A power guarantee control method and system for a station area ac-dc coupling system

Abstract

The application discloses a kind of power guarantee control method and system of AC-DC coupling system of transformer area, comprising: in the AC-DC coupling system under low-voltage distribution transformer area, the operating state of power electronic fast switch under transformer lower end and the operating state of intelligent controllable switch on all load upper end are obtained by transformer area intelligent fusion terminal, and the operating mode of system is determined according to the operating state of obtained intelligent controllable switch;When it is determined that the system enters off-grid operation mode, the intelligent controllable switch on the upper end of the key load of the user side is closed, and the intelligent controllable switch on the upper end of the V2G charging pile connected with the acceptable adjustment control vehicle is closed according to the preset control sequence, to provide the power of input power grid;When the power supply of the upper power grid is restored, the power electronic fast switch under the transformer lower end and the intelligent controllable switch on all load upper end are closed, and the V2G charging pile with acceptable adjustment control vehicle is adjusted from discharge to charging state.

Description

Technical Field

[0001] This invention relates to the field of power control technology, and more specifically, to a power supply protection control method and system for an AC / DC coupling system in a transformer substation. Background Technology

[0002] As the penetration rate of electric vehicles in the power grid continues to increase, their function as distributed energy storage units to achieve bidirectional power interaction with the grid makes their connection with the grid even closer. While meeting the driving requirements of electric vehicles, orderly charging and discharging control of electric vehicles can be implemented, and the power from electric vehicle batteries can be allowed to be fed into the grid in specific scenarios, thereby achieving bidirectional energy and information interaction between electric vehicles and the power grid.

[0003] The development of electric vehicle-grid interaction technology enables electric vehicles to fully leverage their dual characteristics as both power sources and loads, as well as their massive capacity for grid connection and flexible regulation, making them an important component of flexible resources in the new power system. Realizing the power grid security provided by electric vehicles requires the coordinated efforts of charging stations with V2G capabilities, mobile energy storage devices, or vehicles with regulatory potential capable of supplying power to the grid.

[0004] Currently, orderly charging and discharging control is implemented for electric vehicles connected within the distribution area, thereby achieving orderly charging and discharging control based on the real-time demand of the power grid. This technology can provide a strong supplement and guarantee for the power supply of the distribution area. However, the bidirectional power modules and system control functions of V2G charging piles on the market are relatively simple, making it difficult to achieve the function of providing emergency power guarantee for important loads in the distribution area under off-grid mode. Summary of the Invention

[0005] This invention proposes a power control method and system for an AC / DC coupled distribution transformer substation, to solve the problem of providing emergency power guarantee for critical loads in a low-voltage distribution transformer substation in off-grid mode through charging facilities in a typical AC / DC coupled distribution transformer substation system.

[0006] To address the aforementioned problems, according to one aspect of the present invention, a power supply protection control method for a transformer substation AC / DC coupling system is provided, the method comprising:

[0007] In the AC / DC coupling system under the low-voltage distribution substation, the substation intelligent fusion terminal acquires the operating status of the power electronic fast-switching switch at the lower end of the transformer and the operating status of the intelligent controllable switch at the upper end of all loads, and determines the system operating mode based on the acquired operating status of the fast-switching switch and intelligent controllable switch.

[0008] When the power electronic fast-switching switch detection system enters the off-grid operation mode, it closes the intelligent controllable switch at the upper end of the key load on the user side, and closes the intelligent controllable switch at the upper end of the charging pile connected to the charging pile that can be adjusted to discharge to the grid according to the preset control sequence, so that the charging pile that can be adjusted to discharge to the grid can supply power to the grid.

[0009] When the power electronic fast-switching switch detects that the upstream power grid has restored power supply, it closes the power electronic fast-switching switch at the lower end of the transformer and the intelligent controllable switches at the upper end of all loads, and adjusts the charging piles that can be adjusted to discharge to the grid from the discharging state to the charging state.

[0010] Preferably, determining the system's operating mode based on the acquired operating states of all intelligent controllable switches includes:

[0011] When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be closed, the system is determined to enter the grid-connected operation mode.

[0012] When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent control switch at the upper end of other loads in the distribution area is closed, the system utilizes the energy storage devices and electric vehicles in the distribution area to input electrical energy into the grid, queries the start-up control strategies of charging and discharging control and energy storage device start-up, and enters the coordinated control mode of energy storage and charging pile.

[0013] When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent controllable switches at the upper end of other loads in the distribution area is also open, the system operating mode is determined to be off-grid operation mode.

[0014] Preferably, the method further includes:

[0015] When the power electronic fast-switch at the lower end of the transformer detects a fault in the upstream power grid, the operating status of the power electronic fast-switch at the lower end of the transformer is adjusted to open to disconnect the equipment in the distribution area from the power grid.

[0016] Preferably, the intelligent controllable switch at the top of the charging pile, which is connected to the charging pile with adjustable discharge to the power grid according to a preset control sequence, includes:

[0017] After closing the intelligent controllable switch at the upper end of the user-side critical load, check the user-side response status of the V2G charging piles with V2G function under the transformer area.

[0018] When it is determined from the user-side response that there is no electric vehicle connected to the lower end of the transformer area or the electric vehicle connected to the lower end cannot respond to discharge to the grid, this type of V2G charging pile will not be controlled;

[0019] When it is determined from the user-side response that there are charging piles connected to the lower end of the transformer area that can participate in the discharge response to the grid, the number of V2G charging piles and the discharge power of each V2G charging pile are queried, and the intelligent controllable switch at the upper end of each V2G charging pile is closed in descending order of the discharge power of the V2G charging piles.

[0020] Preferably, the intelligent converged terminal of the distribution area communicates with the charging pile equipment via broadband carrier / RS485 / LoRa / MESH / wireless communication.

[0021] According to another aspect of the present invention, a power protection control system for a transformer substation AC / DC coupling system is provided, the system comprising:

[0022] The operation mode determination unit is used to obtain the operation status of the power electronic fast-switching switch at the lower end of the transformer and the operation status of the intelligent controllable switches at the upper end of all loads in the AC / DC coupling system under the low-voltage distribution substation, and to determine the operation mode of the system based on the obtained operation status of all intelligent controllable switches.

[0023] The first control unit is used to close the intelligent controllable switch at the upper end of the key load on the user side when it is determined that the system has entered the off-grid operation mode, and close the intelligent controllable switch at the upper end of the charging pile connected to the charging pile that can be adjusted to discharge to the grid according to the preset control sequence, so that the charging pile that can be adjusted to discharge to the grid can supply power to the grid.

[0024] The second control unit is used to close the power electronic fast-switching switch at the lower end of the transformer and the intelligent controllable switch at the upper end of all loads when the upstream power grid restores power supply, and to adjust the charging piles that can be adjusted to discharge to the grid from the discharging state to the charging state.

[0025] Preferably, the operating mode determination unit determines the system's operating mode based on the acquired operating states of all intelligent controllable switches, including:

[0026] When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be closed, the system is determined to enter the grid-connected operation mode.

[0027] When the operating status of the intelligent controllable switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent controllable switches at the upper end of other loads in the distribution area is closed, it indicates that there is a large-capacity energy storage device supplying power in the distribution area. The start-up of charging and discharging control and the control strategy for starting the energy storage device are queried, and the energy storage and charging pile coordinated control mode is entered.

[0028] When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent controllable switches at the upper end of other loads in the distribution area is also open, the system operating mode is determined to be off-grid operation mode.

[0029] Preferably, the system further includes:

[0030] The operation status adjustment unit is used to adjust the operation status of the power electronic fast-switch at the lower end of the transformer to open when the power electronic fast-switch at the lower end of the transformer detects a fault in the upper-level power grid, so as to disconnect the distribution transformer from the power grid.

[0031] Preferably, the first control unit closes the intelligent controllable switch at the top of the charging pile, which is connected to the charging pile with adjustable discharge to the power grid, according to a preset control sequence, including:

[0032] After closing the intelligent controllable switch at the upper end of the user-side critical load, check the user-side response status of the V2G charging piles with V2G function under the transformer area.

[0033] When it is determined from the user-side response that there is no electric vehicle connected to the lower end of the transformer area or the electric vehicle connected to the lower end cannot respond to discharge to the grid, this type of V2G charging pile will not be controlled;

[0034] When it is determined from the user-side response that there are charging piles connected to the lower end of the transformer area that can participate in the discharge response to the grid, the number of V2G charging piles and the discharge power of each V2G charging pile are queried, and the intelligent controllable switch at the upper end of each V2G charging pile is closed in descending order of the discharge power of the V2G charging piles.

[0035] Preferably, the intelligent converged terminal of the distribution area communicates with the charging pile equipment via broadband carrier / RS485 / LoRa / MESH / wireless communication.

[0036] This invention provides a power supply guarantee control method and system for a transformer substation AC / DC coupling system. It enables V2G electric vehicle charging piles and intelligent integrated terminals in off-grid mode to work collaboratively, forming an interactive system with charging piles and energy storage devices that can be adjusted to discharge to the grid. This allows charging piles and energy storage devices to provide power to the grid via V2G charging piles even during power outages in the distribution substation, effectively improving the interaction capability between the charging piles, energy storage, and grid in the distribution substation connected to electric vehicles and charging / discharging facilities. The control method of this invention can be applied to off-grid power supply to important loads under the distribution substation during disasters or uninterrupted maintenance, and to emergency repairs during grid faults. It can provide off-grid power guarantee for low-voltage distribution substation AC / DC coupling systems through the intelligent integrated terminal. Attached Figure Description

[0037] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0038] Figure 1 This is a flowchart of a power supply protection control method 100 for a low-voltage distribution substation AC / DC coupling system according to an embodiment of the present invention;

[0039] Figure 2 This is a power supply control architecture diagram of a low-voltage distribution substation AC / DC coupling system according to an embodiment of the present invention;

[0040] Figure 3 This is a flowchart of the power supply protection control in the off-grid mode of a low-voltage distribution substation AC / DC coupling system according to an embodiment of the present invention;

[0041] Figure 4 This is a schematic diagram of the power control system 600 of a low-voltage distribution substation AC / DC coupling system according to an embodiment of the present invention. Detailed Implementation

[0042] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0043] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0044] Figure 1 This is a flowchart of a power supply protection control method 100 for a low-voltage distribution substation AC / DC coupling system according to an embodiment of the present invention. Figure 1As shown, the power control method based on the intelligent integrated terminal of the distribution substation provided by the embodiments of the present invention can realize the coordinated cooperation between V2G electric vehicle charging piles and the intelligent integrated terminal of the distribution substation in off-grid mode, and form an interactive system with charging piles and energy storage devices that can be adjusted and controlled to discharge to the grid. This enables the charging piles and energy storage devices that can be adjusted and controlled to discharge to the grid to provide power to the grid through V2G charging piles in the event of a power outage in the distribution substation, and effectively improves the interaction capability of the distribution substation's charging piles, energy storage, and grid when electric vehicles and charging / discharging facilities are connected. The control method of the present invention can be applied to off-grid power supply for important loads under the distribution substation during disasters or uninterrupted maintenance, and to emergency repairs during grid faults. It can realize the off-grid power supply of multiple charging piles in parallel for large loads through the intelligent integrated terminal of the distribution substation. The power security control method 100 based on the intelligent integrated terminal of the distribution substation provided by the embodiments of the present invention starts from step 101. In step 101, the intelligent integrated terminal of the distribution substation obtains the operating status of the power electronic fast-switching switch at the lower end of the transformer and the operating status of the intelligent controllable switches at the upper end of all loads, and determines the system's operating mode based on the obtained operating status of all intelligent controllable switches.

[0045] Preferably, determining the system's operating mode based on the acquired operating states of all intelligent controllable switches includes:

[0046] When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be closed, the system is determined to enter the grid-connected operation mode.

[0047] When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent controllable switch at the upper end of other loads in the distribution area is closed, it indicates that there is a large-capacity energy storage device supplying power in the distribution area. The start-up of charging and discharging control and the control strategy for starting the energy storage device are queried, and the energy storage and charging pile coordinated control mode is entered.

[0048] When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent controllable switches at the upper end of other loads in the distribution area is also open, the system operating mode is determined to be off-grid operation mode.

[0049] Preferably, the method further includes:

[0050] When the power electronic fast-switch at the lower end of the transformer detects a fault in the upstream power grid, the operating status of the power electronic fast-switch at the lower end of the transformer is adjusted to open to disconnect the distribution transformer from the power grid.

[0051] Preferably, the intelligent converged terminal of the distribution area communicates with the charging pile equipment via broadband carrier / RS485 / LoRa / MESH / wireless communication.

[0052] In this invention, an intelligent controllable switch is installed at the upper end of the transformer in the distribution area. The operating status of the intelligent controllable switch is transmitted to the intelligent converged terminal equipment in the distribution area in real time. A communication connection is established between the intelligent converged terminal equipment and the V2G charging pile equipment, typically using broadband carrier / RS485 / LoRa / MESH / wireless communication methods. The communication control system is equipped with an emergency power supply to ensure that the communication system has a certain amount of operating time in the event of a power outage from the upstream power grid.

[0053] In this invention, after the power electronic fast-switching switch at the lower end of the transformer detects a fault in the upstream power grid, it immediately disconnects the distribution transformer from the grid, adjusts the operating state of the power electronic fast-switching switch at the lower end of the transformer to open, and simultaneously reports the switch's operating status to the intelligent integrated terminal of the distribution area. At the same time, after the intelligent controllable switches at the upper end of the distribution area loads detect a fault in the distribution area power grid, the operating state of all intelligent controllable switches at the upper end of the loads will also be adjusted to open. After receiving the status feedback from the intelligent controllable switches, the intelligent integrated terminal of the distribution area determines whether the system has entered off-grid operation mode.

[0054] Figure 2 This is a power supply control architecture diagram of a low-voltage distribution substation AC / DC coupling system according to an embodiment of the present invention. Figure 2 As shown, the system implemented in this invention is an AC / DC coupled power system of a low-voltage distribution substation.

[0055] Combination Figure 3 As shown, in this invention, it is detected whether the power electronic fast-switch at the lower end of the transformer is closed. If the switch is closed, the system enters the normal grid-connected operation mode. If the power electronic fast-switch at the lower end of the transformer is open, it is further determined whether the intelligent controllable switches at the upper end of other loads in the distribution area are closed. If the switches of other loads in the distribution area are closed, it indicates that there is a large energy storage device supplying power in the distribution area. The system further queries the start-up of charging and discharging control and the control strategy for starting the energy storage device, and enters the coordinated control mode of energy storage and charging piles. If the power electronic fast-switch at the lower end of the transformer is open, and the intelligent controllable switches at the upper end of other loads in the distribution area are all open, the system directly enters the off-grid operation control mode.

[0056] The intelligent controllable switch of the present invention can be an STS switch.

[0057] In step 102, when it is determined that the system has entered the off-grid operation mode, the intelligent controllable switch at the upper end of the key load on the user side is closed, and the intelligent controllable switch at the upper end of the charging pile connected to the charging pile that can be adjusted to discharge to the grid is closed according to the preset control sequence, so that the charging pile that can be adjusted to discharge to the grid supplies power to the grid.

[0058] Preferably, the intelligent controllable switch at the top of the charging pile, which is connected to the charging pile with adjustable discharge to the power grid according to a preset control sequence, includes:

[0059] After closing the intelligent controllable switch at the upper end of the user-side critical load, check the user-side response status of the V2G charging piles with V2G function under the transformer area.

[0060] When it is determined from the user-side response that there is no electric vehicle connected to the lower end of the transformer area or the electric vehicle connected to the lower end cannot respond to discharge to the grid, this type of V2G charging pile will not be controlled;

[0061] When it is determined from the user-side response that there are charging piles connected to the lower end of the transformer area that can participate in the discharge response to the grid, the number of V2G charging piles and the discharge power of each V2G charging pile are queried, and the intelligent controllable switch at the upper end of each V2G charging pile is closed in descending order of the discharge power of the V2G charging piles.

[0062] In this invention, when the intelligent converged terminal of the distribution area determines that the system has entered the off-grid operation mode based on the status feedback from the intelligent controllable switch, it closes the intelligent controllable switch at the upper end of the critical load on the user side, and closes the intelligent controllable switch at the upper end of the V2G connected to mobile energy storage devices or vehicles in society (outside the distribution area) with the potential to supply power to the grid in a certain order, thereby realizing the power guarantee for the user's important loads.

[0063] Specifically, in combination Figure 3 As shown, after closing the smart controllable switch at the critical load on the user side, the user-side response status of charging piles with V2G functionality under the distribution area is queried. Specifically, if no electric vehicle is connected to the lower end of the distribution area, or if the connected electric vehicle cannot discharge to the grid, no control is applied to this type of V2G charging pile. If a charging pile capable of discharging to the grid is connected, the number of V2G charging piles and their discharge capacity are further queried. The distribution area's smart fusion terminal then prioritizes closing the smart controllable switch at the V2G charging pile with the highest discharge capacity, and then closes the smart controllable switches at the other V2G charging piles.

[0064] In step 103, when the upstream power grid restores power supply, the power electronic fast-switching switch at the lower end of the transformer and the intelligent controllable switch at the upper end of all loads are closed, and the charging piles that can be adjusted to discharge to the grid are switched from the discharging state to the charging state.

[0065] In this invention, when the upstream power grid restores power supply, the power electronic fast-switching switch at the lower end of the transformer detects the restoration of power supply and adjusts the switch to close; then, the intelligent controllable switches at the upper end of other loads in the distribution area also detect the restoration of power supply and adjust the switches to close; the intelligent controllable switches at the upper end of V2G charging piles and ordinary charging piles that do not supply power to the grid in the off-grid state also detect the restoration of power supply to the distribution area and adjust the switches to close; mobile energy storage devices or non-distribution area vehicles with controllability potential that can supply power to the grid switch from the state of discharging to the grid to the normal charging state.

[0066] This invention addresses the research on the participation of single or multiple electric vehicle charging piles in a power supply guarantee control system based on a smart distribution substation terminal in off-grid mode. It proposes a practical solution to the collaborative control problem of bidirectional power modules among multiple V2G charging piles, implemented through the smart distribution substation terminal equipment. The power supply guarantee control system described in this invention connects the electric vehicle charging piles and the distribution master station system via the smart distribution substation terminal to achieve orderly charging and discharging control of electric vehicles. Specifically, the smart distribution substation terminal obtains real-time load information within the distribution substation through local data acquisition, obtains the response status of electric vehicle users to orderly charging and discharging through the charging and discharging operation control platform of the distribution master station system, and obtains the charging demand of electric vehicles and the real-time operating status of the charging piles through real-time communication with them. By interacting with information at different levels, the smart distribution substation terminal achieves control over the orderly charging and discharging energy flow, enabling efficient utilization of V2G charging pile resources and further improving the intelligence level of charging and discharging control in off-grid mode.

[0067] Figure 4 This is a schematic diagram of the structure of a power control system 600 based on a smart converged terminal for distribution areas according to an embodiment of the present invention. Figure 4 As shown, the power supply protection control system 400 based on the intelligent converged terminal of the distribution area provided in the embodiment of the present invention includes: an operation mode determination unit 401, a first control unit 402, and a second control unit 403.

[0068] Preferably, the operation mode determination unit 401 is used to enable the intelligent fusion terminal of the distribution area to acquire the operation status of the power electronic fast-switching switch at the lower end of the transformer and the operation status of the intelligent controllable switches at the upper end of all loads, and to determine the operation mode of the system based on the acquired operation status of all intelligent controllable switches.

[0069] Preferably, the operating mode determination unit 401 determines the system's operating mode based on the acquired operating states of all intelligent controllable switches, including:

[0070] When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be closed, the system is determined to enter the grid-connected operation mode.

[0071] When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent controllable switch at the upper end of other loads in the distribution area is closed, it indicates that there is a large-capacity energy storage device supplying power in the distribution area. The start-up of charging and discharging control and the control strategy for starting the energy storage device are queried, and the energy storage and charging pile coordinated control mode is entered.

[0072] When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent controllable switches at the upper end of other loads in the distribution area is also open, the system operating mode is determined to be off-grid operation mode.

[0073] Preferably, the system further includes:

[0074] The operation status adjustment unit is used to adjust the operation status of the power electronic fast-switch at the lower end of the transformer to open when the power electronic fast-switch at the lower end of the transformer detects a fault in the upper-level power grid, so as to disconnect the distribution transformer from the power grid.

[0075] Preferably, the first control unit 402 is used to close the intelligent controllable switch at the upper end of the key load on the user side when it is determined that the system has entered the off-grid operation mode, and close the intelligent controllable switch at the upper end of the charging pile connected to the charging pile that can be adjusted to discharge to the grid in a preset control sequence, so that the charging pile that can be adjusted to discharge to the grid supplies power to the grid.

[0076] Preferably, the first control unit 402 closes the intelligent controllable switch at the top of the charging pile, which is connected to the charging pile with adjustable discharge to the power grid, according to a preset control sequence, including:

[0077] After closing the intelligent controllable switch at the upper end of the user-side critical load, check the user-side response status of the V2G charging piles with V2G function under the transformer area.

[0078] When it is determined from the user-side response that there is no electric vehicle connected to the lower end of the transformer area or the electric vehicle connected to the lower end cannot respond to discharge to the grid, this type of V2G charging pile will not be controlled;

[0079] When it is determined from the user-side response that there are charging piles connected to the lower end of the transformer area that can participate in the discharge response to the grid, the number of V2G charging piles and the discharge power of each V2G charging pile are queried, and the intelligent controllable switch at the upper end of each V2G charging pile is closed in descending order of the discharge power of the V2G charging piles.

[0080] Preferably, the second control unit 403 is used to close the power electronic fast-switching switch at the lower end of the transformer and the intelligent controllable switch at the upper end of all loads when the upstream power grid restores power supply, and adjust the charging pile that can be adjusted to discharge to the grid from the discharging state to the charging state.

[0081] Preferably, the intelligent converged terminal of the distribution area communicates with the charging pile equipment via broadband carrier / RS485 / LoRa / MESH / wireless communication.

[0082] The power control system 400 based on the intelligent converged terminal of the distribution area in this embodiment corresponds to the power control method 100 based on the intelligent converged terminal of the distribution area in another embodiment of this invention, and will not be described again here.

[0083] The invention has been described with reference to a few embodiments. However, as will be known to those skilled in the art, and as defined in the appended claims, other embodiments besides those disclosed above fall equivalently within the scope of the invention.

[0084] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the art, unless otherwise expressly defined herein. All references to “a / the / the [device, component, etc.]” ​​are openly interpreted as at least one instance of said device, component, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed unless explicitly stated otherwise.

[0085] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0086] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1A device that provides the functions specified in one or more boxes.

[0087] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0088] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A power supply guarantee control method for a transformer substation AC / DC coupling system, characterized in that, The method includes: In the AC / DC coupling system under the low-voltage distribution substation, the operating status of the power electronic fast-switching switch at the lower end of the transformer and the operating status of the intelligent controllable switch at the upper end of all loads are obtained through the substation intelligent fusion terminal, and the system operation mode is determined based on the obtained operating status of all intelligent controllable switches. When the system is determined to enter the off-grid operation mode, the intelligent controllable switch at the upper end of the key load on the user side is closed, and the intelligent controllable switch at the upper end of the charging pile connected to the charging pile that can be adjusted to discharge to the grid is closed according to the preset control sequence, so that the charging pile that can be adjusted to discharge to the grid supplies power to the grid. When the upstream power grid restores power supply, the power electronic fast-switching switch at the lower end of the transformer and the intelligent controllable switch at the upper end of all loads are closed, and the charging piles that can be adjusted to discharge to the grid are switched from the discharging state to the charging state. The step of determining the system's operating mode based on the acquired operating states of all intelligent controllable switches includes: When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be closed, the system is determined to enter the grid-connected operation mode. When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent controllable switch at the upper end of other loads in the distribution area is closed, it indicates that there is a large-capacity energy storage device supplying power in the distribution area. The start-up of charging and discharging control and the control strategy for starting the energy storage device are queried, and the energy storage and charging pile coordinated control mode is entered. When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent controllable switches at the upper end of other loads in the distribution area is also open, the system operating mode is determined to be off-grid operation mode. The intelligent controllable switch at the top of the charging pile, which is connected to the charging pile for adjustable discharge to the power grid according to a preset control sequence, includes: After closing the intelligent controllable switch at the upper end of the user-side critical load, check the user-side response status of the V2G charging piles with V2G function under the transformer area. When it is determined from the user-side response that there is no electric vehicle connected to the lower end of the transformer area or the electric vehicle connected to the lower end cannot respond to discharge to the grid, this type of V2G charging pile will not be controlled; When it is determined from the user-side response that there are charging piles connected to the lower end of the transformer area that can participate in the discharge response to the grid, the number of V2G charging piles and the discharge power of each V2G charging pile are queried, and the intelligent controllable switch at the upper end of each V2G charging pile is closed in descending order of the discharge power of the V2G charging piles.

2. The method according to claim 1, characterized in that, The method further includes: When the power electronic fast-switch at the lower end of the transformer detects a fault in the upstream power grid, the operating status of the power electronic fast-switch at the lower end of the transformer is adjusted to open to disconnect the distribution transformer from the power grid.

3. The method according to claim 1, characterized in that, The intelligent converged terminal in the distribution area communicates with the charging pile equipment via broadband carrier / RS485 / LoRa / MESH / wireless communication.

4. A power supply protection control system based on a smart integrated terminal for distribution transformer areas, characterized in that, The system includes: The operation mode determination unit is used to enable the intelligent integrated terminal of the distribution area to obtain the operation status of the power electronic fast-switching switch at the lower end of the transformer and the operation status of the intelligent controllable switch at the upper end of all loads, and to determine the operation mode of the system based on the obtained operation status of all intelligent controllable switches. The first control unit is used to close the intelligent controllable switch at the upper end of the key load on the user side when it is determined that the system has entered the off-grid operation mode, and close the intelligent controllable switch at the upper end of the charging pile connected to the charging pile that can be adjusted to discharge to the grid according to the preset control sequence, so that the charging pile that can be adjusted to discharge to the grid can supply power to the grid. The second control unit is used to close the power electronic fast-switching switch at the lower end of the transformer and the intelligent controllable switch at the upper end of all loads when the upper-level power grid restores power supply, and adjust the charging pile that can be adjusted to discharge to the grid from the discharging state to the charging state. The operating mode determination unit determines the system's operating mode based on the acquired operating states of all intelligent controllable switches, including: When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be closed, the system is determined to enter the grid-connected operation mode. When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent controllable switch at the upper end of other loads in the distribution area is closed, it indicates that there is a large-capacity energy storage device supplying power in the distribution area. The start-up of charging and discharging control and the control strategy for starting the energy storage device are queried, and the energy storage and charging pile coordinated control mode is entered. When the operating status of the power electronic fast-switching switch at the lower end of the transformer is detected to be open, and the operating status of the intelligent controllable switches at the upper end of other loads in the distribution area is also open, the system operating mode is determined to be off-grid operation mode. The first control unit, according to a preset control sequence, closes the intelligent controllable switch at the top of the charging pile, which is connected to the charging pile capable of adjusting and controlling discharge to the power grid, including: After closing the intelligent controllable switch at the upper end of the user-side critical load, check the user-side response status of the V2G charging piles with V2G function under the transformer area. When it is determined from the user-side response that there is no electric vehicle connected to the lower end of the transformer area or the electric vehicle connected to the lower end cannot respond to discharge to the grid, this type of V2G charging pile will not be controlled; When it is determined from the user-side response that there are charging piles connected to the lower end of the transformer area that can participate in the discharge response to the grid, the number of V2G charging piles and the discharge power of each V2G charging pile are queried, and the intelligent controllable switch at the upper end of each V2G charging pile is closed in descending order of the discharge power of the V2G charging piles.

5. The system according to claim 4, characterized in that, The system also includes: The operation status adjustment unit is used to adjust the operation status of the power electronic fast-switch at the lower end of the transformer to open when the power electronic fast-switch at the lower end of the transformer detects a fault in the upper-level power grid, so as to disconnect the distribution transformer from the power grid.

6. The system according to claim 4, characterized in that, The intelligent converged terminal in the distribution area communicates with the charging pile equipment via broadband carrier / RS485 / LoRa / MESH / wireless communication.

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