Power synchronization method and device, electronic equipment, storage medium and program product

Abstract

The invention relates to a power synchronization method and device, electronic equipment, a storage medium and a program product. Under the condition of new energy grid connection, the active power of the feed-in point of each receiving-end converter station in the multi-end direct-current power transmission system is obtained, the reference power of each receiving-end converter station is determined according to the active power of the feed-in point of each receiving-end converter station, and the power of each receiving-end converter station is controlled based on the reference power of each receiving-end converter station. Due to the fact that communication delay exists when new energy transmits power to receiving-end converter stations in a large-scale and long-distance mode on the basis of given reference power, active power of feed-in points of all the receiving-end converter stations is collected, and the reference power is determined through the active power of the feed-in points of the receiving-end converter stations; and the power of each receiving-end converter station is controlled based on the reference power, so that the problems of power asynchronization and power reverse transmission of each receiving-end converter station caused by a communication delay problem are avoided.

Description

Technical Field

[0001] This application relates to the technical field of smart grids, and particularly to a power synchronization method, device, electronic device, storage medium, and program product. Background Art

[0002] New energy resources are mainly distributed in the "Three-North" and southwestern regions far from the load centers. Transmitting electricity to the load centers in the central and eastern regions requires long-distance transmission lines. However, traditional AC transmission faces significant energy losses during long-distance transmission, and new energy generation has intermittency and random volatility. Multi-terminal DC transmission systems have more flexible power dispatching and fault management capabilities, improving the stability and reliability of new energy grid connection.

[0003] When the existing multi-terminal DC transmission system starts, new energy outputs power to the converter stations at the receiving end according to the given reference power. However, there is a communication delay in the large-scale long-distance transmission of new energy, resulting in the problem of power asynchronization among the converter stations at the receiving end. Summary of the Invention

[0004] Based on this, to address the above technical problems, it is necessary to provide a power synchronization method, device, electronic device, storage medium, and program product that can achieve power synchronization of the converter stations at the receiving end.

[0005] In a first aspect, this application provides a power synchronization method, which includes:

[0006] Under the condition of new energy grid connection, obtain the active power of the feeding points of each receiving-end converter station in the multi-terminal DC transmission system;

[0007] Determine the reference power of each receiving-end converter station according to the active power of the feeding points of each receiving-end converter station;

[0008] Control the power of each receiving-end converter station based on the reference power of each receiving-end converter station.

[0009] In one embodiment, determining the reference power of each receiving-end converter station according to the active power of the feeding points of each receiving-end converter station includes:

[0010] Determine the reference power of each receiving-end converter station according to the active power of the feeding points of each receiving-end converter station and the capacity ratio of each receiving-end converter station; wherein, the capacity ratio of the i-th controlled receiving-end converter station is the ratio of the capacity of the i-th receiving-end converter station to the total capacity from the i-th receiving-end converter station to the m-th receiving-end converter station, and m is the total number of receiving-end converter stations;

[0011] Take the product of the capacity ratio of the receiving-end converter station and the corresponding active power as the reference power of the receiving-end converter station.

[0012] In one embodiment, controlling the power of each receiving-end converter station based on the reference power of each receiving-end converter station includes:

[0013] In the case where the reference powers of the receiving-end converter stations are inconsistent, determining the corresponding power growth rates according to the reference powers of the receiving-end converter stations;

[0014] Controlling the power of each receiving-end converter station based on the power growth rates of the receiving-end converter stations.

[0015] In one embodiment, the receiving-end converter station includes an MMC converter station, and the method further includes:

[0016] When each MMC converter station is charged to the rated DC voltage, closing the DC switch between the receiving-end converter station and the sending-end converter station in the multi-terminal DC power transmission system to perform uncontrolled charging on each sending-end converter station through the DC line;

[0017] Performing switching control on each sending-end converter station to perform controlled charging on each sending-end converter station;

[0018] When each sending-end converter station is charged to the rated DC voltage, controlling the grid connection of the new energy corresponding to each sending-end converter station.

[0019] In one embodiment, the receiving-end converter station further includes a current-source converter station. When each MMC converter station is charged to the rated DC voltage, closing the DC switch between the receiving-end converter station and the sending-end converter station in the multi-terminal DC power transmission system to perform uncontrolled charging on each sending-end converter station through the DC line includes:

[0020] When each MMC converter station is charged to the rated DC voltage, controlling the current-source converter station by using constant DC current;

[0021] Closing the DC switch between the receiving-end converter station and the sending-end converter station to perform uncontrolled charging on each sending-end converter station through the DC line.

[0022] In one embodiment, the method further includes:

[0023] Controlling the AC power supply corresponding to each MMC converter station to perform uncontrolled charging on each MMC converter station;

[0024] Performing controlled charging on each MMC converter station to the rated DC voltage.

[0025] In a second aspect, the present application further provides a power synchronization device, including:

[0026] An acquisition module, configured to acquire the active power of the feeding points of each receiving-end converter station in the multi-terminal DC power transmission system when the new energy is grid-connected;

[0027] A determination module, configured to determine the reference power of each receiving-end converter station according to the active power of the feeding points of each receiving-end converter station;

[0028] A control module, configured to control the power of each receiving-end converter station based on the reference power of each receiving-end converter station.

[0029] In a third aspect, the present application further provides an electronic device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0030] In the case of new energy grid connection, obtain the active power of the feeding points of each receiving-end converter station in a multi-terminal DC power transmission system;

[0031] Determine the reference power of each receiving-end converter station according to the active power of the feeding points of each receiving-end converter station;

[0032] Control the power of each receiving-end converter station based on the reference power of each receiving-end converter station.

[0033] In a fourth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0034] In the case of new energy grid connection, obtain the active power of the feeding points of each receiving-end converter station in a multi-terminal DC power transmission system;

[0035] Determine the reference power of each receiving-end converter station according to the active power of the feeding points of each receiving-end converter station;

[0036] Control the power of each receiving-end converter station based on the reference power of each receiving-end converter station.

[0037] In a fifth aspect, the present application further provides a computer program product, including a computer program. When the computer program is executed by a processor, the following steps are implemented:

[0038] In the case of new energy grid connection, obtain the active power of the feeding points of each receiving-end converter station in a multi-terminal DC power transmission system;

[0039] Determine the reference power of each receiving-end converter station according to the active power of the feeding points of each receiving-end converter station;

[0040] Control the power of each receiving-end converter station based on the reference power of each receiving-end converter station.

[0041] The above power synchronization method, device, electronic device, storage medium, and program product, in the case of new energy grid connection, obtain the active power of the feeding points of each receiving converter station in the multi-terminal DC transmission system, determine the reference power of each receiving converter station according to the active power of the feeding points of each receiving converter station, and control the power of each receiving converter station based on the reference power of each receiving converter station. Since there is a problem of communication delay in the large-scale long-distance transmission of power from new energy to the receiving converter station based on a given reference power, the embodiments of the present application collect the active power of the feeding points of each receiving converter station, determine the reference power through the active power of the feeding points of the receiving converter station, and control the power of each receiving converter station based on the reference power, avoiding the problems of power desynchronization and power reverse transmission of each receiving converter station caused by communication delay problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0043] Figure 1 It is an application environment diagram of the power synchronization method in an embodiment;

[0044] Figure 2 It is a flowchart of the power synchronization method in an embodiment;

[0045] Figure 3 It is a flowchart of the reference power determination method in an embodiment;

[0046] Figure 4 It is a flowchart of the new energy grid connection method in an embodiment;

[0047] Figure 5 It is a flowchart of the power synchronization method in another embodiment;

[0048] Figure 6 It is a structural block diagram of the power synchronization device in an embodiment;

[0049] Figure 7 It is an internal structure diagram of the electronic device in an embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] In order to make the objectives, technical solutions, and advantages of the present application clearer, the following further describes the present application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0051] The power synchronization method provided by the embodiments of the present application can be applied to, for example, Figure 1 the application environment shown. This application environment is a multi-terminal DC power transmission system, which includes electronic device 11, new energy sending end 12, and receiving end 13. The new energy sending end 12 includes multiple sending-end converter stations, and the receiving end 13 includes multiple receiving-end converter stations. Each sending-end converter station and receiving-end converter station includes a corresponding controller. After the uncontrollable charging of the sending-end converter station or receiving-end converter station is completed by using the electronic device 11, the electronic device 11 further controls the corresponding sending-end converter station or receiving-end converter station to perform controllable charging by sending control signals to each controller, so as to quickly boost the voltage of the sending-end converter station or receiving-end converter station to the rated DC voltage required for steady-state operation, and control the new energy grid connection. In the case of new energy grid connection, the electronic device 11 obtains the active power of the feeding points of each receiving-end converter station, determines the reference power of each receiving-end converter station according to the active power of the feeding points of each receiving-end converter station, and controls the power ramp-up of each receiving-end converter station according to each reference power.

[0052] Among them, the electronic device 11 can be a device including an integrated circuit, or a server. The server can be an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services.

[0053] Optionally, the multi-terminal DC power transmission system can also be a passive network power supply system or a hybrid multi-terminal DC power transmission system.

[0054] In an exemplary embodiment, as Figure 2 shown, a power synchronization method is provided. Taking the electronic device in Figure 1 as an example, it includes the following S201 to S203. Wherein:

[0055] S201, in the case of new energy grid connection, obtain the active power of the feeding points of each receiving-end converter station in the multi-terminal DC power transmission system.

[0056] Among them, the receiving-end converter station can be a modular multilevel converter (MMC), or an MMC converter station and a current source converter station.

[0057] In the embodiments of the present application, in the case of new energy grid connection, voltage sensors and current sensors can be set at the feeding points of each receiving-end converter station in the multi-terminal DC power transmission system. The voltage sensors and current sensors are used to detect the voltage and current at the feeding points of each receiving-end converter station, and the detected voltage and current are sent to the electronic device. The electronic device calculates the active power of the feeding points of each receiving-end converter station according to the voltage and current.

[0058] Optionally, as described above Figure 1 As shown, assuming there are m receiving-end converter stations, there can be m feeding points for the receiving-end converter stations; since after obtaining the reference power of the (m - 1)-th receiving-end converter station based on the active power at the (m - 1)-th feeding point, the active power (i.e., the reference power) of the m-th receiving-end converter station can be directly obtained naturally. Therefore, the feeding points of the receiving-end converter stations can also be m - 1.

[0059] S202. Determine the reference power of each receiving-end converter station according to the active power at the feeding points of each receiving-end converter station.

[0060] In the embodiments of the present application, the capacity ratio of each receiving-end converter station can be determined according to the capacity of each receiving-end converter station (i.e., the product of the rated voltage and the rated current). For example, for the i-th controlled receiving-end converter station, obtain the ratio of the capacity of the i-th receiving-end converter station to the total capacity from the i-th receiving-end converter station to the m-th receiving-end converter station, and determine the reference power of the i-th receiving-end converter station according to the active power at the feeding point of the i-th receiving-end converter station and the capacity ratio of the i-th receiving-end converter station.

[0061] In a possible implementation manner, the weight coefficients of each receiving-end converter station can also be preset based on the capacity of each receiving-end converter station, and the reference power of each receiving-end converter station can be determined according to the active power at the feeding point of the first receiving-end converter station and each weight coefficient.

[0062] S203. Control the power of each receiving-end converter station based on the reference power of each receiving-end converter station.

[0063] In the embodiments of the present application, when the reference powers of each receiving-end converter station are the same, the power of the receiving-end converter stations can be controlled to synchronously climb to the reference power based on a preset same power growth rate.

[0064] In a possible implementation manner, when the reference powers of each receiving-end converter station are different, the power growth rate corresponding to each receiving-end converter station can be determined based on each reference power, and the power of the receiving-end converter stations can be controlled to synchronously climb to the corresponding reference power based on the power growth rate of each receiving-end converter station.

[0065] In the above power synchronization method, in the case of new energy grid connection, the active power of the feeding points of each receiving converter station in the multi-terminal DC transmission system is obtained. Based on the active power of the feeding points of each receiving converter station, the reference power of each receiving converter station is determined, and the power of each receiving converter station is controlled based on the reference power of each receiving converter station. Since there is a problem of communication delay in the large-scale long-distance transmission of power from new energy to the receiving converter station based on a given reference power, the embodiments of the present application collect the active power of the feeding points of each receiving converter station, determine the reference power through the active power of the feeding points of the receiving converter station, and control the power of each receiving converter station based on the reference power, avoiding the problems of power desynchronization and power reverse transmission of each receiving converter station caused by communication delay problems.

[0066] Figure 3 As shown in the flowchart of the reference power determination method in an embodiment, Figure 3 The embodiments of the present application relate to a possible implementation manner of how to determine the reference power of each receiving converter station according to the active power of the feeding points of each receiving converter station, including the following steps:

[0067] S301. Determine the reference power of each receiving converter station according to the active power of the feeding points of each receiving converter station and the capacity ratio of each receiving converter station; where the capacity ratio of the i-th controlled receiving converter station is the ratio of the capacity of the i-th receiving converter station to the total capacity from the i-th receiving converter station to the m-th receiving converter station, and m is the total number of receiving converter stations.

[0068] In the embodiments of the present application, as shown above Figure 1 There are a total of m receiving converter stations. After obtaining m active powers, for the first receiving converter station, obtain the first total capacity from the first receiving converter station to the m-th receiving converter station, and the capacity ratio of the first receiving converter station can be obtained by using the ratio of the capacity of the first receiving converter station to the first total capacity. For the second receiving converter station, obtain the second total capacity from the second receiving converter station to the m-th receiving converter station, and the capacity ratio of the first receiving converter station can be obtained by using the ratio of the capacity of the second receiving converter station to the second total capacity.

[0069] S302. Use the product of the capacity ratio of each receiving converter station and the corresponding active power as the reference power of each receiving converter station.

[0070] In the embodiments of the present application, multiplying the capacity ratio of the same receiving converter station by the corresponding active power can obtain the reference power P i_ref of each receiving converter station, that is , S i is the capacity of the i-th receiving converter station, the total capacity from the i-th receiving converter station to the m-th receiving converter station, Pi is the active power of the i-th receiving converter station.

[0071] In a possible implementation, if the number of feeding points of the receiving converter station is m - 1, according to the capacity ratio of the (m - 1)-th receiving converter station and the active power of the feeding points of the (m - 1)-th receiving converter station, the reference power of the (m - 1)-th receiving converter station is obtained. According to the difference between the active power of the feeding points of the (m - 1)-th receiving converter station and the reference power of the (m - 1)-th receiving converter station, the reference power of the m-th receiving converter station can be obtained.

[0072] If the number of feeding points of the receiving converter station is m, the active power of the feeding points of the m-th receiving converter station is the reference power of the m-th receiving converter station.

[0073] In the embodiments of the present application, according to the active power of the feeding points of each receiving converter station and the capacity ratio of each receiving converter station, the reference power of each receiving converter station is determined, and the product of the capacity ratio of each receiving converter station and the corresponding active power is used as the reference power of each receiving converter station. In the embodiments of the present application, the reference power of the receiving converter station is determined based on the active power of each feeding point, which improves the accuracy of the reference power determination.

[0074] In one embodiment, controlling the power of each receiving converter station based on the reference power of each receiving converter station includes: in the case where the reference powers of each receiving converter station are inconsistent, determining the corresponding power growth rate according to the reference power of each receiving converter station; controlling the power of each receiving converter station based on the power growth rate of each receiving converter station.

[0075] In the embodiments of the present application, in the case where the reference powers of each receiving converter station are inconsistent, determining the corresponding power growth rate according to the reference power of each receiving converter station. For example, the reference power of receiving converter station 1 is 100 kW, the reference power of receiving converter station 2 is 110 kW, the reference power of receiving converter station 3 is 90 kW, and the reference power of receiving converter station 4 is 100 kW. According to the reference power of each receiving converter station, the power growth rate of receiving converter station 1 is determined to be 10 kW / h, the power growth rate of receiving converter station 2 is 11 kW / h, the power growth rate of receiving converter station 3 is 9 kW / h, and the power growth rate of receiving converter station 2 is 10 kW / h, or it can be said that the ratio of the power growth rates of the receiving converter stations is 10:11:9:10.

[0076] After obtaining the power growth rates of each, controlling the power of each receiving converter station to synchronously climb to the corresponding reference power based on the power growth rate of each receiving converter station.

[0077] In the embodiments of the present application, in the case where the reference powers of each receiving-end converter station are inconsistent, the corresponding power growth rates are determined according to the reference powers of each receiving-end converter station; the powers of each receiving-end converter station are controlled based on the power growth rates of each receiving-end converter station, achieving an orderly synchronous climb of the powers of each receiving-end converter station.

[0078] Figure 4 FIG. 4 is a schematic flowchart of a new energy grid connection method in an embodiment, as Figure 4 shown, and includes the following steps:

[0079] S401, when each MMC converter station is charged to the rated DC voltage, close the DC switch between the receiving-end converter station and the sending-end converter station in the multi-terminal DC power transmission system, so as to perform uncontrolled charging on each sending-end converter station through the DC line.

[0080] Wherein, the sending-end converter station is an MMC converter station.

[0081] In the embodiments of the present application, when each MMC converter station is charged to the rated DC voltage, close the DC switch between the receiving-end converter station and the sending-end converter station in the multi-terminal DC power transmission system, and perform uncontrolled charging on each sending-end converter station through the DC line and the MMC converter station to about 50% of the rated DC voltage.

[0082] S402, perform switching control on each sending-end converter station to perform controllable charging on each sending-end converter station.

[0083] In the embodiment of the present application, after uncontrolled charging to about 50% of the rated DC voltage at each sending converter station, the electronic device sends control signals to the controllers of each sending converter station. The controllers of each sending converter station start to work, and the sub-modules in each sending converter station are switched on and off through the controllers to perform controlled charging of each sending converter station to the rated DC voltage. For example, the sending converter station includes sending converter station 1, sending converter station 2, and sending converter station 3. The sub-modules of sending converter station 1 include switch S11, capacitor C11 corresponding to switch S11, switch S12, capacitor C12 corresponding to switch S12, switch S13, and capacitor C13 corresponding to switch S13; the sub-modules of sending converter station 2 include switch S21, capacitor C21 corresponding to switch S21, switch S22, capacitor C22 corresponding to switch S22, switch S23, and capacitor C23 corresponding to switch S23; the sub-modules of sending converter station 3 include switch S31, capacitor C31 corresponding to switch S31, switch S32, capacitor C32 corresponding to switch S32, switch S33, and capacitor C33 corresponding to switch S33. The electronic device sends control signals to the controllers corresponding to each sending converter station. Each controller closes switches S11, S21, and S31. After the capacitors corresponding to switches S11, S21, and S31 are charged, switches S11, S21, and S31 are disconnected, switches S12, S22, and S32 are closed, and the capacitors corresponding to switches S12, S22, and S32 are charged until the capacitors C13, C23, and C33 of each sending converter station are charged simultaneously.

[0084] S403, when each sending converter station is charged to the rated DC voltage, control the new energy corresponding to each sending converter station to be connected to the grid.

[0085] In the embodiment of the present application, when each sending converter station is charged to the rated DC voltage, the AC voltage, frequency, etc. of each sending converter station are controlled by constant AC voltage / constant frequency to reach the voltage, frequency, etc. of the power grid, and each new energy is synchronously connected to the grid.

[0086] In the embodiment of the present application, when each MMC converter station is charged to the rated DC voltage, the DC switch between the receiving converter station and the sending converter stations in the multi-terminal DC power transmission system is closed to perform uncontrolled charging of each sending converter station through the DC line, perform switching control on each sending converter station to perform controlled charging of each sending converter station, and when each sending converter station is charged to the rated DC voltage, control the new energy corresponding to each sending converter station to be connected to the grid. The embodiment of the present application performs switching control on each sending converter station to achieve orderly charging of each sending converter station, which can ensure synchronous unlocking of each sending converter station, avoid the problem of power fluctuation caused by unsynchronized unlocking of each sending converter station, improve the strength of the AC power grid of the sending converter station, and ensure reliable grid connection of new energy.

[0087] In one embodiment, the receiving end converter station further includes a current source converter station. When each MMC converter station is charged to the rated DC voltage, the DC switch between the receiving end converter station and the sending end converter station in the multi-terminal DC power transmission system is closed to uncontrollably charge each sending end converter station through the DC line, including: when each MMC converter station is charged to the rated DC voltage, the current source converter station is controlled with a constant DC current; the DC switch between the receiving end converter station and the sending end converter station is closed to uncontrollably charge each sending end converter station through the DC line.

[0088] In the embodiment of the present application, the receiving end converter station may further include a current source converter station. When each MMC converter station is charged to the rated DC voltage, the current source converter station is controlled with a constant DC current to unlock each current source converter station. Further, the DC switch between the receiving end converter station and the sending end converter station is closed, and each sending end converter station is uncontrollably charged to about 50% of the rated DC voltage through the DC line and the MMC converter station.

[0089] In the embodiment of the present application, when each MMC converter station is charged to the rated DC voltage, the current source converter station is controlled with a constant DC current; the DC switch between the receiving end converter station and the sending end converter station is closed to uncontrollably charge each sending end converter station through the DC line, fully considering the charging of the sending end converter station in various situations of the receiving end converter station, which can effectively adjust the differences in the starting conditions of different types of converter stations in the multi-terminal DC power transmission system and the system pole control strategy, enabling the multi-terminal DC power transmission system to quickly and orderly start to the rated operating condition.

[0090] In one embodiment, the method further includes: controlling the AC power supply corresponding to each MMC converter station to uncontrollably charge each MMC converter station; controllably charging each MMC converter station to the rated DC voltage.

[0091] In the embodiment of the present application, the AC power supply corresponding to each MMC converter station can be controlled to uncontrollably charge each MMC converter station. When each MMC converter station is charged to 60%-70% of the rated DC voltage, the controller in each MMC converter station starts to work, and the electronic device sends a control signal to the controller, and the controller controllably charges each MMC converter station to the rated DC voltage. Optionally, constant DC voltage, constant reactive power control, etc. can be used for controllable charging.

[0092] In the embodiment of the present application, controlling the AC power supply corresponding to each MMC converter station to uncontrollably charge each MMC converter station and controllably charging each MMC converter station to the rated DC voltage lays a foundation for subsequent charging of the sending end converter station based on the MMC converter station.

[0093] Figure 5 It is a schematic flow diagram of a power synchronization method in another embodiment. As Figure 5 shown, it includes the following steps:

[0094] S501, controlling the AC power supplies corresponding to each MMC converter station to perform uncontrolled charging on each MMC converter station;

[0095] S502, performing controllable charging on each MMC converter station until the rated DC voltage is reached;

[0096] S503, when each MMC converter station is charged to the rated DC voltage, using constant DC current to control the current source converter station;

[0097] S504, closing the DC switch between the receiving-end converter station and the sending-end converter station to perform uncontrolled charging on each sending-end converter station through the DC line;

[0098] S505, performing switching control on each sending-end converter station to perform controllable charging on each sending-end converter station;

[0099] S506, when each sending-end converter station is charged to the rated DC voltage, controlling the new energy corresponding to each sending-end converter station to be grid-connected;

[0100] S507, obtaining the active power of the feeding points of each receiving-end converter station in the multi-terminal DC power transmission system;

[0101] S508, determining the reference power of each receiving-end converter station according to the active power of the feeding points of each receiving-end converter station and the capacity ratio of each receiving-end converter station; where the capacity ratio of the i-th controlled receiving-end converter station is the ratio of the capacity of the i-th receiving-end converter station to the total capacity from the i-th receiving-end converter station to the m-th receiving-end converter station, and m is the total number of receiving-end converter stations;

[0102] S509, taking the product of the capacity ratio of each receiving-end converter station and the corresponding active power as the reference power of each receiving-end converter station;

[0103] S510, when the reference powers of each receiving-end converter station are inconsistent, determining the corresponding power growth rate according to the reference powers of each receiving-end converter station;

[0104] S511, controlling the power of each receiving-end converter station based on the power growth rate of each receiving-end converter station.

[0105] In the embodiments of the present application, switching control is performed on each sending-end converter station to achieve orderly charging of the sending-end converter station, which can ensure synchronous unlocking of the sending-end converter station, improve the strength of the AC power grid of the sending-end converter station, and ensure reliable grid connection of new energy. And by collecting the active power at the feeding points of each receiving-end converter station, determining the reference power using the active power at the feeding points of the receiving-end converter station, and controlling the power of each receiving-end converter station based on the reference power, the problems of power asynchronization and power reverse transmission of each receiving-end converter station caused by communication delay are avoided.

[0106] It should be understood that although the steps in the flowcharts involved in the above embodiments are shown in sequence according to the arrows, these steps do not necessarily have to be executed in the order indicated by the arrows. Unless there is a clear description in this article, the execution of these steps does not have a strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages. These steps or stages do not necessarily have to be executed at the same time, but can be executed at different times. The execution order of these steps or stages does not necessarily have to be sequential, but can be executed alternately or alternately with at least a part of other steps or steps or stages in other steps.

[0107] Based on the same inventive concept, the embodiments of the present application also provide a power synchronization device for implementing the power synchronization method involved above. The implementation solutions provided by this device to solve problems are similar to the implementation solutions described in the above method. Therefore, the specific limitations in one or more embodiments of the power synchronization device provided below can refer to the limitations on the power synchronization method in the above text, and will not be repeated here.

[0108] In an exemplary embodiment, as Figure 6 shown, a power synchronization device is provided, including: an acquisition module 61, a determination module 62, and a control module 63, where:

[0109] The acquisition module 61 is configured to acquire the active power at the feeding points of each receiving-end converter station in the multi-terminal DC transmission system in the case of new energy grid connection;

[0110] The determination module 62 is configured to determine the reference power of each receiving-end converter station according to the active power at the feeding points of each receiving-end converter station;

[0111] The control module 63 is configured to control the power of each receiving-end converter station based on the reference power of each receiving-end converter station.

[0112] In one embodiment, the determination module 62 is specifically configured to determine the reference power of each receiving-end converter station according to the active power at the feeding point of each receiving-end converter station and the capacity ratio of each receiving-end converter station; wherein, the capacity ratio of the i-th controlled receiving-end converter station is the ratio of the capacity of the i-th receiving-end converter station to the total capacity from the i-th receiving-end converter station to the m-th receiving-end converter station, and m is the total number of receiving-end converter stations;

[0113] Take the product of the capacity ratio of each receiving-end converter station and the corresponding active power as the reference power of each receiving-end converter station.

[0114] In one embodiment, the control module 63 is specifically configured to, when the reference powers of the receiving-end converter stations are inconsistent, determine the corresponding power growth rate according to the reference powers of the receiving-end converter stations; and control the power of each receiving-end converter station based on the power growth rate of each receiving-end converter station.

[0115] In one embodiment, the power synchronization device further includes:

[0116] The closing module is configured to close the DC switch between the receiving-end converter station and the sending-end converter station in the multi-terminal DC power transmission system when each MMC converter station is charged to the rated DC voltage, so as to perform uncontrolled charging on each sending-end converter station through the DC line;

[0117] The first charging module is configured to perform switching control on each sending-end converter station to perform controllable charging on each sending-end converter station;

[0118] The grid connection module is configured to control the grid connection of the corresponding new energy of each sending-end converter station when each sending-end converter station is charged to the rated DC voltage.

[0119] In one embodiment, the closing module is specifically configured to control the current source converter station by using constant DC current when each MMC converter station is charged to the rated DC voltage; close the DC switch between the receiving-end converter station and the sending-end converter station to perform uncontrolled charging on each sending-end converter station through the DC line.

[0120] In one embodiment, the power synchronization device further includes:

[0121] The second charging module is configured to control the AC power supply corresponding to each MMC converter station to perform uncontrolled charging on each MMC converter station;

[0122] The third charging module is configured to perform controllable charging on each MMC converter station to the rated DC voltage.

[0123] Each module in the above power synchronization device can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above modules can be embedded in the processor of the electronic device in hardware form or independent of it, or stored in the memory of the electronic device in software form, so that the processor can call and execute the operations corresponding to each of the above modules.

[0124] In an exemplary embodiment, an electronic device is provided. The electronic device can be a server, and its internal structure diagram can be as Figure 7 shown. The electronic device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the electronic device is used to store relevant data for power synchronization. The input / output interface of the electronic device is used to exchange information between the processor and external devices. The communication interface of the electronic device is used to communicate with external terminals through a network connection. When the computer program is executed by the processor, a power synchronization method is implemented.

[0125] Those skilled in the art can understand that Figure 7 the structure shown in

[0126] is only a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the electronic device to which the solution of the present application is applied. The specific electronic device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0127] In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above method embodiments are implemented.

[0128] In an embodiment, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the steps of any of the above method embodiments are implemented.

[0129] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0130] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in this application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0131] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this application.

[0132] The above embodiments only express several implementation manners of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the patent scope of this application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several deformations and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application should be subject to the appended claims.

Claims

1. A power synchronization method, characterized in that: The method comprises: In the case of renewable energy grid connection, the active power of the feed-in point of each receiving converter station in the multi-terminal DC transmission system is obtained; Determining the reference power of each receiving-end converter station according to the active power of the feeding point of each receiving-end converter station; The power of each receiving-end converter station is controlled based on the reference power of each receiving-end converter station.

2. The method according to claim 1, characterized in that Determining the reference power of each receiving-end converter station according to the active power of the feed-in point of each receiving-end converter station includes: Determine the reference power of each receiving-end converter station according to the active power of the feed-in point of each receiving-end converter station and the capacity ratio of each receiving-end converter station; wherein the capacity ratio of the i-th controlled receiving-end converter station is the ratio of the capacity of the i-th receiving-end converter station to the total capacity of the i-th receiving-end converter station to the m-th receiving-end converter station, and m is the total number of the receiving-end converter stations; The product of the capacity proportion of each receiving-end converter station and the corresponding active power is used as the reference power of each receiving-end converter station.

3. The method according to claim 1, characterized in that The controlling the power of each receiving-end converter station based on the reference power of each receiving-end converter station comprises: In the case where the reference powers of the receiving-end converter stations are inconsistent, determining the corresponding power growth rate according to the reference powers of the receiving-end converter stations; The power of each receiving-end converter station is controlled based on the power growth rate of each receiving-end converter station.

4. The method according to claim 1, characterized in that: The receiving-end converter station includes an MMC converter station, and the method further includes: When each of the MMC converter stations is charged to a rated DC voltage, a DC switch between the receiving-end converter station and the sending-end converter station in the multi-terminal DC power transmission system is closed to perform uncontrolled charging on each of the sending-end converter stations through the DC line; Performing switching control on each of the sending-end converter stations to controllably charge each of the sending-end converter stations; When each of the sending-end converter stations is charged to a rated DC voltage, the new energy source corresponding to each of the sending-end converter stations is controlled to be connected to the grid.

5. The method according to claim 4, characterized in that The receiving-end converter station further includes a current source converter station, and when each of the MMC converter stations is charged to a rated DC voltage, a DC switch between the receiving-end converter station and the sending-end converter station in the multi-terminal DC power transmission system is closed to perform uncontrolled charging on each of the sending-end converter stations through a DC line, including: When each of the MMC converter stations is charged to a rated DC voltage, a fixed DC current is used to control the current source converter station; The DC switch between the receiving-end converter station and the sending-end converter station is closed to perform uncontrolled charging on each sending-end converter station through a DC line.

6. The method according to claim 4, characterized in that The method further comprises: Controlling the AC power supply corresponding to each of the MMC converter stations to perform uncontrolled charging on each of the MMC converter stations; Each of the MMC converter stations is controllably charged to the rated DC voltage.

7. A power synchronization device, characterized in that: The device comprises: An acquisition module is used to acquire the active power of the feed-in point of each receiving-end converter station in the multi-terminal DC transmission system when the new energy is connected to the grid; A determination module, used to determine the reference power of each receiving-end converter station according to the active power of the feed-in point of each receiving-end converter station; A control module is used to control the power of each receiving-end converter station based on the reference power of each receiving-end converter station.

8. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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