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

Abstract

The application relates to a power synchronization method and device, electronic equipment, a storage medium and a program product. In the case of new energy grid connection, active power of a feed-in point of each receiving end converter station in a multi-terminal DC power transmission system is acquired, 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. Since there is a communication delay problem in large-scale long-distance power transmission from new energy to the receiving end converter station based on a given reference power, the application embodiment collects the active power of the feed-in point of each receiving end converter station, determines the reference power through the active power of the feed-in point of the receiving end converter station, controls the power of each receiving end converter station based on the reference power, and avoids the problems of power asynchronization and power reverse sending of each receiving end converter station caused by the communication delay problem.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of smart grid, and in particular to a power synchronization method and device, electronic equipment, storage medium and program product. BACKGROUND

[0002] New energy resources are mainly distributed in the "three norths" and southwest regions far away from load centers. Long-distance transmission lines are needed to transmit power to the load centers in the middle and eastern regions. However, the traditional alternating current transmission faces a large energy loss in long-distance transmission, and the new energy generation has intermittency and random fluctuation. The multi-terminal direct current transmission system has more flexible power dispatching and fault management capabilities, which improves the stability and reliability of new energy grid connection.

[0003] In the existing multi-terminal direct current transmission system, the new energy outputs power to the receiving end converter station according to the given reference power during startup, but there is a communication delay in large-scale long-distance transmission of new energy, causing the power of each receiving end converter station to be out of synchronization. SUMMARY

[0004] Therefore, it is necessary to provide a power synchronization method, device, electronic equipment, storage medium and program product capable of realizing power synchronization of the receiving end converter station to solve the above technical problems.

[0005] In a first aspect, the present application provides a power synchronization method, which comprises:

[0006] In the case of new energy grid connection, the active power of the feed-in point of each receiving end converter station in the multi-terminal direct current transmission system is obtained;

[0007] 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;

[0008] The power of each receiving end converter station is controlled based on the reference power of each receiving end converter station.

[0009] In one of the embodiments, 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, which comprises:

[0010] 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 capacity proportion of each receiving end converter station; wherein the capacity proportion of the i th controlled receiving end converter station is the proportion 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] The product of the capacity proportion of the receiving end converter station and the corresponding active power is taken as the reference power of the receiving end converter station.

[0012] In one of the embodiments, the power of each receiving converter station is controlled based on the reference power of each receiving converter station, including:

[0013] In the case that the reference power of each receiving converter station is inconsistent, the power growth rate of each receiving converter station is determined according to the reference power of each receiving converter station;

[0014] The power of each receiving converter station is controlled based on the power growth rate of each receiving converter station.

[0015] In one of the embodiments, the receiving converter station includes an MMC converter station, and the method further includes:

[0016] In the case that each MMC converter station is charged to the rated DC voltage, the DC switch between the receiving converter station and the sending converter station in the multi-terminal DC power transmission system is closed to perform uncontrolled charging of each sending converter station through the DC line;

[0017] The sending converter station is controlled to be switched on and off to perform controlled charging of each sending converter station;

[0018] In the case that each sending converter station is charged to the rated DC voltage, the corresponding new energy of each sending converter station is controlled to be connected to the grid.

[0019] In one of the embodiments, the receiving converter station further includes a current source converter station, and in the case that each MMC converter station is charged to the rated DC voltage, the DC switch between the receiving converter station and the sending converter station in the multi-terminal DC power transmission system is closed to perform uncontrolled charging of each sending converter station through the DC line, including:

[0020] In the case that each MMC converter station is charged to the rated DC voltage, the current source converter station is controlled by a constant DC current;

[0021] The DC switch between the receiving converter station and the sending converter station is closed to perform uncontrolled charging of each sending converter station through the DC line.

[0022] In one of the embodiments, the method further includes:

[0023] The MMC converter station is controlled to be charged by the corresponding AC power source of each MMC converter station;

[0024] Each MMC converter station is controlled to be charged to the rated DC voltage.

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

[0026] The acquisition module is configured to acquire the active power of the feed-in point of each receiving converter station in the multi-terminal DC power transmission system in the case that the new energy is connected to the grid;

[0027] determining a reference power of each receiving-end converter station according to the active power of the feed-in point of the receiving-end converter station;

[0028] controlling 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 provides an electronic device, comprising a memory and a processor, the memory storing a computer program, and the processor implementing the following steps when executing the computer program:

[0030] In the case of new energy grid connection, obtaining the active power of the feed-in point of each receiving-end converter station in the multi-terminal DC power transmission system;

[0031] determining a reference power of each receiving-end converter station according to the active power of the feed-in point of the receiving-end converter station;

[0032] controlling 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 provides a computer readable storage medium, which stores a computer program, and the computer program implements the following steps when executed by a processor:

[0034] In the case of new energy grid connection, obtaining the active power of the feed-in point of each receiving-end converter station in the multi-terminal DC power transmission system;

[0035] determining a reference power of each receiving-end converter station according to the active power of the feed-in point of the receiving-end converter station;

[0036] controlling 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 provides a computer program product, comprising a computer program, and the computer program implements the following steps when executed by a processor:

[0038] In the case of new energy grid connection, obtaining the active power of the feed-in point of each receiving-end converter station in the multi-terminal DC power transmission system;

[0039] determining a reference power of each receiving-end converter station according to the active power of the feed-in point of the receiving-end converter station;

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

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

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the drawings needed to be used in the description of the embodiments of the present application or the related art will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other related drawings can be obtained by those skilled in the art without creative labor.

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

[0044] Figure 2 The flowchart of the power synchronization method in an embodiment;

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

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

[0047] Figure 5 The flowchart of the power synchronization method in another embodiment;

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

[0049] Figure 7 The internal structure diagram of the electronic equipment in an embodiment. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0051] The power synchronization method provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. The application environment is a multi-terminal DC transmission system, which includes an electronic device 11, a new energy sending end 12, and a 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 electronic device 11 controls the uncontrolled charging of the sending end converter station or the receiving end converter station, the electronic device 11 sends a control signal to each controller, and further controls the corresponding sending end converter station or the receiving end converter station to perform controllable charging, so as to quickly increase the voltage of the sending end converter station or the receiving end converter station to the rated DC voltage required for steady-state operation, thereby controlling the new energy grid connection. In the case of new energy grid connection, the electronic device 11 obtains the active power of the feed-in point of each receiving end converter station, determines the reference power of each receiving end converter station based on the active power of the feed-in point of each receiving end converter station, and controls the power ramp of each receiving end converter station based on the reference power.

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

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

[0054] In an exemplary embodiment, Figure 2 As shown, a power synchronization method is provided, which is applied to Figure 1 The electronic device in the embodiment is used as an example to illustrate, including the following S201 to S203.

[0055] S201, when new energy is connected to the grid, obtaining the active power of the feed-in point of each receiving-end converter station in the multi-terminal direct current transmission system.

[0056] The receiving-end converter station may be a modular multilevel converter station (MMC), or an MMC converter station and a current source converter station.

[0057] In an embodiment of the present application, when new energy is connected to the grid, a voltage sensor and a current sensor can be set at the feeding point of each receiving converter station in the multi-terminal DC transmission system. The voltage and current of the feeding point of each receiving converter station are detected by using the voltage sensor and the current sensor, and the detected voltage and current are sent to the electronic device. The electronic device calculates the active power of the feeding point of each receiving converter station based on the voltage and current.

[0058] Optionally, as shown in the above Figure 1 m, the feeding points of the receiving end converter stations can be m; since the reference power of the m-1th receiving end converter station is obtained based on the active power of the m-1th feeding point, the active power (i.e. the reference power) of the mth receiving end converter station can be obtained directly, therefore, the feeding points of the receiving end converter stations can also be m-1.

[0059] S202, determining reference powers of the receiving end converter stations according to the active powers of the feeding points of the receiving end converter stations.

[0060] In the embodiments of the present application, the capacity proportion of each receiving end converter station can be determined according to the capacity (i.e. the product of rated voltage and rated current) of each receiving end converter station, for example, for the ith controlled receiving end converter station, the capacity proportion of the ith receiving end converter station to the total capacity of the ith receiving end converter station to the mth receiving end converter station is obtained, and the reference power of the ith receiving end converter station is determined according to the active power of the feeding point of the ith receiving end converter station and the capacity proportion of the ith receiving end converter station.

[0061] In one possible implementation, the weight coefficients of the receiving end converter stations can also be set in advance based on the capacities of the receiving end converter stations, and the reference powers of the receiving end converter stations are determined according to the active power of the feeding point of the first receiving end converter station and the weight coefficients.

[0062] S203, controlling the powers of the receiving end converter stations based on the reference powers of the receiving end converter stations.

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

[0064] In one possible implementation, when the reference powers of the receiving end converter stations are inconsistent, the power increasing rates corresponding to the receiving end converter stations can be determined based on the reference powers, and the powers of the receiving end converter stations can be controlled to synchronously climb to the corresponding reference powers based on the power increasing rates of the receiving end converter stations.

[0065] In the power synchronization method, in the case of grid connection of new energy, active power of a feeding point of each receiving end converter station in a multi-terminal DC power transmission system is obtained, reference power of each receiving end converter station is determined according to the active power of the feeding point of each receiving end converter station, and power of each receiving end converter station is controlled based on the reference power of each receiving end converter station. Since there is a communication delay problem in large-scale long-distance power transmission from the new energy to the receiving end converter station based on the given reference power, the embodiment of the application collects the active power of the feeding point of each receiving end converter station, determines the reference power through the active power of the feeding point of the receiving end converter station, and controls the power of each receiving end converter station based on the reference power, thereby avoiding the problems of power asynchronization and power reverse sending of each receiving end converter station caused by the communication delay problem.

[0066] Figure 3 As shown in a flowchart of a reference power determination method in one embodiment, the embodiment of the application relates to a possible implementation manner of how to determine the reference power of each receiving end converter station according to the active power of the feeding point of each receiving end converter station, and includes the following steps. Figure 3

[0067] S301, reference power of each receiving end converter station is determined according to active power of a feeding point of each receiving end converter station and capacity proportion of each receiving end converter station; wherein the capacity proportion of the i th controlled receiving end converter station is the proportion 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 receiving end converter stations.

[0068] In the embodiment of the application, as shown in the above Figure 1 , the receiving end converter stations are totally m, after obtaining the m active powers, for the 1 st receiving end converter station, the first total capacity of the 1 st receiving end converter station to the m th receiving end converter station is obtained, and the capacity proportion of the 1 st receiving end converter station can be obtained by using the ratio of the capacity of the 1 st receiving end converter station to the first total capacity. For the 2 nd receiving end converter station, the second total capacity of the 2 nd receiving end converter station to the m th receiving end converter station is obtained, and the capacity proportion of the 1 st receiving end converter station can be obtained by using the ratio of the capacity of the 2 nd receiving end converter station to the second total capacity.

[0069] S302, the product of the capacity proportion of each receiving end converter station and the corresponding active power is taken as the reference power of each receiving end converter station.

[0070] In the embodiment of the application, the capacity proportion of the same receiving end converter station is multiplied by the corresponding active power, and the reference power P i_ref of each receiving end converter station can be obtained, that is , S i is the capacity of the i th receiving end converter station, the total capacity of the i th receiving end converter station to the m th receiving end converter station, and P​i Active power of the i-th receiving end converter station.

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

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

[0073] In the embodiments of the present application, the reference power of each receiving end converter station is determined according to the active power of the feeding point of each receiving end converter station and the capacity proportion of each receiving end converter station, and the product of the capacity proportion of each receiving end converter station and the corresponding active power is taken as the reference power of each receiving end converter station. In the embodiments of the present application, the reference power of the receiving end converter station is determined based on the active power of each feeding point, thereby improving the accuracy of the reference power determination.

[0074] In an embodiment, the power of each receiving end converter station is controlled based on the reference power of each receiving end converter station, including: in the case that the reference power of each receiving end converter station is inconsistent, determining the corresponding power growth rate according to the reference power of each receiving end converter station; and controlling the power of each receiving end converter station based on the power growth rate of each receiving end converter station.

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

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

[0077] In an embodiment of the present application, when the reference powers of the receiving converter stations are inconsistent, the corresponding power growth rate is determined according to the reference power of each receiving converter station; the power of each receiving converter station is controlled based on the power growth rate of each receiving converter station, thereby achieving an orderly and synchronous increase in the power of each receiving converter station.

[0078] Figure 4 FIG. 1 is a flow chart of a new energy grid connection method in one embodiment. Figure 4 As shown, the following steps are included:

[0079] S401, 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 transmission system to perform uncontrolled charging on each sending-end converter station through the DC line.

[0080] Among them, the sending-end converter station is the MMC converter station.

[0081] 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-end converter station and the sending-end converter station in the multi-terminal DC transmission system is closed, and each sending-end converter station is uncontrolled charged to about 50% of the rated DC voltage through the DC line and the MMC converter station.

[0082] S402: Control the switching of each sending-end converter station to perform controllable charging of each sending-end converter station.

[0083] In the embodiment of the present application, after each sending-end converter station is charged to about 50% of the rated DC voltage, the electronic device sends a control signal to the controller of each sending-end converter station, and the controller of each sending-end converter station starts to work, and the controller controls the switching of the sub-modules in each sending-end converter station to controllably charge each sending-end converter station to the rated DC voltage. For example, the sending-end converter station includes sending-end converter station 1, sending-end converter station 2 and sending-end converter station 3, the sub-modules of the sending-end 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 the sending-end 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; and the sub-modules of the sending-end 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 a control signal to the controller corresponding to each sending-end converter station, each controller closes switches S11, S21 and S31, and after charging the capacitors corresponding to switches S11, S21 and S31 is completed, switches S11, S21 and S31 are opened, 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-end converter station are simultaneously charged to completion.

[0084] S403, in the case that each sending-end converter station is charged to the rated DC voltage, controlling each sending-end converter station corresponding new energy to be grid-connected.

[0085] In the embodiment of the present application, in the case that each sending-end converter station is charged to the rated DC voltage, the AC voltage and frequency of each sending-end converter station are controlled to reach the voltage and frequency of the grid by fixed AC voltage / fixed frequency control, and each new energy is synchronously grid-connected.

[0086] In the embodiment of the present application, in the case that 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, and the switching control of each sending-end converter station is performed to controllably charge each sending-end converter station, and in the case that each sending-end converter station is charged to the rated DC voltage, the new energy corresponding to each sending-end converter station is controlled to be grid-connected. The switching control of each sending-end converter station in the embodiment of the present application is performed to orderly charge each sending-end converter station, which can ensure that each sending-end converter station is synchronously unlocked, avoid the problem of power fluctuation caused by the unsynchronized unlocking of each sending-end converter station, improve the strength of the AC grid of the sending-end converter station, and ensure the reliable grid-connection of the new energy.

[0087] In one embodiment, the receiving end converter station further comprises a current source converter station, in the case that 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 uncontrolled charge each sending end converter station through the DC line, comprising: in the case that each MMC converter station is charged to the rated DC voltage, using a constant DC current to control the current source converter station; closing the DC switch between the receiving end converter station and the sending end converter station to uncontrolled charge each sending end converter station through the DC line.

[0088] In the embodiments of the present application, the receiving end converter station can further comprise a current source converter station, in the case that each MMC converter station is charged to the rated DC voltage, using a constant DC current to control the current source converter station to unlock each current source converter station, and further closing the DC switch between the receiving end converter station and the sending end converter station to uncontrolled charge each sending end converter station through the DC line and the MMC converter station to about 50% of the rated DC voltage.

[0089] In the embodiments of the present application, in the case that each MMC converter station is charged to the rated DC voltage, using a constant DC current to control the current source converter station; closing the DC switch between the receiving end converter station and the sending end converter station to uncontrolled charge each sending end converter station through the DC line, fully considering the case that the receiving end converter station charges the sending end converter station under various conditions, which can effectively adjust the difference of the starting conditions of different types of converter stations in the multi-terminal DC power transmission system and the system pole control strategy, so that the multi-terminal DC power transmission system can be quickly and orderly started to the rated operating condition.

[0090] In one embodiment, the method further comprises: controlling the corresponding AC power source of each MMC converter station to uncontrolled charge each MMC converter station; and controlled charging each MMC converter station to the rated DC voltage.

[0091] In the embodiments of the present application, the corresponding AC power source of each MMC converter station can be controlled to uncontrolled charge each MMC converter station, in the case that each MMC converter station is charged to 60%-70% of the rated DC voltage, the controller in each MMC converter station starts to work, the electronic device sends a control signal to the controller, and the controller controlled charges each MMC converter station to the rated DC voltage. Optionally, the constant DC voltage, constant reactive power control and other methods can be used for controlled charging.

[0092] In the embodiments of the present application, the corresponding AC power source of each MMC converter station is controlled to uncontrolled charge each MMC converter station, and each MMC converter station is controlled charged to the rated DC voltage, which lays a foundation for subsequent charging of the sending end converter station based on the MMC converter station.

[0093] Figure 5 For another embodiment of the flowchart of the power synchronization method, as shown in Figure 5 includes the following steps:

[0094] S501, control the corresponding AC power of each MMC converter station to charge each MMC converter station without control;

[0095] S502, controllable charging to the rated DC voltage of each MMC converter station;

[0096] S503, in the case of charging to the rated DC voltage of each MMC converter station, using the constant DC current control current source converter station;

[0097] S504, close the DC switch between the receiving end converter station and the sending end converter station, to charge each sending end converter station without control through the DC line;

[0098] S505, switching control of each sending end converter station to controllably charge each sending end converter station;

[0099] S506, in the case of charging to the rated DC voltage of each sending end converter station, control the corresponding new energy grid connection of each sending end converter station;

[0100] S507, obtain the active power of the feed-in point of each receiving end converter station in the multi-terminal DC power transmission system;

[0101] S508, according to the active power of the feed-in point of each receiving end converter station and the capacity proportion of each receiving end converter station, determine the reference power of each receiving end converter station; wherein the capacity proportion of the ith controlled receiving end converter station is the capacity proportion of the ith receiving end converter station to the total capacity of the ith receiving end converter station to the mth receiving end converter station, m is the total number of receiving end converter stations;

[0102] S509, the product of the capacity proportion of each receiving end converter station and the corresponding active power is taken as the reference power of each receiving end converter station;

[0103] S510, in the case that the reference power of each receiving end converter station is inconsistent, determine the corresponding power growth rate according to the reference power of each receiving end converter station;

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

[0105] The embodiments of the present application perform switching control on each sending-end converter station to realize 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 the new energy. In addition, the active power of the feeding point of each receiving-end converter station is collected, the reference power is determined by using the active power of the feeding point of the receiving-end converter station, the power of each receiving-end converter station is controlled based on the reference power, and the problems of power asynchronization and power reverse feeding of each receiving-end converter station caused by communication delay are avoided.

[0106] It should be understood that, although each step in the flowchart involved in the above embodiments is displayed in sequence according to the arrow, these steps are not necessarily executed in the order indicated by the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other orders. Moreover, at least part of the steps in the flowchart involved in the above embodiments can include multiple steps or stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be executed in rotation or alternation with at least 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 above-mentioned power synchronization method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more power synchronization device embodiments provided below can refer to the limitations of the power synchronization method in the above text, which will not be repeated here.

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

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

[0110] The determination module 62 is configured to determine the reference power of each receiving-end converter station according to the active power of the feeding point 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 determining module 62 is specifically configured to determine the reference power of each of the controlled receiving converter stations according to the active power of the feed-in point of each of the receiving converter stations and the capacity proportion of each of the receiving converter stations; wherein the capacity proportion of the i th controlled receiving converter station is the proportion of the capacity of the i th receiving converter station to the total capacity of the i th receiving converter station to the m th receiving converter station, and m is the total number of the receiving converter stations.

[0113] The product of the capacity proportion of each of the receiving converter stations and the corresponding active power is taken as the reference power of each of the receiving converter stations.

[0114] In one embodiment, the control module 63 is specifically configured to determine the power growth rate of each of the receiving converter stations according to the reference power of each of the receiving converter stations in the case that the reference power of each of the receiving converter stations is inconsistent; and control the power of each of the receiving converter stations based on the power growth rate of each of the receiving converter stations.

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

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

[0117] The first charging module is configured to perform switching control on each of the sending converter stations, so as to perform controllable charging on each of the sending converter stations.

[0118] The grid connection module is configured to control the corresponding new energy of each of the sending converter stations to be connected to the grid in the case that each of the sending converter stations is charged to the rated DC voltage.

[0119] In one embodiment, the closing module is specifically configured to adopt the constant DC current control current source converter station in the case that each of the MMC converter stations is charged to the rated DC voltage; and close the DC switch between the receiving converter station and the sending converter station, so as to perform uncontrolled charging on each of the sending converter stations through the DC line.

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

[0121] The second charging module is configured to control the corresponding AC power source of each of the MMC converter stations to perform uncontrolled charging on each of the MMC converter stations.

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

[0123] The modules in the power synchronization device can be implemented by software, hardware, or a combination thereof, in whole or in part. The modules can be embedded in or independent of a processor in the electronic device in hardware form, or stored in a memory in the electronic device in software form, so as to be invoked and executed by the processor to perform the operations corresponding to the modules.

[0124] In an example embodiment, an electronic device, which can be a server, has an internal structure as shown in Figure 7 The electronic device includes a processor, a memory, an input / output interface, and a communication interface. 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. The processor of the electronic device is configured 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 running the operating system and the computer program in the non-volatile storage medium. The database of the electronic device is configured to store related data for power synchronization. The input / output interface of the electronic device is configured to exchange information between the processor and external devices. The communication interface of the electronic device is configured to communicate with external terminals through a network connection. The computer program is executed by the processor to implement a power synchronization method.

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

[0126] In an example embodiment, an electronic device is provided, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of any of the above method embodiments.

[0127] In an embodiment, a computer readable storage medium is provided, which stores a computer program. The computer program is executed by a processor to implement the steps of any of the above method embodiments.

[0128] In an embodiment, a computer program product is provided, which includes a computer program. The computer program is executed by a processor to implement the steps of any of the above method embodiments.

[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 used 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 must comply with relevant regulations.

[0130] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the 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-mentioned methods. Among them, any reference to memory, database or other media 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), magnetic 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 take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), quantum computing-based data processing logic devices, artificial intelligence (AI) processors, and the like.

[0131] Any technical features in the above embodiments can be combined, and for the sake of brevity, not all possible combinations are described above, however, any combination of these technical features is deemed to be within the scope of the present application.

[0132] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be pointed out that, for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A power synchronization method, characterized in that: The method comprises: When renewable energy is connected to the grid, the active power at the feed-in point of each receiving converter station in the multi-terminal DC transmission system is obtained; determining a reference power of each receiving-end converter station according to the active power of the feed-in point of each receiving-end converter station; In the case where the reference powers of the receiving converter stations are inconsistent, determining a corresponding power growth rate according to the reference power of each receiving converter station, and controlling the power of each receiving converter station based on the power growth rate of each receiving converter station; Determining the reference power of each receiving converter station according to the active power of the feed-in point of each receiving converter station includes: determining the reference power of each receiving converter station according to the active power of the feed-in point of each receiving converter station and the capacity ratio of each receiving converter station; wherein 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 of the i-th receiving converter station to the m-th receiving converter station, and m is the total number of the receiving converter stations; The determining of 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 proportion of each receiving-end converter station includes: 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.

2. 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, closing the DC switch between the receiving-end converter station and the sending-end converter station in the multi-terminal DC transmission system 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 perform controllable charging on each of the sending-end converter stations; When each of the sending-end converter stations is charged to the rated DC voltage, the new energy source corresponding to each of the sending-end converter stations is controlled to be connected to the grid.

3. The method according to claim 2, characterized in that The receiving-end converter station further includes a current source converter station. When each of the MMC converter stations is charged to a 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 perform uncontrolled charging on each of the sending-end converter stations through the DC line, including: When each of the MMC converter stations is charged to a rated DC voltage, a constant 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 the DC line.

4. The method according to claim 2, 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.

5. A power synchronization device, characterized in that: The device comprises: An acquisition module is used to obtain the active power of the feed-in point of each receiving-end converter station in the multi-terminal DC transmission system when new energy is connected to the grid; a determination module, configured 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 configured to, when the reference powers of the receiving-end converter stations are inconsistent, determine a corresponding power growth rate according to the reference powers of the receiving-end converter stations, and control the power of the receiving-end converter stations based on the power growth rate of the receiving-end converter stations; The determination module is specifically configured to determine the reference power of each receiving converter station according to the active power of the feed-in point of each receiving converter station and the capacity ratio of each receiving converter station; wherein 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 of the i-th receiving converter station to the m-th receiving converter station, where m is the total number of the receiving converter stations; The determining module is specifically configured to use the product of the capacity proportion of each receiving-end converter station and the corresponding active power as the reference power of each receiving-end converter station.

6. 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 4 are implemented.

7. 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 4 are implemented.

8. 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 4 are implemented.

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