Direct-current power transmission device suitable for new energy transmission and control method and equipment of direct-current power transmission device

Abstract

The invention relates to a direct-current power transmission device suitable for new energy transmission and a control method and equipment thereof, which are applied to a converter station of a transmitting end system, the converter station comprises at least one transmitting line, and each transmitting line comprises a converter transformer and a converter connected with the converter transformer. The direct-current power transmission device comprises a voltage support module which is connected in parallel between a converter transformer and a converter and has an energy consumption function, and the voltage support module is also used for providing reactive power required by operation for the converter and adjusting the voltage of the alternating-current side of the converter. The direct-current power transmission device provides reactive power required by operation of a diode in a current converter through a voltage supporting module, and by adjusting the voltage of the alternating-current side of the diode in the current converter, the direct-current output power of a converter station is adjusted, the controllability of the converter station is enhanced, and the total cost of a sending end system is reduced; when the direct current side of the converter transformer breaks down, energy consumption can be input in time by adopting the voltage supporting module, so that the power of a sending end system reaches a balanced state.

Description

Technical Field

[0001] The present application relates to the field of direct current energy consumption technology, and in particular to a direct current transmission device suitable for transmitting new energy, and a control method and equipment thereof. Background Art

[0002] The large-scale new energy system built in high-altitude areas has external insulation problems that make it unsuitable for the construction of DC converter stations. At the same time, the power grid of the large-scale new energy system is weak. The transmission of the large-scale new energy system causes the nearby AC system to be unable to carry excessive loads, and it needs to be transmitted in the form of an isolated grid, that is, without contact with the local power grid.

[0003] At present, the main transmission topology proposed by the power grid for the transmission of new energy is the flexible DC transmission topology, but this flexible DC transmission topology has two problems: First, the cost of the flexible DC transmission topology is relatively high, which increases the total investment of the project. Second, when energy imbalance occurs at the sending end of the island sending end system, energy-consuming devices need to be invested to balance the energy, such as Figure 5 As shown. Figure 6 and Figure 7 As shown, in the existing new energy system, if a diode-based or thyristor-based converter is used, although the cost is relatively low, it cannot solve the problem of safe and stable operation of the sending-end system, and AC energy-consuming devices are still required to achieve energy balance. Summary of the invention

[0004] The present application provides a direct current transmission device suitable for the transmission of new energy, and a control method and equipment thereof, which are used to solve the technical problems that the transmission method of the existing large-scale new energy system has energy imbalance that affects the operation of the system and its high construction cost.

[0005] In order to achieve the above objectives, this application provides the following technical solutions:

[0006] On the one hand, a direct current transmission device suitable for transmitting new energy is provided, which is applied to a converter station of a sending-end system, wherein the converter station includes at least one transmitting line, and each of the transmitting lines includes a converter transformer and a converter connected to the converter transformer. The direct current transmission device includes a voltage support module with an energy-consuming function connected in parallel between the converter transformer and the converter, and the voltage support module is also used to provide the converter with reactive power required for operation and to adjust the voltage on the AC side of the converter.

[0007] Preferably, the voltage support module comprises a first full-bridge module, a first switching element, an energy-consuming element, a second switching element and a second full-bridge module connected in sequence, and the first full-bridge module and the second full-bridge module are respectively connected to the converter transformer.

[0008] Preferably, the converter transformer is used to adjust the voltage on the AC side of the converter; and / or, the first full-bridge module and the second full-bridge module are used to provide the converter with reactive power required for operation; and / or, the first switching element and the second switching element are used to control the entry or exit of the energy-consuming element; and / or, the energy-consuming element is used to consume active energy.

[0009] Preferably, the energy dissipation element is a resistor.

[0010] Preferably, both the first switch element and the second switch element are fully controlled devices.

[0011] Preferably, the first full-bridge module and the second full-bridge module each include at least four fully-controlled devices connected in series and a capacitor, the four fully-controlled devices are respectively a first fully-controlled device, a second fully-controlled device, a third fully-controlled device and a fourth fully-controlled device, the third end of the first fully-controlled device is connected to the second end of the second fully-controlled device and the connection node is recorded as the first node, the third end of the second fully-controlled device is connected to the third end of the third fully-controlled device, the second end of the third fully-controlled device is connected to the third end of the fourth fully-controlled device and the connection node is recorded as the second node, the second end of the fourth fully-controlled device is connected to the second end of the first fully-controlled device, the first end of the capacitor is connected to the first node, and the second end of the capacitor is connected to the second node.

[0012] Preferably, the converter is a diode based converter.

[0013] On the other hand, a control method for a DC power transmission device suitable for transmitting renewable energy is provided, which is applied to the DC power transmission device suitable for transmitting renewable energy. The control method comprises the following steps:

[0014] Acquire the DC fault signal of the converter transformer in the converter station of the sending-end system;

[0015] The input of energy-consuming elements in the voltage support module is controlled according to the DC fault signal to maintain the power balance of the sending-end system.

[0016] Preferably, the control method of the DC transmission device suitable for renewable energy transmission includes: controlling the operation of the first full-bridge module and the second full-bridge module according to the DC fault signal, and switching on and off the corresponding capacitors; and simultaneously controlling the conduction of the first switching element and the second switching element, so that the energy-consuming element is put into operation to consume the active energy.

[0017] In another aspect, a terminal device is provided, comprising a processor and a memory;

[0018] The memory is used to store program codes and transmit the program codes to the processor;

[0019] The processor is used to execute the above-mentioned control method of the direct current transmission device suitable for renewable energy transmission according to the instructions in the program code.

[0020] The DC power transmission device suitable for transmitting new energy and its control method and equipment are applied to the converter station of the sending-end system. The converter station includes at least one transmitting line. Each transmitting line includes a converter transformer and a converter connected to the converter transformer. The DC power transmission device includes a voltage support module with an energy-consuming function connected in parallel between the converter transformer and the converter. The voltage support module is also used to provide the converter with reactive power required for operation and adjust the voltage on the AC side of the converter.

[0021] It can be seen from the above technical scheme that the present application has the following advantages: the DC transmission device suitable for the transmission of new energy provides the required reactive power for the operation of the diode in the converter through the voltage support module, and adjusts the voltage on the AC side of the diode in the converter to adjust the DC output power of the converter station, thereby enhancing the controllability of the converter station and reducing the overall cost of the sending-end system; when a fault occurs on the DC side of the converter transformer, the voltage support module can be used to consume energy in a timely manner, so that the power of the sending-end system reaches a balanced state, solving the technical problems of the energy imbalance in the transmission mode of the existing large-scale new energy system affecting the operation of the system and its high construction cost.

[0022] The control method of the DC transmission device suitable for renewable energy transmission controls the operation of the voltage support module through a DC fault signal, so that the sending-end system is in a power balance state, which can effectively solve the energy balance and voltage support of the renewable energy isolated grid transmission, while reducing the overall cost of the sending-end system, and solving the technical problems that the energy imbalance in the transmission mode of the existing large-scale renewable energy system affects the operation of the system and its high construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 A schematic diagram of the topological structure of a DC power transmission device suitable for transmitting renewable energy according to an embodiment of the present application;

[0025] Figure 2A schematic diagram of the topological structure of a voltage support module in a DC power transmission device suitable for transmitting new energy according to an embodiment of the present application;

[0026] Figure 3 This is a flowchart of the steps of the control method of the DC power transmission device suitable for transmitting renewable energy according to the embodiment of the present application;

[0027] Figure 4 A schematic diagram of a terminal device according to an embodiment of the present application;

[0028] Figure 5 It is a topological diagram of the existing flexible DC-based transmission system;

[0029] Figure 6 The topology diagram of the existing diode-based transmission system is shown in FIG.

[0030] Figure 7 This is a topological diagram of an existing thyristor-based transmission system. DETAILED DESCRIPTION

[0031] In order to make the purpose, features, and advantages of the invention of this application more obvious and easy to understand, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the embodiments described below are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] In the description of the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0033] In the embodiments of the present application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0034] The embodiments of the present application provide a DC transmission device suitable for the transmission of new energy, and a control method and equipment thereof, which solve the technical problems that the transmission method of the existing large-scale new energy system has energy imbalance that affects the operation of the system and has high construction costs.

[0035] Embodiment 1:

[0036] Figure 1 This is a schematic diagram of the topological structure of a DC transmission device suitable for transmitting renewable energy as described in an embodiment of the present application.

[0037] like Figure 1 As shown, the embodiment of the present application provides a DC power transmission device suitable for transmitting new energy, which is applied to the converter station of the sending end system, and the converter station includes at least one transmission line, and each transmission line includes a converter transformer 10 and a converter 20 connected to the converter transformer 10. The DC power transmission device includes a voltage support module 30 with an energy consumption function connected in parallel between the converter transformer 10 and the converter 20, and the voltage support module 30 is also used to provide the converter 20 with reactive power required for operation and adjust the voltage on the AC side of the converter 20.

[0038] It should be noted that the converter 20 can be selected as a diode-based converter, and the voltage support module 30 is arranged on the valve side of the converter transformer 10. On the one hand, the voltage support module 30 can provide the reactive power required for the operation of the diode in the converter 20. On the other hand, the converter based on the diode can adjust the voltage on the AC side of the converter 20 diode to adjust the output power of the DC of the converter station and enhance the controllability of the converter station. At the same time, when a fault occurs on the DC side of the converter transformer 10, the voltage support module 30 can be put into energy consumption in time, so that the power of the sending end system reaches a balanced state, thereby reducing the injected DC fault current, achieving the function of suppressing the process current and assisting fault recovery. In this embodiment, the converter station is illustrated by two sending lines as a case, and a voltage support module 30 is arranged on each sending line, so that the DC transmission device suitable for the transmission of new energy can be combined with the diode to form the sending end system of the converter station, which can effectively solve the energy balance and voltage support device of the isolated grid of new energy, and reduce the overall cost of the sending end system.

[0039] The present application provides a DC power transmission device suitable for sending out new energy, which is applied to the converter station of the sending end system. The converter station includes at least one sending line, each sending line includes a converter transformer and a converter connected to the converter transformer, and the DC power transmission device includes a voltage support module with energy consumption function connected in parallel between the converter transformer and the converter, and the voltage support module is also used to provide the converter with reactive power required for operation and adjust the voltage on the AC side of the converter. The DC power transmission device suitable for sending out new energy provides the required reactive power for the operation of the diode in the converter through the voltage support module, and adjusts the output power of the DC power of the converter station by adjusting the voltage on the AC side of the diode in the converter, thereby enhancing the controllability of the converter station and reducing the overall cost of the sending end system; when a fault occurs on the DC side of the converter transformer, the voltage support module can be used to timely invest energy consumption, so that the power of the sending end system reaches a balanced state, solving the technical problems that the energy imbalance in the sending mode of the existing large-scale new energy system affects the operation of the system and its high construction cost.

[0040] Figure 2 This is a schematic diagram of the topological structure of a voltage support module in a DC transmission device suitable for transmitting renewable energy as described in an embodiment of the present application.

[0041] like Figure 2 As shown, in one embodiment of the present application, the voltage support module 30 includes a first full-bridge module 32, a first switch element 33, an energy-consuming element 34, a second switch element 35, and a second full-bridge module 36 connected in sequence, and the first full-bridge module 32 and the second full-bridge module 36 are respectively connected to the converter transformer 10. Among them, the converter transformer 10 is used to adjust the voltage on the AC side of the converter 20, the first full-bridge module 32 and the second full-bridge module 36 are used to provide the converter 20 with reactive power required for operation; the first switch element 33 and the second switch element 35 are used to control the input or output of the energy-consuming element 34; the energy-consuming element 34 is used to consume active energy.

[0042] It should be noted that the energy dissipation element 34 can be selected as a resistor. The first switch element 33 and the second switch element 35 can both be selected as fully controlled devices. In this embodiment, the converter transformer 10 is used to achieve voltage changes, reduce the AC voltage requirements of power electronic equipment, reduce the number of fully controlled devices used, and thus reduce the overall equipment cost.

[0043] like Figure 2As shown, in an embodiment of the present application, the first full-bridge module 32 and the second full-bridge module 36 each include at least four fully-controlled devices connected in series and a capacitor, the four fully-controlled devices are respectively a first fully-controlled device, a second fully-controlled device, a third fully-controlled device and a fourth fully-controlled device, the third end of the first fully-controlled device is connected to the second end of the second fully-controlled device and the connection node is recorded as the first node, the third end of the second fully-controlled device is connected to the third end of the third fully-controlled device, the second end of the third fully-controlled device is connected to the third end of the fourth fully-controlled device and the connection node is recorded as the second node, the second end of the fourth fully-controlled device is connected to the second end of the first fully-controlled device, the first end of the capacitor is connected to the first node, and the second end of the capacitor is connected to the second node.

[0044] It should be noted that the first fully controlled device, the second fully controlled device, the third fully controlled device and the fourth fully controlled device can all be selected from triodes, the emitter of the triode serves as the third end of the first fully controlled device, the second fully controlled device, the third fully controlled device and the fourth fully controlled device, and the collector of the triode serves as the second end of the first fully controlled device, the second fully controlled device, the third fully controlled device and the fourth fully controlled device. In this embodiment, the first full-bridge module 32 and the second full-bridge module 36 are both connected in series using modules of the same structure (such as fully controlled devices) to achieve control of the voltage support module 30. The working principle of the full-bridge module is to control the switching of the capacitor by controlling the opening and closing of the fully controlled device, thereby achieving control of the output reactive power to the outside.

[0045] In the embodiment of the present application, the DC power transmission device suitable for sending out new energy forms a certain DC voltage on both sides of the energy-consuming element 34 by controlling the DC side of the first full-bridge module 32 and the second full-bridge module 36, thereby realizing the consumption of the externally fed functional energy. At the same time, the first switch element 33 and the second switch element 35 composed of fully controlled devices are arranged on both sides of the energy-consuming element 34 to control the energy-consuming element to be put into or out of operation, thereby realizing the control of the energy of the energy-consuming element 34.

[0046] Embodiment 2:

[0047] Figure 3 This is a flow chart of the steps of a control method for a DC power transmission device suitable for transmitting renewable energy as described in an embodiment of the present application.

[0048] like Figure 3 As shown, the embodiment of the present application provides a control method for a DC power transmission device suitable for transmitting renewable energy, which is applied to the above-mentioned DC power transmission device suitable for transmitting renewable energy. The control method includes the following steps:

[0049] S1. Obtain a DC fault signal of a converter transformer in a converter station of a sending-end system.

[0050] It should be noted that in step S1, a DC fault signal of a converter transformer in a converter station of the sending-end system is obtained. In this embodiment, the content of the DC power transmission device applicable to the transmission of new energy has been explained in the first embodiment.

[0051] S2. Control the input of energy-consuming components in the voltage support module according to the DC fault signal to maintain the power balance of the sending-end system.

[0052] It should be noted that in step S2, the operation of the voltage support module is controlled according to the DC fault signal of step S1, so that the sending-end system is in a power balance state.

[0053] The present application provides a control method for a DC transmission device suitable for sending out new energy, including obtaining a DC fault signal of a converter transformer in a converter station of a sending-end system; and controlling the input of energy-consuming components in a voltage support module according to the DC fault signal to maintain the power balance of the sending-end system. The control method for a DC transmission device suitable for sending out new energy controls the operation of the voltage support module through a DC fault signal, so that the sending-end system is in a power balance state, and can effectively solve the energy balance and voltage support of the isolated grid of new energy, while reducing the overall cost of the sending-end system, and solving the technical problems that the energy imbalance in the sending mode of the existing large-scale new energy system affects the operation of the system and its high construction cost.

[0054] In one embodiment of the present application, the control method of the DC transmission device suitable for transmitting new energy includes: controlling the operation of the first full-bridge module and the second full-bridge module according to the DC fault signal, and switching the corresponding capacitors; and simultaneously controlling the conduction of the first switching element and the second switching element, so that the energy-consuming element is put into operation to consume the active energy.

[0055] It should be noted that the control method of the DC transmission device suitable for renewable energy transmission controls the operation of the voltage support module, which can be understood as: controlling the operation of the first full-bridge module and the second full-bridge module to switch on the corresponding capacitors, and at the same time controlling the conduction of the first switching element and the second switching element, so that the energy-consuming elements are put into use to consume the functional energy of the fault, so that the power of the sending-end system reaches a balanced state, thereby reducing the injected DC fault current, achieving the function of suppressing the process current and assisting fault recovery.

[0056] Embodiment three:

[0057] Figure 4 A schematic diagram of a terminal device described in an embodiment of the present application.

[0058] like Figure 4 As shown, an embodiment of the present application provides a terminal device, including a processor and a memory;

[0059] A memory, used for storing program codes and transmitting the program codes to a processor;

[0060] The processor is used to execute the control method of the DC transmission device suitable for renewable energy transmission according to the instructions in the program code.

[0061] It should be noted that the processor is used to execute the steps in the above-mentioned control method embodiment of a DC power transmission device suitable for renewable energy transmission according to the instructions in the program code. Alternatively, the processor implements the functions of each module / unit in the above-mentioned system / device embodiments when executing the computer program.

[0062] Exemplarily, the computer program may be divided into one or more modules / units, one or more modules / units are stored in a memory and executed by a processor to complete the present application. One or more modules / units may be a series of computer program instruction segments capable of completing a specific function, and the instruction segments are used to describe the execution process of the computer program in a terminal device.

[0063] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that this does not constitute a limitation on the terminal device, and may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal device may also include input and output devices, network access devices, buses, etc.

[0064] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (dSIC), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0065] The memory may be an internal storage unit of the terminal device, such as a hard disk or memory of the terminal device. The memory may also be an external storage device of the terminal device, such as a plug-in hard disk, a smart memory card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal device. Furthermore, the memory may include both an internal storage unit of the terminal device and an external storage device. The memory is used to store computer programs and other programs and data required by the terminal device. The memory may also be used to temporarily store data that has been output or is to be output.

[0066] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0067] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0068] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0069] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0070] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0071] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A DC power transmission device suitable for sending out new energy, applied to a converter station of a sending-end system, wherein the converter station comprises at least one sending line, each of which comprises a converter transformer and a converter connected to the converter transformer, characterized in that: The DC power transmission device comprises a voltage support module with an energy-consuming function connected in parallel between the converter transformer and the converter. The voltage support module is also used to provide the converter with reactive power required for operation and to adjust the voltage on the AC side of the converter.

2. The DC power transmission device suitable for transmitting new energy according to claim 1 is characterized in that: The voltage support module includes a first full-bridge module, a first switch element, an energy-consuming element, a second switch element, and a second full-bridge module which are connected in sequence. The first full-bridge module and the second full-bridge module are respectively connected to the converter transformer.

3. The DC power transmission device suitable for transmitting new energy according to claim 2 is characterized in that: The converter transformer is used to adjust the voltage on the AC side of the converter; and / or, the first full-bridge module and the second full-bridge module are used to provide the converter with reactive power required for operation; and / or, the first switching element and the second switching element are used to control the entry or exit of the energy-consuming element; and / or, the energy-consuming element is used to consume active energy.

4. The DC power transmission device suitable for transmitting new energy according to claim 2 is characterized in that: The energy consumption element is a resistor.

5. The DC power transmission device suitable for transmitting new energy according to claim 2 is characterized in that: The first switch element and the second switch element are both fully controlled devices.

6. The DC power transmission device suitable for transmitting new energy according to claim 2, characterized in that: The first full-bridge module and the second full-bridge module each include at least four fully-controlled devices connected in series and a capacitor, the four fully-controlled devices are respectively a first fully-controlled device, a second fully-controlled device, a third fully-controlled device and a fourth fully-controlled device, the third end of the first fully-controlled device is connected to the second end of the second fully-controlled device and the connection node is recorded as a first node, the third end of the second fully-controlled device is connected to the third end of the third fully-controlled device, the second end of the third fully-controlled device is connected to the third end of the fourth fully-controlled device and the connection node is recorded as a second node, the second end of the fourth fully-controlled device is connected to the second end of the first fully-controlled device, the first end of the capacitor is connected to the first node, and the second end of the capacitor is connected to the second node.

7. The DC power transmission device suitable for transmitting new energy according to any one of claims 1 to 6, characterized in that: The inverter is a diode-based inverter.

8. A control method for a DC power transmission device suitable for transmitting renewable energy, applied to a DC power transmission device suitable for transmitting renewable energy as claimed in any one of claims 1 to 7, characterized in that: The control method comprises the following steps: Acquire the DC fault signal of the converter transformer in the converter station of the sending-end system; The input of energy-consuming elements in the voltage support module is controlled according to the DC fault signal to maintain the power balance of the sending-end system.

9. The control method for a DC power transmission device suitable for transmitting renewable energy according to claim 8, characterized in that: include: According to the DC fault signal, the first full-bridge module and the second full-bridge module are controlled to operate and the corresponding capacitors are switched on and off; at the same time, the first switch element and the second switch element are controlled to be turned on and the energy-consuming element is put into operation to consume the active energy.

10. A terminal device, characterized in that: including a processor and a memory; The memory is used to store program codes and transmit the program codes to the processor; The processor is used to execute the control method of the direct current transmission device suitable for renewable energy transmission as claimed in claim 8 or 9 according to the instructions in the program code.

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