Trunk line selection method and trunk line selection program

Abstract

To efficiently select main lines. [Solution] The main line selection method includes a related information acquisition step of acquiring related information regarding shared main lines, branch main lines and distribution boards, and a specification selection step of selecting the specifications of shared main lines and branch main lines based on the related information. The related information includes main line route information showing the route of the main lines connecting the power receiving equipment and multiple distribution boards, load current information showing the load current for each distribution board, and wiring specification information showing the type of shared main line and branch main line, the allowable current value for each type, parameters correlated with voltage drop, and evaluation value per unit length. In the specification selection step, based on the related information, the combination of specifications for shared main lines and branch main lines that results in a voltage drop rate being below the allowable value and a superior total evaluation value obtained using the evaluation value is selected as the optimal specification.

Description

Technical Field

[0001] The present invention relates to a main line selection method and a main line selection program.

Background Art

[0002] In Patent Document 1, a drawing input method for a wiring route is disclosed, in which a drawing position is indicated on CAD, a cross-section of a path passing through a specified point is displayed, and a wiring route is indicated while displaying a plurality of wiring route patterns to determine a wiring route, and three-dimensional wiring route data is accurately generated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As disclosed in Patent Document 1, various techniques for improving the efficiency of creating a wiring route for electrical wiring are known. On the other hand, the selection of the specifications of the main line, which is the electrical wiring connecting the power receiving equipment and the distribution board, has conventionally been performed based on manual calculations. Therefore, there is a need to improve the efficiency and automation of the main line selection work.

[0005] An object of the present invention is to efficiently select a main line.

Means for Solving the Problems

[0006] The present invention relates to a method for selecting a main line that connects a power receiving facility and a distribution board, comprising: a related information acquisition step for acquiring related information relating to the common main line, branch main lines, and distribution boards; and a specification selection step for selecting the specifications of the common main line and branch main lines based on the related information. The related information includes main line route information showing the route of the main line connecting the power receiving facility and the multiple distribution boards; load current information showing the load current for each distribution board; and wiring specification information showing the type of the common main line and branch main lines, the allowable current value for each type, parameters correlated with voltage drop, and an evaluation value per unit length. In the specification selection step, based on the related information, a combination of specifications for the common main line and branch main lines that results in a voltage drop rate being less than or equal to the allowable value and a superior total evaluation value obtained using the evaluation value is selected as the optimal specification.

[0007] Furthermore, the present invention relates to a trunk line selection program for selecting a shared trunk line shared by multiple distribution boards and branch trunk lines branching off from the shared trunk line and connected to each distribution board, among the trunk lines connecting the power receiving equipment and the distribution boards, wherein the program causes a computer to perform a related information acquisition step to acquire related information regarding the shared trunk line, branch trunk lines and distribution boards, and a specification selection step to select the specifications of the shared trunk line and the branch trunk lines based on the related information, wherein the related information includes trunk line route information showing the route of the trunk lines connecting the power receiving equipment and multiple distribution boards, load current information showing the load current for each distribution board, and wiring specification information showing the type of shared trunk line and branch trunk lines, the allowable current value for each type, parameters correlated with voltage drop, and an evaluation value per unit length, and in the specification selection step, based on the related information, the combination of specifications of the shared trunk line and the branch trunk line that results in a voltage drop rate being less than or equal to the allowable value and a superior total evaluation value obtained using the evaluation value is selected as the optimal specification. [Effects of the Invention]

[0008] The present invention aims to efficiently select main lines. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows an example of a structure to which the trunk line selection method according to an embodiment of the present invention is applied. [Figure 2] This is a block diagram showing the configuration of an information processing device that performs a trunk line selection method according to an embodiment of the present invention. [Figure 3] This is a flowchart showing the steps performed in the trunk line selection method according to an embodiment of the present invention. [Figure 4] This figure shows an example of related information concerning wiring specifications. [Figure 5] This is a list showing examples of related information concerning wiring specifications. [Figure 6] This table illustrates the method for selecting wiring specifications performed by the trunk line selection method according to an embodiment of the present invention. [Figure 7] This table illustrates the method for selecting wiring specifications performed by the trunk line selection method according to an embodiment of the present invention, and is a table illustrating the calculation process following Figure 6. [Figure 8] This table illustrates the method for selecting wiring specifications performed by the trunk line selection method according to an embodiment of the present invention, and is a table illustrating the calculation process following Figure 7. [Figure 9] This table illustrates the wiring specification selection method performed by the trunk line selection method according to an embodiment of the present invention, and is a table illustrating the calculation process following Figure 8. [Figure 10] This table illustrates the method for selecting wiring specifications performed by the trunk line selection method according to an embodiment of the present invention, and is a table illustrating the calculation process following Figure 9. [Figure 11] This is a modified example of a table used in the wiring specification selection method performed by the trunk line selection method according to an embodiment of the present invention. [Modes for carrying out the invention]

[0010] Hereinafter, with reference to the drawings, a trunk line selection method and trunk line selection program according to embodiments of the present invention will be described.

[0011] The trunk line selection method and trunk line selection program according to the embodiment of the present invention perform the process of selecting the optimal wiring specifications for trunk lines connecting power receiving equipment and distribution boards in buildings such as large commercial facilities, office buildings, and factories. In particular, when there are branches in the trunk line connecting power receiving equipment and distribution boards, and there is a shared trunk line that supplies power to multiple distribution boards, the method selects the wiring specifications for this shared trunk line and the wiring specifications for branch trunk lines that branch off from the shared trunk line and are connected to each distribution board.

[0012] The following section describes the case where the trunk line for which the optimal wiring specifications are selected by the trunk line selection method and trunk line selection program is a trunk line located within Building 1 along the route shown in Figure 1.

[0013] As shown in Figure 1, a cubicle-type high-voltage power receiving and transforming equipment is installed on the rooftop floor of building 1 as power receiving equipment 10, and a first shared main line L1 extending from the power receiving equipment 10 is connected on the rooftop floor to a second shared main line L2, which is a vertical main line that runs vertically through the building 1.

[0014] The second shared main line L2 is connected to the first horizontal main line L31 and the second horizontal main line L32, which are shared main lines installed on each floor. The first horizontal main line L31, installed on the first floor, is connected to distribution boards D11 to D13 via branch main lines L41 to L43, and the second horizontal main line L32, installed on the second floor, has a branch section in the middle and is connected to distribution boards D21 to D24 via branch main lines L51 to L54. Note that the arrangement of the main lines shown in Figure 1 is just an example and is not limited to this. For example, the power receiving equipment 10 may be installed outdoors on the first floor instead of on the rooftop floor.

[0015] As shown in FIG. 2, an information processing apparatus 100 that executes a main line selection method includes a storage unit 11 that stores in advance or temporarily the related information necessary for selecting the wiring specifications of each main line, and a processing unit 12 that selects the wiring specifications of each main line using dynamic programming based on the related information stored in the storage unit 11. The storage unit 11 also stores a main line selection program. When the related information necessary for executing the main line selection program is complete, the processing unit 12 executes the main line selection method according to the control flow shown in FIG. 3. Note that each component of the information processing apparatus 100 shown in FIG. 2 shows each function of the information processing apparatus 100 as a virtual unit, and does not necessarily mean that it physically exists.

[0016] Specifically, the information processing apparatus 100 is a general-purpose computer having a CPU (Central Processing Unit) that executes a control program or the like, a ROM (Read-Only Memory) that stores the control program executed by the CPU, a RAM (Random Access Memory) that stores the calculation results of the CPU, and an I / O interface (input / output interface), etc. When the main line selection program stored in the ROM or the like in advance is started, the main line selection method is executed according to the control flow shown in FIG. 3. Note that the information processing apparatus 100 may be composed of one computer, or may be composed of a plurality of microcomputers and configured to perform distributed processing of each control by a plurality of computers.

[0017] In addition, an input device 20 that is operated by a main line designer or the like when inputting information such as related information to the information processing apparatus 100 or instructing the execution of the main line selection program, and a display device 22 that displays the result processed by the information processing apparatus 100 are connected to the information processing apparatus 100.

[0018] Next, referring to FIGS. 3 to 9, a main line selection method for selecting the optimal wiring specifications of each main line connecting the power receiving facility 10 and each distribution board D11 to D13, D21 to D24 will be described.

[0019] When the execution of the trunk line selection program is instructed via the input device 20 or the like, the processing unit 12 first acquires relevant information necessary to select the wiring specifications for each trunk line in step S10 (relevant information acquisition step).

[0020] The relevant information acquired in step S10 includes, as shown in Figure 4, trunk line route information showing the routes of each trunk line L1, L2, L31, L32, L41~L43, L51~L54 connecting the power receiving equipment 10 and multiple distribution boards D11~D13, D21~D24; as shown in Figure 5(a), load current information showing the load current, transmission method, and frequency for each distribution board D11~D13, D21~D24; and as shown in Figure 5(b), wiring specification information showing the type of wiring used as common trunk lines L1, L2, L31, L32 and branch trunk lines L41~L43, L51~L54, the allowable current value for each type of wiring, parameters correlated with voltage drop (impedance value), and evaluation value per unit length (installation cost per unit length).

[0021] This related information may be stored in the storage unit 11 in advance, or it may be obtained by downloading it from a predetermined server via a network such as the Internet and temporarily stored in the storage unit 11.

[0022] The main line route information shown in Figure 4 is based on design drawing data and includes information such as the location of the power receiving equipment 10, the locations of each distribution board D11-D13, D21-D24, and the routes and lengths of each main line L1, L2, L31, L32, L41-L43, L51-L54 connecting the power receiving equipment 10 to each distribution board D11-D13, D21-D24. The main line route information may be obtained from BIM (Building Information Modeling), which is three-dimensional shape data of the building, or it may be obtained from two-dimensional drawings.

[0023] The load current information shown in Figure 5(a) represents the load currents A11-A13 and A21-A24 for each distribution board D11-D13 and D21-D24, and is pre-set for each distribution board D11-D13 and D21-D24. If the load currents for each distribution board D11-D13 and D21-D24 have not been determined, a provisional value for the load current may be input via the input device 20 by the main line designer or the like in step S10.

[0024] The wiring specifications shown in Figure 5(b) include the cross-sectional area size and number of wires, as well as the allowable current value, impedance value, and installation cost per unit length corresponding to this wiring. As specific examples of wiring, Figure 5(b) shows the specifications of power transmission and distribution cables (CVT cables) CVT1-4 and bus ducts BD1-3. Note that the wiring specifications shown in Figure 5(b) are examples only, and the information included in the wiring specifications is not limited to these, nor is the wiring used as a main line limited to the CVT cables and bus ducts with the specifications shown in Figure 5(b).

[0025] Furthermore, the wiring specification information shown in Figure 5(b) indicates the impedance value as a parameter correlated with voltage drop, but the parameter correlated with voltage drop may also be the cross-sectional area of ​​the wiring. In addition, the evaluation value per unit length is shown as the installation cost required to install a unit length of wiring, for example, the sum of the cost of the 1m of wiring itself and the wiring work cost for 1m of wiring, but the evaluation value may also be the weight of the copper used in the wiring or the life cycle CO2 (LCCO2) amount related to the amount of carbon dioxide emitted during the manufacturing of the wiring, or a combination of these. Below, we will explain the case where the installation cost is used as the evaluation value, that is, the case in which the wiring with a smaller total installation cost calculated using the installation cost per unit length is evaluated as superior.

[0026] The aforementioned load current information and wiring specification information are stored in the storage unit 11 either in advance or temporarily in a format such as a list.

[0027] Once relevant information is obtained, the processing unit 12 selects the specifications of the shared trunk lines L1, L2, L31, and L32, and the specifications of the branch trunk lines L41-L43 and L51-L54 based on the relevant information in steps S11 and later (specification selection step).

[0028] In the specification selection step, based on relevant information, the optimal specification is selected for a combination of specifications for the shared main line and the branch main line such that the voltage drop rate, which is the ratio of the voltage drop that occurs in the shared main line and branch main line relative to the voltage at the distribution board (receiving voltage), is less than or equal to the allowable voltage drop rate (allowable value), and the total evaluation value (total installation cost) calculated using the evaluation value per unit length (installation cost per unit length) is superior.

[0029] Furthermore, in the specification selection step, a dynamic programming algorithm is used to select the optimal specifications, with the selection of specifications for shared trunk lines and branch trunk lines, based on relevant information, as subproblems. Specifically, the overall problem is to find the specifications for the shared trunk lines and branch trunk lines with the highest evaluation (optimal specifications). To solve this, the subproblems are to find the wiring candidates for the shared trunk lines and the wiring candidates for the branch trunk lines, and the results of these subproblems are used to finally find the optimal solution to the overall problem.

[0030] In step S11, a standard distribution board is set, which will be used as the basis when selecting the specifications for the shared main lines L1, L2, L31, and L32, and the branch main lines L41-L43 and L51-L54.

[0031] Specifically, among the distribution boards D11-D13 and D21-D24, the distribution board with the longest total route length—that is, the route length from the power receiving equipment 10 to each distribution board D11-D13 and D21-D24—is set as the standard distribution board. This is determined by adding the route lengths of the shared main lines L1, L2, L31, and L32 and the branch main lines L41-L43 and L51-L54.

[0032] Therefore, in step S11, the total route length of each distribution board D11~D13 and D21~D24 is first determined based on the main line route information. The storage unit 11 stores drawing creation software (so-called computational design software) that can extract the route lengths of the shared main lines L1, L2, L31, and L32, as well as the route lengths of the branch main lines L41~L43 and L51~L54, from data such as design drawings acquired as main line route information.

[0033] The route length from the power receiving equipment 10 to each distribution board D11-D13 and D21-D24 can be determined, for example, by searching for a route from each distribution board to the power receiving equipment 10 and calculating the length of that route. Specifically, with the power receiving equipment 10 as the upstream side and each distribution board as the downstream side, the route search is performed by tracing the route upstream from the downstream side, and when a branching point is reached, the route towards the upstream side is selected. This obtains the route search and the route length from each distribution board D11-D13 and D21-D24 to the power receiving equipment 10.

[0034] Once the total path lengths for each distribution board D11-D13 and D21-D24 are obtained, they are compared, and the distribution board with the longest total path length is selected as the standard distribution board.

[0035] In the example shown in Figure 4, the combined route length of the first shared main line L1, the second shared main line L2 connected to the first shared main line L1 at connection point J1, the first horizontal main line L31 from connection point J21 connected to the second shared main line L2 to connection point J32 connected to branch main line L42, and the branch main line L42 connected to the first horizontal main line L31 at connection point J32 is the longest. Therefore, the distribution board D12 connected to the first horizontal main line L31 via branch main line L42 is selected as the standard distribution board. The following describes the case where this distribution board D12 is set as the standard distribution board.

[0036] Once the standard distribution board is set, the distribution boards are grouped into D11-D13 and D21-D24.

[0037] Specifically, distribution boards D11 and D13, which are supplied with power through the same common main line (first horizontal main line L31) as distribution board D12, which was selected as the standard distribution board, are assigned to the same first group G1 as distribution board D12. Distribution boards D21 to D24, which are supplied with power through a different common main line (second horizontal main line L32) than distribution board D12, which was selected as the standard distribution board, are assigned to a different second group G2 than distribution board D12. In the example shown in Figure 4, there are two horizontal main lines L31 and L32 branching from the second common main line L2, but if there is another horizontal main line branching further from the second common main line L2, the distribution boards supplied with power through this additional horizontal main line will be assigned to yet another group.

[0038] Once the standard distribution board has been set up and the distribution boards have been grouped, in the following step S12, candidate wiring specifications for the shared main line that supplies power to the distribution boards in the group including the standard distribution board are selected based on the voltage drop rate and the total evaluation value (total installation cost).

[0039] Specifically, candidate wiring specifications for the first shared main line L1, the second shared main line L2, and the first horizontal main line L31, which supply power to distribution boards D11, D12, and D13 of the first group G1, including the standard distribution board D12, are selected in order.

[0040] First, for the first shared trunk line L1, the relationship between the total installation cost of the wiring and the voltage drop rate is determined as shown in Figure 6(a).

[0041] The first shared main line L1 connects the power receiving equipment 10 installed outdoors to the second shared main line L2, which is a vertical main line. As a main line that requires a certain degree of flexibility in its routing, and carries the current supplied to all distribution boards D11-D13 and D21-D24, for example, a CVT cable is provisionally selected as the wiring type, whose allowable current value exceeds the total current AA (=A11+A12+A13+A21+A22+A23+A24) supplied to all distribution boards D11-D13 and D21-D24. Alternatively, a demand factor may be set separately in advance, and a wiring type may be selected whose allowable current value exceeds the demand current DAA obtained by multiplying the total current AA by the demand factor (for example, 70%).

[0042] Then, for the selected wiring type, the voltage drop rate when the total current AA flows and the total installation cost when installed are determined based on the previously acquired relevant information.

[0043] Specifically, the voltage drop rate can be calculated using the following equations (1) and (2).

[0044] Voltage drop [V] = Load current [A] × Impedance [Ω / km] × K value × Path length [km] ... (1) Voltage drop rate [%] = Voltage drop ÷ Line voltage [V] × 100 ... (2)

[0045] In equation (1) above, the K value is calculated as 2 for single-phase two-wire systems, 1 for single-phase three-wire systems, √3 for three-phase three-wire systems, and 1 for three-phase four-wire systems. The voltage drop rate may be determined by a known simplified formula based on the cross-sectional area of ​​the wiring, instead of the above basic formula (impedance method) using impedance values.

[0046] Furthermore, the total installation cost can be calculated using the following formula (3).

[0047] Total installation cost = Installation cost per unit length [1 / (m·strip)] × Number of strips × Wiring length [m] ... (3)

[0048] Examples of the voltage drop rate and total installation cost obtained from these equations are shown in (a) of FIG. 6.

[0049] In the example shown in (a) of FIG. 6, when the wiring type is CVT2, the voltage drop rate is v3, the total installation cost is 60; when the wiring type is CVT3, the voltage drop rate is v2, the total installation cost is 75; when the wiring type is CVT4, the voltage drop rate is v1, and the total installation cost is 60. Note that the magnitude of the voltage drop rate is v1 < v2 < v3, and it is assumed that the allowable current values of CVT2, CVT3, and CVT4 each exceed the total current AA.

[0050] According to the calculation results shown in (a) of FIG. 6, for example, when the required voltage drop rate allowed in the first common trunk line L1 is v2 or less, CVT2 cannot be adopted as the first common trunk line L1. Although both CVT3 and CVT4 can be adopted, since the total installation cost of CVT3 (75) is higher than the total installation cost of CVT4 (60), the evaluation of CVT4 is more advantageous than that of CVT3.

[0051] Based on such evaluation advantages and the voltage drop rate, as shown in (b) of FIG. 6, the wiring candidates for the first common trunk line L1 are selected.

[0052] According to the wiring candidates shown in (b) of FIG. 6, in the range where the voltage drop rate is v1 or more and less than v3, CVT4 with a total installation cost of 60 is the dominant specification; in the range where the voltage drop rate is v3 or more, CVT2 with a total installation cost of 60 is the dominant specification. Incidentally, when the total installation costs are the same, the one with a smaller wiring installation space, that is, the one with a smaller wiring size (cross-sectional area) is selected as the dominant specification.

[0053] In the example shown in FIG. 6, the calculation results of the voltage drop rates and total installation costs of the three provisionally selected wiring types are shown. However, the wiring types to be calculated may be all the wiring types obtained in step S10 without being provisionally selected. Further, the wiring types to be calculated may be specified by the main line designer or the like via the input device 20.

[0054] When the candidates for the wiring specifications of the first common main line L1 are selected in this way, subsequently, the candidates for the wiring specifications of the second common main line L2 are selected.

[0055] The second common main line L2 is installed along an indoor wall surface or the like and is a vertical main line for which little freedom of handling is required. Similar to the first common main line L1, since the current supplied to all the distribution boards D11 to D13, D21 to D24 flows, for example, as the wiring type, a bus duct is provisionally selected, and the allowable current value exceeds the total current AA of the current supplied to all the distribution boards D11 to D13, D21 to D24. Note that a wiring type in which the allowable current value exceeds the required current DAA obtained by multiplying the total current AA by the demand factor (for example, 70%) may be selected.

[0056] Then, for the selected wiring type, the voltage drop rate when the total current AA flows and the total installation cost when installed are obtained by the above formulas (1), (2), and (3) based on the previously obtained related information. The wiring length of the second common main line L2 is the length from the connection point J1 with the first common main line L to the connection point J21 with the first lateral main line L31. An example of the obtained voltage drop rate and total installation cost is shown in (a) of FIG. 7.

[0057] In the example shown in (a) of FIG. 7, when the wiring type is BD1, the voltage drop rate is v5, and the total installation cost is 120. When the wiring type is BD2, the voltage drop rate is v4, and the total installation cost is 150. Note that the magnitude of the voltage drop rate is v4 < v5, and the allowable current values of BD1 and BD2 are both assumed to exceed the total current AA.

[0058] Here, the calculation results shown in Figure 7(a) only show the voltage drop rate for the second shared main line L2, and it is difficult to determine the superiority of the wiring type used for the second shared main line L2 based solely on these results. Furthermore, the voltage drop rate including the first shared main line L1 cannot be determined until the wiring specifications for the first shared main line L1 are decided.

[0059] Therefore, using the previously obtained selection results for the wiring specifications of the first shared trunk line L1, and as shown in Figure 7(b), the voltage drop rate and total installation cost of the wiring candidates for the first shared trunk line L1 shown in Figure 6(b) are reflected in the calculation results shown in Figure 7(a), thereby deriving a result for determining the superiority of the wiring type to be used as the second shared trunk line L2. In other words, the result of the subproblem of selecting the wiring candidates for the first shared trunk line L1 is used to obtain the solution to the subproblem of selecting the wiring candidates for the second shared trunk line L2.

[0060] According to the results shown in Figure 7(b), if the wiring type of the second shared trunk line L2 is BD1, and the wiring type of the first shared trunk line L1 is the wiring candidate CVT4, the voltage drop rate will be v5 + v1, and the total installation cost will be 180 (=120 + 60). If the wiring type of the first shared trunk line L1 is the wiring candidate CVT2, the voltage drop rate will be v5 + v3, and the total installation cost will be 180 (=120 + 60).

[0061] Furthermore, if the wiring type of the second shared trunk line L2 is set to BD2, and the wiring type of the first shared trunk line L1 is set to the wiring candidate CVT4, the voltage drop rate will be v4 + v1, and the total installation cost will be 210 (= 150 + 60). If the wiring type of the first shared trunk line L1 is set to the wiring candidate CVT2, the voltage drop rate will be v4 + v3, and the total installation cost will be 210 (= 150 + 60). Note that the magnitude of the voltage drop rate is v5 + v1 <v4+v3であるとする。

[0062] Therefore, for example, if the required voltage drop rate from the first shared trunk line L1 to the second shared trunk line L2 is v4 + v1 or less, BD1 cannot be adopted as the second shared trunk line L2. If the required voltage drop rate is v5 + v1 or less, both BD1 and BD2 can be adopted, but the total installation cost of BD2 (210), including the total installation cost of the first shared trunk line L1, is higher than the total installation cost of BD1 (180), so BD1 is evaluated as superior to BD2.

[0063] Based on the advantages of this evaluation and the voltage drop rate, a candidate wiring configuration for the second shared trunk line L2 is selected, as shown in Figure 7(c).

[0064] According to the wiring candidates shown in Figure 7(c), BD2 is the preferred specification when the voltage drop rate is in the range of v4+v1 or more and less than v5+v1, as the total installation cost, including the total installation cost of the first shared trunk line L1, is 210. When the voltage drop rate is in the range of v5+v1 or more, BD1 is the preferred specification when the total installation cost, including the total installation cost of the first shared trunk line L1, is 180.

[0065] In the example shown in Figure 7, the calculation results for the voltage drop rate and total installation cost for two provisionally selected wiring types are shown. However, the wiring types to be calculated may not be provisionally selected, but may be, for example, all wiring types obtained in step S10. Furthermore, the wiring types to be calculated may be specified by the trunk line designer or the like via the input device 20.

[0066] Once the candidate wiring specifications for the second shared trunk line L2 are selected in this manner, the candidate wiring specifications for the first lateral trunk line L31 are then selected.

[0067] The first horizontal main line L31 is installed along the ceiling surface indoors and is a horizontal main line that does not require much flexibility in its routing. Since the current supplied to distribution boards D11 to D13, which belong to the first group G1, flows through it, for example, a bus duct type of wiring is provisionally selected, in which case the allowable current value exceeds the total current AA1 (=A11+A12+A13) supplied to the three distribution boards D11 to D13. Alternatively, a wiring type is selected in which the allowable current value exceeds the demand current DAA1 obtained by multiplying the total current AA1 by the demand factor (for example, 70%).

[0068] Then, for the selected wiring type, the voltage drop rate when the total current AA1 flows and the total installation cost when installed are determined by the above formulas (1), (2), and (3) based on the relevant information obtained earlier. Note that the wiring length of the first horizontal main line L31 is the length from the connection point J21 with the second shared main line L2 to the connection point J32 with the branch main line L42 that supplies power to the standard distribution board (distribution board D12). An example of the determined voltage drop rate and total installation cost is shown in Figure 8(a).

[0069] In the example shown in Figure 8(a), when the wiring type is BD1, the voltage drop rate is v7 and the total installation cost is 120, and when the wiring type is BD2, the voltage drop rate is v6 and the total installation cost is 150. Note that the magnitude of the voltage drop rate is v6. <v7であるとする。

[0070] The calculation results shown in Figure 8(a) only show the voltage drop rate for the first horizontal trunk line L31. It is difficult to determine the superiority of the wiring type used for the first horizontal trunk line L31 based solely on these results. Furthermore, the voltage drop rate including the first shared trunk line L1 and the second shared trunk line L2 cannot be determined until the wiring specifications for the first shared trunk line L1 and the second shared trunk line L2 are decided.

[0071] Therefore, by using the selection result of the wiring specification candidates of the second common trunk line L2 obtained previously, as shown in (b) of FIG. 8, with respect to the calculation result shown in (a) of FIG. 8, by reflecting the voltage drop rate and the total installation cost of the wiring candidates of the second common trunk line L2 shown in (c) of FIG. 7, a result for discriminating the superiority of the wiring type to be used as the first lateral trunk line L31 is derived. That is, in order to obtain the solution of the sub-problem of selecting the wiring candidates of the first lateral trunk line L31, the result of the sub-problem of selecting the wiring candidates of the second common trunk line L2 is used. As described above, the result of the sub-problem of selecting the wiring candidates of the second common trunk line L2 is obtained by using the result of the sub-problem of selecting the wiring candidates of the first common trunk line L1.

[0072] According to the result shown in (b) of FIG. 8, when the wiring type of the first lateral trunk line L31 is BD1 and the wiring type of the second common trunk line L2 is BD2 which is a wiring candidate, the voltage drop rate is v7 + v4 + v1, and the total installation cost is 330 (= 120 + 210). When the wiring type of the second common trunk line L2 is BD1 which is a wiring candidate, the voltage drop rate is v7 + v5 + v1, and the total installation cost is 300 (= 120 + 180).

[0073] Also, when the wiring type of the first lateral trunk line L31 is BD2, when the wiring type of the second common trunk line L2 is BD2 which is a wiring candidate, the voltage drop rate is v6 + v4 + v1, and the total installation cost is 360 (= 150 + 210). When the wiring type of the second common trunk line L2 is BD1 which is a wiring candidate, the voltage drop rate is v6 + v5 + v1, and the total installation cost is 330 (= 150 + 180). It is assumed that the magnitude of the voltage drop rate is v7 + v4 + v1 < v6 + v5 + v1. However, generally, since the size of the downstream trunk line is set so as not to exceed the size of the upstream trunk line, when the wiring type of the first lateral trunk line L31 is BD2, BD1 with a smaller size may be excluded from the wiring candidates of the second common trunk line L2.

[0074] Therefore, for example, if the required voltage drop rate for the section from the first shared trunk line L1 to the first lateral trunk line L31 is v6 + v4 + v1 or less, BD1 cannot be adopted as the first lateral trunk line L31. If the required voltage drop rate is v7 + v4 + v1 or less, both BD1 and BD2 can be adopted, but the total installation cost of BD2 (360), which includes the total installation costs of the first shared trunk line L1 and the second shared trunk line L2, is higher than the total installation cost of BD1 (330), so BD1 is evaluated as superior to BD2.

[0075] Based on the advantages of this evaluation and the voltage drop rate, the wiring candidates for the first horizontal trunk line L31 are selected, as shown in Figure 8(c).

[0076] According to the wiring candidates shown in Figure 8(c), in the range where the voltage drop rate is between v6+v4+v1 and less than v7+v4+v1, BD2 is the preferred specification as the total installation cost, including the total installation costs of the first and second shared main lines L1 and L2, is 360. In the range where the voltage drop rate is between v7+v4+v1 and less than v7+v5+v1, BD1 is the preferred specification as the total installation cost, including the total installation costs of the first and second shared main lines L1 and L2, is 330. In the range where the voltage drop rate is v7+v5+v1 or higher, BD1 is the preferred specification as the total installation cost, including the total installation costs of the first and second shared main lines L1 and L2, is 300. If the total installation costs are the same, the specification that requires less wiring space, i.e., the one with a smaller wiring size (cross-sectional area), is selected as the preferred specification.

[0077] In the example shown in Figure 8, the calculation results for the voltage drop rate and total installation cost for two provisionally selected wiring types are shown. However, the wiring types to be calculated may not be provisionally selected, but may be, for example, all wiring types obtained in step S10. Furthermore, the wiring types to be calculated may be specified by the trunk line designer or the like via the input device 20.

[0078] Once the selection of candidate wiring specifications for the first horizontal main line L31 is complete, in the following step S13, candidate wiring specifications for the branch main line L42 (standard branch main line) that supplies power to the distribution board D12 (standard distribution board) are selected based on the voltage drop rate and the total evaluation value (total installation cost).

[0079] The branch main line L42 (standard branch main line) connects the first horizontal main line L31 to the distribution board D12 (standard distribution board). As a main line that requires a certain degree of flexibility in routing, and as it supplies current to only one distribution board D12, for example, a CVT cable is provisionally selected as the wiring type, with an allowable current value that exceeds the current A12 supplied to distribution board D12.

[0080] Then, for the selected wiring type, the voltage drop rate when current A12 flows and the total installation cost when installed are determined using the above formulas (1), (2), and (3) based on the previously obtained relevant information. Note that the wiring length of the branch main line L42 is the length from the connection point J32 with the first horizontal main line L31 to the standard distribution board (distribution board D12). An example of the determined voltage drop rate and total installation cost is shown in Figure 9(a).

[0081] In the example shown in Figure 9(a), when the wiring type is CVT1, the voltage drop rate is v9 and the total installation cost is 50, and when the wiring type is CVT2, the voltage drop rate is v8 and the total installation cost is 100. Note that the magnitude of the voltage drop rate is v8. <v9であるとする。

[0082] The calculation results shown in Figure 9(a) only show the voltage drop rate for branch main line L42, making it difficult to determine the superiority of the wiring type used for branch main line L42 based solely on these results. Furthermore, the voltage drop rate including the shared main lines (first shared main line L1, second shared main line L2, and first horizontal main line L31) cannot be determined until the wiring specifications for the shared main lines are finalized.

[0083] Therefore, by using the selection result of the wiring specification candidates of the shared main line obtained previously, as shown in (b) of FIG. 9, for the calculation result shown in (a) of FIG. 9, the voltage drop rate and the total installation cost of the wiring candidates of the first horizontal main line L31 shown in (c) of FIG. 8, that is, the voltage drop rate and the total installation cost of the wiring candidates of the shared main line are reflected, and the result for discriminating the superiority of the wiring type used as the branch main line L42 is derived. That is, in order to obtain the solution of the sub-problem of selecting the wiring candidates of the branch main line L42, the result of the sub-problem of selecting the wiring candidates of the shared main line is used.

[0084] According to the result shown in (b) of FIG. 9, when the wiring type of the branch main line L42 is CVT1 and the wiring type of the first horizontal main line L31 is BD2 which is a wiring candidate, the voltage drop rate is v9 + v6 + v4 + v1, and the total installation cost is 410 (= 50 + 360). When the wiring type of the first horizontal main line L31 is BD1 with a total installation cost of 330 which is a wiring candidate, the voltage drop rate is v9 + v7 + v4 + v1, and the total installation cost is 380 (= 50 + 330). When the wiring type of the first horizontal main line L31 is BD1 with a total installation cost of 300 which is a wiring candidate, the voltage drop rate is v9 + v7 + v5 + v1, and the total installation cost is 350 (= 50 + 300).

[0085] Also, when the wiring type of the branch main line L42 is CVT2 and the wiring type of the first horizontal main line L31 is BD2 which is a wiring candidate, the voltage drop rate is v8 + v6 + v4 + v1, and the total installation cost is 460 (= 100 + 360). When the wiring type of the first horizontal main line L31 is BD1 with a total installation cost of 330 which is a wiring candidate, the voltage drop rate is v8 + v7 + v4 + v1, and the total installation cost is 430 (= 100 + 330). When the wiring type of the first horizontal main line L31 is BD1 with a total installation cost of 300 which is a wiring candidate, the voltage drop rate is v8 + v7 + v5 + v1, and the total installation cost is 400 (= 100 + 300). It is assumed that the magnitude of the voltage drop rate is v9 + v6 + v4 + v1 < v8 + v7 + v4 + v1 and v9 + v7 + v4 + v1 < v8 + v7 + v5 + v1.

[0086] Therefore, for example, if the required voltage drop rate for the section from the first shared trunk line L1 to the branch trunk line L42 is less than or equal to v8+v6+v4+v1, CVT1 cannot be used as the branch trunk line L42. If the required voltage drop rate is less than or equal to v9+v6+v4+v1, both CVT1 and CVT2 can be used, but the total installation cost of CVT2 (460), which includes the total installation costs of the first shared trunk line L1, the second shared trunk line L2, and the first horizontal trunk line L31, is higher than the total installation cost of CVT1 (410), so CVT1 is evaluated as superior to CVT2.

[0087] Based on the advantages of this evaluation and the voltage drop rate, the wiring candidates for branch line L42 are selected, as shown in Figure 9(c).

[0088] According to the wiring candidates shown in Figure 9(c), in the range where the voltage drop rate is between v8+v6+v4+v1 and less than v9+v6+v4+v1, CVT2 is the superior specification as the total installation cost, including the total installation costs of the first shared trunk line L1, the second shared trunk line L2, and the first horizontal trunk line L31, is 460. In the range where the voltage drop rate is between v9+v6+v4+v1 and less than v9+v7+v4+v1, the total installation cost, including the total installation costs of the first shared trunk line L1, the second shared trunk line L2, and the first horizontal trunk line L31, is 41. CVT1, which results in a value of 0, is the preferred specification. In the range where the voltage drop rate is between v9+v7+v4+v1 and less than v9+v7+v5+v1, CVT1 is the preferred specification because the total installation cost, including the total installation costs of the first shared trunk line L1, the second shared trunk line L2, and the first horizontal trunk line L31, is 380. In the range where the voltage drop rate is between v9+v7+v5+v1 and above, CVT1 is the preferred specification because the total installation cost, including the total installation costs of the first shared trunk line L1, the second shared trunk line L2, and the first horizontal trunk line L31, is 350.

[0089] In the example shown in Figure 9, the calculation results for the voltage drop rate and total installation cost for two provisionally selected wiring types are shown. However, the wiring types to be calculated may not be provisionally selected, but may be, for example, all wiring types obtained in step S10. Furthermore, the wiring types to be calculated may be specified by the trunk line designer or the like via the input device 20.

[0090] Once the selection of candidate wiring specifications for branch main line L42 (reference branch main line) is complete, the process proceeds to step S14, where the wiring specification with the highest evaluation among the candidate wiring specifications for branch main line L42 (reference branch main line) obtained in step S13 is selected as the optimal specification.

[0091] Even with highly-rated wiring specification candidates, that is, wiring specification candidates with low total installation costs, if the voltage drop rate, which is the ratio of voltage drop that occurs in the common main line and branch main line relative to the voltage at the distribution board (receiving voltage), exceeds the allowable voltage drop rate (allowable value), the voltage drop will become so large that electrical equipment may not be able to be used properly.

[0092] In other words, regardless of the evaluation, the condition is that the voltage drop rate is below a predetermined allowable voltage drop rate (for example, 3%). Note that the allowable voltage drop rate is not limited to 3%, but can be arbitrarily set depending on the length of the electrical wiring, etc.

[0093] Therefore, in step S14, among the wiring candidates for branch main line L42 (reference branch main line) shown in Figure 9(c), the one in which the voltage drop rate is less than or equal to a predetermined allowable voltage drop rate and the total evaluation value, which is the total installation cost calculated using the installation cost per unit length (evaluation value), is the most advantageous is selected as the optimal specification for branch main line L42.

[0094] Specifically, for example, if the voltage drop rate v9+v7+v5+v1 is 3% or less, CVT1, which has the lowest total installation cost of 350, will be selected as the optimal specification for branch line L42. However, if the voltage drop rate v9+v7+v5+v1 exceeds 3% and the voltage drop rate v9+v7+v4+v1 is 3% or less, the combination with a total installation cost of 350 will not be selected because, although the overall evaluation value is superior, it exceeds the allowable voltage drop rate. The combination with a total installation cost of 380 will be selected as the optimal specification for branch line L42 because it is below the allowable voltage drop rate and has the most superior overall evaluation value.

[0095] Once the optimal specifications for the branch main line L42 (reference branch main line) are selected in this way, the process proceeds to step S15. From the wiring specification candidates for the shared main lines (first shared main line L1, second shared main line L2, and first horizontal main line L31) obtained in step S12, the wiring specification that allows the voltage drop rate at the reference distribution board (distribution board D12) to be kept below the allowable voltage drop rate and has the highest evaluation is selected as the optimal specification for each.

[0096] In the following explanation, we will proceed assuming that in step S14, CVT1 was selected as the optimal specification for branch line L42, where the voltage drop rate v9+v7+v4+v1 is 3% or less, the voltage drop rate v9+v7+v5+v1 exceeds 3%, and the total installation cost (total evaluation value) is 380.

[0097] In step S14, the voltage drop rate of CVT1, which was selected as the optimal specification for the branch main line L42, is v9, as described above (see Figure 9(a)). Therefore, in order to maintain the voltage drop rate at the reference distribution board (distribution board D12) below the allowable voltage drop rate, the voltage drop rate at the first horizontal main line L31 must be less than or equal to v7+v4+v1 (=(v9+v7+v4+v1)-v9).

[0098] Therefore, the optimal specification for the first horizontal trunk line L31 is selected from the candidates for wiring specifications that has a voltage drop rate of v7 + v4 + v1 or less and the most advantageous total installation cost (total evaluation value).

[0099] According to the above-mentioned candidate wiring specifications for the first horizontal trunk line L31 (see Figure 8(c)), the combination resulting in a total installation cost of 300 is not selected because, although the overall evaluation value is superior, it exceeds the required voltage drop rate v7+v4+v1. The combination resulting in a total installation cost of 330 is less than or equal to the required voltage drop rate v7+v4+v1 and has the most superior overall evaluation value. Therefore, BD1 of this combination is selected as the optimal specification for the first horizontal trunk line L31.

[0100] Thus, the voltage drop rate of BD1, which was selected as the optimal specification for the first horizontal main line L31, is v7 as described above (see Figure 8(a)). Therefore, in order to maintain the voltage drop rate at the reference distribution board (distribution board D12) below the allowable voltage drop rate, the voltage drop rate at the second shared main line L2 must be v4 + v1 (= (v7 + v4 + v1) - v7) or less.

[0101] Therefore, the optimal specification for the second shared trunk line L2 is selected from the candidates for wiring specifications that has a voltage drop rate of v4 + v1 or less and the most advantageous total installation cost (total evaluation value).

[0102] According to the candidate wiring specifications for the second shared trunk line L2 (see Figure 7(c)) mentioned above, the combination with a total installation cost of 180 is not selected because, although the overall evaluation value is superior, it exceeds the required voltage drop rate v4+v1. The combination with a total installation cost of 210 is less than or equal to the required voltage drop rate v4+v1 and has the most superior overall evaluation value, so BD2 is selected as the optimal specification for the second shared trunk line L2.

[0103] Thus, the voltage drop rate of BD2, which was selected as the optimal specification for the second shared main line L2, is v4 as described above (see Figure 7(a)). Therefore, in order to maintain the voltage drop rate at the reference distribution board (distribution board D12) below the allowable voltage drop rate, the voltage drop rate at the first shared main line L1 must be v1 (=(v4+v1)-v4) or less.

[0104] Therefore, the optimal specification for the first shared trunk line L1 is selected from the candidates for wiring specifications that has a voltage drop rate of v1 or less and the most advantageous total installation cost (total evaluation value).

[0105] According to the candidate wiring specifications for the first shared trunk line L1 described above (see Figure 6(b)), CVT2, with a total installation cost of 60, is not selected because it exceeds the required voltage drop rate v1. CVT4, with a total installation cost of 60, is selected as the optimal specification for the first shared trunk line L1 because it is less than or equal to the required voltage drop rate v1 and has the most advantageous overall evaluation value.

[0106] Once the optimal specifications for the shared main lines (first shared main line L1, second shared main line L2, and first horizontal main line L31) are selected, the process proceeds to step S16, where the optimal wiring specifications for the other branch main lines L41 and L43, which are connected to the same shared main line (first horizontal main line L31) as the distribution board D12 (standard distribution board), are selected based on the voltage drop rate and the total evaluation value (total installation cost).

[0107] In step S16, the voltage drop rate from each branch line L41 and L43 to connection points J31 and J33 where they are connected to the first horizontal branch line L31 is first determined. The voltage drop rate obtained by adding the determined voltage drop rate and the voltage drop rate at the branch lines L41 and L43 is less than or equal to a predetermined allowable voltage drop rate (for example, 3%), and the wiring specification that is superior in terms of overall evaluation value (total installation cost) is selected as the optimal specification for branch lines L41 and L43.

[0108] Specifically, since the wiring specifications for the shared main lines (first shared main line L1, second shared main line L2, and first horizontal main line L31) are selected in step S15, the voltage drop rate to each connection point J31 and J33 can be determined when the selected wiring is used as a shared main line.

[0109] For example, the voltage drop rate up to connection point J31 is the sum of the voltage drop rate v1 of the first shared main line L1, the voltage drop rate v4 of the second shared main line L2, and the voltage drop rate v71 of the first horizontal main line L31. Note that the voltage drop rate v71 of the first horizontal main line L31 is the voltage drop rate when the wiring length of the first horizontal main line L31 is the length from connection point J21 with the second shared main line L2 to connection point J31 with the branch main line L41.

[0110] Furthermore, branch line L41, which branches off from connection point J31, is a main line that requires flexibility in routing, similar to branch line L42 (reference branch line). Since the current supplied to only one distribution board D11 flows through it, for example, a CVT cable with an allowable current value exceeding the current A11 supplied to distribution board D11 is provisionally selected as the wiring type.

[0111] Then, for the selected wiring type, the voltage drop rate when current A11 flows and the total installation cost when installed are determined using the above formulas (1), (2), and (3) based on the previously obtained relevant information. Note that the wiring length of the branch main line L41 is the length from the connection point J31 with the first horizontal main line L31 to the distribution board D11. An example of the determined voltage drop rate and total installation cost is shown in Figure 10.

[0112] In the example shown in Figure 10, when the wiring type is CVT1, the voltage drop rate is v11 and the total installation cost is 25, while when the wiring type is CVT2, the voltage drop rate is v10 and the total installation cost is 50. Note that the magnitude of the voltage drop rate is v10. <v11であるとする。

[0113] Therefore, if the sum of the voltage drop rate v1+v4+v71 up to connection point J31 and the voltage drop rate v11 when the wiring type of branch main line L41 is CVT1 is less than or equal to the predetermined allowable voltage drop rate, then CVT1, which has an advantage in total installation cost (total evaluation value), is selected as the optimal specification for branch main line L41. If this voltage drop rate exceeds the predetermined allowable voltage drop rate, and the sum of the voltage drop rate v1+v4+v71 up to connection point J31 and the voltage drop rate v10 when the wiring type of branch main line L41 is CVT2 is less than or equal to the predetermined allowable voltage drop rate, then CVT2 is selected as the optimal specification for branch main line L41. The optimal specifications for other branch main lines L43 are selected in the same manner.

[0114] As such, the optimal specifications for branch lines L41 and L43, which connect distribution boards D11 and D13 (excluding distribution board D12 (standard distribution board) that receive power through the first horizontal main line L31 (shared main line) for which the optimal specifications have been selected, to the first horizontal main line L31 (shared main line), are selected such that the sum of the voltage drop rate in the shared main lines (first shared main line L1, second shared main line L2, and first horizontal main line L31) for which the optimal specifications have been selected and the voltage drop rate in branch lines L41 and L43 is less than or equal to the allowable voltage drop rate, and the wiring specification that is most advantageous in terms of the total evaluation value (total installation cost) of the branch lines, which is calculated using the evaluation value per unit length (installation cost per unit length).

[0115] Once the optimal specifications for the other branch lines L41 and L43, which are connected to the same common main line (first horizontal main line L31) as the standard distribution board (distribution board D12), have been selected, the process proceeds to step S17, where it is determined whether the selection of optimal specifications for all common main lines and branch lines has been completed.

[0116] If the selection of optimal specifications for all shared and branch trunk lines has been completed, the process is terminated and the selection results for the shared and branch trunk lines are displayed on the display device 22.

[0117] On the other hand, if there is a shared main line for which the optimal specifications have not yet been selected, for example, as in the example above, if the optimal specifications for the second horizontal main line L32 have not yet been selected, the process proceeds to step S18, where a reference distribution board is set that will be used as the basis when selecting the specifications for the shared main line (second horizontal main line L32) for which the optimal specifications have not yet been selected.

[0118] Specifically, among the distribution boards D21 to D24 connected to the second horizontal main line L32 (shared main line), for which the optimal specifications have not yet been selected, via branch main lines L51 to L54, the distribution board with the longest total route length—that is, the route length from the power receiving equipment 10 to each distribution board D21 to D24—is set as the standard distribution board. This total route length is calculated by adding the route lengths of the shared main lines L1, L2, and L32 to the route lengths of the branch main lines L51 to L54.

[0119] Looking at the distribution boards D21 to D24, which are supplied with power from the second horizontal main line L32, in the example shown in Figure 4, the combined route length of the first shared main line L1, the second shared main line L2 which is connected to the first shared main line L1 at connection point J1 and extends to connection point J22, the second horizontal main line L32 which is connected to the second shared main line L2 at connection point J22, and the branch main line L54 which is connected to the second horizontal main line L32 at connection point J44 is the longest. Therefore, distribution board D24, which is connected to the second horizontal main line L32 via the branch main line L54, is selected as the standard distribution board.

[0120] Once the reference distribution board is reset in step S18, the process returns to step S12, where candidate wiring specifications for the shared main lines supplying power to the group of distribution boards, including the reset reference distribution board (distribution board D24), are selected based on the voltage drop rate and the total evaluation value (total installation cost). For shared main lines for which the optimal specifications have already been selected (first shared main line L1 and second shared main line L2), no candidate wiring specifications are selected; instead, the voltage drop rate and total evaluation value (total installation cost) are calculated based on the selected wiring specifications.

[0121] From this point onward, the selection of candidate wiring specifications for the second horizontal main line L32, the selection of candidate wiring specifications for the branch main line L54 (reference branch main line), the selection of the optimal specifications for the second horizontal main line L32 and the branch main line L54, and the selection of the optimal specifications for the other branch main lines L51, L52, and L53 are carried out in the same manner as described above. In this way, the selection of main line specifications is carried out for each group of distribution boards that have a common shared main line. Although the second horizontal main line L32 is provided with a branch section J40, it is preferable from the viewpoint of improving maintainability and preventing miswiring that the wiring specifications for the second horizontal main line L32 remain unchanged at the branch section J40 and that the same wiring specifications be used throughout the entire second horizontal main line L32. Alternatively, assuming that the wiring specifications change at the branch section J40, it is also possible to select the optimal specifications for the second horizontal main line L32 upstream and downstream of the branch section J40, respectively, in the same manner as described above.

[0122] Through the steps described above, the optimal wiring specifications for the main line connecting the power receiving equipment and the distribution board are selected according to the main line selection method.

[0123] According to the above embodiments, the following effects are achieved.

[0124] According to the trunk line selection method and trunk line selection program described above, a combination of specifications for a shared trunk line and branch trunk lines is selected based on relevant information including trunk line route information, load current information, and wiring specification information, such that the voltage drop rate is less than or equal to the allowable voltage drop rate and the total evaluation value obtained using the evaluation value is superior.

[0125] In this way, by automatically selecting the optimal combination of shared trunk line specifications and branch trunk line specifications that meet predetermined conditions, trunk line selection can be performed efficiently.

[0126] Furthermore, according to the trunk line selection method and trunk line selection program described above, a dynamic programming method is used as the algorithm for selecting the optimal specifications for shared trunk lines and branch trunk lines, with the selection of specifications for shared trunk lines and the selection of specifications for branch trunk lines, which are performed based on relevant information, being treated as subproblems.

[0127] In this way, dynamic programming is used to determine the optimal specifications for shared and branch lines, which are the most highly evaluated overall problem. To solve this, the routing candidates for shared lines and branch lines are treated as subproblems. By using the results of these subproblems to find the optimal solution to the overall problem, the optimal specifications for shared and branch lines can be selected accurately with less computational load.

[0128] Furthermore, the following modifications are also within the scope of the present invention, and it is possible to combine the configurations shown in the modifications with the configurations described in the embodiments described above, or to combine the configurations described in the following different modifications.

[0129] In the above embodiment, the table showing the total installation cost of wiring according to the voltage drop rate is a table in which the wiring type is listed in the rows and the calculated voltage drop rate for each wiring type is listed in the columns, and the table showing the candidate wiring specifications is a table in which the range of the voltage drop rate is listed in the columns. Alternatively, the table showing the total installation cost of wiring according to the voltage drop rate and the table showing the candidate wiring specifications may be tables in which the columns are increased in steps from 0% to a predetermined step (e.g., 0.1%) and the maximum value is the allowable voltage drop rate (e.g., 3%), as shown in Figures 10(a) and (b), respectively, and generated by sequentially filling in the total installation cost for each wiring type and the candidate wiring specifications in each cell, and stored in the storage unit 11 in tabular format.

[0130] Furthermore, in the above embodiment, the installation cost required to install a unit length of wiring is used as the evaluation value per unit length, and wiring specifications with a low total installation cost based on this installation cost per unit length are considered superior. Alternatively, or in addition to this, the weight of copper used in a unit length of wiring [kg / (m·strip)] may be adopted as the evaluation value per unit length, and wiring specifications with less copper use may be considered superior. Alternatively, the life cycle CO2 (LCCO2) [kg / (m·strip)] related to the amount of carbon dioxide emitted when manufacturing a unit length of wiring may be adopted as the evaluation value per unit length, and wiring specifications with less life cycle CO2 may be considered superior. Alternatively, the superiority of wiring specifications may be determined by combining these evaluation indicators.

[0131] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. [Explanation of symbols]

[0132] 1...Buildings 10. Power receiving equipment L1...1st shared trunk line (shared trunk line) L2...Second shared trunk line (shared trunk line) L31...First horizontal trunk line (shared trunk line) L32...Second horizontal main line (shared main line) D11~D13, D21~D24... Distribution board L41~L43, L51~L54... Branch main lines 100... Information Processing Device

Claims

1. A method for selecting a main line that connects power receiving equipment and distribution boards, comprising: a common main line shared by multiple distribution boards; and branch main lines that branch off from the common main line and are connected to the respective distribution boards, A related information acquisition step for acquiring related information regarding the shared main line, the branch main line, and the distribution board, A specification selection step of selecting the specifications of the shared trunk line and the branch trunk line based on the aforementioned related information, The aforementioned related information includes: Main line route information indicating the route of the main line connecting the power receiving equipment and the multiple distribution boards, The load current information for each distribution board is shown, The wiring specification information includes the type of the shared main line and the branch main line, the allowable current value for each type, parameters correlated with voltage drop, and an evaluation value per unit length. In the specification selection step, based on the relevant information, the combination of the specifications of the shared main line and the branch main line that results in a voltage drop rate being below an allowable value and a superior overall evaluation value obtained using the evaluation value is selected as the optimal specification. Method for selecting main lines.

2. In the specification selection step, a dynamic programming method is used as the algorithm for selecting the optimal specifications, with the selection of the specifications for the shared trunk line and the selection of the specifications for the branch trunk line, both performed based on the relevant information, as subproblems. The method for selecting a trunk line according to claim 1.

3. In the aforementioned specification selection step, The distribution board with the longest total route length, which is the sum of the route length of the shared main line and the route length of the branch main lines, is set as the standard distribution board. The combination of the specifications of the reference branch main line and the shared main line that results in the sum of the voltage drop rate of the reference branch main line connected to the reference distribution board and the voltage drop rate of the shared main line being less than or equal to the allowable value, and in which the sum of the total evaluation value of the reference branch main line and the total evaluation value of the shared main line, obtained using the evaluation value, is most advantageous, is selected as the optimal specification. The method for selecting a trunk line according to claim 1 or 2.

4. In the aforementioned specification selection step, As the optimal specification for the branch main line connecting the distribution boards other than the reference distribution board to the common main line, which is supplied with power through the common main line to which the optimal specification has been selected, the specification is selected such that the sum of the voltage drop rate of the common main line and the voltage drop rate of the branch main line is less than or equal to the allowable value, and the total evaluation value of the branch main line, which is obtained using the evaluation value, is the most advantageous. The trunk line selection method according to claim 3.

5. A trunk line selection program that selects a shared trunk line shared by multiple distribution boards and branch trunk lines that branch off from the shared trunk line and are connected to the distribution boards, among the trunk lines connecting the power receiving equipment and the distribution boards, On the computer, A related information acquisition step for acquiring related information regarding the shared main line, the branch main line, and the distribution board, A specification selection step is performed to select the specifications of the shared trunk line and the branch trunk line based on the aforementioned related information. The aforementioned related information includes: Main line route information indicating the route of the main line connecting the power receiving equipment and the multiple distribution boards, The load current information for each distribution board is shown, The wiring specification information includes the type of the shared main line and the branch main line, the allowable current value for each type, parameters correlated with voltage drop, and an evaluation value per unit length. In the specification selection step, based on the relevant information, the combination of the specifications of the shared main line and the branch main line that results in a voltage drop rate being below an allowable value and a superior overall evaluation value obtained using the evaluation value is selected as the optimal specification. Trunk line selection program.

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