A power evacuation method and device for maximizing the transmission capacity of a flexible DC power grid

Abstract

An embodiment of the present invention discloses a power evacuation method and device for maximizing the power transmission capacity of a flexible DC power grid. The method collects the power of the sending-end converter station in the normal operating state, and then when a DC monopole blocking fault occurs at any sending-end converter station, compares the maximum transmission power PR1 of the bipolar DC line with the maximum exchange power PR2 between the bipolar converter station and the AC system, and formulates different power distribution strategies according to the size relationship between the two to evacuate power between the sending-end converter stations. By transferring the power of the sending-end converter station where the monopole fault occurs from the faulty pole to the healthy pole through inter-pole transfer, and transferring it between the faulty pole stations to the sending-end converter station operating normally, the flexible DC power grid system is in a critical operating state, thus ensuring that the flexible DC power grid system has the maximum power transmission capacity when a monopole fault occurs, and fully ensuring the efficiency and stability of the power transmission of the flexible DC system.

Description

Technical Field

[0001] The present invention relates to the technical field of UHV power transmission, and in particular to a power evacuation method and device for maximizing the transmission capacity of a flexible DC power grid, as well as a storage medium and an electronic device. Background Art

[0002] With the vigorous development of DC systems, more and more flexible DC system projects have been put into operation, and a DC power grid has gradually taken shape. However, the calculation method for the transmission capacity of a cross-section in a DC power grid is not clear. In the prior art, the transmission capacity of an AC power grid cross-section is mainly determined by the static stability, transient stability, and dynamic stability of the AC system. Due to its own characteristics, the DC power grid system does not have problems such as voltage, power angle, and frequency stability, so the transmission capacity of the cross-section cannot be determined by the security and stability of the system. However, the transmission capacity of DC is restricted by problems such as DC monopole blocking and equipment overload after a DC monopole line short-circuit fault. Therefore, to ensure the long-term safe and stable operation of the power system, there is an urgent need to provide a power evacuation method that can optimize the transmission capacity of the DC power grid system when a monopole blocking fault occurs in the sending-end converter of the DC power grid system, so as to ensure the efficient and stable operation of the DC power grid system. Summary of the Invention

[0003] To solve the technical problem in the prior art that there is a lack of a power evacuation method for maximizing the transmission capacity of a DC power grid system when a monopole blocking fault occurs in the sending-end converter of the DC power grid system, the present invention is proposed. Embodiments of the present invention provide a power evacuation method and device for maximizing the transmission capacity of a flexible DC power grid, as well as a storage medium and an electronic device.

[0004] According to one aspect of an embodiment of the present invention, a power evacuation method for maximizing the transmission capacity of a flexible DC power grid is provided. The flexible DC power grid includes two sending-end bipolar converters VSC1 and VSC2, and two receiving-end bipolar converters VSC3 and VSC4. Among them, VSC1 and VSC4 are connected by a bipolar DC line L1, VSC1 and VSC2 are connected by a bipolar DC line L2, VSC2 and VSC3 are connected by a bipolar DC line L3, and VSC3 and VSC4 are connected by a bipolar DC line L4. The method includes:

[0005] Collect the powers P1 and P2 of VSC1 and VSC2 in the working state;

[0006] When any one of VSC1 and VSC2 has a DC monopole blocking, compare the pre-set power PR1 and power PR2, where the power PR1 is the maximum transmission power of the bipolar DC line limited by the current-carrying capacity of the DC circuit breaker, and the power PR2 is the maximum exchange power between the bipolar converter station and the AC system limited by the long-term current-carrying capacity of the converter.

[0007] When PR2 ≤ PR1, based on powers P1 and P2, a first power distribution strategy is adopted to evacuate power between VSC1 and VSC2;

[0008] When PR1 < PR2 ≤ 2PR1, based on powers P1 and P2, a second power distribution strategy is adopted to evacuate power between VSC1 and VSC2;

[0009] When PR2 > 2PR1, based on powers P1 and P2, a third power distribution strategy is adopted to evacuate power between VSC1 and VSC2.

[0010] Optionally, in each of the above method embodiments of the present invention, when PR2 ≤ PR1, based on powers P1 and P2, adopting a first power distribution strategy to evacuate power between VSC1 and VSC2 includes:

[0011] When PR2 ≤ PR1, based on powers P1 and P2, adopting a first power distribution strategy to evacuate power between VSC1 and VSC2 includes:

[0012] When a DC monopole blocking fault occurs in VSCi, VSCi transfers power from the faulty pole to the healthy pole through pole - to - pole transfer; to the healthy pole;

[0013] VSCi transfers power PR2 - Pj from the faulty pole to VSCj through inter - station transfer on the faulty pole;

[0014] VSCj transfers power from the faulty pole through pole - to - pole transfer to the healthy pole;

[0015] wherein, when i = 1, j = 2, and when i = 2, j = 1.

[0016] Optionally, in each of the above method embodiments of the present invention, when PR1 < PR2 ≤ 2PR1, based on powers P1 and P2, adopting a second power distribution strategy to evacuate power between VSC1 and VSC2 includes:

[0017] When a DC monopole blocking fault occurs in VSCi, VSCi transfers power from the faulty pole to the healthy pole through pole - to - pole transfer to the healthy pole;

[0018] VSCi transfers power PR1 - Pj from the faulty pole to VSCj through inter - station transfer on the faulty pole;

[0019] VSCj transfers power from the faulty pole through pole - to - pole transfer to the healthy pole;

[0020] wherein, when i = 1, j = 2, and when i = 2, j = 1.

[0021] Optionally, in each of the above method embodiments of the present invention, when PR2 > 2PR1, based on the powers P1 and P2, the power evacuation between VSC1 and VSC2 using the second power distribution strategy includes:

[0022] When a DC monopole blocking fault occurs in VSCi, VSCi transmits power from the faulty pole to the healthy pole through pole - to - pole transfer, where i is equal to 1 or 2. to the healthy pole, where i is equal to 1 or 2.

[0023] According to another aspect of the embodiments of the present invention, there is provided a power evacuation device for maximizing the power transmission capacity of a flexible DC grid. The flexible DC grid includes two sending - end bipolar converter stations VSC1 and VSC2, and two receiving - end bipolar converter stations VSC3 and VSC4. Among them, VSC1 and VSC4 are connected by a bipolar DC line L1, VSC1 and VSC2 are connected by a bipolar DC line L2, VSC2 and VSC3 are connected by a bipolar DC line L3, and VSC3 and VSC4 are connected by a bipolar DC line L4. The device includes:

[0024] A data acquisition unit for acquiring the powers P1 and P2 of VSC1 and VSC2 in the working state;

[0025] A data comparison unit for comparing a preset power PR1 and a power PR2 when any one of VSC1 and VSC2 has a DC monopole block. Among them, the power PR1 is the maximum transmission power of the bipolar DC line limited by the current - carrying capacity of the DC breaker, and the power PR2 is the maximum exchange power between the bipolar converter station and the AC system limited by the long - term current - passing capacity of the converter;

[0026] A first distribution unit for, when PR2 ≤ PR1, evacuating power between VSC1 and VSC2 based on the powers P1 and P2 using a first power distribution strategy;

[0027] A second distribution unit for, when PR1 < PR2 ≤ 2PR1, evacuating power between VSC1 and VSC2 based on the powers P1 and P2 using a second power distribution strategy;

[0028] A third distribution unit for, when PR2 > 2PR1, evacuating power between VSC1 and VSC2 based on the powers P1 and P2 using a third power distribution strategy.

[0029] Optionally, in each of the above device embodiments of the present invention, the first distribution unit evacuating power between VSC1 and VSC2 based on the powers P1 and P2 using a first power distribution strategy when PR2 ≤ PR1 includes:

[0030] When a DC monopole blocking fault occurs in VSCi, VSCi transmits power from the faulty pole to the healthy pole through inter-pole transfer. To the healthy pole;

[0031] VSCi transmits the power PR2 - Pj from the faulty pole to VSCj through inter-station transfer on the faulty pole;

[0032] VSCj transmits power from the faulty pole to the healthy pole through inter-pole transfer To the healthy pole;

[0033] Wherein, when i = 1, j = 2, and when i = 2, j = 1.

[0034] Optionally, in each of the above device embodiments of the present invention, when PR1 < PR2 ≤ 2PR1, the second distribution unit performs power evacuation between VSC1 and VSC2 based on the powers P1 and P2 and adopts a second power distribution strategy, including:

[0035] When a DC monopole blocking fault occurs in VSCi, VSCi transmits power from the faulty pole to the healthy pole through inter-pole transfer To the healthy pole;

[0036] VSCi transmits the power PR1 - Pj from the faulty pole to VSCj through inter-station transfer on the faulty pole;

[0037] VSCj transmits power from the faulty pole to the healthy pole through inter-pole transfer To the healthy pole;

[0038] Wherein, when i = 1, j = 2, and when i = 2, j = 1.

[0039] Optionally, in each of the above device embodiments of the present invention, when PR2 > 2PR1, the third distribution unit performs power evacuation between VSC1 and VSC2 based on the powers P1 and P2 and adopts a second power distribution strategy, including:

[0040] When a DC monopole blocking fault occurs in VSCi, VSCi transmits 1 / 2 Pi of the power from the faulty pole to the healthy pole, where i is equal to 1 or 2.

[0041] According to another aspect of the embodiments of the present invention, there is provided a computer-readable storage medium storing a computer program for executing the method described in any one of the above embodiments of the present invention.

[0042] According to another aspect of the embodiments of the present invention, there is provided an electronic device, characterized in that the electronic device includes:

[0043] A processor;

[0044] A memory for storing the executable instructions of the processor;

[0045] The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method according to any one of the above embodiments of the present invention.

[0046] Based on the power evacuation method and device for maximizing the transmission capacity of a flexible DC power grid, as well as the storage medium and electronic device provided by the above embodiments of the present invention, the power of the sending converter station in the normal operating state is collected. Then, when a DC monopole blocking fault occurs at any one of the sending converter stations, the maximum transmission power PR1 of the bipolar DC line limited by the current-carrying capacity of the DC circuit breaker is compared with the maximum exchange power PR2 between the bipolar converter station and the AC system limited by the long-term current-carrying capacity of the converter, and different power distribution strategies formulated in combination with the power of the sending converter in the normal operating state are used to evacuate power among the sending converter stations. By transferring the power of the sending converter station where the monopole fault occurs from the faulty pole to the healthy pole through inter-pole transfer, and transferring it to the normally operating sending converter station through inter-station transfer of the faulty pole, the flexible DC power grid system is in a critical operating state, thereby ensuring that the flexible DC power grid system still has the maximum transmission capacity when a monopole fault occurs, and fully ensuring the efficiency and stability of the flexible DC system transmission.

[0047] The technical solution of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0048] By describing the embodiments of the present invention in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present invention will become more apparent. The drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings, the same reference numerals generally represent the same components or steps.

[0049] Figure 1 is a flowchart of the power evacuation method for maximizing the transmission capacity of a flexible DC power grid provided by an exemplary embodiment of the present invention;

[0050] Figure 2 is a schematic diagram of the structure of a flexible DC power grid provided by an exemplary embodiment of the present invention;

[0051] Figure 3 is a schematic diagram of the structure of the power evacuation device for maximizing the transmission capacity of a flexible DC power grid provided by an exemplary embodiment of the present invention.

[0052] Figure 4 is the structure of an electronic device provided by an exemplary embodiment of the present invention. Detailed Embodiments

[0053] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments of the present invention. It should be understood that the present invention is not limited by the exemplary embodiments described herein.

[0054] It should be noted that: Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention.

[0055] Those skilled in the art can understand that terms such as "first" and "second" in the embodiments of the present invention are only used to distinguish different steps, devices, or modules, etc., and neither represent any specific technical meaning nor indicate an inevitable logical order between them.

[0056] It should also be understood that in the embodiments of the present invention, "a plurality of" may refer to two or more, and "at least one" may refer to one, two, or more.

[0057] It should also be understood that for any component, data, or structure mentioned in the embodiments of the present invention, in the absence of a clear limitation or a contrary indication in the context, it can generally be understood as one or more.

[0058] In addition, the term "and / or" in the present invention is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally represents an "or" relationship between the associated objects before and after.

[0059] It should also be understood that the present invention emphasizes the differences between the various embodiments. The same or similar parts can be referred to each other. For the sake of brevity, they will not be described one by one.

[0060] At the same time, it should be understood that for the sake of description, the dimensions of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0061] The following description of at least one exemplary embodiment is actually only illustrative and in no way restricts the present invention and its application or use.

[0062] Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the specification.

[0063] It should be noted that like reference numerals and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

[0064] Embodiments of the present invention can be applied to electronic devices such as terminal devices, computer systems, servers, etc., which can operate together with many other general-purpose or special-purpose computing system environments or configurations. Examples of well-known terminal devices, computing systems, environments, and / or configurations suitable for use with electronic devices such as terminal devices, computer systems, servers, etc. include, but are not limited to: personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network personal computers, small computer systems, large computer systems, and distributed cloud computing technology environments including any of the above systems, and so on.

[0065] Electronic devices such as terminal devices, computer systems, servers, etc. can be described in the general context of computer system-executable instructions (such as program modules) executed by a computer system. Generally, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. The computer system / server can be implemented in a distributed cloud computing environment where tasks are executed by remote processing devices linked through a communication network. In a distributed cloud computing environment, program modules can be located on local or remote computing system storage media including storage devices.

[0066] Exemplary method

[0067] Figure 1 is a schematic flowchart of a power evacuation method for maximizing the transmission capacity of a flexible DC grid provided by an exemplary embodiment of the present invention. Figure 2 is a schematic diagram of the structure of a flexible DC grid provided by an exemplary embodiment of the present invention. As Figure 2 shown, the flexible DC grid described in this preferred embodiment includes two sending-end bipolar converters VSC1 and VSC2, and two receiving-end bipolar converters VSC3 and VSC4. Among them, VSC1 and VSC4 are connected by a bipolar DC line L1, VSC1 and VSC2 are connected by a bipolar DC line L2, VSC2 and VSC3 are connected by a bipolar DC line L3, and VSC3 and VSC4 are connected by a bipolar DC line L4. This embodiment can be applied to electronic devices. As Figure 1 shown, the method includes the following steps:

[0068] Step 101, collect the powers P1 and P2 of VSC1 and VSC2 in the working state.

[0069] Step 102: When any one of VSC1 and VSC2 experiences a DC monopole block, compare the pre-set power PR1 and power PR2. Among them, power PR1 is the maximum transmission power of the bipolar DC line limited by the current-carrying capacity of the DC breaker, and power PR2 is the maximum exchange power between the bipolar converter station and the AC system limited by the long-term current-carrying capacity of the converter.

[0070] Step 103: When PR2 ≤ PR1, based on power P1 and P2, adopt the first power distribution strategy to evacuate power between VSC1 and VSC2.

[0071] Optionally, when PR2 ≤ PR1, evacuating power between VSC1 and VSC2 based on power P1 and P2 includes:

[0072] When VSCi experiences a DC monopole block fault, VSCi transfers power from the faulty pole to the healthy pole through inter-pole transfer. to the healthy pole;

[0073] VSCi transfers power PR2 - Pj from the faulty pole to VSCj through inter-station transfer at the faulty pole;

[0074] VSCj transfers power from the faulty pole to the healthy pole through inter-pole transfer. to the healthy pole;

[0075] Among them, when i = 1, j = 2, and when i = 2, j = 1.

[0076] When PR2 ≤ PR1, the maximum power transmission capacity of the flexible DC grid system is mainly restricted by power PR2. In an embodiment, assume that VSC1 experiences a monopole block fault, then i = 1, j = 2, and VSC1 transfers power to the healthy pole through inter-pole transfer; VSC1 transfers PR2 - P2 power to VSC2 through inter-station transfer at the faulty pole; VSC2 transfers power to the healthy pole through inter-pole transfer. At this time, VSC1 inputs power to the DC grid system. VSC2 inputs power PR2 to the DC grid system, VSC3 outputs power from the DC grid system. VSC4 outputs power PR2 from the DC grid system; The transmission power of PL1 is The transmission power of PL2 is PR2 - P2, the transmission power of PL3 is PR2, and the transmission power of PL4 is 0. At this time, the flexible DC grid system reaches the critical operating state, and the power transmission capacity is the largest, and its value is

[0077] Step 104, when PR1 < PR2 ≤ 2PR1, based on powers P1 and P2, perform power evacuation between VSC1 and VSC2 using the second power distribution strategy.

[0078] Optionally, when PR1 < PR2 ≤ 2PR1, performing power evacuation between VSC1 and VSC2 based on powers P1 and P2 using the second power distribution strategy includes:

[0079] When a DC monopole blocking fault occurs in VSCi, VSCi transmits power from the faulty pole to the healthy pole through inter-pole transfer. to the healthy pole;

[0080] VSCi transmits power PR1 - Pj from the faulty pole to VSCj through inter-station transfer between faulty poles;

[0081] VSCj transmits power from the faulty pole to the healthy pole through inter-pole transfer. to the healthy pole;

[0082] where, when i = 1, j = 2, and when i = 2, j = 1.

[0083] When PR1 < PR2 ≤ 2PR1, the maximum power transmission capacity of the flexible DC grid system is mainly restricted by power PR1. In an embodiment, assume that a monopole blocking fault occurs in VSC1, then i = 1, j = 2, and VSC1 transmits power to the healthy pole through inter-pole transfer; VSC1 transmits power PR1 - P2 to VSC2 through inter-station transfer between faulty poles; VSC2 transmits power to the healthy pole through inter-pole transfer. At this time, VSC1 inputs power to the DC grid system VSC2 inputs power PR1 to the DC grid system, VSC3 outputs power from the DC grid system VSC4 outputs power PR1 from the DC grid system; The transmission power of PL1 is The transmission power of PL2 is PR1 - P2, the transmission power of PL3 is PR1, and the transmission power of PL4 is 0. At this time, the flexible DC grid system reaches the critical operating state, and the power transmission capacity is the largest, and its value is

[0084] Step 105, when PR2 > 2PR1, based on powers P1 and P2, perform power evacuation between VSC1 and VSC2 using the third power distribution strategy.

[0085] Optionally, when PR2 > 2PR1, performing power evacuation between VSC1 and VSC2 based on powers P1 and P2 using the second power distribution strategy includes:

[0086] When a DC monopole blocking fault occurs in VSCi, VSCi transmits power from the faulty pole to the healthy pole through inter-pole transfer, where i is equal to 1 or 2. to the healthy pole.

[0087] When PR2 > 2PR1, the maximum power transmission capacity of the flexible DC grid system is still mainly constrained by the power PR1. In one embodiment, under normal operating conditions, P1 < PR1. Assuming that a monopole blocking fault occurs in VSC1, then i = 1 and j = 2. VSC1 transmits power to the healthy pole through inter-pole transfer. At this time, VSC1 inputs power P1 to the DC grid system, VSC2 inputs power P2 to the DC grid system, VSC3 outputs power P3 from the DC grid system, and VSC4 outputs power P4 from the DC grid system; the transmission power of PL1 is P1, the transmission power of PL2 is 0, the transmission power of PL3 is P2, and the transmission power of PL4 is 0, where P3 and P4 are the powers of the receiving converters in the normal operating state. At this time, the flexible DC grid system reaches the critical operating state, and the maximum power transmission capacity is P2 + P1.

[0088] It can be seen from the above embodiments that when a monopole blocking fault occurs in the sending converter of the flexible DC grid system, by considering the maximum transmission power PR1 of the bipolar DC line limited by the current-carrying capacity of the DC circuit breaker and the maximum exchange power PR2 between the bipolar converter station and the AC system limited by the long-term current-carrying capacity of the converter, different power evacuation strategies of the sending converter are distinguished, so as to maximize the power transmission capacity of the flexible DC grid system.

[0089] Exemplary apparatus

[0090] Figure 3 is a schematic structural diagram of a power evacuation device that maximizes the power transmission capacity of a flexible DC grid provided by an exemplary embodiment of the present invention. In this embodiment, the flexible DC grid includes two sending bipolar converter stations VSC1 and VSC2, and two receiving bipolar converter stations VSC3 and VSC4. Among them, VSC1 and VSC4 are connected by a bipolar DC line L1, VSC1 and VSC2 are connected by a bipolar DC line L2, VSC2 and VSC3 are connected by a bipolar DC line L3, and VSC3 and VSC4 are connected by a bipolar DC line L4. As Figure 3 shown, this embodiment includes:

[0091] A data acquisition unit 301 for acquiring the powers P1 and P2 of VSC1 and VSC2 in the working state;

[0092] A data comparison unit 302, configured to compare a preset power PR1 and a power PR2 when any one of VSC1 and VSC2 has a DC monopole block, where the power PR1 is the maximum transmission power of a bipolar DC line limited by the current-carrying capacity of the DC breaker, and the power PR2 is the maximum exchange power between the bipolar converter station and the AC system limited by the long-term current-carrying capacity of the converter;

[0093] A first distribution unit 303, configured to perform power evacuation between VSC1 and VSC2 based on the powers P1 and P2 using a first power distribution strategy when PR2 ≤ PR1;

[0094] A second distribution unit 304, configured to perform power evacuation between VSC1 and VSC2 based on the powers P1 and P2 using a second power distribution strategy when PR1 < PR2 ≤ 2PR1;

[0095] A third distribution unit 305, configured to perform power evacuation between VSC1 and VSC2 based on the powers P1 and P2 using a third power distribution strategy when PR2 > 2PR1.

[0096] Optionally, when PR2 ≤ PR1, the first distribution unit 301 performing power evacuation between VSC1 and VSC2 based on the powers P1 and P2 using a first power distribution strategy includes:

[0097] When VSCi has a DC monopole block fault, VSCi transfers power from the faulty pole to the healthy pole through inter-pole transfer; to the healthy pole;

[0098] VSCi transfers the power PR2 - Pj to VSCj through transfer between stations of the faulty pole;

[0099] VSCj transfers power from the faulty pole to the healthy pole through inter-pole transfer; to the healthy pole;

[0100] where, when i = 1, j = 2, and when i = 2, j = 1.

[0101] Optionally, when PR1 < PR2 ≤ 2PR1, the second distribution unit 304 performing power evacuation between VSC1 and VSC2 based on the powers P1 and P2 using a second power distribution strategy includes:

[0102] When VSCi has a DC monopole block fault, VSCi transfers power from the faulty pole to the healthy pole through inter-pole transfer; to the healthy pole;

[0103] VSCi transfers the power PR1 - Pj to VSCj through transfer between stations of the faulty pole;

[0104] VSCj transfers power from the fault pole through the inter-pole transfer belt To the soundest extreme;

[0105] Among them, when i=1, j=2, and when i=2, j=1.

[0106] Optionally, when PR2>2PR1, the third allocating unit 305 adopts a second power allocation strategy to perform power evacuation between VSC1 and VSC2 based on the powers P1 and P2, including:

[0107] When a DC single-pole blocking fault occurs in VSCi, VSCi transfers power from the faulty pole through the inter-pole transfer belt. To the sound pole, where i is equal to 1 or 2.

[0108] The power evacuation device provided in this embodiment to maximize the transmission capacity of the flexible DC grid collects the power of the sending-end converter in normal operation, and sets the maximum transmission power PR1 of the bipolar DC line limited by the current-carrying capacity of the DC circuit breaker and the maximum exchange power PR2 between the bipolar converter station and the AC system limited by the long-term current carrying capacity of the converter, and distinguishes the steps of the power evacuation strategy of the sending-end converter in different situations. The steps are the same as those taken by the power evacuation method for maximizing the transmission capacity of the flexible DC grid provided in this embodiment, and the technical effects achieved are also the same, which will not be repeated here.

[0109] Exemplary electronic device

[0110] Figure 4 The electronic device provided by an exemplary embodiment of the present invention may be any one or both of the first device and the second device, or a stand-alone device independent of them, and the stand-alone device may communicate with the first device and the second device to receive the collected input signals from them. Figure 4 FIG. 1 is a block diagram of an electronic device according to an embodiment of the present disclosure. Figure 4 As shown, the electronic device includes one or more processors 401 and a memory 402 .

[0111] The processor 401 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0112] The memory 402 may include one or more computer program products, and the computer program products may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory, etc. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage media, and the processor 401 may run the program instructions to implement the method for information mining of historical change records in the software programs of the various disclosed embodiments described above and / or other desired functions. In one example, the electronic device may further include: an input device 403 and an output device 404, and these components are interconnected through a bus system and / or other forms of connection mechanisms (not shown).

[0113] In addition, the input device 403 may further include, for example, a keyboard, a mouse, and the like.

[0114] The output device 404 may output various information to the outside. The output device 404 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, and the like.

[0115] Of course, for simplicity, Figure 4 only some of the components related to the present disclosure in the electronic device are shown, and components such as buses, input / output interfaces, etc. are omitted. In addition, according to specific application scenarios, the electronic device may further include any other appropriate components.

[0116] Exemplary computer program product and computer-readable storage medium

[0117] In addition to the above methods and devices, an embodiment of the present disclosure may also be a computer program product, which includes computer program instructions that, when run by a processor, cause the processor to execute the steps in the power evacuation method for maximizing the transmission capacity of a flexible DC power grid according to various embodiments of the present disclosure described in the "Exemplary Method" section above of this specification.

[0118] The computer program product may be written in any combination of one or more programming languages for programming code to perform the operations of the embodiments of the present disclosure. The programming languages include object-oriented programming languages, such as Java, C++, etc., and also include conventional procedural programming languages, such as the "C" language or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, executed as an independent software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0119] In addition, an embodiment of the present disclosure may also be a computer-readable storage medium having computer program instructions stored thereon, and when the computer program instructions are run by a processor, the processor is caused to execute the steps in the power evacuation method that maximizes the power transmission capacity of a flexible DC power grid according to various embodiments of the present disclosure described in the above "Exemplary Method" section of this specification.

[0120] The computer-readable storage medium may employ any combination of one or more readable media. The readable media may be a readable signal medium or a readable storage medium. The readable storage medium may, for example, include but is not limited to an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (a non-exhaustive list) of the readable storage medium include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0121] The basic principles of the present disclosure have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, benefits, effects, etc. mentioned in the present disclosure are only examples and not limitations, and it cannot be considered that these advantages, benefits, effects, etc. are essential for each embodiment of the present disclosure. In addition, the above-described specific details are only for the purpose of illustration and facilitating understanding, rather than limitations, and the above details do not limit the present disclosure to necessarily implement using the above specific details.

[0122] Each embodiment in this specification is described in a progressive manner, and the key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts between each embodiment, reference may be made to each other. For system embodiments, since they are basically corresponding to method embodiments, the description is relatively simple, and reference may be made to the partial description of the method embodiments for relevant parts.

[0123] The block diagrams of the devices, apparatuses, equipment, and systems involved in the present disclosure are only illustrative examples and do not intend to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open-ended words, meaning "including but not limited to", and can be used interchangeably with each other. The words "or" and "and" used herein refer to the word "and / or" and can be used interchangeably with each other, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to" and can be used interchangeably with each other.

[0124] The methods and apparatuses of the present disclosure can be implemented in many ways. For example, the methods and apparatuses of the present disclosure can be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above order of steps for the methods is for illustration purposes only, and the steps of the methods of the present disclosure are not limited to the specific order described above, unless otherwise specifically stated. In addition, in some embodiments, the present disclosure can also be implemented as a program recorded in a recording medium, and these programs include machine-readable instructions for implementing the methods according to the present disclosure. Therefore, the present disclosure also covers a recording medium storing a program for executing the methods according to the present disclosure.

[0125] It should also be noted that in the apparatuses, devices, and methods of the present disclosure, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent solutions of the present disclosure. The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to these aspects are very obvious to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but to the broadest scope consistent with the principles and novel features disclosed herein.

[0126] The above description has been given for purposes of illustration and description. In addition, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions, and sub-combinations thereof.

Claims

1. A power evacuation method for maximizing the transmission capacity of a flexible DC power grid, the flexible DC power grid including two sending-end bipolar converters VSC1 and VSC2, and two receiving-end bipolar converters VSC3 and VSC4, wherein, VSC1 and VSC4 are connected by a bipolar DC line L1, VSC1 and VSC2 are connected by a bipolar DC line L2, VSC2 and VSC3 are connected by a bipolar DC line L3, and VSC3 and VSC4 are connected by a bipolar DC line L4. The method is characterized in that it includes: Collecting the powers P1 and P2 of VSC1 and VSC2 in the working state; When any one of VSC1 and VSC2 has a DC monopole block, comparing the preset powers PR1 and PR2, wherein the power PR1 is the maximum transmission power of the bipolar DC line limited by the current-carrying capacity of the DC breaker, and the power PR2 is the maximum exchange power between the bipolar converter station and the AC system limited by the long-term current-carrying capacity of the converter; When PR2 ≤ PR1, based on the powers P1 and P2, adopting a first power distribution strategy to evacuate power between VSC1 and VSC2, including: When a DC monopole blocking fault occurs in the VSCi, the VSCi transmits power from the faulty pole to the healthy pole through pole-to-pole transfer ; VSCi transfers the transmission power PR2 - Pj between the faulty pole stations to VSCj; The VSCj transfers power from the faulty pole to the healthy pole through pole-to-pole power transfer to the healthy pole; wherein, when i = 1, j = 2, and when i = 2, j = 1; When PR1 < PR2 ≤ 2PR1, based on the powers P1 and P2, adopting a second power distribution strategy to evacuate power between VSC1 and VSC2, including: When a DC monopole blocking fault occurs in VSCi, VSCi transmits power from the faulty pole to the healthy pole through pole-to-pole transfer ; VSCi transfers the transmission power PR1 - Pj between the faulty pole stations to VSCj; The VSCj transfers power from the faulty pole to the healthy pole through pole-to-pole transfer belt to the healthy pole; wherein, when i = 1, j = 2, and when i = 2, j = 1; When PR2 > 2PR1, based on the powers P1 and P2, adopting a third power distribution strategy to evacuate power between VSC1 and VSC2, including: When a DC monopole blocking fault occurs in VSCi, VSCi transmits power from the faulty pole to the healthy pole through pole - to - pole transfer, where i is equal to 1 or 2. ​ 2. A power evacuation device for maximizing the transmission capacity of a flexible DC power grid, the flexible DC power grid including two sending-end bipolar converters VSC1 and VSC2, and two receiving-end bipolar converters VSC3 and VSC4, wherein, VSC1 and VSC4 are connected by a bipolar DC line L1, VSC1 and VSC2 are connected by a bipolar DC line L2, VSC2 and VSC3 are connected by a bipolar DC line L3, and VSC3 and VSC4 are connected by a bipolar DC line L4. The device is characterized in that it includes: A data acquisition unit for collecting the powers P1 and P2 of VSC1 and VSC2 in the working state; A data comparison unit for comparing the preset powers PR1 and PR2 when any one of VSC1 and VSC2 has a DC monopole block, wherein the power PR1 is the maximum transmission power of the bipolar DC line limited by the current-carrying capacity of the DC breaker, and the power PR2 is the maximum exchange power between the bipolar converter station and the AC system limited by the long-term current-carrying capacity of the converter; The first distribution unit is configured to perform power evacuation between VSC1 and VSC2 based on power P1 and P2 using a first power distribution strategy when PR2 ≤ PR1, including: When a DC monopole blocking fault occurs in the VSCi, the VSCi transmits power from the faulty pole to the healthy pole through inter-pole power transfer ; VSCi transfers the transmitted power PR2 - Pj between the faulty pole stations to VSCj; The VSCj transfers power from the faulty pole to the healthy pole through pole-to-pole power transfer to the healthy pole; wherein, when i = 1, j = 2, and when i = 2, j = 1; The second distribution unit is configured to perform power evacuation between VSC1 and VSC2 based on power P1 and P2 using a second power distribution strategy when PR1 < PR2 ≤ 2PR1, including: When a DC monopole blocking fault occurs in the VSCi, the VSCi transmits power from the faulty pole to the healthy pole through inter-pole power transfer ; VSCi transfers the transmitted power PR1 - Pj between the faulty pole stations to VSCj; The VSCj transfers power from the faulty pole to the healthy pole through pole-to-pole transfer belt to the healthy pole; wherein, when i = 1, j = 2, and when i = 2, j = 1; The third distribution unit is configured to perform power evacuation between VSC1 and VSC2 based on power P1 and P2 using a third power distribution strategy when PR2 > 2PR1, including: When a DC monopole blocking fault occurs in VSCi, VSCi transmits power from the faulty pole to the healthy pole through pole-to-pole transfer, where i is equal to 1 or 2. ​ 3. A computer-readable storage medium characterized in that the storage medium stores a computer program, and the computer program is used to execute the method described in claim 1 above.

4. An electronic device characterized in that the electronic device includes: a processor; a memory for storing executable instructions of the processor; the processor is configured to read the executable instructions from the memory and execute the instructions to implement the method described in claim 1 above.

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