CN110361581B - Step voltage evaluation device and method for lightning distribution network line broken line short circuit tower - Google Patents
Step voltage evaluation device and method for lightning distribution network line broken line short circuit tower Download PDFInfo
- Publication number
- CN110361581B CN110361581B CN201910714462.2A CN201910714462A CN110361581B CN 110361581 B CN110361581 B CN 110361581B CN 201910714462 A CN201910714462 A CN 201910714462A CN 110361581 B CN110361581 B CN 110361581B
- Authority
- CN
- China
- Prior art keywords
- voltage
- current
- phase
- test point
- step voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention discloses a step voltage evaluation device and a step voltage evaluation method for lightning distribution network line broken line short-circuit towers. The step voltage evaluation method comprises the following steps: the method comprises the steps of simulating lightning strike of a broken line short circuit tower fault of a distribution network line, further measuring the current of each current test point of an experimental ground net and the step voltage values of different positions obtained through measurement, then obtaining a Gaussian error coefficient optimal value considering contact resistance by utilizing a particle swarm optimization algorithm, and finally conducting safety evaluation on the area around the fault point. The invention can carry out fault inversion aiming at the condition of the line disconnection and the pole connection of the distribution network line, and evaluate the step voltage in the area around the fault point, thereby providing a solid foundation for making related safety warning and insulation protection measure suggestions.
Description
Technical Field
The invention belongs to the technical field of power system grounding, and particularly relates to a step voltage evaluation device and method for lightning stroke distribution network line broken line short circuit pole towers.
Background
With the rapid development of power grid construction, the number of line towers in a region with intensive personnel activities is increased, as bare conductors are corroded in the operation process, spots are formed on the surfaces, after lightning flashover occurs, power frequency electric arc movement is hindered by corrodes and cracks on the surfaces of the bare conductors, arc roots cannot move freely, and the bare conductors are burnt for a long time at the cracks to break. When distribution lines break the line ground fault, perhaps short circuit to the shaft tower on, therefore the electric shock injury that causes to nearby resident, maintenance work personnel often takes place, if: hainan power grid 9.17 accidents, Yunnan power grid 7.30 disconnection accidents and the like. Among them, the 7.30 electricity-related safety accidents occur in the small Meng town of Yongde county in Lincang City, and 4 villagers die due to the fact that a 220V phase line of a distribution line of the town is broken and falls to the ground. Therefore, the step voltage can cause great harm to human bodies, skin, organs and the like are burnt if the step voltage is light, scars are left, and life danger is caused by excessive current when the step voltage is serious. In addition, the step voltage has close relation with the fault current, the resistivity of the soil surface layer, the human body electric shock position and the current duration, so that when the line breaking fault is considered under lightning stroke, in order to ensure the life safety of maintenance workers, the step voltage evaluation device and method for lightning stroke distribution network line broken line short circuit pole towers are especially important to develop.
For step voltage, existing research basically focuses on the aspects of lightning protection of a power transmission line, simulation and calculation of overvoltage grounding of a transformer substation and a power transmission tower and the like, but lacks comprehensive risk test and evaluation technology for disconnection and grounding faults of a power distribution network and a risk test and evaluation device matched with the comprehensive risk test and evaluation technology. Therefore, in order to ensure the life safety of residents and workers, a set of step voltage evaluation device and method for lightning-striking the broken line short-circuit pole tower of the distribution network line is developed, so that the safety evaluation of the broken line ground faults of the distribution network with different voltage levels is enhanced, a solid foundation is provided for making related safety warning and insulation protection measure suggestions, and an important guarantee is provided for improving the safe operation of the distribution network line in future.
Disclosure of Invention
The invention aims to provide a step voltage evaluation device and a step voltage evaluation method for lightning distribution network line disconnection and short connection towers, which are used for carrying out safety evaluation when lightning distribution network line disconnection and tower connection faults occur, and provide a solid foundation for making related safety warning and insulation protection measure suggestions.
The technical scheme for realizing the purpose of the invention is as follows:
the step voltage evaluation device for lightning strike distribution network line broken line short circuit pole tower comprises an impulse voltage source (2), a line module (32), a step voltage test module (33), an experiment box (19) and a data analysis module (20);
the experimental box (19) comprises a line module (32) carried at the upper end and a step voltage testing module (33) carried at the lower end;
the line module (32) comprises an A-phase line (5), a B-phase line (6) and a C-phase line (7); the three-phase load (16) is an RLC load; the output end of the impulse voltage source (2) is connected to the input ends of the A-phase line (5), the B-phase line (6) and the C-phase line (7); the A-phase line (5) comprises a first line resistor (8), a fourth line resistor (12) and an A-phase voltage changing unit of a load transformer (15) which are sequentially connected, and the output end of the A-phase voltage changing unit is connected to a three-phase load (16); the phase B circuit (6) comprises a circuit resistor II (9), a circuit resistor V (13) and a phase B voltage conversion unit of a load transformer (15) which are connected in sequence, and the output end of the phase B voltage conversion unit is also connected to a three-phase load (16); the C-phase circuit (7) comprises a circuit resistor III (10), a circuit resistor VI (14) and a C-phase voltage transformation unit of a load transformer (15), wherein the input end of the circuit resistor III (10) is the input end of the C-phase circuit (7), the output end of the circuit resistor III (10) is connected to an input lead (101) of the disconnection simulator (11), an output lead (102) of the disconnection simulator (11) is connected to the input end of the circuit resistor VI (14), the output end of the circuit resistor VI (14) is connected to the input end of the C-phase voltage transformation unit, and the output end of the C-phase voltage transformation unit is also connected to a three-phase load (16);
the disconnection simulator (11) comprises a first current sensor (104), a second current sensor (105), a third current sensor (106), a first high-voltage switch (107), a second high-voltage switch (108), a third high-voltage switch (109), a current collecting device (113), a switching action judging device (114), a central processing unit (115) and a wireless transceiver (116); an input lead (101), an output lead (102) and a grounding lead (103) of the disconnection simulator (11) are respectively connected to input ends of a first high-voltage switch (107), a second high-voltage switch (108) and a third high-voltage switch (109), and output ends of the first high-voltage switch (107), the second high-voltage switch (108) and the third high-voltage switch (109) are mutually connected; the current sensor I (104), the current sensor II (105) and the current sensor III (106) are respectively sleeved on an input lead (101), an output lead (102) and a grounding lead (103) of the disconnection simulator (11), and output ends of the current sensors are connected to a current acquisition device (113); the high-voltage switch I (107), the high-voltage switch II (108) and the high-voltage switch III (109) are also respectively provided with a relay I (110), a relay II (111) and a relay III (112) which control the on-off of the switches of the high-voltage switch I, the high-voltage switch II and the high-voltage switch III, and the relay I (110), the relay II (111) and the relay III (112) are all connected to a switch action judgment device (114); the current acquisition device (113) and the switch action judgment device (114) are connected to the central processing unit (115), and the central processing unit (115) is connected to the data analysis module (20) through the wireless transceiver (116);
the step voltage testing module (33) comprises a tower (150), an experimental ground net (151), a simulated ground (17) and a voltage measuring robot (18); the simulated ground (17) is filled with evenly distributed soil; a grounding wire (103) of the wire breakage simulator (11) is connected to a tower (150), and an experimental ground net (151) is connected below the tower (150); the experimental ground net (151) is square, is horizontally buried below the simulated ground (17), and is connected to tower feet of the tower (150); sleeving a current sensor four (152) at intervals from any end part of the experimental ground screen (151), and taking the position of the sleeved current sensor four (152) as a current test point; the voltage measuring robot (18) is located on the simulated ground (17) and is wirelessly connected to the data analysis module (20).
The evaluation method of the evaluation device comprises the following steps:
firstly, simulating lightning stroke distribution network line broken line short circuit pole tower fault, and setting fault current duration time ts(ii) a Collecting the current of a current test point of an experimental earth screen (151) through a current sensor IV (152); the data analysis module (20) controls the voltage measurement robot (18) to measure the step voltage of different voltage test points and the distance r from each voltage test point to the midpoint of any two adjacent current test points in the experimental earth grid (151)ikWhen k is 1,2,3, n-1, rikRepresents the distance from the ith voltage test point to the middle point of the kth current test point and the adjacent kth +1 test point in the experimental earth mat (151), and when k is n, r isikRepresenting the distance from the ith voltage test point to the middle point of the nth current test point and the adjacent 1 st test point in the experimental ground grid (151), and the step voltage and r of all the voltage test pointsikWirelessly transmitting to a data analysis module (20); recording current waveforms of all current test points in an experimental ground grid (151);
step two, calculating the step voltage theoretical value of each test point simultaneously according to the following formula:
ωl＝2πlf,l＝0,1,2,3,...,271 (1)
in the formula (1), ω islThe first angular frequency is represented, and f is the fundamental frequency; in the formula (2), philThe first phase, α is the wave front attenuation coefficient, β is the wave tail attenuation coefficient, in the formula (3), B is the wave shape correction coefficient, Uti(g) Representing a step voltage theoretical calculation value of the ith voltage test point; i iskThe absolute value of the difference between the current amplitude measured by the kth current test point and the current amplitude measured by the adjacent (k + 1) th test point is k, and k is 1,2,3, …, n-1; i isnThe absolute value of the difference of the current amplitude values measured by the nth current test point and the 1 st test point is obtained; n is the number of current test points, m is the number of voltage test points, RbIs the body resistance, rho is the resistivity of the soil in the experimental box, S is the stride distance, R0ρ/(4b) is the contact resistance, b is the equivalent ground radius, g is the gaussian error coefficient taking into account the contact resistance, η is the integral variable;
thirdly, modeling a step voltage formula by adopting a particle swarm optimization algorithm, and calculating a g value which enables the error between a measured value and a theoretical value of the step voltage to be minimum, wherein the step voltage formula comprises the following steps:
1) generating an initial population having uniformly distributed particles and velocities, setting a stopping condition;
2) the objective function value for each particle position is calculated according to equation (4):
wherein f (g) represents an objective function, UfiRepresenting a step voltage measurement value of the ith voltage test point;
3) updating the individual historical optimal position of each particle and the optimal position of the whole population;
4) updating the velocity and position of each particle;
5) if the stopping condition is met, stopping searching and outputting a searching result; otherwise, returning to the step 2);
6) obtaining an optimal value g from the optimization0Substituting the formula (5) into the optimized theoretical formula：
In the formula (5), UtRepresenting a theoretical calculation value of the optimized step voltage; when k is 1,2,3, n-1, rkRepresents the distance from any position of the simulated ground (17) to the middle point of the k < th > current test point and the adjacent k +1 < th > current test point in the experimental earth mat (151), when k is n, rkRepresenting the distance from any position of the simulated ground (17) to the middle point of the nth current test point and the adjacent 1 st test point in the experimental earth screen (151); g0The optimal value is obtained;
fourthly, according to the duration time t of the fault currentsCalculating the maximum step voltage limit value U born by the human body, and dividing the danger level:
the data analysis module (20) calculates the maximum step voltage limit value U which can be born by a human body according to the formula (6), and carries out danger grade division according to the rule: when U is turnedt<When U is detected, the operation is safe; when U is turnedtWhen the number of U is more than or equal to U, the product is dangerous.
The invention has the beneficial effects that:
1) the step voltage of the area around the fault point is evaluated under the condition of the fault of the distribution network line disconnection tower connection under lightning stroke, so that the personal safety is guaranteed;
2) the step voltage evaluation device can simulate the fault condition of the line breaking and pole connecting of the distribution network line, and further invert the fault condition;
3) the step voltage evaluation method considers transition resistance of a human body, including contact resistance and human body resistance, and is closer to a real situation.
Drawings
Fig. 1(a) and 1(b) are schematic structural views of a step voltage evaluation device according to the present invention;
FIG. 2 is a schematic view of current sensor placement of the experimental counterpoise of the present invention;
FIG. 3 is a flow chart of the step voltage evaluation in the present invention.
Detailed Description
The following further describes embodiments of the present invention with reference to the drawings. The specific implementation mode of the step voltage evaluation device and the step voltage evaluation method for lightning distribution network line broken line short circuit pole towers comprises the following steps:
firstly, constructing a step voltage evaluation device of a distribution network line broken line short circuit tower under lightning stroke, which mainly comprises an impulse voltage source (2), a line module (32), a step voltage test module (33), an experiment box (19) and a data analysis module (20); composition is carried out;
the impulse voltage source (2) is an impulse voltage generating source with adjustable gap and voltage grade, and can generate 8/20 mu s impulse voltage waveform meeting the requirement of an experimental system;
the upper end of the experiment box (19) is provided with a circuit module (32), the lower end of the experiment box is provided with a step voltage testing module (33), the lower end face of the experiment box (19) is provided with an opening, and the rest faces are built by a transparent acrylic insulating plate;
the line module (32) comprises an A-phase line (5), a B-phase line (6) and a C-phase line (7); the three-phase load (16) is an RLC load; the output end of the impulse voltage source (2) is connected to the input ends of the A-phase line (5), the B-phase line (6) and the C-phase line (7); the A-phase line (5) comprises a first line resistor (8), a fourth line resistor (12) and an A-phase voltage changing unit of a load transformer (15) which are sequentially connected, and the output end of the A-phase voltage changing unit is connected to a three-phase load (16); the phase B circuit (6) comprises a circuit resistor II (9), a circuit resistor V (13) and a phase B voltage conversion unit of a load transformer (15) which are connected in sequence, and the output end of the phase B voltage conversion unit is also connected to a three-phase load (16); the C-phase circuit (7) comprises a circuit resistor III (10), a circuit resistor VI (14) and a C-phase voltage transformation unit of a load transformer (15), wherein the input end of the circuit resistor III (10) is the input end of the C-phase circuit (7), the output end of the circuit resistor III (10) is connected to an input lead (101) of the disconnection simulator (11), an output lead (102) of the disconnection simulator (11) is connected to the input end of the circuit resistor VI (14), the output end of the circuit resistor VI (14) is connected to the input end of the C-phase voltage transformation unit, and the output end of the C-phase voltage transformation unit is also connected to a three-phase load (16);
the disconnection simulator (11) comprises a first current sensor (104), a second current sensor (105), a third current sensor (106), a first high-voltage switch (107), a second high-voltage switch (108), a third high-voltage switch (109), a current collecting device (113), a switching action judging device (114), a central processing unit (115) and a wireless transceiver (116); an input lead (101), an output lead (102) and a grounding lead (103) of the disconnection simulator (11) are respectively connected to the input ends of a high-voltage switch I (107), a high-voltage switch II (108) and a high-voltage switch III (109); the current sensor I (104), the current sensor II (105) and the current sensor III (106) are respectively sleeved on an input lead (101), an output lead (102) and a grounding lead (103) of the disconnection simulator (11), and output ends of the current sensors are connected to a current acquisition device (113); the output ends of the high-voltage switch I (107), the high-voltage switch II (108) and the high-voltage switch III (109) are respectively provided with a relay I (110), a relay II (111) and a relay III (112), and the relay I (110), the relay II (111) and the relay III (112) are all connected to a switching action judgment device (114); the current acquisition device (113) and the switch action judgment device (114) are connected to the central processing unit (115), and the central processing unit (115) is connected to the data analysis module (20) through the wireless transceiver (116);
in the step voltage testing module (33), a broken line simulator (11) is connected with a tower (150) through a grounding wire (103), an experimental ground net (151) is connected below the tower (150), the experimental ground net (151) is horizontally buried on a plane 0.8m below the surface of a simulation ground (17), the experimental ground net (151) is connected with tower feet of the tower (150), a current sensor is arranged at intervals of 1m from any end part, current testing points are sequentially numbered, the number is k which is equal to 1,2,3, … …, n and n which are total current numbers, and I is recordedkWhen k is 1,2,3, n-1, IkThe absolute value of the difference between the current amplitude values measured by the kth current test point and the adjacent (k + 1) th current test point is represented by A; when k is n, IkThe absolute value of the difference between the current amplitude values measured by the nth current test point and the adjacent 1 st current test point is represented, and the unit is A; and consists of a simulated ground (17) and a voltage measuring robot (18); the simulated ground (17) is filled with uniformly arranged soilThe pressure measurement robot (18) is a movable real human body proportion model which is remotely controlled, simulation shoes and socks are worn on the soles of the feet, equivalent resistors are arranged inside the pressure measurement robot and used for simulating human body resistors and are respectively connected with the shoes and socks of the two feet, and a distance sensor is also arranged at the same time, so that the more specific internal structure is not repeated as the related robot technology is mature; the voltage measurement robot (18) moves in the range of a simulated ground (17), and wirelessly transmits the measured step voltage and distance data between the voltage test point and the midpoint of any two adjacent current test points in an experimental ground grid (151) to the data analysis module (20);
secondly, simulating lightning stroke distribution network line broken line short circuit pole tower fault:
the data analysis module (20) is used for controlling the high-voltage switch I (107) and the high-voltage switch II (108) to be conducted, the high-voltage switch III (109) to be disconnected, then the surge voltage source (2) is turned on, meanwhile, the data analysis module (20) is used for sending a side disconnection grounding signal of the surge voltage source (2), the signal is transmitted to the central processing unit (115) through the wireless transceiver (116), the switch action judgment device (114) controls the relay II (111) to act so as to disconnect the high-voltage switch II (108), controls the relay III (112) to conduct the high-voltage switch III (109), and the fault current duration time t is setsThe unit is s; the data analysis module (20) controls the voltage measurement robot (18) to measure the step voltage of the voltage test points and the distance r from each voltage test point to the midpoint of any two adjacent current test points in the experimental earth grid (151)ikIn meters, when k is 1,2,3, n-1, rikRepresents the distance from the ith voltage test point to the middle point of the kth current test point and the adjacent kth +1 test point in the experimental earth mat (151), and when k is n, r isikRepresenting the distance from the ith voltage test point to the middle point of the nth current test point and the adjacent 1 st test point in the experimental earth screen (151); after the step voltage is obtained through measurement, the impulse voltage source (2) is closed, all switches are restored to the original state, the interval is 10 minutes, the voltage measurement robot (18) is controlled to move randomly within the range of the simulated ground (17), a new voltage test point is selected, the impulse voltage source (2) is opened, the high-voltage switch is set again according to the method, and the step voltage and the voltage test are measuredDistance r from test point to midpoint of any two adjacent current test points in experimental earth mat (151)ik(ii) a Step voltage and r of all voltage test pointsikWirelessly transmitting to a data analysis module (20); recording current waveforms of all current test points in an experimental ground grid (151);
and thirdly, simultaneously calculating the step voltage theoretical value of each test point according to the following formula:
ωl＝2πlf,l＝0,1,2,3,...,271 (7)
in the formula (7), ωlThe first angular frequency is shown, f is the fundamental frequency, and the value is 3333 HZ; in the formula (8), philIs the first phase, α is the wave front attenuation coefficient, β is the wave tail attenuation coefficient, in the formula (9), Uti(g) The unit of the theoretical calculated value of the step voltage of the ith voltage test point is V, B is a waveform correction coefficient, the value is 2.33, n is the number of the current test points, m is the number of the voltage test points, and R isb1000(Ω) is the body resistance, ρ is the soil resistivity in the experimental box, S0.8 (m) is the stride distance, R0ρ/(4b) is the contact resistance, b 0.08(m) is the equivalent ground radius, g is the gaussian error coefficient taking into account the contact resistance, η is the integral variable;
fourthly, modeling a step voltage formula by adopting a particle swarm optimization algorithm, and calculating a g value which enables the error between a measured value and a theoretical value of the step voltage to be minimum, wherein the step voltage formula comprises the following steps:
1) generating an initial population having uniformly distributed particles and velocities, setting a stopping condition;
2) the objective function value for each particle position is calculated according to equation (4):
wherein f (g) represents an objective function, UfiRepresenting a step voltage measurement value of the ith voltage test point;
3) updating the individual historical optimal position of each particle and the optimal position of the whole population;
4) updating the velocity and position of each particle;
5) if the stopping condition is met, stopping searching and outputting a searching result; otherwise, returning to the step 2);
6) obtaining an optimal value g from the optimization0Substituting the following formula (5) into the optimized theoretical formula:
in formula (11), UtRepresenting a theoretical calculation value of the optimized step voltage; when k is 1,2,3, n-1, rkRepresents the distance from any position of the simulated ground (17) to the middle point of the k < th > current test point and the adjacent k +1 < th > current test point in the experimental earth mat (151), when k is n, rkThe distance from any position of the simulated ground (17) to the middle point of the nth current test point and the adjacent 1 st test point in the experimental ground grid (151) is represented by m; g0The optimal value is obtained;
fifthly, according to the duration time t of the fault currentsCalculating the maximum step voltage limit value U born by the human body, and dividing the danger level:
the data analysis module (20) calculates the maximum step voltage limit value U which can be born by a human body according to the formula (12), and carries out danger grade division according to the rule: when U is turnedt<When U is detected, the operation is safe; when U is turnedtWhen the number of U is more than or equal to U, the product is dangerous.
Claims (1)
1. The method for evaluating the step voltage of the lightning distribution network line broken line short circuit tower is characterized by comprising an impulse voltage source (2), a line module (32), a step voltage testing module (33), an experimental box (19) and a data analysis module (20);
the experimental box (19) comprises a line module (32) carried at the upper end and a step voltage testing module (33) carried at the lower end;
the line module (32) comprises an A-phase line (5), a B-phase line (6) and a C-phase line (7); the three-phase load (16) is an RLC load; the output end of the impulse voltage source (2) is connected to the input ends of the A-phase line (5), the B-phase line (6) and the C-phase line (7); the A-phase line (5) comprises a first line resistor (8), a fourth line resistor (12) and an A-phase voltage changing unit of a load transformer (15) which are sequentially connected, and the output end of the A-phase voltage changing unit is connected to a three-phase load (16); the phase B circuit (6) comprises a circuit resistor II (9), a circuit resistor V (13) and a phase B voltage conversion unit of a load transformer (15) which are connected in sequence, and the output end of the phase B voltage conversion unit is also connected to a three-phase load (16); the C-phase circuit (7) comprises a circuit resistor III (10), a circuit resistor VI (14) and a C-phase voltage transformation unit of a load transformer (15), wherein the input end of the circuit resistor III (10) is the input end of the C-phase circuit (7), the output end of the circuit resistor III (10) is connected to an input lead (101) of the disconnection simulator (11), an output lead (102) of the disconnection simulator (11) is connected to the input end of the circuit resistor VI (14), the output end of the circuit resistor VI (14) is connected to the input end of the C-phase voltage transformation unit, and the output end of the C-phase voltage transformation unit is also connected to a three-phase load (16);
the disconnection simulator (11) comprises a first current sensor (104), a second current sensor (105), a third current sensor (106), a first high-voltage switch (107), a second high-voltage switch (108), a third high-voltage switch (109), a current collecting device (113), a switching action judging device (114), a central processing unit (115) and a wireless transceiver (116); an input lead (101), an output lead (102) and a grounding lead (103) of the disconnection simulator (11) are respectively connected to input ends of a first high-voltage switch (107), a second high-voltage switch (108) and a third high-voltage switch (109), and output ends of the first high-voltage switch (107), the second high-voltage switch (108) and the third high-voltage switch (109) are mutually connected; the current sensor I (104), the current sensor II (105) and the current sensor III (106) are respectively sleeved on an input lead (101), an output lead (102) and a grounding lead (103) of the disconnection simulator (11), and output ends of the current sensors are connected to a current acquisition device (113); the high-voltage switch I (107), the high-voltage switch II (108) and the high-voltage switch III (109) are also respectively provided with a relay I (110), a relay II (111) and a relay III (112) which control the on-off of the switches of the high-voltage switch I, the high-voltage switch II and the high-voltage switch III, and the relay I (110), the relay II (111) and the relay III (112) are all connected to a switch action judgment device (114); the current acquisition device (113) and the switch action judgment device (114) are connected to the central processing unit (115), and the central processing unit (115) is connected to the data analysis module (20) through the wireless transceiver (116);
the step voltage testing module (33) comprises a tower (150), an experimental ground net (151), a simulated ground (17) and a voltage measuring robot (18); the simulated ground (17) is filled with evenly distributed soil; a grounding wire (103) of the wire breakage simulator (11) is connected to a tower (150), and an experimental ground net (151) is connected below the tower (150); the experimental ground net (151) is square, is horizontally buried below the simulated ground (17), and is connected to tower feet of the tower (150); sleeving a current sensor four (152) at intervals from any end part of the experimental ground screen (151), and taking the position of the sleeved current sensor four (152) as a current test point; the voltage measuring robot (18) is a remote control movable real human body proportion model, simulation shoes and socks are worn on the soles of the feet, equivalent resistors are arranged inside the voltage measuring robot and used for simulating human body resistors and are respectively connected with the shoes and socks of two feet, and the voltage measuring robot is also provided with a distance sensor; the voltage measurement robot (18) is positioned on the simulated ground (17) and is wirelessly connected to the data analysis module (20);
firstly, simulating lightning stroke distribution network line broken line short circuit pole tower fault, and setting fault current duration time ts(ii) a Collecting the current of a current test point of an experimental earth screen (151) through a current sensor IV (152); the data analysis module (20) controls the voltage measurement robot (18) to measure the step voltage of different voltage test points and the distance r from each voltage test point to the midpoint of any two adjacent current test points in the experimental earth grid (151)ikWhen k is 1,2,3, n-1, rikRepresents the distance from the ith voltage test point to the middle point of the kth current test point and the adjacent kth +1 test point in the experimental earth mat (151), and when k is n, r isikRepresenting the ith voltage test point into an experimental earth mat (151)The distance between the nth current test point and the midpoint of the adjacent 1 st test point is used for measuring the step voltage of all the voltage test points and rikWirelessly transmitting to a data analysis module (20); recording current waveforms of all current test points in an experimental ground grid (151);
step two, calculating the step voltage theoretical value of each test point simultaneously according to the following formula:
ωl＝2πlf,l＝0,1,2,3,...,271 (1)
in the formula (1), ω islThe first angular frequency is represented, and f is the fundamental frequency; in the formula (2), philThe first phase, α is the wave front attenuation coefficient, β is the wave tail attenuation coefficient, in the formula (3), B is the wave shape correction coefficient, Uti(g) Representing a step voltage theoretical calculation value of the ith voltage test point; i iskThe absolute value of the difference between the current amplitude measured by the kth current test point and the current amplitude measured by the adjacent (k + 1) th test point is k, and k is 1,2,3, …, n-1; i isnThe absolute value of the difference of the current amplitude values measured by the nth current test point and the 1 st test point is obtained; n is the number of current test points, m is the number of voltage test points, RbIs the body resistance, rho is the resistivity of the soil in the experimental box, S is the stride distance, R0ρ/(4b) is the contact resistance, b is the equivalent ground radius, g is the gaussian error coefficient taking into account the contact resistance, η is the integral variable;
thirdly, modeling a step voltage formula by adopting a particle swarm optimization algorithm, and calculating a g value which enables the error between a measured value and a theoretical value of the step voltage to be minimum, wherein the step voltage formula comprises the following steps:
1) generating an initial population having uniformly distributed particles and velocities, setting a stopping condition;
2) the objective function value for each particle position is calculated according to equation (4):
wherein f (g) represents an objective function, UfiRepresenting a step voltage measurement value of the ith voltage test point;
3) updating the individual historical optimal position of each particle and the optimal position of the whole population;
4) updating the velocity and position of each particle;
5) if the stopping condition is met, stopping searching and outputting a searching result; otherwise, returning to the step 2);
6) obtaining an optimal value g from the optimization0Substituting the following formula (5) into the optimized theoretical formula:
in the formula (5), UtRepresenting a theoretical calculation value of the optimized step voltage; when k is 1,2,3, n-1, rkRepresents the distance from any position of the simulated ground (17) to the middle point of the k < th > current test point and the adjacent k +1 < th > current test point in the experimental earth mat (151), when k is n, rkRepresenting the distance from any position of the simulated ground (17) to the middle point of the nth current test point and the adjacent 1 st test point in the experimental earth screen (151); g0The optimal value is obtained;
fourthly, according to the duration time t of the fault currentsCalculating the maximum step voltage limit value U born by the human body, and dividing the danger level:
the data analysis module (20) calculates the maximum step voltage limit value U which can be born by a human body according to the formula (6), and carries out danger grade division according to the rule: when U is turnedt<When U is detected, the operation is safe; when U is turnedtWhen the number of U is more than or equal to U, the product is dangerous.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910714462.2A CN110361581B (en) | 2019-08-04 | 2019-08-04 | Step voltage evaluation device and method for lightning distribution network line broken line short circuit tower |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910714462.2A CN110361581B (en) | 2019-08-04 | 2019-08-04 | Step voltage evaluation device and method for lightning distribution network line broken line short circuit tower |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110361581A CN110361581A (en) | 2019-10-22 |
| CN110361581B true CN110361581B (en) | 2020-09-29 |
Family
ID=68222248
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910714462.2A Active CN110361581B (en) | 2019-08-04 | 2019-08-04 | Step voltage evaluation device and method for lightning distribution network line broken line short circuit tower |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110361581B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111239474B (en) * | 2020-02-24 | 2022-06-10 | 云南电网有限责任公司临沧供电局 | Step voltage detection method and system for single-phase broken line short-circuit tower of power transmission line |
| CN111239473B (en) * | 2020-02-24 | 2022-02-01 | 云南电网有限责任公司临沧供电局 | Broken string connects pole tower trouble step voltage risk evaluation system under perpendicular layering soil |
| CN112014620B (en) * | 2020-07-31 | 2023-07-07 | 深圳供电局有限公司 | Step voltage simulator |
| CN111983360B (en) * | 2020-08-24 | 2021-07-02 | 西南交通大学 | Transmission tower safety risk evaluation system considering multiple lightning strokes |
| CN112083251B (en) * | 2020-09-18 | 2021-07-02 | 西南交通大学 | Human internal organ electrical loss risk assessment method considering various shapes |
| CN113252989B (en) * | 2021-07-15 | 2021-09-24 | 广东电网有限责任公司江门供电局 | Contact resistance measuring method for overhead ground wire and tower |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103424647B (en) * | 2013-05-28 | 2015-12-23 | 上海理工大学 | The soil body electrically responds determinator under lightning impulse effect |
| CN106093534A (en) * | 2016-08-08 | 2016-11-09 | 三峡大学 | A kind of method testing earth mat step voltage and contact voltage |
-
2019
- 2019-08-04 CN CN201910714462.2A patent/CN110361581B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110361581A (en) | 2019-10-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110361581B (en) | Step voltage evaluation device and method for lightning distribution network line broken line short circuit tower | |
| CN110361584B (en) | Risk assessment experiment platform and method for lightning stroke of single-phase earth fault of power transmission line | |
| CN110412423B (en) | Biological safety evaluation platform and method for single-phase broken line short-circuit tower of power transmission line | |
| CN103257293B (en) | A kind of power transmission line lightning shielding electro-magnetic transient moving die experiment system | |
| CN103278709B (en) | A kind of lightning travelling wave in transmission line characteristic test system | |
| CN105425118A (en) | Multi-information fusion fault arc detection method and device | |
| CN110361579B (en) | System and method for evaluating safety of two-phase grounding surrounding environment of power transmission line under layered soil | |
| CN110361577B (en) | Power transmission line single-phase wire break and grounding fault risk assessment experiment platform and method | |
| CN102435921A (en) | Method for determining insulation and lightning impulse withstanding properties of same-tower double-loop power transmission line | |
| CN112287523B (en) | Method and device for detecting overvoltage of circuit breaker under multiple lightning strokes | |
| Long et al. | Online monitoring of substation grounding grid conditions using touch and step voltage sensors | |
| CN114236288B (en) | Fault positioning method based on power transmission line | |
| CN108896883A (en) | Arcing fault simulator and analogy method of the overhead transmission line under surge voltage | |
| CN110361580B (en) | Step voltage evaluation platform and method for horizontal soil stratification under lightning stroke | |
| CN102879688A (en) | Test system for grounding grid | |
| CN105160049A (en) | Method for calculating direct lightning tripping-out rate of distribution line up to 35kV | |
| CN110361578B (en) | Single-phase line short-circuit tower personal safety assessment system and method considering soil stratification | |
| CN108896882B (en) | Overhead transmission line icing flashover influence factor appraisal procedure under impact and industrial frequency superimposed voltage | |
| CN106872861B (en) | Lightning current inversion method and system for direct-hit conductor of ultra-high voltage transmission engineering line | |
| CN110361582B (en) | Biological safety evaluation system and method for taking two-phase broken line grounding into account of human body transition resistance | |
| CN110361585B (en) | Single-phase broken line extension rod tower risk assessment platform and method considering soil stratification under lightning strike | |
| CN203084089U (en) | Test system of grounding grid | |
| CN103245896B (en) | Distribution line thunder and lightning induction voltage analog platform based on rocket triggered lightning technology | |
| CN110361583B (en) | Step voltage risk assessment platform and method for single-phase earth fault of distribution network under layered soil | |
| CN112578204B (en) | Lightning protection true type test system for power distribution network and multi-space-time scale dynamic evaluation method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |