Method for transforming alternating current loop into direct current operation loop

Abstract

The invention provides a method for transforming an alternating-current loop into a direct-current operation loop. The method comprises the following steps: acquiring an original alternating-current loop; determining an AC-to-DC AC loop according to the tower head type of the original AC loop; determining section positions of the main direct current pole and the splicing pole according to lead characteristics of the whole alternating current loop, and selecting an adjacent strain tower as a splicing point; and according to the tower type of the splicing point, selecting a splicing mode of a wire in an alternating current loop, and taking the loop spliced according to the splicing mode as a direct current operation loop. According to the invention, the electric energy transmission loss caused by transforming an alternating current loop into direct current operation is greatly reduced, and the energy utilization efficiency is improved; through reasonable design of polar lead arrangement and parallel splicing, effective and uniform reduction of polar lead direct-current resistance is realized, reasonable utilization of resources is realized, waste is avoided, alternating-current circulation loss generated by parallel splicing is avoided, and economical efficiency and operation stability of a power system are remarkably improved while energy is saved.

Description

Technical Field

[0001] The invention relates to the technical field of direct current power transmission, and in particular to a method for transforming an alternating current circuit into a direct current operating circuit. Background Art

[0002] The conversion of AC circuits to DC operating circuits has shown significant advantages in the development of smart grids. The conversion of AC to DC fully utilizes the resources of existing transmission corridors and reduces construction costs. In areas where the contradiction between power supply and demand is prominent, the conversion of AC to DC effectively taps the transmission potential and ensures the stability of power supply. After the conversion of AC to DC, the skin effect and capacitor charging current of AC are eliminated, which greatly reduces the power transmission loss and improves energy utilization efficiency. At the same time, the DC transmission system, with its unique flexibility and reliability, does not rely on the synchronous operation of the AC system, allowing the power grid to respond more quickly and accurately to load fluctuations and the demand for new energy access, providing strong support for building a more intelligent and flexible power grid system.

[0003] It is worth noting that when the double-circuit AC circuit on the same tower is transformed into a DC circuit, it is an efficient way to utilize resources by flexibly combining it into three DC circuits and splicing every three phases to form the positive and negative poles of the DC circuit. This strategy not only maximizes the use of the original wire resources, but also significantly improves the transmission capacity through the high efficiency characteristics of DC transmission. In contrast, when only one of the double circuits on the same tower is converted to DC, while the other remains in AC operation, or when a single AC circuit is directly converted to DC, a significant problem may be that one of the phases of the conductor is idle because it is no longer involved in transmission. This is undoubtedly a waste of existing resources, especially after the circuit is converted to DC, its current density and utilization hours increase significantly. Making full use of these idle conductors to reduce line losses is of immeasurable value for improving overall transmission efficiency and economy. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for transforming an AC circuit into a DC operating circuit, which achieves rational utilization of resources and avoids waste by reasonably designing the arrangement and parallel splicing of polar conductors.

[0005] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0006] In one aspect, the present invention provides a method for transforming an AC circuit into a DC operating circuit, comprising:

[0007] Get the original AC loop;

[0008] Determine the AC circuit for converting AC to DC according to the tower head type of the original AC circuit;

[0009] According to the conductor characteristics of the entire AC circuit, the section positions of the main DC pole and the splicing pole are determined, and the adjacent tension tower is selected as the splicing point;

[0010] According to the tower type of the splicing point, a splicing method of the conductors in the AC circuit is selected, and the circuit spliced ​​according to the splicing method is used as a DC operating circuit.

[0011] Optionally, the original AC circuit is an original single-circuit AC circuit or an original double-circuit AC circuit;

[0012] The original single-circuit AC circuit includes a first middle-phase conductor and two side-phase conductors;

[0013] The original double-circuit AC circuit includes two AC circuits, and both AC circuits include an upper phase conductor, a second middle phase conductor and a lower phase conductor.

[0014] When the original AC circuit is the original single-circuit AC circuit, the two side phase conductors are used as the positive and negative poles of the main DC pole, and the first middle phase conductor is used as the splicing pole;

[0015] When the original AC circuit is the original double-circuit AC circuit, the upper phase conductor and the phase conductor in one of the AC circuits are used as the positive and negative poles of the main DC pole, or the upper phase conductor and the lower phase conductor in the AC circuit are used as the negative and positive poles of the main DC pole, and the second middle phase conductor in the AC circuit is used as the splicing pole; the other AC circuit maintains the original AC circuit.

[0016] Optionally, when the conductor characteristics of the entire AC loop are the same, the tension towers within a preset range of one-half of the AC loop are used as splicing points to form two splicing sections of similar length.

[0017] Optionally, when the conductor characteristics of the entire AC circuit are different, the DC resistance of the AC circuit is calculated;

[0018] According to the distribution principle of DC resistance balance, the segment positions of the main DC pole and the splicing pole are determined, and the tension towers within a preset range from the splicing pole segment position are used as splicing points to form two splicing segments with similar lengths.

[0019] Optionally, for the tension tower at the boundary of the splicing point, disconnect the phase jump conductor of the spliced ​​pole, splice the two ends of one splicing section in parallel with the positive pole or the negative pole through the phase jump conductor, and splice the two ends of the other splicing section in parallel with the negative pole or the positive pole through the phase jump conductor.

[0020] Optionally, also include:

[0021] When one of the original double-circuit AC circuits is converted from AC to DC, the induced voltage of the other AC circuit on the DC circuit and the AC circulating current loss caused by the DC splicing are calculated;

[0022] When the AC circulation loss exceeds a preset threshold, the AC circuit of the spliced ​​section of another AC circuit is completely cyclically transposed; otherwise, the original AC circuit is maintained.

[0023] Optionally, the conductor characteristics of the entire AC circuit include the number of conductor splits and the conductor model.

[0024] In a second aspect, the present invention provides a computer system, comprising:

[0025] Memory, for storing computer instructions;

[0026] The processor is used to execute the computer instructions to implement the steps of the method for converting an AC circuit into a DC operating circuit as described in the first aspect.

[0027] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for converting an AC circuit to a DC operating circuit as described in the first aspect.

[0028] Beneficial Effects

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention greatly reduces the power transmission loss when the AC circuit is transformed into a DC operating circuit, and improves the energy utilization efficiency; through the reasonable design of the pole conductor arrangement and parallel splicing, the DC resistance of the pole conductor is effectively and evenly reduced, the rational utilization of resources is achieved, and waste is avoided; at the same time, through the reasonable transposition of the AC circuit on the same tower, the AC circulating current loss caused by parallel splicing is avoided, which significantly improves the economy and operation stability of the power system while saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The figure is a schematic flow chart of a method for converting an AC circuit into a DC operating circuit in one embodiment of the present invention;

[0032] Figure 2 The figure shows a schematic diagram of the polar conductors for converting a single-circuit AC circuit into a DC operating circuit according to the present invention;

[0033] Figure 3 The figure shows a schematic diagram of a phase jump conductor for converting a single-circuit AC circuit into a DC operating circuit according to the present invention;

[0034] Figure 4 The figure shows a schematic diagram of the pole conductors of the double-circuit AC circuit converted into a DC operating circuit of the present invention;

[0035] Figure 5 Shown is a schematic diagram of the phase jump conductor for converting a double-circuit AC circuit into a DC operating circuit according to the present invention. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. The embodiments of the present invention and the technical features in the embodiments may be combined with each other unless there is a conflict.

[0037] The term "and / or" is only a description of the association relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " generally indicates that the related objects are in an "or" relationship.

[0038] Example 1

[0039] like Figure 1 As shown, this embodiment introduces a method for transforming an AC circuit into a DC operating circuit, which specifically includes the following steps:

[0040] Step 1: Obtain the original AC circuit;

[0041] The original AC circuit is an original single-circuit AC circuit or an original double-circuit AC circuit. In this embodiment, the original double-circuit AC circuit can be a double-circuit AC circuit on the same tower;

[0042] The original single-circuit AC circuit includes a first middle-phase conductor and two side-phase conductors;

[0043] The original double-circuit AC circuit includes two AC circuits, and both AC circuits include an upper phase conductor, a second middle phase conductor and a lower phase conductor.

[0044] Step 2: Determine the AC circuit for converting AC to DC according to the tower head type of the original AC circuit;

[0045] In a specific embodiment, Figure 2 As shown, for a single-circuit AC circuit, from the perspective of facilitating pole conductor overlap and meeting electrical safety distance requirements, the two side phase conductors are determined as the positive and negative poles of the main DC pole, and the first middle phase conductor is used as the segmented splicing pole.

[0046] In another specific embodiment, Figure 4As shown, for a double-circuit AC circuit, from the perspective of facilitating the overlapping of pole conductors and meeting the requirements of electrical safety distance, the upper phase conductor and the lower phase conductor in one of the AC circuits are used as the positive and negative poles of the main DC pole, or the upper phase conductor and the lower phase conductor in the AC circuit are used as the negative and positive poles of the main DC pole, and the second middle phase conductor in the AC circuit is used as a segmented splicing pole; the other AC circuit maintains the original AC operation and does not participate in the transformation of the AC circuit.

[0047] Step 3: Determine the section positions of the main DC pole and the splicing pole according to the conductor characteristics of the entire AC circuit, and select the adjacent tension tower as the splicing point to form two splicing sections;

[0048] The conductor characteristics of the entire AC circuit include the number of conductor splits and the conductor model.

[0049] like Figure 2 and Figure 4 As shown, when the conductor characteristics such as the number of conductor splits and conductor model of the entire AC circuit are the same, the tension tower within a preset range of one-half of the position of the AC circuit is used as a splicing point to form two splicing sections of similar length.

[0050] When the conductor characteristics such as the number of conductor splits and the conductor model of the entire AC circuit are different, calculating the DC resistance of the AC circuit;

[0051] According to the distribution principle of DC resistance balance, the segment positions of the main DC pole and the splicing pole are determined, and the tension towers within a preset range from the splicing pole segment position are used as splicing points to form two splicing sections with similar lengths.

[0052] Step 4: Select a splicing method for the conductors in the AC circuit according to the tower type of the splicing point, and use the circuit spliced ​​according to the splicing method as a DC operating circuit.

[0053] like Figure 3 and Figure 5 As shown, for the tension tower at the boundary of the splicing point, disconnect the phase jump conductor of the spliced ​​pole, splice the two ends of one splicing section in parallel with the positive pole or the negative pole through the phase jump conductor, and splice the two ends of the other splicing section in parallel with the negative pole or the positive pole through the phase jump conductor.

[0054] In a specific embodiment, Figure 3 As shown, for the tension tower at the boundary of the splicing point, it is necessary to disconnect the phase jump conductor of the first phase conductor of the original AC circuit, and splice the two sides of one splicing section of the first phase conductor in parallel with the "+" pole of the side phase through the phase jump conductor, and at the same time, splice the two sides of the other splicing section of the first phase conductor in parallel with the "-" pole of the side phase through the phase jump conductor.

[0055] In another specific embodiment, Figure 5 As shown, for the tension tower at the boundary of the splicing point, it is necessary to disconnect the phase jumper conductor of the second phase conductor of the original AC circuit on the AC-to-DC circuit side, and splice the two sides of one splicing section of the second phase conductor of the original AC circuit on the AC-to-DC circuit side in parallel with the "+ / -" of the upper phase conductor through the phase jumper conductor, and at the same time, splice the two sides of the other splicing section of the second phase conductor of the original AC circuit on the AC-to-DC circuit side in parallel with the "- / +" of the lower phase conductor through the phase jumper conductor.

[0056] like Figure 4 As shown, for the conversion of the first AC circuit into DC in the double-circuit AC circuit on the same tower, it is necessary to calculate the induced voltage of the second AC circuit on the DC circuit and the AC circulating current loss caused by the DC splicing. If the shared tower distance is long, resulting in excessive AC circulating current loss, affecting the safe and stable operation of the DC system, it is necessary to take full-cycle transposition measures for the two spliced ​​sections of the second AC circuit to eliminate the influence of AC induction.

[0057] In this embodiment, when the original AC circuit is a double-circuit AC circuit on the same tower, only one of the circuits is converted from an AC circuit to a DC operation circuit, and the other AC circuit maintains the original AC operation.

[0058] According to the voltage level, electromagnetic environment requirements and lightning protection performance after the transformation, electrical performance tests and mechanical performance safety assessments are carried out to ensure that the circuit system after the transformation meets all performance requirements.

[0059] Assume that the DC current in the electrode conductor is , the DC resistance per unit length of the split conductor 20 degrees before splicing is , the temperature resistance coefficient is Under the operating conditions, the wire temperatures before and after the wires are spliced ​​in the AC circuit are , ,here , then the resistance losses before and after the wires are spliced ​​in the AC circuit are , , the formula is:

[0060] ;

[0061] .

[0062] In the formula, After splicing, the resistance loss can be reduced to less than 75% of the original circuit resistance loss.

[0063] The method provided in this embodiment is particularly suitable for the conversion of AC to DC in high-voltage and ultra-high-voltage circuits, especially for the AC-to-DC circuit in which the path of the DC system with symmetrical single-pole connection is long, the circuit voltage drop is large, and the power loss is serious. For the conversion of a single AC circuit to DC in a double-circuit AC circuit, it is necessary to take measures to replace the entire AC circuit in the splicing section to eliminate the influence of AC induction.

[0064] The present invention realizes the rational utilization of existing resources, effectively reduces power loss, lowers operating costs, and is simple to implement and highly reliable by reasonably utilizing the spliced ​​poles. It is suitable for the splicing of remaining phase conductors after AC-DC conversion at various voltage levels.

[0065] Example 2

[0066] This embodiment introduces a computer system, including:

[0067] Memory, for storing computer instructions;

[0068] The processor is used to execute the computer instructions to implement the steps of the method for converting an AC circuit into a DC operating circuit as described in Example 1.

[0069] Example 3

[0070] This embodiment introduces a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for converting an AC circuit to a DC operating circuit described in Embodiment 1 are implemented.

[0071] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0072] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0073] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0074] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0075] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A method for transforming an AC circuit into a DC operating circuit, characterized in that: include: Get the original AC loop; Determine the AC circuit for converting AC to DC according to the tower head type of the original AC circuit; According to the conductor characteristics of the entire AC circuit, the section positions of the main DC pole and the splicing pole are determined, and the adjacent tension tower is selected as the splicing point; According to the tower type of the splicing point, a splicing method of the conductors in the AC circuit is selected, and the circuit spliced ​​according to the splicing method is used as a DC operating circuit.

2. The method for transforming an AC circuit into a DC operating circuit according to claim 1, characterized in that: The original AC circuit is an original single-circuit AC circuit or an original double-circuit AC circuit; The original single-circuit AC circuit includes a first middle-phase conductor and two side-phase conductors; The original double-circuit AC circuit includes two AC circuits, and both AC circuits include an upper phase conductor, a second middle phase conductor and a lower phase conductor.

3. The method for transforming an AC circuit into a DC operating circuit according to claim 2, characterized in that: When the original AC circuit is the original single-circuit AC circuit, the two side phase conductors are used as the positive and negative poles of the main DC pole, and the first middle phase conductor is used as the splicing pole; When the original AC circuit is the original double-circuit AC circuit, the upper phase conductor and the lower phase conductor in one of the AC circuits are used as the positive and negative poles of the main DC pole, or the upper phase conductor and the lower phase conductor in the AC circuit are used as the negative and positive poles of the main DC pole, and the second middle phase conductor in the AC circuit is used as the splicing pole; the other AC circuit maintains the original AC circuit.

4. The method for transforming an AC circuit into a DC operating circuit according to claim 1, characterized in that: When the conductor characteristics of the entire AC loop are the same, the tension towers within a preset range of one-half of the AC loop are used as splicing points to form two splicing sections of similar length.

5. The method for transforming an AC circuit into a DC operating circuit according to claim 1, characterized in that: When the conductor characteristics of the entire AC circuit are different, calculating the DC resistance of the AC circuit; According to the distribution principle of DC resistance balance, the segment positions of the main DC pole and the splicing pole are determined, and the tension towers within a preset range from the splicing pole segment position are used as splicing points to form two splicing sections with similar lengths.

6. The method for transforming an AC circuit into a DC operating circuit according to claim 4 or 5, characterized in that: For the tension tower at the boundary of the splicing point, disconnect the phase jump conductor of the spliced ​​pole, splice the two ends of one splicing section in parallel with the positive or negative pole through the phase jump conductor, and splice the two ends of the other splicing section in parallel with the negative or positive pole through the phase jump conductor.

7. The method for transforming an AC circuit into a DC operating circuit according to claim 2, characterized in that: Also includes: When one of the original double-circuit AC circuits is converted from AC to DC, the induced voltage of the other AC circuit on the DC circuit and the AC circulating current loss caused by the DC splicing are calculated; When the AC circulation loss exceeds a preset threshold, the AC circuit of the spliced ​​section of another AC circuit is completely cyclically transposed; otherwise, the original AC circuit is maintained.

8. The method for transforming an AC circuit into a DC operating circuit according to claim 1, characterized in that: The conductor characteristics of the entire AC circuit include the number of conductor splits and the conductor model.

9. A computer system, characterized in that: include: Memory, for storing computer instructions; A processor is used to execute the computer instructions to implement the steps of the method for converting an AC circuit into a DC operating circuit as described in any one of claims 1-8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for converting an AC circuit into a DC operating circuit according to any one of claims 1 to 8 are implemented.

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