or coniferous and broad mixed forests exist and the continuity of combustible materials in the vertical direction is good, the vegetation is crown fire;
and the warning power transmission line information module is used for acquiring the information of the warning power transmission line, including the voltage grade U of the power transmission line and the ground distance H of the lead tl The splitting number N of the power transmission line;
a meteorological data module for acquiring meteorological data including real-time wind speed V at the position of mountain fire w And a temperature;
the mountain fire height calculation module is used for calculating the mountain fire heights of the flame area, the departure area and the smoke area, and the heights are respectively D 1 、D 2 And D 3 The method comprises the following steps:
the mountain fire spreading speed calculation module is used for calculating the mountain fire spreading speed R according to the formulas (20) to (21);
R＝R 0 ·K s ·exp(0.1783·V w ·cosθ)·exp(3.533tanφ) 1.2 (21)
in the formula, R 0 The initial propagation speed of the volcano is obtained; v w Is the wind speed; k s Correcting the coefficient for the hill fire spreading combustible; phi is the slope angle of the mountain fire spreading area; theta is an included angle between the wind speed and the slope;
the fire wire intensity calculating module is used for calculating the fire wire intensity I according to the formula (22);
I＝0.000049HWR (22)
in the formula, H is the effective combustible calorific value of the combustible; w is the effective combustible load;
a flame zone height calculating module for calculating the flame zone height D of the surface fire or the crown fire according to the formula (23) or (24) 1 ；
An ion zone height calculation module for calculating an ion zone height D according to equation (25) 2 ；
D 2 ＝0.1D 1 (25)
A smoke zone height calculating module for calculating the smoke zone height D according to the formula (26) 3 ；
D 3 ＝H tl -D 1 -D 2 -z d (26)
A flame zone breakdown voltage calculation module for calculating the flame zone breakdown voltage U under flame conditions according to the formulas (27) to (30) f ；
U f ＝K j1 ·U f ′ (30)
Wherein T is the temperature at which the height of the flame body to the ground is z, wherein z d ≤z≤D 1 +z d ；T a Is ambient temperature; i is the intensity of mountain fire; u shape f ' is the breakdown voltage of the flame zone under the action of temperature only; k is j1 The vegetation combustion correction factor is obtained for the salt proportion contained in the combustion of different vegetation and the temperature generated by the combustion; e 0 Gap length of H for standard atmospheric conditions tl Power frequency breakdown field strength;
an ion region breakdown voltage calculation module for calculating the ion region breakdown voltage U under flame conditions according to the formula (31) z ；
In the formula of U z Is the breakdown voltage of the ion zone under flame conditions; c is a vegetation correction factor of the breakdown field strength of the ion region;
a smoke region breakdown voltage calculation module for calculating the smoke region breakdown voltage U under flame conditions according to the formula (32) s ；
U s ＝K j2 ·K T3 ·E 0 ·D 3 (32)
Wherein the radiant heat temperature influence factor K T3 Calculated by the formulas (33) and (34);
in the formula, T s The temperature of the smoke zone caused by heating the air above by means of the radiation generated by the flame; z is a radical of formula s For calculating the height of the point to the ground, the value range is as follows: z is a radical of d +D 1 +D 2 ≤z s ≤H tl ；
In the formula, K j2 A smoke volume fraction correction factor for the smoke region; k is T3 Is a radiant heat temperature influence factor;
the mountain fire tripping probability calculation module is used for calculating the tripping probability of the power transmission line under the mountain fire condition, and comprises the following steps:
a division number correction factor calculation module for determining the transmission line division number correction factor K according to the formula (35) j3 ；
A breakdown voltage calculation module for calculating a breakdown voltage U under flame conditions according to equation (36) by combining equations (30) to (32) and (35) jc ；
U jc ＝K j3 (U f +U z +U s ) (36)
A breakdown voltage tolerance calculation module for calculating a breakdown voltage tolerance of 99% when the coefficient of variation is 4% at the time of breakdown of the mountain fire according to (37);
U 99 ＝0.756U jc (37)
the tripping probability calculation module is used for calculating the tripping probability P (U) of the mountain fire of the power transmission line at the mountain fire occurrence position according to the formula (38);
and the danger grade evaluation module is used for dividing the danger grade of the mountain fire trip of the power transmission line according to the calculated mountain fire trip probability P (U) of the power transmission line:
for the transmission line with the voltage class of 500kV and above, when P (U) is more than 70%, serious danger is caused; when P (U) is more than or equal to 30% and less than or equal to 70%, the danger is generally high; when P (U) < 30%, the risk is slight;
for the transmission line with the voltage class of 220kV and below, when P (U) is more than 80%, serious danger is caused; when P (U) is more than or equal to 50 percent and less than or equal to 80 percent, the danger is generally high; when P (U) < 50%, the danger is slight.
7. The line forest fire disaster evaluation system according to claim 6, wherein in the forest fire height calculation module, the forest fire spreading combustible substance correction coefficient K is s The values are as follows:
when the combustible is flat needle leaf, K s The value is 0.8;
when the combustible is dry branches and fallen leaves, K s The value is 1.2;
when the combustible is thatch, K s The value is 1.6;
when the combustible is shrub, K s The value is 1.8;
when the combustible is pasture grassland, K s The value is 2.0;
when the combustible is arbor, K s The value is 1.0.
8. The system for evaluating a mountain fire disaster on a railway according to claim 6, wherein in the module for calculating the breakdown voltage of the flame zone, the ratio of the salt contained in the combustion of different vegetation and the temperature generated by the combustion are used to obtain a correction factor K for the combustion vegetation of the flame zone j1 The values of (A) are as follows:
when the vegetation type is conifer forest, K j1 The value is 0.8;
when the vegetation type is broad-leaved forest, K j1 The value is 0.9;
when the vegetation type is pin-broad mixed forest, K j1 The value is 0.85;
when vegetation classWhen the type is shrub, K j1 The value is 0.7;
when the vegetation type is thatch, K j1 The value is 1.
9. The line forest fire disaster evaluation system of claim 6, wherein in the ion region breakdown voltage calculation module, a vegetation correction factor C of the ion region breakdown field strength is related to the type and concentration of ions generated by vegetation combustion, is influenced by the vegetation type, ranges from 2 to 4, and has the following values:
when the vegetation type is conifer forest, the value of C is 4;
when the vegetation type is broad-leaved forest, the value of C is 3;
when the vegetation type is a pin-wide mixed forest, the value of C is 3.5;
when the vegetation type is shrub, the value of C is 4;
when the vegetation type is thatch, the value of C is 2.
10. The line forest fire disaster evaluation system according to claim 6, wherein in the smoke region breakdown voltage calculation module, the smoke volume fraction correction factor K in the smoke region j2 The method is related to factors of vegetation type, vegetation water content, wind speed and landform type, and the product is carried out according to the value of each factor, and the coefficient value of each factor is as follows:
when the vegetation type is conifer, the coefficient value is 0.5;
when the vegetation type is broadleaf forest, the coefficient value is 0.6;
when the vegetation type is pin-broad mixed forest, the coefficient value is 0.55;
when the vegetation type is shrub, the coefficient value is 0.6;
when the vegetation type is thatch, the coefficient value is 0.75;
when the water content of the vegetation is more than or equal to 40% and more than or equal to 25%, the coefficient value is 0.6;
when the water content of vegetation is more than 25% and is more than or equal to 10%, the coefficient value is 0.7;
when the water content of the vegetation is less than 10%, the coefficient value is 0.8;
when the wind speed grade is 0-2, the coefficient value is 1;
when the wind speed grade is 3-5, the coefficient value is 1.1;
when the wind speed grade is 6-8, the coefficient value is 1.2;
when the landform type is flat ground or mountain top, the coefficient value is 1;
when the landform type is valley, the coefficient value is 0.8;
when the landform type is climbing, the coefficient value is 0.6;
when the landform type is along a slope, the coefficient value is 0.85;
when the landscape type is valley crossing, the coefficient value is 1.05.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
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| CN108831116B (en) * | 2018-06-22 | 2020-11-06 | 国网湖南省电力有限公司 | Multi-stage correction method and system for forest fire spreading behavior of power transmission line and storage medium |
| CN109119976B (en) * | 2018-09-05 | 2020-11-06 | 国网湖南省电力有限公司 | Automatic adjusting method and system for relay protection fixed value of power transmission line forest fire |
| CN110379113A (en) * | 2019-06-28 | 2019-10-25 | 北京中科锐景科技有限公司 | A method of based on satellite remote sensing date Forest Fire Alarm |
| CN110567741B (en) * | 2019-08-07 | 2021-06-29 | 中国科学技术大学 | Fire extinguishing efficiency detection method and system of wind-driven dominant field fire extinguishing machine |
| CN111967193B (en) * | 2020-08-25 | 2024-03-12 | 国网安徽省电力有限公司 | Power transmission line tripping probability calculation method under forest fire condition |
| CN112651662B (en) * | 2021-01-12 | 2022-09-20 | 国电南瑞科技股份有限公司 | Method and system for minimizing risk of cascading failures of power grid under multi-fire disaster |
| CN113514737A (en) * | 2021-04-29 | 2021-10-19 | 广东电网有限责任公司电力科学研究院 | Method, equipment and medium for calculating breakdown voltage of gap of power transmission line |
| CN113159639A (en) * | 2021-05-17 | 2021-07-23 | 广东电网有限责任公司 | Power transmission line forest fire trip risk assessment method and device |
| CN113469494B (en) * | 2021-05-25 | 2023-10-27 | 国网浙江省电力有限公司台州供电公司 | Mountain fire-induced line fault risk assessment method |
| CN113592022B (en) * | 2021-08-11 | 2022-07-05 | 中国科学院空天信息创新研究院 | Forest fire dangerous terrain identification method considering vegetation types |
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Effective date of registration: 20231208 Address after: 410131 building 4, 55 East Longhua Road, Changsha Economic and Technological Development Zone, Changsha City, Hunan Province Patentee after: Hunan Disaster Prevention Technology Co.,Ltd. Patentee after: XIANG-ELECTRIC EXPERIMENT AND RESEARCH TECHNOLOGY COMPANY OF HUNAN PROVINCE Address before: 410205, 2nd Floor, Rear Building, Software Center Building, No. 662 Lugu Avenue, High tech Development Zone, Changsha City, Hunan Province Patentee before: XIANG-ELECTRIC EXPERIMENT AND RESEARCH TECHNOLOGY COMPANY OF HUNAN PROVINCE |