Passive converter station online input method and system

Abstract

The invention relates to the technical field of direct current transmission, and discloses a passive converter station on-line input method and system, which can complete on-line input of a passive converter station under the condition that each operating converter station is not stopped, reduce the power interruption time of each operating converter station, and improve the power supply efficiency. The wind curtailment phenomenon caused by too long input operation time of the passive converter station is avoided, the economy and flexibility of offshore multi-terminal flexible direct delivery are improved, and the technical problem of how to realize online input of the passive converter station is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of direct current transmission, and in particular to an online input method and system for a passive converter station. Background Art

[0002] So far, many offshore wind power transmission projects have been built around the world. Considering that offshore wind power resources are very rich in coastal areas, but the distance between offshore wind power and the landing point and the load center area is relatively long, if DC is used to set up an on-site inverter station on land, there will be difficulties in absorbing the AC power grid. With the large-scale cluster development of offshore wind power, more new AC lines need to be built to meet the demand for high-power transmission. This method is costly and inefficient, and it will also waste a lot of line corridor resources, making it difficult to achieve economical, efficient and accurate power transmission.

[0003] By using multiple offshore wind farms to send power to onshore collection stations via multiple DC cable lines, and then converging DC pole lines and sending them directly to load centers via multi-terminal DC overhead lines, the problem of large-capacity offshore wind power transmission and consumption can be well solved, and the power supply reliability and availability can be improved. Using DC overhead lines to transmit power on land can reduce project costs and construction difficulties, and save line corridor resources. Setting up multiple landing points at the receiving end can solve the problem of power transmission to multiple load centers and play a positive role in the safety and stability of the power grid.

[0004] However, there is a possibility of failure and shutdown of offshore converter stations, resulting in the disconnection of grid-connected wind turbines. The offshore converter stations will be in a passive state and will need to be black-started after troubleshooting. After starting the converter, the AC voltage is established through converter control to complete the grid-connected operation of the wind turbines. Currently, there is no online commissioning technology for passive converter stations, and only the commissioning technology for offshore active converter stations exists. In existing projects, the commissioning of offshore active converter stations requires the shutdown of the operating stations, and then the connection of the converter stations to the DC system, and finally the unlocking of each converter station to complete the commissioning of the converter stations. However, this commissioning method involves long-term power interruptions, which has a significant impact on the operation of the converter stations in operation, reducing the economy and flexibility of multi-terminal flexible DC transmission. There is an urgent need for an online commissioning solution for passive converter stations. Summary of the invention

[0005] The invention provides a method and system for online input of a passive converter station, which solves the technical problem of how to realize online input of a passive converter station.

[0006] A first aspect of the present invention provides a method for online commissioning of a passive converter station, comprising:

[0007] In response to an online input request for an offshore DC system, a passive converter station of the offshore DC system is determined, wherein the offshore DC system includes a plurality of operating converter stations and the passive converter station, and the passive converter station is an operating converter station disconnected from a generator set in the offshore DC system;

[0008] When the passive converter station meets the preset grid-connected condition, the plurality of operating converter stations are adjusted based on the first preset adjustment strategy and the first preset adjustment condition, so that the operating converter stations suspend power transmission;

[0009] When the voltage of the passive converter station reaches a preset voltage value, the isolating switch on the DC line of the passive converter station is controlled to close, a DC transmission channel is established, and based on a second preset adjustment strategy and a second preset adjustment condition, a plurality of the operating converter stations are adjusted so that the operating converter stations resume power transmission;

[0010] When the passive converter station meets the preset input conditions, the passive converter station is unlocked.

[0011] Optionally, responding to the online commissioning request for the offshore DC system and determining the passive converter station of the offshore DC system comprises:

[0012] In response to receiving an online commissioning request of an offshore DC system, determining a plurality of operating converter stations corresponding to the offshore DC system;

[0013] Determining whether the backup power supply of the operating converter station is in working state;

[0014] If the backup power supply of the operating converter station is in a working state, it is determined that the operating converter station is the passive converter station.

[0015] Optionally, the preset grid-connected condition is whether the control and protection system of the passive converter station and the primary energized area are in normal operating state.

[0016] Optionally, adjusting the plurality of operating converter stations based on a first preset adjustment strategy and a first preset adjustment condition includes:

[0017] Adjusting the first voltage and the first power of the plurality of operating converter stations according to the first preset adjustment strategy until the first voltage and the first power of each operating converter station meet the first preset adjustment condition;

[0018] Wherein, the first preset adjustment strategy is to simultaneously reduce the first voltage and the first power of the plurality of operating converter stations according to the preset adjustment gradient;

[0019] Among them, the first preset adjustment condition is that the first voltage and the first power of all the operating converter stations are adjusted to the first preset adjustment threshold, and the first power of each operating converter station is adjusted to the first preset adjustment threshold before the first voltage.

[0020] Optionally, adjusting the plurality of operating converter stations based on a second preset adjustment strategy and a second preset adjustment condition includes:

[0021] adjusting the second voltage and the second power of the plurality of operating converter stations according to a second preset adjustment strategy until the second voltage and the second power of the plurality of operating converter stations meet a second preset adjustment condition;

[0022] Wherein, the second preset regulation strategy is to simultaneously raise the second voltage and the second power of the plurality of operating converter stations according to the preset regulation gradient;

[0023] Among them, the second preset adjustment condition is that the second voltage of each of the operating converter stations is raised to a second preset voltage adjustment threshold, and the second power of each of the operating converter stations is raised to the associated first power.

[0024] Optionally, when the passive converter station meets a preset input condition, the unlocking operation is performed on the passive converter station, including:

[0025] The preset input condition is that the passive converter station meets the preset charging requirements and the operation mode of the passive converter station is the preset control mode;

[0026] When the passive converter station meets the preset charging requirement, determining whether the operation mode of the passive converter station is a preset control mode;

[0027] The preset charging requirement is that the passive converter station sequentially performs uncontrolled charging on the DC side and controlled charging on the DC side, and the passive converter station completes controlled charging on the DC side;

[0028] When the operation mode is the preset control mode, the passive converter station is unlocked.

[0029] A second aspect of the present invention provides a passive converter station online input system, comprising:

[0030] A response module, used to respond to an online input request for an offshore DC system, and determine a passive converter station of the offshore DC system, wherein the offshore DC system includes a plurality of operating converter stations and the passive converter station, and the passive converter station is an operating converter station disconnected from a generator set in the offshore DC system;

[0031] A grid connection judgment module, configured to adjust the plurality of operating converter stations based on a first preset adjustment strategy and a first preset adjustment condition when the passive converter station meets the preset grid connection condition, so that the operating converter stations suspend power transmission;

[0032] A voltage judgment module is used to control the disconnector on the DC line of the passive converter station to close when the voltage of the passive converter station reaches a preset voltage value, establish a DC transmission channel, and adjust the plurality of operating converter stations based on a second preset adjustment strategy and a second preset adjustment condition, so that the operating converter stations resume power transmission;

[0033] The online activation module is used to unlock the passive converter station when the passive converter station meets the preset activation conditions.

[0034] A third aspect of the present invention provides an electronic device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the method for online commissioning of a passive converter station as described in any one of the above items.

[0035] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed, the method for online commissioning of a passive converter station as described in any one of the above items is implemented.

[0036] A fifth aspect of the present invention provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer executes the method for online commissioning of a passive converter station as described in any one of the above items.

[0037] It can be seen from the above technical solutions that the present invention has the following advantages:

[0038] In the present invention, in response to an online input request for an offshore DC system, a passive converter station of the offshore DC system is determined, wherein the offshore DC system includes a plurality of operating converter stations and a passive converter station, and the passive converter station is an operating converter station disconnected from the generator set in the offshore DC system; when the passive converter station meets a preset grid-connected condition, based on a first preset adjustment strategy and a first preset adjustment condition, the plurality of operating converter stations are adjusted so that the operating converter station suspends power transmission; when the voltage of the passive converter station reaches a preset voltage value, the isolating switch on the DC line of the passive converter station is controlled to perform a closing operation to establish a DC transmission channel, and based on a second preset adjustment strategy and a second preset adjustment condition, the plurality of operating converter stations are adjusted so that The operating converter station resumes power transmission; when the passive converter station meets the preset input conditions, the passive converter station is unlocked. The present invention adopts a control strategy consisting of a grid-connected condition, a first preset adjustment strategy, a first preset adjustment condition, a second preset adjustment strategy, a second preset adjustment condition and a preset input condition, and adopts the control strategy to respectively control multiple operating converter stations and passive converter stations, so that the online input of the passive converter station can be completed without stopping the operation of each operating converter station, thereby reducing the power interruption time of each operating converter station, avoiding the wind abandonment caused by the passive converter station being put into operation for too long, improving the economy and flexibility of offshore multi-terminal flexible direct current transmission, and solving the technical problem of how to realize the online input of the passive converter station. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0040] Figure 1 A flowchart of the steps of a method for online operation of a passive converter station provided in Embodiment 1 of the present invention;

[0041] Figure 2 A flowchart of the steps of a method for online operation of a passive converter station provided in the second embodiment of the present invention;

[0042] Figure 3 This is a structural diagram of an offshore wind power multi-terminal DC transmission system;

[0043] Figure 4 The topological structure diagram of the offshore converter station and the onshore converter station;

[0044] Figure 5 Schematic diagram of the charging circuit for uncontrolled charging on the DC side of the passive converter station;

[0045] Figure 6 A schematic diagram of the positive current path of the half-bridge submodule in a locked state;

[0046] Figure 7 It is a schematic diagram of the negative current path when the half-bridge submodule is in a locked state;

[0047] Figure 8 It is a schematic diagram of the positive current path when the full-bridge submodule is in a locked state;

[0048] Fig. 9 It is a schematic diagram of the negative current path when the full-bridge submodule is in a locked state;

[0049] Fig.10 It is a schematic diagram of the positive current path when the half-bridge submodule is in the on state;

[0050] Fig.11 It is a schematic diagram of the negative current path when the half-bridge submodule is in the on state;

[0051] Fig.12 It is a schematic diagram of the positive current path of the full-bridge submodule in the positive input state;

[0052] Fig.13 It is a schematic diagram of the negative current path when the full-bridge submodule is in the positive input state;

[0053] Fig.14 It is a schematic diagram of the positive current path of the full-bridge submodule in the negative input state;

[0054] Fig.15 It is a schematic diagram of the negative current path when the full-bridge submodule is in a negative input state;

[0055] Fig.16 Schematic diagram of the charging circuit for controlling DC side charging of the passive converter station;

[0056] Fig.17 It is a schematic diagram of the positive current path when the half-bridge submodule is in the cut-off state;

[0057] Fig.18 It is a schematic diagram of the negative current path when the half-bridge submodule is in the cut-off state;

[0058] Fig.19 It is a schematic diagram of the positive current path when the full-bridge submodule is in the cut-off state;

[0059] Fig. 20 It is a schematic diagram of the negative current path when the full-bridge submodule is in the cut-off state;

[0060] Fig.21 A structural block diagram of a passive converter station online input system provided in Embodiment 3 of the present invention;

[0061] Fig. 22 This is a structural block diagram of a computer device provided in Embodiment 4 of the present invention. DETAILED DESCRIPTION

[0062] The embodiment of the present invention provides a method and system for online input of a passive converter station, which are used to solve the technical problem of how to realize online input of a passive converter station.

[0063] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] See also Figure 1 , Figure 1 A flowchart of the steps of a method for online commissioning of a passive converter station provided in Embodiment 1 of the present invention.

[0065] The present invention provides a method for online operation of a passive converter station, comprising:

[0066] Applied to the multi-terminal DC transmission system of offshore renewable energy power generation, the multi-terminal DC transmission system of offshore renewable energy power generation includes multiple offshore renewable energy power plants, which are connected to DC submarine cables through offshore converter stations, and the DC submarine cables are connected to the DC busbar of the onshore switch station through high-speed DC disconnectors HSS. The DC switch station is connected to multiple DC overhead lines through high-speed DC disconnectors HSS, and each DC overhead line is connected to a load center onshore converter station.

[0067] A DC voltage measuring device is installed near the DC busbar side of the overhead line high-speed DC disconnector HSS of each offshore converter station in the onshore switch station to measure the DC voltage of the positive and negative lines of each overhead line, and send the DC voltage measurement signal to the control host of the onshore switch station to determine whether the DC voltage is controlled to zero when the passive converter station is put into operation online, which serves as the operating condition for closing the high-speed DC disconnector HSS during the operation process.

[0068] Step 101: respond to an online input request for an offshore DC system and determine a passive converter station of the offshore DC system, wherein the offshore DC system includes a plurality of operating converter stations and a passive converter station, and the passive converter station is an operating converter station disconnected from a generator set in the offshore DC system.

[0069] The offshore DC system refers to a power system that generates electricity from offshore renewable energy in the marine environment and transmits the electricity to the onshore power grid through DC power transmission technology. The offshore DC system is a multi-terminal DC transmission system for offshore renewable energy power generation, which generates electricity through multi-terminal offshore renewable energy generators and transmits it to the onshore power grid.

[0070] The online activation request refers to a request instruction to activate the passive converter station in the offshore DC system online when a passive converter station is detected in the offshore DC system.

[0071] The operating converter station refers to the offshore converter station connected to the new energy generator set. The offshore DC system is an offshore multi-terminal DC power generation system. Therefore, the offshore DC system has multiple new energy generator sets, and one new energy generator set is connected to one operating converter station.

[0072] A passive converter station refers to a converter station that does not rely on an external power source to drive its operation, but instead achieves electrical energy conversion through the flow of energy within the system.

[0073] It should be noted that in the offshore DC system, there will be problems of fault shutdown, which will cause the grid-connected new energy generator sets to be disconnected from the grid, and then cause the operating converter station connected to the new energy generator sets to be in a passive state, becoming a passive converter station. Specifically, fault shutdown includes but is not limited to line protection tripping, new energy generator set failure (generator failure and converter failure), power grid failure (grid voltage abnormality and grid frequency abnormality), converter station internal failure (converter failure and control circuit failure), communication failure (communication interruption), protection system action (overcurrent protection and overvoltage protection), external environmental factors (lightning strikes and natural disasters: such as typhoons, earthquakes, etc. causing equipment damage). When the above faults occur, the converter station may not be able to obtain sufficient power or control signals from the new energy generator set or the power grid, causing the converter station to be in a passive state and unable to work normally.

[0074] In an embodiment of the present invention, in response to receiving a request for online commissioning of an offshore DC system, a passive converter station is determined from a plurality of operating converter stations in the offshore DC system, wherein the offshore DC system includes a plurality of operating converter stations and a passive converter station.

[0075] Step 102: When the passive converter station meets the preset grid-connected condition, multiple operating converter stations are adjusted based on the first preset adjustment strategy and the first preset adjustment condition, so that the operating converter stations suspend power transmission.

[0076] The preset grid-connected condition refers to whether the passive converter station meets the conditions for grid-connected operation.

[0077] In an embodiment of the present invention, if the passive converter station meets the preset grid-connected conditions, multiple operating converter stations are adjusted according to a first preset adjustment strategy until the multiple operating converter stations meet the first preset adjustment conditions, so that the multiple operating converter stations suspend power transmission.

[0078] Step 103: When the voltage of the passive converter station reaches a preset voltage value, the isolating switch on the DC line of the passive converter station is controlled to close, a DC transmission channel is established, and based on a second preset adjustment strategy and a second preset adjustment condition, multiple operating converter stations are adjusted so that the operating converter stations resume power transmission.

[0079] In an embodiment of the present invention, when the voltage of a passive converter station reaches a preset voltage value, multiple DC disconnectors on the DC line of the passive converter station are controlled to perform a closing operation. When all DC disconnectors complete the closing operation, multiple operating converter stations are adjusted according to a second preset adjustment strategy until the multiple operating converter stations meet the second preset adjustment condition, so that the multiple operating converter stations resume power transmission.

[0080] Step 104: When the passive converter station meets the preset input conditions, the passive converter station is unlocked.

[0081] In the embodiment of the present invention, when the passive converter station meets the preset commissioning conditions, the passive converter station is unlocked to complete the online commissioning of the passive converter station and realize grid connection.

[0082] In the present invention, in response to an online input request for an offshore DC system, a passive converter station of the offshore DC system is determined, wherein the offshore DC system includes a plurality of operating converter stations and a passive converter station, and the passive converter station is an operating converter station disconnected from a generator set in the offshore DC system; when the passive converter station meets a preset grid-connected condition, based on a first preset adjustment strategy and a first preset adjustment condition, the plurality of operating converter stations are adjusted so that the operating converter station suspends power transmission; when the voltage of the passive converter station reaches a preset voltage value, the isolating switch on the DC line of the passive converter station is controlled to be closed to establish a DC transmission. Channel, and based on the second preset adjustment strategy and the second preset adjustment condition, adjust multiple operating converter stations so that the operating converter stations resume power transmission; when the passive converter station meets the preset input conditions, the passive converter station is unlocked. The online input method of the present invention can complete the online input of the offshore passive converter station without stopping the operation of each operating converter station, reducing the power interruption time of each operating converter station, avoiding the wind abandonment phenomenon caused by the passive converter station being put into operation for too long, improving the economy and flexibility of offshore multi-terminal flexible direct current transmission, and solving the technical problem of how to realize the online input of the passive converter station.

[0083] See also Figure 2 , Figure 2A flowchart of the steps of a method for online commissioning of a passive converter station provided in Embodiment 2 of the present invention.

[0084] The present invention provides a method for online operation of a passive converter station, comprising:

[0085] Step 201: In response to receiving an online commissioning request of an offshore DC system, a plurality of operating converter stations corresponding to the offshore DC system are determined; wherein the offshore DC system includes a plurality of operating converter stations and passive converter stations, and the passive converter station is an operating converter station disconnected from a generator set in the offshore DC system.

[0086] It should be noted that the online commissioning method of the present invention requires the operating converter station to operate at a level where the DC voltage is zero. Therefore, the online commissioning method of the passive converter station of the present invention is applied to an offshore DC system using a converter with a "full half-bridge hybrid structure" (the converter includes a rectifier converter and an inverter), and the full-bridge topology power devices of each converter in the offshore DC system account for more than 50%. When the converter of the "full half-bridge hybrid structure" is put into operation, the zero-voltage control outputs a negative voltage through the full-bridge sub-module to offset the positive voltage generated by the half-bridge sub-module, and the redundant full-bridge sub-modules can output positive and negative voltages, thereby achieving the control of the DC voltage to zero, so that the converter of the "full half-bridge hybrid structure" has zero-voltage control capability, and is adapted to the regulation strategy of the passive converter station and the operating converter in the online commissioning method of the present invention, so that the passive converter station can complete the online commissioning of the offshore passive converter station without stopping the operation of each operating converter station.

[0087] It should be noted that the isolating switch HSS (High-Speed ​​Switch, high-speed DC isolating switch).

[0088] In the embodiment of the present invention, the specific implementation process of step 201 is similar to step 101 and will not be repeated here.

[0089] Step 202: Determine whether the backup power supply of the operating converter station is in working state.

[0090] In the embodiment of the present invention, it is determined whether the backup power supply of the operating converter station is in a working state.

[0091] Step 203: If the backup power supply of the operating converter station is in working state, it is determined that the operating converter station is a passive converter station.

[0092] In the embodiment of the present invention, if the backup power supply of the operating converter station is in a working state, it is determined that the operating converter station is a passive converter station.

[0093] Furthermore, it is determined whether the passive converter station meets the preset grid-connected conditions.

[0094] When the passive converter station does not meet the preset grid-connected conditions, a stop input instruction is generated.

[0095] In an embodiment of the present invention, if the passive converter station does not meet the preset grid-connected conditions, a stop input instruction is generated, and the maintenance personnel perform maintenance on the passive converter station. After the maintenance is completed, the process jumps to the step of determining whether the passive converter station meets the preset grid-connected conditions.

[0096] Step 204: When the passive converter station meets the preset grid-connected condition, multiple operating converter stations are adjusted based on the first preset adjustment strategy and the first preset adjustment condition, so that the operating converter stations suspend power transmission.

[0097] Furthermore, the preset grid-connected condition is whether the control and protection system of the passive converter station and the primary energized area are in normal operation.

[0098] Further, step 204 may include the following sub-steps:

[0099] S11, when the passive converter station meets the preset grid connection conditions;

[0100] S12. Adjust the first voltage and the first power of the plurality of operating converter stations according to the first preset adjustment strategy until the first voltage and the first power of each operating converter station meet the first preset adjustment condition, so that the operating converter station suspends power transmission.

[0101] Wherein, the first preset regulation strategy is to simultaneously reduce the first voltage and the first power of multiple operating converter stations according to the preset regulation gradient;

[0102] Among them, the first preset adjustment condition is that the first voltage and the first power of all operating converter stations are adjusted to the first preset adjustment threshold, and the first power of each operating converter station is adjusted to the first preset adjustment threshold before the first voltage.

[0103] In an embodiment of the present invention, if the control and protection system of the passive converter station and the primary energized area are both in normal operation, the first voltage and the first power of the plurality of operating converter stations are simultaneously reduced according to a preset adjustment gradient, wherein the first voltage refers to the operating voltage of the operating converter station at the current moment, and the first power refers to the operating power of the operating converter station at the current moment, and the current moment can be understood as when adjusting the operating converter station;

[0104] The first preset regulation threshold includes a first preset voltage regulation threshold and a first preset power regulation threshold;

[0105] Each operating converter station synchronously reduces the first voltage to a first preset voltage adjustment threshold at a certain rate, and each operating converter station synchronously reduces the first power to a first preset power adjustment threshold at a certain rate, where the first preset voltage adjustment threshold and the first preset power adjustment threshold are both 0, and the first power should be reduced to 0 before the first voltage;

[0106] It is worth mentioning that the first power should be reduced to 0 before the first voltage to avoid the voltage dropping to zero first, at which time the power reference value is zero, forming a large DC current.

[0107] After the multiple operating converter stations are adjusted so that the operating converter stations suspend power transmission, it is determined whether the voltage of the passive converter station reaches a preset voltage value.

[0108] Further, if the voltage of the passive converter station does not reach the preset voltage value, jump to step 202;

[0109] In the embodiment of the present invention, when the voltage of the passive converter station does not reach the preset voltage value, the process jumps to the step of determining whether the passive converter station meets the preset grid-connected condition.

[0110] Step 205: When the voltage of the passive converter station reaches a preset voltage value, the isolating switch on the DC line of the passive converter station is controlled to close, a DC transmission channel is established, and based on a second preset adjustment strategy and a second preset adjustment condition, multiple operating converter stations are adjusted so that the operating converter stations resume power transmission.

[0111] Further, step 205 may include the following sub-steps:

[0112] S21. When the voltage of the passive converter station reaches a preset voltage value, the isolating switch on the DC line of the passive converter station is controlled to close to establish a DC transmission channel;

[0113] In an embodiment of the present invention, when the voltage of the passive converter station reaches a preset voltage value, a switch closing instruction is received to control all DC disconnectors HSS on the DC line of the passive converter station to perform a closing operation. When all the multiple DC disconnectors HSS on the DC line of the passive converter station complete the closing operation, the DC transmission channel between the passive converter station and the onshore converter station is re-established.

[0114] S22, adjusting the second voltage and the second power of the plurality of operating converter stations according to the second preset adjustment strategy until the second voltage and the second power of the plurality of operating converter stations meet the second preset adjustment condition, so that the operating converter stations resume power transmission;

[0115] The second preset regulation strategy is to simultaneously raise the second voltage and the second power of multiple operating converter stations according to the preset regulation gradient;

[0116] Among them, the second preset adjustment condition is that the second voltage of each operating converter station is raised to the second preset voltage adjustment threshold, and the second power of each operating converter station is raised to the associated first power.

[0117] In an embodiment of the present invention, the DC line of the passive converter station is connected to the DC busbar, and after the positive and negative disconnectors HSS are detected to be closed, the second voltage and the second power of multiple operating converter stations are simultaneously raised according to the preset adjustment gradient. The second voltage refers to the operating voltage of the operating converter station at the current moment, where the second voltage is 0, and the second power refers to the operating power of the operating converter station at the current moment, where the second power is 0. The preset adjustment gradient refers to a preset adjustment step size, for example, raising the voltage of 10V and the power of 5MW every 10 seconds;

[0118] Each operating converter station synchronously raises the second voltage to the second preset voltage regulation threshold at a certain rate, and each operating offshore converter station synchronously raises the second power to the first power at a certain rate. The second preset voltage regulation threshold here is not limited here and is set according to actual needs. Here, each operating converter station synchronously raises the second power to the power level before reduction at a certain rate, that is, the operating power of the operating converter station at the time of no adjustment, specifically referring to the first power.

[0119] When multiple operating converter stations are adjusted so that the operating converter stations resume power transmission, it is determined whether the passive converter stations meet the preset input conditions.

[0120] Step 206: When the passive converter station meets the preset input conditions, the passive converter station is unlocked.

[0121] Among them, the preset input conditions are that the passive converter station meets the preset charging requirements and whether the operation mode of the passive converter station is the preset control mode.

[0122] Further, step 206 may include the following sub-steps:

[0123] S31. When the passive converter station meets the preset charging requirements, determining whether the operation mode of the passive converter station is a preset control mode;

[0124] Among them, the preset charging requirement is that the passive converter station performs uncontrolled charging on the DC side and controlled charging on the DC side in sequence, and the passive converter station completes controlled charging on the DC side.

[0125] Furthermore, when the passive converter station does not meet the preset charging requirement, the process jumps to step 202 .

[0126] S32. When the operation mode is the preset control mode, the passive converter station is unlocked to complete the online operation of the passive converter station.

[0127] Among them, the preset control mode is the voltage and frequency control mode.

[0128] Further, when the operation mode of the passive converter station is not the preset control mode, jump to step 202.

[0129] In the embodiment of the present invention, during the process of voltage and power raising of each operating converter station, the passive converter station also performs uncontrolled charging on the DC side and controlled charging on the DC side. At this time, it is necessary to determine whether the passive converter station performs uncontrolled charging on the DC side and controlled charging on the DC side in sequence, and whether the passive converter station completes controlled charging on the DC side;

[0130] If the passive converter station does not meet the preset charging requirements, jump to step 202;

[0131] If the passive converter station meets the preset charging requirements, it is determined whether the operating mode of the passive converter station is in the voltage and frequency control mode. If the operating mode of the passive converter station is not the preset control mode, it jumps to the step of determining whether the passive converter station meets the preset input conditions. If it is in the voltage and frequency control mode, the passive converter station is unlocked to complete the online input of the passive converter station.

[0132] For ease of understanding, the following is an application example, taking an offshore wind farm as an example:

[0133] See also Figure 3 , Figure 3 This is a structural diagram of an offshore wind power multi-terminal DC transmission system;

[0134] In the figure, WT represents a wind turbine and G represents an onshore generator.

[0135] The offshore wind power multi-terminal DC transmission system includes an offshore converter station, an onshore DC switch station and an onshore converter station;

[0136] The offshore converter station is connected to one end of the onshore DC switch station via a DC cable;

[0137] The onshore converter station is connected to the other end of the onshore DC switch station via a DC cable;

[0138] The offshore converter station includes multiple wind turbines and multiple offshore converter stations;

[0139] Multiple wind turbines are connected to multiple offshore converter stations in a one-to-one correspondence;

[0140] The onshore DC switch station includes a DC power supply and a DC voltage measuring device;

[0141] Each offshore converter station is connected to the positive disconnector HSS in the onshore DC switch station via two DC submarine cables;

[0142] Each positive isolating switch HSS is connected to the positive pole of the DC power supply through a DC voltage measuring device;

[0143] The onshore converter terminal includes multiple onshore converter stations and multiple onshore generators;

[0144] A plurality of onshore converter stations are connected to a plurality of onshore generators in a one-to-one correspondence;

[0145] The onshore converter station is connected to the negative pole disconnector HSS in the onshore DC switch station via two DC submarine cables;

[0146] Each negative pole isolation switch HSS is connected to the negative pole of the DC power source.

[0147] It should be noted that the DC voltage measuring device is a conventional DC voltage measuring device.

[0148] See also Figure 4 , Figure 4 The topological structure diagram of the offshore converter station and the onshore converter station. Both the offshore converter station and the onshore converter station are full half-bridge hybrid topology structures, and the full-bridge topology power devices in each converter account for more than 50%, with zero DC voltage control capability.

[0149] In the figure, FBSM represents the full-bridge submodule, HBSM represents the half-bridge submodule, and L arm Indicates the bridge arm reactance, U dc Indicates the port DC voltage, U H Indicates the bus voltage on the grid side of the converter transformer, U L It represents the bus voltage on the converter transformer valve side, and A, B and C represent three-phase lines.

[0150] Specifically, take the offshore converter station 1 as an example where a fault occurs and the station becomes a passive converter station:

[0151] When receiving an online input request for the offshore wind power multi-terminal DC transmission system, according to the working status of the backup power supply of each offshore converter station, a passive converter station (offshore converter station 1) is determined from multiple operating offshore converter stations;

[0152] Determine whether the control and protection system and the primary energized area of ​​the passive converter station are in normal operation. The control and protection system includes PLC, DSP, communication system, monitoring system, etc. These devices are the core of converter station control and protection. The primary energized area refers to the first energized area formed after the converter is started, which is identified by the monitoring system, including the converter transformer, converter valve hall, DC line, grounding switch, etc.

[0153] If the control and protection system of the passive converter station and the primary energized area are in normal operation, the first voltage and the first power of multiple operating offshore converter stations are reduced simultaneously according to the preset adjustment gradient. The first voltage refers to the operating voltage of the operating offshore converter station at the current moment, and the first power refers to the operating power of the operating offshore converter station at the current moment. The current moment can be understood as the adjustment of the operating offshore converter station;

[0154] The first preset regulation threshold includes a first preset voltage regulation threshold and a first preset power regulation threshold;

[0155] Each operating offshore converter station (offshore converter station 2~n) synchronously reduces the first voltage to a first preset voltage adjustment threshold at a certain rate, and each operating offshore converter station synchronously reduces the first power to a first preset power adjustment threshold at a certain rate, where the first preset voltage adjustment threshold and the first preset power adjustment threshold are both 0, and the first power should be reduced to 0 before the first voltage;

[0156] It is worth mentioning that the first power should be reduced to 0 before the first voltage to avoid the voltage dropping to zero first, at which time the power reference value is zero, forming a large DC current.

[0157] After the DC voltage measuring device on the DC line of the passive converter station detects that the DC voltage of the passive converter station reaches a preset voltage value, where the preset voltage value is 0, the control host in the onshore DC switch station issues a switch closing command to close all the disconnectors HSS on the DC line of the passive converter station (including two positive disconnectors HSS connected to the positive pole of the power supply and two negative disconnectors HSS connected to the negative pole of the power supply), and connects the DC line of the passive converter station to the DC busbar. After detecting that the positive and negative disconnectors HSS are closed, the second voltage and the second power of multiple offshore converter stations in operation are simultaneously raised according to the preset adjustment gradient. The second voltage refers to the operating voltage of the offshore converter station in operation at the current moment, where the second voltage is 0, and the second power refers to the operating power of the offshore converter station in operation at the current moment, where the second power is 0;

[0158] Each operating offshore converter station (offshore converter station 2~n) synchronously raises the second voltage to the second preset voltage regulation threshold at a certain rate, and each operating offshore converter station synchronously raises the second power to the first power at a certain rate. The second preset voltage regulation threshold here is not limited here and is specifically set according to actual needs. Here, each operating offshore converter station synchronously raises the second power to the power level before reduction at a certain rate, that is, the operating power of the operating offshore converter station at the time of no adjustment, specifically refers to the first power;

[0159] It is worth mentioning that, whether in the process of lowering or lifting, the preset adjustment gradient specifically adopts segmented gradient adjustment. By dividing the adjustment range into multiple sections, each section adopts a different gradient, which can more accurately control the changes in voltage and power to avoid over-adjustment or under-adjustment. At the same time, it helps to maintain the stability of the system and reduce the impact of sudden changes in voltage and power on the system. Smooth gradient adjustment can reduce equipment wear and loss and extend the service life of the equipment.

[0160] During the process of voltage and power raising at each operating offshore converter station, the passive converter station also performs uncontrolled charging on the DC side and controlled charging on the DC side. At this time, it is necessary to determine whether the passive converter station performs uncontrolled charging on the DC side and controlled charging on the DC side in sequence, and whether the passive converter station completes controlled charging on the DC side;

[0161] Among them, see Figure 5 , Figure 5 Schematic diagram of the charging circuit for uncontrolled DC side charging of the passive converter station. When performing uncontrolled DC side charging, please refer to Figure 6-Figure 7 , Figure 6 It is a schematic diagram of the positive current path of the half-bridge submodule in the locked state. Figure 7 This is a schematic diagram of the negative current path of the half-bridge submodule in the locked state. The half-bridge submodules T1 and T2 are both in the locked state. The locked state is only used to handle faults. In normal operation, each submodule works in the input and removal state. The full-bridge submodules T1, T2, T3, and T4 are all in the locked state. Please refer to Figure 8-Figure 9 , Figure 8 It is a schematic diagram of the positive current path of the full-bridge submodule in the locked state. Fig. 9 The schematic diagram of the negative current path of the full-bridge module in the locked state, all four IGBTs are turned off, and the current flows through the path during the DC voltage rise. Figure 5 As shown by the red line, all currents form a loop through the diode to charge the capacitor. After the uncontrolled charging stage, the capacitors of all submodules are charged and provide power to the submodule control board, which can control the input and output of the submodule IGBT. Please refer to Figure 10-11 , Fig.10 This is a schematic diagram of the positive current path when the half-bridge submodule is in the on state. Fig.11 This is a schematic diagram of the negative current path when the half-bridge module is in the on state. IGBTT1 is turned on, T2 is turned off, and the current passes through T1 or the diode in parallel with T1 to charge and discharge the capacitor. Please refer to 12- Fig.13 , Fig.12 This is a schematic diagram of the positive current path when the full-bridge submodule is in the positive input state. Fig.13 This is a schematic diagram of the negative current path of the full-bridge submodule in the positive input state. The positive input state is when IGBT T1 and T4 are turned on. Figure 14-15 , Fig.14 This is a schematic diagram of the positive current path of the full-bridge submodule in the negative input state. Fig.15 It is a schematic diagram of the negative current path of the full-bridge submodule in the negative input state, and the negative input state is that IGBT T2 and T3 are turned on.

[0162] It is worth mentioning that uncontrolled charging does not involve valve control. The trigger pulses of all IGBTs are blocked, the sub-module is in the exit state, and the charging current charges the sub-module capacitor through the diode. The sum of all sub-module capacitor voltages is equal to the DC voltage. Controllable charging involves valve control, the purpose is to make the sub-module capacitor voltage reach the minimum voltage value required for unlocking. The valve control system will open VT2 of some charging bridge arm sub-modules to isolate the sub-module. In this way, the number of charged sub-modules is reduced, and the capacitor voltage of the sub-module being charged will increase. By cyclically shutting down VT2 of the sub-module in turn, the capacitor voltage of each sub-module in the entire bridge arm can reach the optimal voltage value required for unlocking. The DC voltage supported by the capacitor voltage in this stage is the same as that in the natural charging stage.

[0163] After the DC side uncontrolled charging is completed, the DC side controlled charging is performed. Fig.16 , Fig.16 Schematic diagram of the charging circuit for controlled DC side charging of passive converter stations; During the controlled DC side charging process, in order to make the submodule capacitor voltage in the converter station reach the minimum voltage value required for unlocking, the valve control system will cut off some full-bridge submodules and half-bridge submodules, so that the number of submodules being charged is reduced, the DC side voltage remains unchanged, and the capacitor voltage of the submodule being charged will increase. By cutting off the submodules in turn, the capacitor voltage of each submodule in the entire bridge arm can reach the optimal voltage value required for unlocking. The DC voltage supported by the capacitor voltage in this stage is the same as that in the uncontrolled charging stage. Please refer to Figure 17-Figure 18 , Fig.17 It is a schematic diagram of the positive current path when the half-bridge submodule is in the cut-off state. Fig.18 This is a schematic diagram of the negative current path of the half-bridge submodule in the cut-off state. The cut-off state is that IGBT T2 is turned on, T1 is turned off, and the current forms a loop through T2 or the diode in parallel with T2. The capacitor is in the cut-off state. Please refer to Figure 19-20 , Fig.19 It is a schematic diagram of the positive current path when the full-bridge submodule is in the cut-off state. Fig. 20 It is a schematic diagram of the negative current path of the full-bridge submodule in the cut-off state, in which all four IGBTs are turned on.

[0164] It should be noted that Figure 5-Figure 20 In the figure, the red line indicates the path where the current flows.

[0165] When the passive converter station performs uncontrolled charging on the DC side and controlled charging on the DC side in sequence, and after the passive converter station completes controlled charging on the DC side, it is determined whether the current passive converter station is in the voltage and frequency control mode. If it is in the voltage and frequency control mode, the converter of the passive converter station is unlocked to complete the online operation of the passive converter station.

[0166] It is worth mentioning that the conditions for judging whether the controlled charging of the DC side is completed are: judging whether the DC side voltage reaches a certain value, which is different for each project, and judging whether the average voltage of the sub-modules put into use reaches a certain value (which is different for each project, some reach 90% or 95% of the rated value, which is generally a range).

[0167] In the present invention, in response to an online input request for an offshore DC system, a passive converter station of the offshore DC system is determined, wherein the offshore DC system includes a plurality of operating converter stations and a passive converter station, and the passive converter station is an operating converter station disconnected from a generator set in the offshore DC system; when the passive converter station meets a preset grid-connected condition, based on a first preset adjustment strategy and a first preset adjustment condition, the plurality of operating converter stations are adjusted so that the operating converter station suspends power transmission; when the voltage of the passive converter station reaches a preset voltage value, the isolating switch on the DC line of the passive converter station is controlled to be closed to establish a DC transmission. Channel, and based on the second preset adjustment strategy and the second preset adjustment condition, adjust multiple operating converter stations so that the operating converter stations resume power transmission; when the passive converter station meets the preset input conditions, the passive converter station is unlocked. The online input method of the present invention can complete the online input of the offshore passive converter station without stopping the operation of each operating converter station, reducing the power interruption time of each operating converter station, avoiding the wind abandonment phenomenon caused by the passive converter station being put into operation for too long, improving the economy and flexibility of offshore multi-terminal flexible direct current transmission, and solving the technical problem of how to realize the online input of the passive converter station.

[0168] See also Fig.21 , Fig.21 This is a structural block diagram of a passive converter station online input system provided in Embodiment 3 of the present invention.

[0169] The present invention provides a passive converter station online input system, comprising:

[0170] A response module 301 is used to respond to an online input request for an offshore DC system and determine a passive converter station of the offshore DC system, wherein the offshore DC system includes a plurality of operating converter stations and a passive converter station, and the passive converter station is an operating converter station disconnected from a generator set in the offshore DC system;

[0171] The grid connection judgment module 302 is used to adjust the multiple operating converter stations based on the first preset adjustment strategy and the first preset adjustment condition when the passive converter station meets the preset grid connection condition, so that the operating converter station suspends power transmission;

[0172] The voltage judgment module 303 is used to control the isolating switch on the DC line of the passive converter station to close when the voltage of the passive converter station reaches a preset voltage value, establish a DC transmission channel, and adjust multiple operating converter stations based on a second preset adjustment strategy and a second preset adjustment condition so that the operating converter station resumes power transmission;

[0173] The online activation module 304 is used to unlock the passive converter station when the passive converter station meets the preset activation conditions.

[0174] Furthermore, the response module 301 includes:

[0175] A request submodule, configured to determine a plurality of operating converter stations corresponding to the offshore DC system in response to receiving an online input request of the offshore DC system;

[0176] A state judgment submodule is used to judge whether the backup power supply of the operating converter station is in working state;

[0177] The passive converter station determination submodule is used to determine that the operating converter station is a passive converter station if the backup power supply of the operating converter station is in a working state.

[0178] Furthermore, the preset grid-connected condition is whether the control and protection system of the passive converter station and the primary energized area are in normal operation.

[0179] Furthermore, the grid connection determination module 302 includes:

[0180] A first regulating submodule, used for adjusting the first voltage and the first power of the plurality of operating converter stations according to a first preset regulating strategy, until the first voltage and the first power of each operating converter station satisfy a first preset regulating condition;

[0181] Wherein, the first preset regulation strategy is to simultaneously reduce the first voltage and the first power of multiple operating converter stations according to the preset regulation gradient;

[0182] Among them, the first preset adjustment condition is that the first voltage and the first power of all operating converter stations are adjusted to the first preset adjustment threshold, and the first power of each operating converter station is adjusted to the first preset adjustment threshold before the first voltage.

[0183] Furthermore, the voltage determination module 303 includes:

[0184] A second regulating submodule, used for regulating the second voltage and the second power of the plurality of operating converter stations according to a second preset regulating strategy, until the second voltage and the second power of the plurality of operating converter stations meet a second preset regulating condition;

[0185] The second preset regulation strategy is to simultaneously raise the second voltage and the second power of multiple operating converter stations according to the preset regulation gradient;

[0186] Among them, the second preset adjustment condition is that the second voltage of each operating converter station is raised to the second preset voltage adjustment threshold, and the second power of each operating converter station is raised to the associated first power.

[0187] Furthermore, the online investment module 304 includes:

[0188] Among them, the preset input condition is that the passive converter station meets the preset charging requirements and whether the operation mode of the passive converter station is the preset control mode;

[0189] A mode judgment submodule is used to judge whether the operation mode of the passive converter station is a preset control mode when the passive converter station meets the preset charging requirements;

[0190] Among them, the preset charging requirement is that the passive converter station performs uncontrolled charging on the DC side and controlled charging on the DC side in sequence, and the passive converter station completes controlled charging on the DC side;

[0191] The unlocking submodule is used to unlock the passive converter station when the operating mode is a preset control mode.

[0192] In the present invention, in response to an online input request for an offshore DC system, a passive converter station of the offshore DC system is determined, wherein the offshore DC system includes a plurality of operating converter stations and a passive converter station, and the passive converter station is an operating converter station disconnected from a generator set in the offshore DC system; when the passive converter station meets a preset grid-connected condition, based on a first preset adjustment strategy and a first preset adjustment condition, the plurality of operating converter stations are adjusted so that the operating converter station suspends power transmission; when the voltage of the passive converter station reaches a preset voltage value, the isolating switch on the DC line of the passive converter station is controlled to be closed to establish a DC transmission. Channel, and based on the second preset adjustment strategy and the second preset adjustment condition, adjust multiple operating converter stations so that the operating converter stations resume power transmission; when the passive converter station meets the preset input conditions, the passive converter station is unlocked. The online input method of the present invention can complete the online input of the offshore passive converter station without stopping the operation of each operating converter station, reducing the power interruption time of each operating converter station, avoiding the wind abandonment phenomenon caused by the passive converter station being put into operation for too long, improving the economy and flexibility of offshore multi-terminal flexible direct current transmission, and solving the technical problem of how to realize the online input of the passive converter station.

[0193] See also Fig. 22 , Fig. 22 This is a structural block diagram of a computer device provided in Embodiment 4 of the present invention.

[0194] An electronic device according to an embodiment of the present invention comprises: a memory 401 and a processor 402, wherein the memory 402 stores a computer program; when the computer program is executed by the processor 402, the processor 402 executes the method for online commissioning of a passive converter station as in any of the above embodiments.

[0195] The memory 401 may be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read-only memory), an EPROM, a hard disk or a ROM. The memory 401 has a storage space 403 for a program code 413 for executing any method step in the above method. For example, the storage space 403 for the program code may include individual program codes 413 for implementing the various steps in the above method, respectively. These program codes may be read from or written to one or more computer program products. These computer program products include program code carriers such as hard disks, compact disks (CDs), memory cards or floppy disks. The program code may be compressed, for example, in an appropriate form. When these codes are run by a computing and processing device, the computing and processing device performs the various steps in the method described above. These program codes may be read from or written to one or more computer program products. These computer program products include program code carriers such as hard disks, compact disks (CDs), memory cards or floppy disks. The program code may be compressed, for example, in an appropriate form. When these codes are executed by a computing and processing device, the computing and processing device is caused to execute each step of the above-described method for online commissioning of a passive converter station.

[0196] Embodiment 5 of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method for online commissioning of a passive converter station as described in any of the above embodiments is implemented.

[0197] Embodiment 6 of the present invention further provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer executes the method for online commissioning of a passive converter station as described in any of the above embodiments.

[0198] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0199] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0200] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0201] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0202] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0203] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for online operation of a passive converter station, characterized in that: include: In response to an online input request for an offshore DC system, a passive converter station of the offshore DC system is determined, wherein the offshore DC system includes a plurality of operating converter stations and the passive converter station, and the passive converter station is an operating converter station disconnected from a generator set in the offshore DC system; When the passive converter station meets the preset grid-connected condition, the plurality of operating converter stations are adjusted based on the first preset adjustment strategy and the first preset adjustment condition, so that the operating converter stations suspend power transmission; When the voltage of the passive converter station reaches a preset voltage value, the isolating switch on the DC line of the passive converter station is controlled to close, a DC transmission channel is established, and based on a second preset adjustment strategy and a second preset adjustment condition, a plurality of the operating converter stations are adjusted so that the operating converter stations resume power transmission; When the passive converter station meets the preset input conditions, the passive converter station is unlocked.

2. The method for online operation of a passive converter station according to claim 1, characterized in that: The step of responding to the online input request for the offshore DC system and determining the passive converter station of the offshore DC system comprises: In response to receiving an online commissioning request of an offshore DC system, determining a plurality of operating converter stations corresponding to the offshore DC system; Determining whether the backup power supply of the operating converter station is in working state; If the backup power supply of the operating converter station is in a working state, it is determined that the operating converter station is the passive converter station.

3. The method for online commissioning of a passive converter station according to claim 1, characterized in that: The preset grid-connected condition is whether the control and protection system of the passive converter station and the primary energized area are both in normal operation.

4. The method for online operation of a passive converter station according to claim 1, characterized in that: The step of adjusting the plurality of operating converter stations based on the first preset adjustment strategy and the first preset adjustment condition comprises: Adjusting the first voltage and the first power of the plurality of operating converter stations according to the first preset adjustment strategy until the first voltage and the first power of each operating converter station meet the first preset adjustment condition; Wherein, the first preset adjustment strategy is to simultaneously reduce the first voltage and the first power of the plurality of operating converter stations according to the preset adjustment gradient; Among them, the first preset adjustment condition is that the first voltage and the first power of all the operating converter stations are adjusted to the first preset adjustment threshold, and the first power of each operating converter station is adjusted to the first preset adjustment threshold before the first voltage.

5. The method for online operation of a passive converter station according to claim 4, characterized in that: The adjusting the plurality of operating converter stations based on the second preset adjustment strategy and the second preset adjustment condition comprises: adjusting the second voltage and the second power of the plurality of operating converter stations according to a second preset adjustment strategy until the second voltage and the second power of the plurality of operating converter stations meet a second preset adjustment condition; Wherein, the second preset regulation strategy is to simultaneously raise the second voltage and the second power of the plurality of operating converter stations according to the preset regulation gradient; Among them, the second preset adjustment condition is that the second voltage of each of the operating converter stations is raised to a second preset voltage adjustment threshold, and the second power of each of the operating converter stations is raised to the associated first power.

6. The method for online commissioning of a passive converter station according to claim 1, characterized in that: When the passive converter station meets the preset input conditions, the passive converter station is unlocked. include: The preset input condition is that the passive converter station meets the preset charging requirements and the operation mode of the passive converter station is the preset control mode; When the passive converter station meets the preset charging requirement, determining whether the operation mode of the passive converter station is a preset control mode; The preset charging requirement is that the passive converter station sequentially performs uncontrolled charging on the DC side and controlled charging on the DC side, and the passive converter station completes controlled charging on the DC side; When the operation mode is the preset control mode, the passive converter station is unlocked.

7. A passive converter station online input system, characterized in that: include: A response module, used to respond to an online input request for an offshore DC system, and determine a passive converter station of the offshore DC system, wherein the offshore DC system includes a plurality of operating converter stations and the passive converter station, and the passive converter station is an operating converter station disconnected from a generator set in the offshore DC system; A grid connection judgment module, configured to adjust the plurality of operating converter stations based on a first preset adjustment strategy and a first preset adjustment condition when the passive converter station meets the preset grid connection condition, so that the operating converter stations suspend power transmission; A voltage judgment module is used to control the disconnector on the DC line of the passive converter station to close when the voltage of the passive converter station reaches a preset voltage value, establish a DC transmission channel, and adjust the plurality of operating converter stations based on a second preset adjustment strategy and a second preset adjustment condition, so that the operating converter stations resume power transmission; The online activation module is used to unlock the passive converter station when the passive converter station meets the preset activation conditions.

8. An electronic device, characterized in that: It comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor executes the steps of the method for online commissioning of a passive converter station as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed, the method for online commissioning of a passive converter station as described in any one of claims 1 to 6 is implemented.

10. A computer program product, characterized in that The computer program product comprises a computer program stored on a non-transitory computer-readable storage medium, wherein the computer program comprises program instructions, wherein when the program instructions are executed by a computer, the computer is caused to execute the method for online commissioning of a passive converter station as described in any one of claims 1 to 6.

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