CN113032933A - Multi-objective optimized laying method and system for power cable duct bank - Google Patents
Multi-objective optimized laying method and system for power cable duct bank Download PDFInfo
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Abstract
The invention provides a multi-objective optimized laying method and a system for power cable ducts, which comprises the following steps: acquiring cable structure parameters; substituting the structural parameters of the cable into a pre-constructed optimization model to perform optimization solution to obtain a code corresponding to the cable duct arrangement laying mode; determining an optimal cable duct bank laying scheme based on the codes corresponding to the cable duct bank laying modes; and in the optimizing solving process, codes corresponding to the cable duct arrangement laying mode are used as population individuals, and the optimizing model is constructed according to the temperature rise value of each cable. According to the invention, based on the influence factors of the current-carrying capacity of the cable under the cable duct arrangement laying, the optimal cable duct arrangement laying mode is obtained by combining a multi-objective optimization method, and the current-carrying capacity of the circuit is further improved by effectively planning the cable laying position.
Description
Technical Field
The invention relates to the technical field of power transmission and distribution, in particular to a multi-objective optimized laying method and system for power cable ducts.
Background
In recent years, urban clusters develop rapidly, and the demand for electricity is increasing day by day, and as a core carrier of energy transmission, the effect of a power cable circuit on power supply is important. The power cable calandria laying mode has the advantages of investment saving, small occupied area, flexible wiring, capability of accommodating more loop cables, convenience in construction and the like, and is widely applied to urban cable laying engineering. The power grid is formed by stacking a plurality of pipelines, the pipelines are separated by pipe sleepers, and the outside of the power grid is covered by bricks or reinforced concrete.
In the operation process of the power cable, the cable generates electromagnetic loss, temperature rise is generated, and the transmission capacity of the cable is reduced. At present, under the condition of relatively simple laying, the current-carrying capacity of the cable is usually calculated according to the IEC standard. The method can be mainly used for calculating cables in air or in a direct-buried laying mode, but in the case of the complex external environment such as a pipe arrangement, accurate values are difficult to obtain through simple formula calculation. For the power cable duct bank, in consideration of construction convenience and cost saving, the MPP material is usually adopted to manufacture the pipeline at present, but the heat conductivity is poor, the thermal resistance coefficient is as high as 6 Km/W, and heat dissipation is influenced; in addition, the heat transfer from the cable to the gauntlet is limited due to the small amount of air present in the gauntlet and the lack of air fluidity in this part. Due to the factors, the heat dissipation performance of a cable line in a calandria laying mode is poor, and the current-carrying capacity of the cable is reduced, so that the current-carrying capacity of the calandria laying cable needs to be reasonably analyzed to improve the conveying capacity of the calandria laying cable.
The outside cladding of calandria has concrete or brick wall, contains many pipelines in the calandria passageway, and different position calandria hole site heat dispersion is different, places the great cable of heating power in the calandria that heat dispersion is relatively poor, must lead to this return circuit cable temperature to rise obviously, influences its current-carrying capacity, and will effectively increase the circuit current-carrying capacity with placing the cable that heating power is the highest in the best hole site of heat dispersion, therefore it is necessary to optimize the calandria cable of laying to improve circuit economic benefits.
In the prior art, according to a standard IEC (International electrotechnical Commission) current-carrying capacity calculation formula, an optimization strategy of arranging and laying power cables under unequal loads is researched, and compared with a CYMCAP software calculation result, the current-carrying capacity of the optimized cable can be improved by at least 10%, but the mutual restriction effect among all loop cables is not considered in the calculation process, and the obtained result is not accurate enough.
Disclosure of Invention
In order to solve the problem of lower current-carrying capacity caused by poorer heat dissipation performance of a cable line in a sequential calandria laying mode in the prior art, the invention provides a multi-objective optimized laying method of a power cable calandria, which comprises the following steps:
acquiring cable structure parameters;
substituting the structural parameters of the cable into a pre-constructed optimization model to perform optimization solution to obtain a code corresponding to the cable duct arrangement laying mode;
determining an optimal cable duct bank laying scheme based on the codes corresponding to the cable duct bank laying modes;
and in the optimizing solving process, codes corresponding to the cable duct arrangement laying mode are used as population individuals, and the optimizing model is constructed according to the temperature rise value of each cable.
Preferably, the cable structure parameters include: the thermal resistance of the cable and the metal sleeve in unit length, the thermal resistance of the liner layer between the metal sleeve and the armor in unit length, the thermal resistance of the cable outer sheath in unit length, the thermal resistance of the medium around the cable, the core number of the cable, the ratio of the loss of the metal sleeve of the cable to the total loss of all conductors of the cable, the ratio of the loss of the armor layer of the cable to the total loss of all conductors of the cable, the loss factor of the cable and the loss of the insulating medium of the cable.
Preferably, the construction of the optimization model comprises:
constructing an objective function by taking the minimum actual temperature rise value of each cable as a target;
and setting constraint conditions by taking the preset cable number and hole position information as the objective function.
Preferably, the objective function is determined according to the following formula:
in the formula,. DELTA.theta.iIs the actual temperature rise value of the ith cable,
is the thermal resistance per unit length between the ith cable and the metal sheath,
is the thermal resistance per unit length of the cushion layer between the metal sleeve and the armor of the ith cable,
is the thermal resistance per unit length of the ith cable outer sheath,
is the thermal resistance of the surrounding medium of the ith cable, niIs the ith powerCore number of cable, IiIs the current value of the ith cable, RiIs the ac resistance value of the ith cable,
the ratio of the sheath loss of the ith cable to the total loss of all conductors of the cable,
is the ratio of the armor loss of the ith cable relative to the total loss of all conductors of the cable, mu is the cable loss factor,
insulation dielectric loss, Delta theta, of the ith cableniThe temperature rise value generated by heating the ith cable for the nth cable.
Preferably, the temperature rise value delta theta generated by heating the ith cable by the nth cableniDetermined as follows:
in the formula,. DELTA.theta.niTemperature rise value, n, generated by heating of ith cable for nth cablenIs the core number of the nth cable, InIs the current value of the nth cable, RnIs the value of the alternating current resistance of the nth cable,
is the ratio of the metal sheath loss of the nth cable to the total loss of all conductors of that cable,
the ratio of the sheath loss of the nth cable to the total loss of all conductors of the cable, munFor the nth cable loss factor calculated from the daily load factor,
is the insulation dielectric loss, rho, of the nth cablesIs the thermal resistivity of the insulating material, dinIs the distance between the ith cable and the nth cable, din' is the distance between the nth cable and the mirror image of the ith cable relative to the earth surface-air.
Preferably, the constraint condition includes:
the optimal laying scheme of the cable duct bank belongs to all permutation and combination determined based on the preset number of cables and hole site information;
wherein the information of the hole site includes: the number of holes and the spacing between holes.
Preferably, the process of acquiring the code corresponding to the cable duct arrangement laying mode includes:
each hole site in the row pipe group is represented by binary codes, and the hole sites represented by the binary codes are sequentially expanded in a row;
the hole positions for placing the cables are represented by binary codes corresponding to the cables placed in the hole positions, the hole positions for not placing the cables are represented by binary codes with decimal numerical value 0, and the binary codes corresponding to the cables are configured according to the types of the cables.
Based on the same invention concept, the invention also provides a power cable duct multi-objective optimization laying system, which comprises: the parameter acquisition module is used for acquiring cable structure parameters;
the optimization solving module is used for substituting the structural parameters of the cable and the set calandria group into a pre-constructed optimization model to perform optimization solving to obtain an optimal solution represented by codes;
the scheme determining module is used for determining an optimal scheme for laying the cable arranging pipe based on the codes corresponding to the cable arranging pipe laying modes;
and in the optimizing solution process, codes corresponding to the tube bank groups are used as population individuals, and the optimizing model is constructed according to the temperature rise value of each cable.
Preferably, the cable structure parameters include: the thermal resistance of the cable and the metal sleeve in unit length, the thermal resistance of the liner layer between the metal sleeve and the armor in unit length, the thermal resistance of the cable outer sheath in unit length, the thermal resistance of the medium around the cable, the core number of the cable, the ratio of the loss of the metal sleeve of the cable to the total loss of all conductors of the cable, the ratio of the loss of the armor layer of the cable to the total loss of all conductors of the cable, the loss factor of the cable and the loss of the insulating medium of the cable.
Preferably, the construction of the optimization model comprises:
constructing an objective function by taking the minimum actual temperature rise value of each cable as a target;
and setting constraint conditions by taking the preset cable number and hole position information as the objective function.
Compared with the prior art, the invention has the beneficial effects that:
the invention provides a multi-objective optimized laying method and a system for power cable ducts, which comprises the following steps: acquiring cable structure parameters; substituting the structural parameters of the cable into a pre-constructed optimization model to perform optimization solution to obtain a code corresponding to the cable duct arrangement laying mode; determining an optimal cable duct bank laying scheme based on the codes corresponding to the cable duct bank laying modes; and in the optimizing solving process, codes corresponding to the cable duct arrangement laying mode are used as population individuals, and the optimizing model is constructed according to the temperature rise value of each cable. According to the invention, based on the influence factors of the current-carrying capacity of the cable under the cable duct arrangement laying, the optimal cable duct arrangement laying mode is obtained by combining a multi-objective optimization method, and the current-carrying capacity of the circuit is further improved by effectively planning the cable laying position.
Drawings
FIG. 1 is a schematic diagram of a multi-objective optimized laying method for power cable ducts of the present invention;
FIG. 2 is a schematic diagram of a multi-objective optimized laying system for power cable ducts of the present invention;
FIG. 3 is a flow chart of a multi-objective optimization method of the present invention;
FIG. 4 is a schematic cross-sectional view of a gauntlet according to the present invention;
FIG. 5 is a schematic diagram showing equivalent thermal resistance at the outside of each hole site of the gauntlet in the present invention;
fig. 6 is a schematic view of the initial laying of the cable-duct bank in the present invention;
FIG. 7 is a schematic diagram of temperature rise variance for each optimized arrangement of the present invention;
fig. 8 is a schematic view of a preferred pipe laying scheme in the present invention.
Detailed Description
Example 1
The invention provides a power cable calandria multi-objective optimization laying method, aiming at the problem that in the prior art, cables are sequentially arranged according to the sequence of calandria hole sites, and the difference of the heat productivity of each loop cable and the heat dispersion performance of the calandria hole sites is not considered, so that the problem that cables with large heat are arranged at hole sites with poor local heat dispersion in calandria is caused, and the cable carrying capacity is low, wherein the power cable calandria multi-objective optimization laying method comprises the following steps of:
step 2, substituting the structural parameters of the cable into a pre-constructed optimization model to perform optimization solution to obtain a code corresponding to an optimal cable duct arrangement laying mode;
step 3, determining an optimal cable duct arrangement laying scheme based on the codes corresponding to the cable duct arrangement laying modes;
in the optimizing solving process, codes corresponding to cable pipe arrangement laying modes are used as population individuals, and the optimizing model is constructed according to the temperature rise value of each cable;
the structural parameters of the cable include: the thermal resistance of the cable and the metal sleeve in unit length, the thermal resistance of the liner layer between the metal sleeve and the armor in unit length, the thermal resistance of the cable outer sheath in unit length, the thermal resistance of the medium around the cable, the core number of the cable, the ratio of the loss of the metal sleeve of the cable to the total loss of all conductors of the cable, the ratio of the loss of the armor layer of the cable to the total loss of all conductors of the cable, the loss factor of the cable and the loss of the insulating medium of the cable.
In the step 1, the number of cables and the structural parameters of the cables are obtained;
wherein the structural parameters of the cable to be acquired include: the thermal resistance of the cable and the metal sleeve in unit length, the thermal resistance of the liner layer between the metal sleeve and the armor in unit length, the thermal resistance of the cable outer sheath in unit length, the thermal resistance of the medium around the cable, the core number of the cable, the ratio of the loss of the metal sleeve of the cable to the total loss of all conductors of the cable, the ratio of the loss of the armor layer of the cable to the total loss of all conductors of the cable, the loss factor of the cable and the loss of the insulating medium of the cable.
In the step 2, an optimization model for optimizing the cable duct laying is firstly established, and the optimization model is established according to the temperature rise value of each cable. It is therefore necessary to calculate the temperature rise of each cable and its current carrying capacity.
When laying multi-loop cables in a pipe, due to the mutual heating effect among a plurality of groups of cables, a temperature rise value delta theta is smaller than the difference value between the highest temperature of a cable core and the initial environment temperature, the cables are randomly sequenced, the 1 st cable and the 2 nd cable are marked for analysis, and the temperature rise generated by heating the 1 st cable by the 2 nd cable is calculated according to the following formula:
Δθ21＝P2T12 (1)
in the formula,. DELTA.theta.21Temperature rise, P, caused by heating of No. 1 cable for No. 2 cable2For the heating power of the second cable, T12Is the thermal resistance between the first cable and the second cable;
wherein the heating power P of the 2 nd cable2Calculated as follows:
in the formula, n2Is the core number of the 2 nd cable, I2Current value of 2 nd cable, R2Is the ac resistance value of the 2 nd cable,
for the 2 nd cable the sheath loss is related to the total loss of all conductors of the cableIn the ratio of (a) to (b),
is the ratio of the armor loss of the 2 nd cable relative to the total loss of all conductors of the cable, μ 2 is the 2 nd cable loss factor calculated from the daily load factor, set here to 1,
the insulation dielectric loss of the 2 nd cable;
thermal resistance T between the first cable and the second cable12Calculated as follows:
in the formula, ρsAs a thermal resistance of the environment, dinIs the distance between the ith cable and the nth cable, din' is the distance between the nth cable and the mirror image of the ith cable relative to the earth surface-air.
Substituting the (2) and (3) into (1), and determining according to the following formula:
the heating effect of the 1 st cable on the ith cable laid in the row can be deduced on the basis of the above formula, which is determined as follows:
by utilizing the above formula, the heating effect of each cable on the 1 st cable is integrated, and the actual allowable temperature rise of the obtained cable is shown as the following formula:
Δθ＝Δθ1-Δθ21-Δθ31-…-Δθn1 (6)
substituting the formula (6) into the formula (4), and performing temperature correction after considering the temperature rise value generated by heating the 1 st cable by all cables to obtain a current-carrying capacity calculation formula of the 1 st cable as follows:
calculating the current-carrying capacity of the ith cable according to the formula (7), wherein the current-carrying capacity is shown as the following formula:
wherein, formula (8) can also be represented as follows:
in this embodiment, according to equation (9), when calculating the current-carrying capacity of the cable, the temperature rise value of each cable itself is calculated, and then the actual temperature rise value of each cable is calculated according to the temperature rise values generated by heating all the cables, where (9) is to calculate the current-carrying capacity of the cable after considering the temperature rise values generated by heating all the cables, respectively, and therefore the current-carrying capacity of the cable laid in the pipe is calculated according to (9).
The optimal arrangement of the calandria laying power cables is an optimal cable arrangement method which is analyzed, so that the current-carrying capacity of each loop cable is maximized, namely the current calculation result in the formula (9) is maximized under the selected arrangement method, as can be seen from the formula (9), the current-carrying capacity of the cables has a functional relation with the current of other cables, and the calculation of the maximum value from the ith cable to the nth cable in all the cables is an optimization problem of an implicit function. Optimizing implicit functions greatly increases the complexity of the problem, where the problem is translated into explicit functions for analysis.
In the embodiment, a certain cable model is selected by considering that the cable line can be combined with the electric load during design, namely, when the design capacity of the cable is selected, the design value of the cable transmission current required by the cable can be determined according to the line voltage information; meanwhile, the temperature is taken into consideration as the controlled factor of the current-carrying capacity of the cable, namely the problem can be converted into the problem that the temperature of each loop cable is reduced as much as possible by reasonably arranging cable hole positions under a certain current. When the temperature is lower than the upper temperature limit, the current of the cable has further rising space, namely the cable line has larger current carrying capacity; on the contrary, if the temperature of a loop cable exceeds the limit in a certain laying mode, the current-carrying capacity of the cable line can be reduced.
The actual temperature rise value of the 1 st cable is determined according to the following formula after the temperature rise values of all cables to the 1 st cable are considered under the action of a certain current, wherein the cable group arranged in a certain sequence can be obtained according to the formula (9):
the actual temperature rise value of the ith cable can be obtained based on the formula (10), and is determined according to the following formula:
in the formula,. DELTA.theta.iIs the actual temperature rise value of the ith cable,
is the thermal resistance per unit length between the ith cable and the metal sheath,
is the thermal resistance per unit length of the cushion layer between the metal sleeve and the armor of the ith cable,
is the thermal resistance per unit length of the ith cable outer sheath,
is the thermal resistance of the surrounding medium of the ith cable, niIs the core number of the ith cable, IiIs the ith rootCurrent value of cable, RiIs the ac resistance value of the ith cable,
the ratio of the sheath loss of the ith cable to the total loss of all conductors of the cable,
is the ratio of the armor loss of the ith cable relative to the total loss of all conductors of the cable, mu is the cable loss factor,
insulation dielectric loss, Delta theta, of the ith cableniThe temperature rise value generated by heating the ith cable for the nth cable, dinIs the distance between the ith cable and the nth cable, din' is the distance between the nth cable and the mirror image of the ith cable relative to the earth surface-air.
Equation (11) is a single objective function of the optimization problem, and the total objective function of the problem can be obtained by combining the single objective functions, as shown below.
The constraint condition of the objective function comprises: the optimal laying scheme of the cable duct bank belongs to all permutation and combination determined based on the preset number of cables and hole site information;
wherein the information of the hole site includes: the number of holes and the spacing between holes.
In the step 2, based on the optimization model, a multi-objective optimization method is used for solving, and a calandria optimization arrangement scheme is analyzed, as shown in fig. 3.
Firstly, setting the total iteration number N, which can be generally 1000;
setting an initial arrangement scheme set, and determining the type of a cable duct bank, the type of a cable, an initial arrangement scheme and the like; and the initialized pipe laying mode is converted into binary code representation, which comprises the following steps: each hole site in the row pipe group is represented by binary codes, the hole sites represented by the binary codes are sequentially unfolded in a row, the hole sites for placing cables are represented by the binary codes corresponding to the cables placed in the hole sites, the hole sites not placing the cables are represented by the binary codes with the decimal value of 0, and the binary codes corresponding to the cables are configured according to the types of the cables;
secondly, calculating the electromagnetic loss of each loop cable, including calculating the direct current resistance of the cable, the skin effect factor of the cable, the proximity effect factor of the cable, the alternating current resistance of the cable, the metal sleeve and shielding loss factor of the cable and the loss factor of an armor layer of the cable; further calculating the thermal resistance of each loop cable, including calculating the thermal insulation resistance T of each cable1Thermal resistance T between metal sheath and armor2Cable outer sheath thermal resistance T3Cable external thermal resistance T4And equivalent thermal resistance T between cablesij(ii) a And then calculating the temperature rise value of each cable under the initial arrangement scheme, solving by using a multi-objective optimization method to obtain a next generation population, adding one to the number of iterations, comparing whether the preset total number of iterations is reached, generating a new arrangement scheme set by using the next generation population generated by using the multi-objective optimization method when the preset total number of iterations is not reached, and outputting an optimization result set, namely the cable duct arrangement laying optimization arrangement scheme when the preset total number of iterations is reached, as shown in fig. 3.
In this embodiment, a subgoal optimization function is constructed by deriving a calculation formula for each cable temperature rise, targeting the minimum cable temperature rise, and combining the subgoal optimization functions to form a multi-objective optimization function, and an optimization model is constructed by using the preset number of cables and the preset number of holes as constraints. And laying three-loop cables in a typical 3 x 4 row pipe, coding the laying scheme according to cable laying hole positions so as to facilitate computer program identification, analyzing a pareto solution of the problem by adopting an NSGA-III algorithm in a multi-objective algorithm, and screening out a code corresponding to a relatively most appropriate row pipe laying mode under the condition that the variance of temperature rise of each cable is minimum.
In the step 3, the code corresponding to the most appropriate pipe-arranging laying method calculated in the step 2 is converted into an optimal power cable pipe-arranging laying scheme by converting the initialized pipe-arranging laying mode into a binary coding method in the step 2, so that the current-carrying capacity and the temperature rise of the cable can be calculated.
In this embodiment, a calculation formula of the current-carrying capacity of the cable laid in the cable duct is derived and obtained based on the influence factors of the current-carrying capacity of the cable laid in the cable duct. And considering the temperature as a restriction factor influencing the current-carrying capacity of the cable, converting the maximum solved current into the minimum solved cable temperature rise, and obtaining a cable current-carrying capacity analysis formula convenient to solve. Meanwhile, considering that the cables are laid in the hole sites and belong to the problem of spatial arrangement, the cable laying is converted into binary code strings which can be identified by a computer through a coding mode, and the optimum laying mode of the calandria cabling is obtained through analysis by combining with an NSGA-III multi-objective optimization algorithm. The method can be effectively used for guiding the cable laying method of the pipe bank and improving the economic benefit of the pipe bank.
Example 2
Based on the same inventive concept, the invention also provides a power cable duct multi-objective optimization laying system, as shown in fig. 2, comprising:
the parameter acquisition module is used for acquiring cable structure parameters;
the optimization solving module is used for substituting the structural parameters of the cable into a pre-constructed optimization model to carry out optimization solving to obtain a code corresponding to the optimal cable duct arrangement laying mode;
the scheme determining module is used for determining an optimal scheme for laying the cable arranging pipe based on the codes corresponding to the cable arranging pipe laying modes;
in the optimizing solving process, codes corresponding to cable pipe arrangement laying modes are used as population individuals, and the optimizing model is constructed according to the temperature rise value of each cable;
the structural parameters of the cable include: the thermal resistance of the cable and the metal sleeve in unit length, the thermal resistance of the liner layer between the metal sleeve and the armor in unit length, the thermal resistance of the cable outer sheath in unit length, the thermal resistance of the medium around the cable, the core number of the cable, the ratio of the loss of the metal sleeve of the cable to the total loss of all conductors of the cable, the ratio of the loss of the armor layer of the cable to the total loss of all conductors of the cable, the loss factor of the cable and the loss of the insulating medium of the cable.
The parameter acquiring module is used for acquiring the number of the cables and the structural parameters of the cables, and comprises the following steps: the thermal resistance of the cable and the metal sleeve in unit length, the thermal resistance of the liner layer between the metal sleeve and the armor in unit length, the thermal resistance of the cable outer sheath in unit length, the thermal resistance of the medium around the cable, the core number of the cable, the ratio of the loss of the metal sleeve of the cable to the total loss of all conductors of the cable, the ratio of the loss of the armor layer of the cable to the total loss of all conductors of the cable, the loss factor of the cable and the loss of the insulating medium of the cable.
In the optimization solution module, the method comprises the following steps: an optimization model construction submodule and an optimization model solving submodule.
And building an optimization model for optimizing the laying of the cable duct bank by using the optimization module building submodule, wherein the optimization model is built according to the temperature rise value of each cable. It is therefore necessary to calculate the temperature rise of each cable and its current carrying capacity.
When laying multi-loop cables in a pipe, due to the mutual heating effect among a plurality of groups of cables, a temperature rise value delta theta is smaller than the difference value between the highest temperature of a cable core and the initial environment temperature, the cables are randomly sequenced, the 1 st cable and the 2 nd cable are marked for analysis, and the temperature rise generated by heating the 1 st cable by the 2 nd cable is calculated according to the following formula:
Δθ21＝P2T12 (1)
in the formula,. DELTA.theta.21Temperature rise, P, caused by heating of No. 1 cable for No. 2 cable2For the heating power of the second cable, T12Is the thermal resistance between the first cable and the second cable;
wherein the heating power P of the 2 nd cable2Calculated as follows:
in the formula, n2Is the core number of the 2 nd cable, I2Current value of 2 nd cable, R2Is the ac resistance value of the 2 nd cable,
the ratio of the sheath loss of the 2 nd cable to the total loss of all conductors of the cable,
is the ratio of the armor loss of the 2 nd cable relative to the total loss of all conductors of the cable, μ 2 is the 2 nd cable loss factor calculated from the daily load factor, set here to 1,
the insulation dielectric loss of the 2 nd cable;
thermal resistance T between the first cable and the second cable12Calculated as follows:
in the formula, ρsAs a thermal resistance of the environment, dinIs the distance between the ith cable and the nth cable, din' is the distance between the nth cable and the mirror image of the ith cable relative to the earth surface-air.
Substituting the (2) and (3) into (1), and determining according to the following formula:
the heating effect of the 1 st cable on the ith cable laid in the row can be deduced on the basis of the above formula, which is determined as follows:
by utilizing the above formula, the heating effect of each cable on the 1 st cable is integrated, and the actual allowable temperature rise of the obtained cable is shown as the following formula:
Δθ＝Δθ1-Δθ21-Δθ31-…-Δθn1 (6)
substituting the formula (6) into the formula (4), and performing temperature correction after considering the temperature rise value generated by heating the 1 st cable by all cables to obtain a current-carrying capacity calculation formula of the 1 st cable as follows:
calculating the current-carrying capacity of the ith cable according to the formula (7), wherein the current-carrying capacity is shown as the following formula:
wherein, formula (8) can also be represented as follows:
in this embodiment, according to equation (9), when calculating the current-carrying capacity of the cable, the temperature rise value of each cable itself is calculated, and then the actual temperature rise value of each cable is calculated according to the temperature rise values generated by heating all the cables, where (9) is to calculate the current-carrying capacity of the cable after considering the temperature rise values generated by heating all the cables, respectively, and therefore the current-carrying capacity of the cable laid in the pipe is calculated according to (9).
The optimal arrangement of the calandria laying power cables is an optimal cable arrangement method which is analyzed, so that the current-carrying capacity of each loop cable is maximized, namely the current calculation result in the formula (9) is maximized under the selected arrangement method, as can be seen from the formula (9), the current-carrying capacity of the cables has a functional relation with the current of other cables, and the calculation of the maximum value from the ith cable to the nth cable in all the cables is an optimization problem of an implicit function. Optimizing implicit functions greatly increases the complexity of the problem, where the problem is translated into explicit functions for analysis.
In the embodiment, a certain cable model is selected by considering that the cable line can be combined with the electric load during design, namely, when the design capacity of the cable is selected, the design value of the cable transmission current required by the cable can be determined according to the line voltage information; meanwhile, the temperature is taken into consideration as the controlled factor of the current-carrying capacity of the cable, namely the problem can be converted into the problem that the temperature of each loop cable is reduced as much as possible by reasonably arranging cable hole positions under a certain current. When the temperature is lower than the upper temperature limit, the current of the cable has further rising space, namely the cable line has larger current carrying capacity; on the contrary, if the temperature of a loop cable exceeds the limit in a certain laying mode, the current-carrying capacity of the cable line can be reduced.
The actual temperature rise value of the 1 st cable is determined according to the following formula after the temperature rise values of all cables to the 1 st cable are considered under the action of a certain current, wherein the cable group arranged in a certain sequence can be obtained according to the formula (9):
the actual temperature rise value of the ith cable can be obtained based on the formula (10), and is determined according to the following formula:
in the formula,. DELTA.theta.iIs the actual temperature rise value of the ith cable,
between the ith cable and the metal sleeveThe thermal resistance per unit length of the sheet,
is the thermal resistance per unit length of the cushion layer between the metal sleeve and the armor of the ith cable,
is the thermal resistance per unit length of the ith cable outer sheath,
is the thermal resistance of the surrounding medium of the ith cable, niIs the core number of the ith cable, IiIs the current value of the ith cable, RiIs the ac resistance value of the ith cable,
the ratio of the sheath loss of the ith cable to the total loss of all conductors of the cable,
is the ratio of the armor loss of the ith cable relative to the total loss of all conductors of the cable, mu is the cable loss factor,
insulation dielectric loss, Delta theta, of the ith cableniThe temperature rise value generated by heating the ith cable for the nth cable, dinIs the distance between the ith cable and the nth cable, din' is the distance between the nth cable and the mirror image of the ith cable relative to the earth surface-air.
Equation (11) is a single objective function of the optimization problem, and the total objective function of the problem can be obtained by combining the single objective functions, as shown below.
The constraint condition of the objective function comprises: the optimal laying scheme of the cable duct bank belongs to all permutation and combination determined based on the preset number of cables and hole site information;
wherein the information of the hole site includes: the number of holes and the spacing between holes.
Based on the optimization model constructed by the optimization model construction submodule, solving by the optimization model solving submodule by adopting a multi-objective optimization method, and analyzing the calandria optimization arrangement scheme, as shown in fig. 3;
firstly, setting the total iteration number N, which can be generally 1000;
setting an initial arrangement scheme set, determining the type, the cable type, the initial arrangement scheme and the like of the cable duct bank, and converting the initialized duct bank laying mode into binary code representation, wherein the method comprises the following steps: each hole site in the row pipe group is represented by binary codes, the hole sites represented by the binary codes are sequentially unfolded in a row, the hole sites for placing cables are represented by the binary codes corresponding to the cables placed in the hole sites, the hole sites not placing the cables are represented by the binary codes with the decimal value of 0, and the binary codes corresponding to the cables are configured according to the types of the cables;
secondly, calculating the electromagnetic loss of each loop cable, including calculating the direct current resistance of the cable, the skin effect factor of the cable, the proximity effect factor of the cable, the alternating current resistance of the cable, the metal sleeve and shielding loss factor of the cable and the loss factor of an armor layer of the cable; further calculating the thermal resistance of each loop cable, including calculating the thermal insulation resistance T of each cable1Thermal resistance T between metal sheath and armor2Cable outer sheath thermal resistance T3Cable external thermal resistance T4And equivalent thermal resistance T between cablesij(ii) a And then calculating the temperature rise value of each cable under the initial arrangement scheme, solving by using a multi-objective optimization method to obtain a next generation population, adding one to the number of iterations, comparing whether the preset total number of iterations is reached, generating a new arrangement scheme set by using the next generation population generated by using the multi-objective optimization method when the preset total number of iterations is not reached, and outputting an optimization result set, namely the cable duct arrangement laying optimization arrangement scheme when the preset total number of iterations is reached, as shown in fig. 3.
In this embodiment, a subgoal optimization function is constructed by deriving a calculation formula for each cable temperature rise, targeting the minimum cable temperature rise, and combining the subgoal optimization functions to form a multi-objective optimization function, and an optimization model is constructed by using the preset number of cables and the preset number of holes as constraints. And laying three-loop cables in a typical 3 x 4 row pipe, coding the laying scheme according to cable laying hole positions so as to facilitate computer program identification, analyzing a pareto solution of the problem by adopting an NSGA-III algorithm in a multi-objective algorithm, and screening out a code corresponding to a relatively most appropriate row pipe laying mode under the condition that the variance of temperature rise of each cable is minimum.
In the scheme determination module, the code corresponding to the most appropriate calandria laying method calculated in the optimization solving module is converted into a binary coding method from the initialized calandria laying mode in the optimization model solving submodule, and then the power cable calandria laying optimal scheme is converted, and further the current-carrying capacity and the temperature rise of the cable can be calculated.
Example 3
In this embodiment, according to the multi-objective optimized laying method for power cable pipes provided by the present invention, taking a typical 3 × 4 cross-section pipe laying power cable as an example, an arrangement manner in which three-circuit single-core ac cables are placed is studied, as shown in fig. 4.
in this embodiment, according to actual needs, three types of cables are selected and laid in the rack pipe, which are respectively:
YJLW02-64/110kV-1×800mm2the copper core crosslinked polyethylene insulating corrugated aluminum sheath polyvinyl chloride outer sheath single core power cable;
YJQ03-Z-64/110kV-1×500mm2the copper core crosslinked polyethylene insulated alloy lead sheath polyethylene outer sheath longitudinal water-blocking single-core power cable;
YJLW03-64/110kV-1×630mm2the copper core crosslinked polyethylene insulating corrugated aluminum sheath polyethylene outer sheath single core power cable;
the three cable types and the structural parameters thereof are shown in table 1.
TABLE 1
The cable parameters were calculated according to the parameters in table 1 and according to the IEC60287 standard as shown in table 2.
TABLE 2
The calculated thermal resistance according to the thermal resistance calculation formula of each layer of the cable is shown in table 3.
TABLE 3
In this embodiment, since the external thermal resistance of the power cable changes according to different laying environments, and the external thermal resistance of the cable laid in the pipe arrangement is affected by various environmental factors such as pipe arrangement, air, concrete, soil, and the like, a simple formula cannot be used to express the thermal resistance value, and the product of the external thermal resistance of the cable and the heating power is the temperature rise of the cable due to the external thermal resistance, the external thermal resistance of the cable can be calculated by an equivalent method according to the following formula:
in the formula, t1Is the initial temperature of the cable, t2The temperature of the cable after heating is shown, and P is the heating power.
In this embodiment, considering that the finite element can analyze the temperature field distribution of the cable system with high precision, the finite element analysis method is adopted to calculate the temperature rise of the cable in different hole sites under a certain heating power.
Placing cables in each hole site in sequence, establishing a finite element model, calculating temperature distribution after grid division, selecting the first hole site for cable arrangement for analysis, applying 800A current to the laid cables to heat the cables, placing cables in other hole sites in sequence, calculating the temperature distribution, and analyzing by combining an equivalent calculation formula (14) to obtain the external thermal resistance of each hole site of the calandria cable, as shown in figure 5.
Step 2, substituting the structural parameters of the cable into a pre-constructed optimization model to perform optimization solution to obtain a code corresponding to an optimal cable duct arrangement laying mode;
and initially laying the power cable duct bank according to the structural parameters and the model of the cable.
In this embodiment, as a result of calculating the external thermal resistance of the cable by the finite element method, the thermal resistance of the hole site near the edge of the cable tube bank is small, and the heat dissipation performance is good, while the thermal resistance of the hole site in the middle of the tube bank is large, and the heat dissipation performance is poor.
The cable circular telegram generates heat, and the heat source mainly includes cable conductor core joule heat, metal level and shielding layer loss, armor loss and insulating medium loss, and the power of generating heat of ith cable is calculated according to the following formula:
in the formula, PiThe heating power of the ith cable.
In this embodiment, considering that a plurality of cables are laid in the rack pipe at the same time and considering the universality of the example, the currents of the three-loop cables can be set as follows: 680A, 530A and 620A (and possibly other values) at a voltage of 110kV, and a three-loop cable with a power supply capacity of 74.8MVA, 58.3MVA and 68.6MVA, respectively. The calculated heating power of the three-circuit cable is shown in table 4.
TABLE 4
When the initialization arrangement is carried out, the cable with higher heating power is arranged at the hole position with better heat dissipation performance, and the cable with lower heating power is arranged at the hole position with poorer heat dissipation performance. The three-circuit cable is laid in the calandria group by combining the cable heating power and the calandria hole site heat dissipation performance, and the initial arrangement mode is as shown in fig. 6.
In this embodiment, since the computer cannot recognize the graphical language, the pipe arrangement method needs to be converted into a code form for the computer to read, and includes: each hole site in the row pipe group is represented by a binary code, the hole sites represented by the binary codes are sequentially unfolded in a row, the hole sites for placing the cables are represented by the binary codes corresponding to the cables placed in the hole sites, the hole sites not placing the cables are represented by the binary codes with the decimal value of 0, and the binary codes corresponding to the cables are configured according to the types of the cables.
In this embodiment, the row pipe set shown in fig. 6 is regarded as a 3 × 4 matrix, and the row pipes are sequentially expanded in columns to obtain 1 × 12 row vectors, wherein [1,1] hole locations correspond to the position of the row vector [1,1], [2,1] hole locations correspond to the position of the row vector [1,2], and [2,1] hole locations correspond to the position of the row vector [1,4], and so on. The cables in the same loop are all of the same type, and the current values are consistent, namely, the same coding identification is adopted without distinguishing phases, and a three-loop cable is used in the position and can be represented by two-bit binary coding. For example, the ABC three phases of the first loop cable are all represented by 01, the ABC three phases of the second loop cable are all represented by 10, and the ABC three phases of the third loop cable are all represented by 11. Each hole site is represented by two binary codes, the hole site for placing the cable is filled with the corresponding loop code, the hole site for not placing the cable is represented by '00', the cable laying mode in the figure 6 is represented as a binary code, and the form is as follows: "111001011000001011010011". The laying modes of the cables in the subsequent calculation are all represented in a binary coding mode, the evaluation, selection, intersection, variation and other operations in the genetic algorithm are all executed based on the binary coding, and the obtained results can be converted into the corresponding laying modes through coding rules.
After binary codes corresponding to the calandria are set, an optimization model is solved by adopting an NSGA-III method in a multi-objective optimization algorithm, and the laying and arrangement scheme of the power cable calandria is further optimized; the initial arrangement mode is used as the start, the temperature rise of 9 cables in the three loops is used as an objective function, the initial population size is set to be 9 multiplied by 10 to 90, 90 groups of the initial arrangement mode are copied, a calculation program is entered, 1000 generations of iteration are carried out, a group of optimal arrangement solution sets are obtained, and the solutions are pareto solutions of the problem and are all located on the front face. The layout binary is shown with five sets of solutions as examples as:
111011011000010011001001
010111011110000000111010
101000111100011000010111
011001110010000111100011
011110001000101111010001
and obtaining the cable arrangement mode corresponding to each group of solutions according to the five coding rules. In the five laying modes, the temperature rise values of the first-return phase-a cable to the third-return phase-C cable are shown in table 5 in sequence.
TABLE 5
In table 5, only the first five solutions are selected and displayed, and there are 90 solutions obtained by the optimization solution, and only one scheme can be applied when the cable is actually arranged, so that a screening strategy needs to be adopted to select the relatively most appropriate arrangement scheme for arrangement. As shown in table 5, the lowest temperature rise in the mode 3 was the second loop phase a cable, 55.7 ℃, and the highest temperature rise was the first loop phase a cable, 69.8 ℃. Although the second loop A-phase cable obtains relatively low temperature rise by the laying mode, the solution can not be adopted by comprehensive consideration at the cost of high temperature of the first loop cable. The arrangement mode of relative balance of the temperature rise values is selected as an arrangement scheme, namely, the arrangement mode with small fluctuation is selected as a final solution, the variance of the temperature rise obtained by each group of solutions is solved by considering that the variance can represent the fluctuation range of the number series, and the arrangement scheme corresponding to the minimum variance of the temperature rise is output. And calculating the temperature rise variance of the cables corresponding to each group of laying modes, as shown in fig. 7.
And screening out the arrangement scheme with the minimum temperature rise variance in the 90 groups of optimization solutions, wherein the corresponding binary codes are as follows: 100001101111010010011100, the corresponding arrangement scheme is shown in fig. 8, wherein the numbers 1,2, 3 respectively represent the first, second, third loop cables, the cable types used in the same loop are identical, only the current phase angle difference exists, the ABC mark of each cable is used to distinguish the phase of the cable in sequence, the mark is from the upper left corner to the lower right corner of the rack pipe, and it does not have specific phase meaning, the specific transposition is adjusted during the actual construction.
The temperature rise of each cable arranged according to the arrangement scheme in fig. 8 is shown in table 6.
TABLE 6
| Cable with a | |
|
1C | 2A | 2B | ||
| Temperature rise deg.C | 59.8 | 59.1 | 64.1 | 60.3 | 60.9 | ||
| Cable with a | |
3A | 3B | 3C | |||
| Temperature rise deg.C | 59.5 | 62.3 | 62.2 | 63.7 |
As can be seen from Table 6, the temperature rise of each cable is relatively uniform, and the arrangement effect is better without large values as shown in Table 5.
In the embodiment, the mutual heating effect among a plurality of groups of cables is considered, and a calculation formula of the current-carrying capacity of the cables laid in the tube bank is derived;
secondly, deducing a temperature rise calculation formula when a single cable is influenced by other cables to form a multi-objective optimization function group, and constructing an optimization model by using the preset number of cables and the preset number of hole sites as constraints;
and then, solving the optimization model by using an NSGA-III algorithm in the multi-objective optimization method, analyzing pareto solutions of an optimal solution set, proposing a coding rule to discretize the problem so as to facilitate a computer to identify the laying method, screening out the optimal solution by using a variance analysis method, obtaining an optimal arrangement scheme for cable duct laying, and deducing to obtain a duct laying cable carrying capacity matrix calculation formula.
Example 4
According to the multi-objective optimized laying method for the power cable duct bank, the carrying capacity calculation formula is used for comparing the initialized laying scheme with the carrying capacity after laying according to the method in the invention, and the overall carrying capacity of the cable is improved by using the laying scheme obtained by the invention.
In this embodiment, for a group of line systems with n cables, the temperature rise of the environment around the first cable is acted on by the other n-1 cables, and the current of the first cable can be obtained by considering the temperature rise.
When the temperature rise of the cable reaches the maximum value, the current of the cable reaches the maximum value, namely the current-carrying capacity of the first cable can be obtained, and for convenient representation, the square of the current-carrying capacity can be represented as:
in the formula,. DELTA.theta.1maxThe maximum allowable temperature rise of the first wire is measured in units of;
the above formula (16) is simplified to obtain:
further simplification can be achieved:
order:
substituting (19) and (20) into (18) yields:
namely:
the same can get 2 nd cable:
by analogy, the ith cable can be obtained
The composition matrix form is:
namely, it is
CI＝D (26)
The current carrying capacity of each cable can be obtained by solving the matrix (26).
In the present embodiment, c is calculated using the above equation according to the optimal arrangement of cables shown in fig. 8ijAnd dkThe matrices C and D are formed, and the maximum allowable current of each cable is obtained by solving the matrices as shown in table 7.
TABLE 7
In this embodiment, since the current values of the cables in the same loop are the same, the minimum current value in one loop is taken as the current-carrying capacity, and the current-carrying capacities of the cables in the three loops are respectively: 703.7A, 580.2A, and 684.6a, the power supply capacities were 77.4MVA, 63.8MVA, and 75.3MVA, respectively, and the boost capacities of the loop cables in the initial state (77.4-74.8)/74.8-3.5%, (63.8-58.3)/58.3-9.4%, and (75.3-68.6)/68.6-9.8%, respectively.
The cables were laid in an optimal arrangement and the temperature rise of the conductors of the respective loop cables under the maximum allowable current running condition of the cables is shown in table 8.
TABLE 8
As can be seen from Table 8, the temperature rise of the cable conductor is within 70 ℃, and the requirement of the cable on the highest operation temperature is met according to the condition that the basic environment temperature is 20 ℃.
It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The present invention is not limited to the above embodiments, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are included in the scope of the claims of the present invention which are filed as the application.
Claims (10)
1. A multi-objective optimization laying method for power cable ducts is characterized by comprising the following steps:
acquiring cable structure parameters;
substituting the structural parameters of the cable into a pre-constructed optimization model to perform optimization solution to obtain a code corresponding to the cable duct arrangement laying mode;
determining an optimal cable duct bank laying scheme based on the codes corresponding to the cable duct bank laying modes;
and in the optimizing solving process, codes corresponding to the cable duct arrangement laying mode are used as population individuals, and the optimizing model is constructed according to the temperature rise value of each cable.
2. The method of claim 1, wherein the cable configuration parameters comprise: the thermal resistance of the cable and the metal sleeve in unit length, the thermal resistance of the liner layer between the metal sleeve and the armor in unit length, the thermal resistance of the cable outer sheath in unit length, the thermal resistance of the medium around the cable, the core number of the cable, the ratio of the loss of the metal sleeve of the cable to the total loss of all conductors of the cable, the ratio of the loss of the armor layer of the cable to the total loss of all conductors of the cable, the loss factor of the cable and the loss of the insulating medium of the cable.
3. The method of claim 2, wherein the constructing of the optimization model comprises:
constructing an objective function by taking the minimum actual temperature rise value of each cable as a target;
and setting constraint conditions by taking the preset cable number and hole position information as the objective function.
4. The method of claim 3, wherein the objective function is determined according to the following equation:
in the formula,. DELTA.theta.iIs the actual temperature rise value of the ith cable,
is the thermal resistance per unit length between the ith cable and the metal sheath,
is the thermal resistance per unit length of the cushion layer between the metal sleeve and the armor of the ith cable,
is the thermal resistance per unit length of the ith cable outer sheath,
is the thermal resistance of the surrounding medium of the ith cable, niIs the core number of the ith cable, IiIs the current value of the ith cable, RiIs the ac resistance value of the ith cable,
the ratio of the sheath loss of the ith cable to the total loss of all conductors of the cable,
is the ratio of the armor loss of the ith cable relative to the total loss of all conductors of the cable, mu is the cable loss factor,
insulation dielectric loss, Delta theta, of the ith cableniThe temperature rise value generated by heating the ith cable for the nth cable.
5. The method of claim 4, wherein the nth cable heats the ith cable to produce a temperature rise Δ θniDetermined as follows:
in the formula,. DELTA.theta.niTemperature rise value, n, generated by heating of ith cable for nth cablenIs the core number of the nth cable, InIs the current value of the nth cable, RnFor alternating current of nth cableThe resistance value of the resistor is set to be,
is the ratio of the metal sheath loss of the nth cable to the total loss of all conductors of that cable,
the ratio of the sheath loss of the nth cable to the total loss of all conductors of the cable, munFor the nth cable loss factor calculated from the daily load factor,
is the insulation dielectric loss, rho, of the nth cablesIs the thermal resistivity of the insulating material, dinIs the distance between the ith cable and the nth cable, din' is the distance between the nth cable and the mirror image of the ith cable relative to the earth surface-air.
6. The method of claim 3, wherein the constraint condition comprises:
the optimal laying scheme of the cable duct bank belongs to all permutation and combination determined based on the preset number of cables and hole site information;
wherein the information of the hole site includes: the number of holes and the spacing between holes.
7. The method according to claim 1, wherein the acquiring of the code corresponding to the cable-arranging manner comprises:
each hole site in the row pipe group is represented by binary codes, and the hole sites represented by the binary codes are sequentially expanded in a row;
the hole positions for placing the cables are represented by binary codes corresponding to the cables placed in the hole positions, the hole positions for not placing the cables are represented by binary codes with decimal numerical value 0, and the binary codes corresponding to the cables are configured according to the types of the cables.
8. A power cable duct multi-objective optimization laying system, characterized by comprising: the parameter acquisition module is used for acquiring cable structure parameters;
the optimization solving module is used for substituting the structural parameters of the cable and the set calandria group into a pre-constructed optimization model to perform optimization solving to obtain an optimal solution represented by codes;
the scheme determining module is used for determining an optimal scheme for laying the cable arranging pipe based on the codes corresponding to the cable arranging pipe laying modes;
and in the optimizing solution process, codes corresponding to the tube bank groups are used as population individuals, and the optimizing model is constructed according to the temperature rise value of each cable.
9. The system of claim 8, wherein the structural parameters of the cable include: the thermal resistance of the cable and the metal sleeve in unit length, the thermal resistance of the liner layer between the metal sleeve and the armor in unit length, the thermal resistance of the cable outer sheath in unit length, the thermal resistance of the medium around the cable, the core number of the cable, the ratio of the loss of the metal sleeve of the cable to the total loss of all conductors of the cable, the ratio of the loss of the armor layer of the cable to the total loss of all conductors of the cable, the loss factor of the cable and the loss of the insulating medium of the cable.
10. The system of claim 9, wherein the construction of the optimization model comprises:
constructing an objective function by taking the minimum actual temperature rise value of each cable as a target;
and setting constraint conditions by taking the preset cable number and hole position information as the objective function.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114091218A (en) * | 2021-11-22 | 2022-02-25 | 国网天津市电力公司 | Power cable arrangement method and device based on optimal current-carrying capacity |
| CN115267348A (en) * | 2022-07-11 | 2022-11-01 | 江苏亨通高压海缆有限公司 | Submarine cable armored loss factor test system and test calculation method thereof |
| CN116050040A (en) * | 2023-03-28 | 2023-05-02 | 中国建筑第二工程局有限公司 | Intelligent arrangement method and system based on pipeline arrangement spatial characteristics |
| CN116611341A (en) * | 2023-05-31 | 2023-08-18 | 广船国际有限公司 | Arrangement method, device, equipment and medium of marine cable |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114091218A (en) * | 2021-11-22 | 2022-02-25 | 国网天津市电力公司 | Power cable arrangement method and device based on optimal current-carrying capacity |
| CN115267348A (en) * | 2022-07-11 | 2022-11-01 | 江苏亨通高压海缆有限公司 | Submarine cable armored loss factor test system and test calculation method thereof |
| CN116050040A (en) * | 2023-03-28 | 2023-05-02 | 中国建筑第二工程局有限公司 | Intelligent arrangement method and system based on pipeline arrangement spatial characteristics |
| CN116050040B (en) * | 2023-03-28 | 2023-08-15 | 中国建筑第二工程局有限公司 | Intelligent arrangement method and system based on pipeline arrangement spatial characteristics |
| CN116611341A (en) * | 2023-05-31 | 2023-08-18 | 广船国际有限公司 | Arrangement method, device, equipment and medium of marine cable |
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