TWI790743B - Calculation method of grid-connectable capacity of feeder - Google Patents

Abstract

A feeder grid-connectable capacity calculation method, comprising: (A) judging whether the difference between the wholesale capacity of a feeder and the sum of multiple capacity parameters is greater than zero; (B) when it is determined that the difference is greater than zero, the A grid-connectable capacity of a busbar to be calculated in the feeder is initialized to the difference; (C) use a load flow analysis to obtain a voltage change rate corresponding to each busbar in the feeder; (D) determine all busbars (E) When it is determined that the maximum voltage change rate is within the preset range, determine whether the sum of the grid-connectable capacity plus these capacity parameters is greater than the wholesale capacity; and (F) when it is determined that the sum is not greater than the wholesale capacity, use the grid-connectable capacity as the result of the grid-connectable capacity of the busbar to be calculated.

Description

Calculation method of grid-connectable capacity of feeder

The invention relates to a method for analyzing the carrying capacity of a feeder, in particular to a method for calculating the grid-connectable capacity of a feeder.

Renewable energy, such as the energy generated by the sun, wind and ocean, has the advantages of reusability, less pollution and high environmental sustainability. The potential of development is that all countries in the world are actively developing renewable energy power generation. However, when installing a new renewable energy on the feeder, it must meet the country's voltage regulations. Since there are nearly 10,000 feeders in Taiwan's power distribution lines, it is possible to The combined capacity section is as high as more than 3 million pieces of data. To calculate the grid-connected capacity of each busbar one by one requires a lot of manpower, so it is necessary to find a solution.

Therefore, the object of the present invention is to provide a method for calculating the grid-connectable capacity of feeders that automatically calculates the grid-connectable capacity of each busbar.

Therefore, the method for calculating the feeder grid-connectable capacity of the present invention is implemented by a computing device, and the computing device stores a feeder input file related to a feeder, and the feeder input file includes a set of transformer parameters, a set of conductor parameters, a wholesale capacity of the feeder, a maximum load of the feeder, feeder parameters associated with busbars, and capacity parameters associated with distributed generation nodes attached to the busbars, The feeder parameters indicate the distance between two adjacent busbars and the type of wire. The calculation method of the grid-connectable capacity of the feeder includes the following steps:

(A) Determine whether the difference between the wholesale capacity and the sum of these capacity parameters is greater than zero;

(B) When it is determined that the difference is greater than zero, initialize a grid-connectable capacity of a bus to be calculated among the bus bars to the difference;

(C) According to the group of transformer parameters, the group of wire parameters, the feeder parameters, the maximum load, the capacity parameters and the grid-connectable capacity of the busbar to be calculated, use a load flow analysis to obtain each A voltage change rate corresponding to the bus bar;

(D) determining whether a maximum voltage variation rate among the voltage variation rates of all bus bars is within a preset interval;

(E) When it is determined that the maximum voltage change rate is within the preset range, determine whether the sum of the grid-connectable capacity of the bus to be calculated plus the capacity parameters is greater than the wholesale capacity; and

(F) When it is determined that the sum of the grid-connectable capacity of the busbar to be calculated plus the capacity parameters is not greater than the wholesale capacity, the grid-connectable capacity of the busbar to be calculated is used as the busbar to be calculated The grid-connectable capacity results of the row.

The effect of the present invention lies in that: according to the feeder input file, the calculation device obtains the grid-connectable capacity result of the busbar to be calculated, thereby automatically calculating the grid-connectable capacity of each busbar.

Referring to FIG. 1 , the method for calculating the feeder grid-connectable capacity of the present invention is implemented by a computing device 1 , which includes a storage module 11 and a processing module 12 electrically connected to the storage module 11 . The implementation of the computing device 1 is, for example, a server, a personal computer, a notebook computer, a tablet computer, or a smart phone.

The storage module 11 stores a feeder input file related to a feeder. The feeder input file includes a set of transformer parameters, a set of conductor parameters, a wholesale capacity of the feeder, a maximum load of the feeder, a plurality of The feeder parameters related to multiple bus bars, and the capacity parameters related to distributed power generation nodes attached to the bus bars, the feeder parameters indicate the distance between two adjacent bus bars and the wire type. It is worth mentioning that a feeder model (see Figure 2) can be drawn by regularly collecting the feeder's load information, wire diagram data, connectivity data, established and approved renewable energy data every month. The bus bars including the feeder, multiple edges connecting two of the bus bars, and the distributed generation nodes (Distributed Generation, DG for short) attached to the bus bars, each edge indicates the connected The distance between the busbars and the wire type. The feeder input file is generated based on the feeder model using a power distribution system simulation software, such as OpenDSS software.

Referring to FIG. 1 and FIG. 3 , how to obtain the grid-connectable capacity of one of the busbars to be calculated for the feeder will be described below by using an embodiment of the method for calculating the feeder grid-connectable capacity of the present invention, which includes the following steps. It is worth mentioning that the grid-connectable capacity of each busbar is obtained in the same way, so in the following description, only the busbar to be calculated is used for illustration.

In step 201, the processing module 12 determines whether the difference between the wholesale capacity and the sum of the capacity parameters is greater than zero. When the processing module 12 determines that the difference is greater than zero, the process proceeds to step 202 ; when the processing module 12 determines that the difference is not greater than zero, the process proceeds to step 213 .

In step 202, the processing module 12 initializes a grid-connectable capacity of the bus to be calculated among the bus bars as the difference.

，及在有分散式發電節點併聯時每一匯流排對應的一電壓

，並將每一匯流排對應的

與

之差值除以

後取絕對值，並乘以100%以獲得每一匯流排對應的電壓變動率。 In step 203, the processing module 12 utilizes a A load flow analysis is performed to obtain a voltage change rate corresponding to each bus bar. Wherein, the processing module 12 is based on the group of transformer parameters, the group of conductor parameters, the feeder parameters, the maximum load, the capacity parameters and the grid-connectable capacity of the busbar to be calculated, using the load flow Analyze and obtain a voltage corresponding to each busbar when no distributed generation nodes are connected in parallel

, and a voltage corresponding to each busbar when distributed generation nodes are connected in parallel

, and each bus corresponding to

and

The difference divided by

Then take the absolute value and multiply it by 100% to obtain the voltage change rate corresponding to each bus bar.

In step 204 , the processing module 12 determines whether a maximum voltage variation rate among the voltage variation rates of all bus bars is within a predetermined interval. When the processing module 12 determines that the maximum voltage variation rate is not within the preset interval, the process proceeds to step 205; when the processing module 12 determines that the maximum voltage variation rate is within the preset interval, the process proceeds to step 208 . In this embodiment, the preset interval is greater than 2.9% but less than 2.99%. However, in other embodiments, the preset interval can also be changed according to requirements, and is not limited thereto.

In step 205, the processing module 12 adjusts the interconnectable capacity of the bus to be calculated.

It is worth mentioning that step 205 includes the following sub-steps (see Figure 4).

In sub-step 205A, the processing module 12 determines whether the maximum voltage variation rate is greater than a second preset percentage. When the processing module 12 determines that the maximum voltage variation rate is greater than the second preset percentage, the process proceeds to sub-step 205B; when the processing module 12 determines that the maximum voltage variation rate is not greater than the second preset percentage , the process proceeds to sub-step 205C. In this embodiment, the second preset percentage is 3%, but in other embodiments, the second preset percentage can also be changed according to requirements, and is not limited thereto.

In sub-step 205B, the processing module 12 subtracts a first correction value from the interconnectable capacity of the bus to be calculated. In this embodiment, the first correction value is divided by two for the grid-connectable capacity of the bus to be calculated, but it is not limited thereto.

In sub-step 205C, the processing module 12 adds a second correction value to the interconnectable capacity of the bus to be calculated. In this embodiment, the second correction value is divided by two after subtracting the grid-connectable capacity of the busbar to be calculated from the difference, but it is not limited thereto.

In step 206, the processing module 12 according to the set of transformer parameters, the set of wire parameters, the feeder parameters, the maximum load, the capacity parameters and the adjusted grid-connectable capacity of the busbar to be calculated , using the load flow analysis to obtain another voltage change rate corresponding to each busbar.

In step 207, the processing module 12 determines whether another maximum voltage variation rate among the other voltage variation rates of all bus bars is within the preset interval. When the processing module 12 determines that the other maximum voltage variation rate is within the preset interval, the process proceeds to step 208; when the processing module 12 determines that the other maximum voltage variation rate is not within the preset interval, The process goes to step 211.

In step 208, the processing module 12 determines whether the sum of the interconnectable capacity of the busbar to be calculated plus the capacity parameters is greater than the wholesale capacity. When the processing module 12 determines that the sum of the grid-connectable capacity of the busbar to be calculated plus the capacity parameters is not greater than the wholesale capacity, the process proceeds to step 209; when the processing module 12 determines that the to-be-calculated When the sum of the grid-connectable capacity of the calculated busbar plus the capacity parameters is greater than the wholesale capacity, the process proceeds to step 210 .

In step 209, the processing module 12 uses the grid-connectable capacity of the bus to be calculated as the result of the grid-connectable capacity of the bus to be calculated.

In step 210, the processing module 12 subtracts an adjustment value from the grid-connectable capacity of the busbar to be calculated, and uses the grid-connectable capacity minus the adjustment value as the grid-connectable capacity of the busbar to be calculated. Network capacity results. Wherein, the adjustment value is the second correction value added in sub-step 205C.

In step 211, the processing module 12 determines whether the grid-connectable capacity of the busbar to be calculated obtained after performing step 205 this time is the same as that of the busbar to be calculated obtained after performing step 205 twice before The grid-connectable capacity. When the processing module 12 determines that the grid-connectable capacity obtained after executing step 205 this time is the same as the grid-connectable capacity obtained after performing step 205 twice before, the process proceeds to step 212; when the processing module When the group 12 determines that the grid-connectable capacity obtained after executing step 205 this time is different from the grid-connectable capacity obtained after executing step 205 twice before, the process returns to step 205 .

In step 212, the processing module 12 designates the grid-connectable capacity of the busbar to be calculated as all grid-connectable capacities obtained after performing step 205 this time, the previous time, and the previous two times. The grid-connectable capacity corresponding to the maximum voltage variation rate less than a first preset percentage in the maximum voltage variation rate, and proceed to step 208 . In this embodiment, the first preset percentage is 2.90%. However, in other embodiments, the first preset percentage can also be changed according to requirements, which is not limited thereto.

In step 213, the processing module 12 sets a grid-connectable capacity of each busbar to zero as the grid-connectable capacity result of each busbar.

One of the busbars whose grid-connectable capacity has not been obtained is used as another busbar to be calculated, and the above-mentioned process is repeated to obtain the grid-connectable capacity of each busbar of the feeder.

To sum up, in the method for calculating the feeder grid-connectable capacity of the present invention, the calculation device 1 obtains the result of the grid-connectable capacity of the busbar to be calculated according to the input file of the feeder line, thereby automatically calculating the grid-connectable capacity of each busbar Grid-connectable capacity, and can ensure that the grid-connected capacity of renewable energy does not exceed the maximum wholesale capacity of the feeder, and the voltage fluctuation rate of each busbar does not exceed the allowable voltage fluctuation rate of the system, so as to meet the voltage specification, so it can indeed be achieved purpose of the present invention.

But the above-mentioned ones are only embodiments of the present invention, and should not limit the scope of the present invention. All simple equivalent changes and modifications made according to the patent scope of the present invention and the content of the patent specification are still within the scope of the present invention. Within the scope covered by the patent of the present invention.

1: computing device 11: Storage module 12: Processing module 201~213: Steps 205A~205C: sub-steps

Other features and effects of the present invention will be clearly presented in the implementation manner with reference to the drawings, wherein: Fig. 1 is a block diagram, illustrates and implements a calculating device of the embodiment of the feeder grid-connectable capacity calculation method of the present invention; Figure 2 is a schematic diagram illustrating a feeder model; Fig. 3 is a flow chart, illustrates the embodiment of the feeder grid-connectable capacity calculation method of the present invention; and FIG. 4 is a flowchart illustrating how to adjust the interconnectable capacity of a bus to be calculated.

201~213: Steps

Claims (9)

A method for calculating feeder grid-connectable capacity, implemented by a computing device, the computing device stores a feeder input file related to a feeder, and the feeder input file includes a set of transformer parameters, a set of wire parameters, and a set of feeder parameters. A wholesale capacity, a maximum load of the feeder, a plurality of feeder parameters related to a plurality of busbars, and a plurality of capacity parameters related to distributed generation nodes attached to the busbars, the feeder The parameter indicates the distance between two adjacent busbars and the type of conductor. The calculation method of the grid-connectable capacity of the feeder includes the following steps: (A) determine whether the difference between the wholesale capacity and the sum of the capacity parameters is greater than zero; ( B) When it is determined that the difference is greater than zero, a grid-connectable capacity of a bus to be calculated among the bus bars is initialized as the difference; (C) according to the group of transformer parameters, the group of wire parameters, The feeder parameters, the maximum load, the capacity parameters and the grid-connectable capacity of the busbar to be calculated are obtained by using a load flow analysis to obtain a voltage change rate corresponding to each busbar; (D) determine all Whether a maximum voltage change rate among the voltage change rates of the bus bar is within a preset range; (E) when it is determined that the maximum voltage change rate is within the preset range, determine the grid-connectable capacity of the bus bar to be calculated Whether the sum of these capacity parameters is greater than the wholesale capacity; (F) When it is determined that the sum of the grid-connectable capacity of the busbar to be calculated plus the capacity parameters is not greater than the wholesale capacity, the grid-connectable capacity of the busbar to be calculated is used as the busbar to be calculated and (G) when it is determined that the sum of the grid-connectable capacity of the bus bar to be calculated plus the capacity parameters is greater than the wholesale capacity, the grid-connectable capacity of the bus bar to be calculated An adjustment value is subtracted from the grid-connected capacity, and the grid-connectable capacity minus the adjustment value is used as the result of the grid-connectable capacity of the bus to be calculated. The feeder grid-connectable capacity calculation method as described in claim 1, after step (D), also includes the following steps: (H) when it is determined that the maximum voltage change rate is not within the preset interval, adjust the to-be-calculated The grid-connectable capacity of the busbar; (1) according to the parameters of the group of transformers, the parameters of the wires, the parameters of the feeder, the maximum load, the parameters of the capacity and the adjusted grid-connectable capacity of the busbar to be calculated Network capacity, using the load flow analysis to obtain another voltage change rate corresponding to each bus bar; (J) determine whether another maximum voltage change rate among the other voltage change rates of all bus bars is within the preset interval; (K) When it is determined that the other maximum voltage variation rate is within the preset interval, proceed to steps (E)-(G). The feeder grid-connectable capacity calculation method as described in claim 2, after step (J), also includes the following steps: (L) When it is determined that the other maximum voltage change rate is not within the preset interval, determine whether the grid-connectable capacity of the busbar to be calculated obtained after performing step (H) this time is the same as that of the previous two The grid-connectable capacity of the busbar to be calculated obtained after performing step (H); (M) when it is determined that the grid-connectable capacity obtained after performing step (H) this time is the same as the previous two execution steps For the grid-connectable capacity obtained after (H), specify the grid-connectable capacity of the busbar to be calculated as the grid-connectable capacity obtained after performing step (H) this time, the previous time, and the previous two times Among all the maximum voltage fluctuation rates obtained from the grid capacity, the grid-connectable capacity corresponding to the maximum voltage fluctuation rate less than a first preset percentage is carried out, and steps (E)~(G) are performed; and (N) when it is determined that this When the grid-connectable capacity obtained after performing step (H) for the second time is different from the grid-connectable capacity obtained after performing step (H) twice before, perform steps (H)~(L). The feeder grid-connectable capacity calculation method as described in claim 2, step (H) includes the following sub-steps: (H-1) When it is determined that the maximum voltage variation rate is not within the preset interval, determine the maximum voltage Whether the change rate is greater than a second preset percentage; (H-2) When it is determined that the maximum voltage change rate is greater than the second preset percentage, the grid-connectable capacity of the bus to be calculated is subtracted by a first correction value; and (H-3) When it is determined that the maximum voltage variation rate is not greater than the second preset percentage, adding a second correction value to the grid-connectable capacity of the bus to be calculated. The method for calculating feeder grid-connectable capacity according to claim 4, wherein, in step (H-2), the first correction value is divided by two for the grid-connectable capacity of the busbar to be calculated. The feeder grid-connectable capacity calculation method as described in claim 4, wherein, in step (H-3), the second correction value is divided by subtracting the grid-connectable capacity of the busbar to be calculated from the difference Take two. The feeder grid-connectable capacity calculation method according to claim 4, wherein, in step (G), the adjustment value is the second correction value added in step (H-3). The feeder grid-connectable capacity calculation method as described in claim 1, after step (A), also includes the following steps: (O) when it is determined that the difference is not greater than zero, a grid-connectable capacity of each busbar The grid capacity is set to zero as a result of the interconnectable capacity of each busbar. The feeder grid-connectable capacity calculation method as described in claim item 1, after step (F), further includes the following steps: (P) for one of the busbars that has not obtained the result of grid-connectable capacity among the busbars As another busbar to be calculated, and repeat steps (B)~(F).

Images