Parameter Optimization Method for Low-Voltage Ride-Through Reactive Power Control Strategy of New Energy Connected to DC Sending End

Abstract

The present application relates to a method, system and device for optimizing parameters of a low-voltage ride-through reactive power control strategy for new energy integrated into the grid at the DC sending end. The method gradually adjusts the new energy reactive power control parameters according to whether the voltages of the DC sending-end converter bus and the new energy grid connection point meet the voltage constraints, so as to optimize the low-voltage ride-through reactive power strategy control parameters for new energy in the DC sending-end new energy intensive area. After the optimized reactive power control optimization parameters are applied to the transmission system, the voltages of the sending-end converter bus and the new energy grid connection point can be maintained at a reasonable level after an AC fault occurs at the DC receiving end, solving the technical problem that in the existing DC sending-end new energy intensive area, after an AC fault occurs at the DC receiving end, overvoltage exists at the DC sending end, resulting in equipment damage or large-scale disconnection of new energy from the grid.

Description

Technical Field

[0001] The present application relates to the technical field of DC sending ends of power systems, and particularly relates to a method, system, and device for optimizing parameters of a low-voltage ride-through reactive power control strategy for new energy integrated into the grid at a DC sending end. Background Art

[0002] New energy will develop rapidly, and a large amount of new energy is integrated into the grid in the vicinity of the DC sending end of the AC transmission system, forming a dense area of new energy at the DC sending end. After an AC short-circuit fault occurs at the DC receiving end of the AC transmission system, the response of the DC sending end of the AC transmission system is as Figure 5 shown. The DC current of the AC transmission system increases rapidly in a short time and then gradually decreases under the control action. The sending-end converter of the AC transmission system will absorb a large amount of reactive power from the sending-end AC system in a short time and then emit reactive power, resulting in the sending-end AC bus voltage of the AC transmission system decreasing first and then increasing. For areas where there is a large amount of new energy integrated into the grid at the DC sending end of the AC transmission system, the transient reactive power characteristics of the new energy (as Figure 6 shown) will directly affect the voltage stability of the AC transmission system. If the AC transmission system is not properly matched, it may lead to transient overvoltage problems, thereby resulting in the risk of new energy tripping and / or equipment damage. Summary of the Invention

[0003] Embodiments of the present application provide a method, system, and device for optimizing parameters of a low-voltage ride-through reactive power control strategy for new energy integrated into the grid at a DC sending end, which are used to solve the technical problem that in areas with a dense distribution of new energy at the DC sending end, when an AC fault occurs at the DC receiving end, overvoltage exists at the DC sending end, resulting in equipment damage or large-scale tripping of new energy.

[0004] To achieve the above object, the embodiments of the present application provide the following technical solutions:

[0005] A method for optimizing parameters of a low-voltage ride-through reactive power control strategy for new energy integrated into the grid at a DC sending end includes the following steps:

[0006] Obtain the initial transmission parameters of the power transmission system for new energy integrated into the grid at the DC sending end, where the initial transmission parameters include the initial value of the reactive current recovery during the new energy low-voltage ride-through recovery process, the maximum tolerable bus voltage of the DC sending-end converter bus, and the maximum tolerable grid connection voltage of the new energy grid connection point;

[0007] Use DSP-EMTDC hybrid simulation software to simulate the three-phase AC short-circuit fault of the DC sending-end converter bus of the power transmission system to obtain the first voltage parameters during the fault, where the first voltage parameters include the first maximum bus voltage of the DC sending-end converter bus and the first maximum grid connection voltage of the new energy grid connection point;

[0008] If the first voltage parameter does not meet the voltage constraint, gradually adjust the new energy reactive power control parameter of the power transmission system based on the initial value of the reactive current recovery, and obtain the second voltage parameter during the fault corresponding to each adjustment of the new energy reactive power control parameter until the obtained second voltage parameter meets the voltage constraint, and then stop adjusting the new energy reactive power control parameter;

[0009] Obtain the new energy reactive power control parameter that meets the voltage constraint and record this new energy reactive power control parameter as the reactive power control optimization parameter.

[0010] Preferably, gradually adjusting the new energy reactive power control parameter of the power transmission system based on the initial value of the reactive current recovery and obtaining the second voltage parameter during the fault corresponding to each adjustment of the new energy reactive power control parameter includes: the new energy reactive power control parameter I adjusted each time based on the initial value of the reactive current recovery qn is I qn = I qn-1 -ΔI, where n is the number of adjustments, ΔI is the adjustment data, and I qn-1 is the previous new energy reactive power control parameter corresponding to the nth adjustment of the new energy reactive power control parameter; when n = 1, I qn-1 is the initial value of the reactive current recovery.

[0011] Preferably, the adjustment data is 0.1 pu, and pu is the per-unit value of the reactive current.

[0012] Preferably, both the first voltage parameter and the second voltage parameter include the highest bus voltage and the highest grid-connected voltage, and the voltage constraint is that the highest bus voltage is less than the highest withstand bus voltage, and the highest grid-connected voltage is less than the highest withstand grid-connected voltage.

[0013] This application also provides a low-voltage ride-through reactive power control strategy parameter optimization system for DC sending-end grid-connected new energy, including a data acquisition module, a simulation module, an adjustment module, and an optimization parameter acquisition module;

[0014] The data acquisition module is used to acquire the initial power transmission parameters of the power transmission system of DC sending-end grid-connected new energy, and the initial power transmission parameters include the initial value of the reactive current recovery during the new energy low-voltage ride-through recovery process, the highest withstand bus voltage of the DC sending-end converter bus, and the highest withstand grid-connected voltage of the new energy grid connection point;

[0015] The simulation module is used to simulate the three-phase AC short-circuit fault of the DC sending-end converter bus of the power transmission system by using DSP-EMTDC hybrid simulation software, and obtain the first voltage parameter during the fault, and the first voltage parameter includes the first highest bus voltage of the DC sending-end converter bus and the first highest grid-connected voltage of the new energy grid connection point;

[0016] The adjustment module is used to gradually adjust the new - energy reactive - power control parameters of the power - transmission system based on the initial value of the reactive - current recovery when the first voltage parameter does not meet the voltage constraint, obtain the second voltage parameter during the fault corresponding to each adjustment of the new - energy reactive - power control parameters, and stop adjusting the new - energy reactive - power control parameters until the obtained second voltage parameter meets the voltage constraint.

[0017] The optimization - parameter acquisition module is used to obtain the new - energy reactive - power control parameters that meet the voltage constraint and record the new - energy reactive - power control parameters as reactive - power control optimization parameters.

[0018] Preferably, the adjustment module is further used to adjust the new - energy reactive - power control parameter \(I\) each time based on the initial value of the reactive - current recovery. qn to \(I\) qn \(=I\) qn-1 \(-\Delta I\), where \(n\) is the number of adjustments, \(\Delta I\) is the adjustment data, and \(I\) qn-1 is the previous new - energy reactive - power control parameter corresponding to the \(n\)th adjustment of the new - energy reactive - power control parameter; when \(n = 1\), \(I\) qn-1 is the initial value of the reactive - current recovery.

[0019] Preferably, the adjustment data is \(0.1\ pu\), and \(pu\) is the per - unit value of the reactive - current.

[0020] Preferably, both the first voltage parameter and the second voltage parameter include the highest bus voltage and the highest grid - connection voltage, and the voltage constraint is that the highest bus voltage is less than the highest tolerable bus voltage, and the highest grid - connection voltage is less than the highest tolerable grid - connection voltage.

[0021] This application also provides a storage device, in which multiple program codes are stored, and the program codes are adapted to be loaded and run by a processor to execute the above - mentioned method for optimizing the low - voltage - ride - through reactive - power control strategy parameters of new energy in a DC sending - end grid - connection system.

[0022] This application also provides a terminal device, including a processor and a memory;

[0023] The memory is used to store the program codes and transmit the program codes to the processor;

[0024] The processor is used to execute the above - mentioned method for optimizing the low - voltage - ride - through reactive - power control strategy parameters of new energy in a DC sending - end grid - connection system according to the instructions in the program codes.

[0025] As can be seen from the above technical solutions, the embodiments of the present application have the following advantages: The method, system and device for optimizing the low-voltage ride-through reactive power control strategy parameters of DC sending-end grid-connected new energy. The method includes obtaining the initial transmission parameters of the transmission system of the DC sending-end grid-connected new energy; using the DSP-EMTDC hybrid simulation software to simulate the three-phase AC short-circuit fault of the DC sending-end converter bus of the transmission system, and obtaining the first voltage parameters during the fault, where the first voltage parameters include the first highest bus voltage of the DC sending-end converter bus and the first highest grid-connected voltage of the new energy grid-connection point; if the first voltage parameters do not meet the voltage constraints, gradually adjust the new energy reactive power control parameters of the transmission system based on the initial value of the reactive current recovery, and obtain the second voltage parameters during the fault corresponding to each adjustment of the new energy reactive power control parameters until the obtained second voltage parameters meet the voltage constraints, and then stop adjusting the new energy reactive power control parameters; obtain the new energy reactive power control parameters that meet the voltage constraints and record the new energy reactive power control parameters as the optimized reactive power control parameters. The method for optimizing the low-voltage ride-through reactive power control strategy parameters of DC sending-end grid-connected new energy realizes the optimization of the low-voltage ride-through reactive power strategy control parameters of new energy in the DC sending-end new energy-intensive area by gradually adjusting the new energy reactive power control parameters according to whether the voltages of the DC sending-end converter bus and the new energy grid-connection point meet the voltage constraints on the DSP-EMTDC hybrid simulation software. Applying the optimized optimized reactive power control parameters to the transmission system can keep the voltages of the sending-end converter bus and the new energy grid-connection point at a reasonable level after an AC fault occurs at the DC receiving-end of the transmission system, and solves the technical problem that in the existing DC sending-end new energy-intensive area, after an AC fault occurs at the DC receiving-end, there is overvoltage at the DC sending-end, resulting in equipment damage or large-scale disconnection of new energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a flowchart of the steps of the method for optimizing the low-voltage ride-through reactive power control strategy parameters of DC sending-end grid-connected new energy according to the embodiments of the present application;

[0028] Figure 2 It is a curve graph of the reactive power generated by new energy in the method for optimizing the low-voltage ride-through reactive power control strategy parameters of DC sending-end grid-connected new energy according to the embodiments of the present application;

[0029] Figure 3Voltage parameter curve graph of the low-voltage ride-through reactive power control strategy parameter optimization method for DC sending-end grid-connected new energy in the embodiments of this application;

[0030] Figure 4 Frame diagram of the low-voltage ride-through reactive power control strategy parameter optimization system for DC sending-end grid-connected new energy in the embodiments of this application;

[0031] Figure 5 Curve graph of the DC sending-end response in the existing AC transmission system;

[0032] Figure 6 Curve graph of the transient reactive power characteristics without new energy at the DC sending-end of the existing AC transmission system. Specific implementation manners

[0033] To make the invention objectives, features, and advantages of this application more obvious and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the embodiments described below are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0034] This application proposes a low-voltage ride-through reactive power control strategy parameter optimization method, system, and device for DC sending-end grid-connected new energy, which are used to solve the technical problem that in the existing areas with intensive new energy at the DC sending-end, after an AC fault occurs at the DC receiving-end, there is overvoltage at the DC sending-end, resulting in equipment damage or large-scale disconnection of new energy from the grid.

[0035] Embodiment 1:

[0036] Figure 1 Step flowchart of the low-voltage ride-through reactive power control strategy parameter optimization method for DC sending-end grid-connected new energy in the embodiments of this application.

[0037] As Figure 1 shown, this application provides a low-voltage ride-through reactive power control strategy parameter optimization method for DC sending-end grid-connected new energy, including the following steps:

[0038] S10. Obtain the initial transmission parameters of the power transmission system for DC sending-end grid-connected new energy. The initial transmission parameters include the initial value of the reactive current recovery during the new energy low-voltage ride-through recovery process, the maximum tolerable bus voltage of the DC sending-end commutation bus, and the maximum tolerable grid connection voltage of the new energy grid connection point.

[0039] It should be noted that in step S10, it is mainly to obtain the initial transmission parameters in the power transmission system for DC sending-end grid-connected new energy. The initial transmission parameters include the initial value I of the reactive current recovery during the new energy low-voltage ride-through recovery process q0, the maximum withstand bus voltage U of the DC sending - end commutation bus 1max and the maximum withstand grid - connection voltage U of the new - energy grid - connection point 2max . In this embodiment, the initial value of the reactive - current recovery I q0 = 0.3 pu, where pu refers to the per - unit value of the reactive current. In the art, pu, i.e., the per - unit value, is a commonly used numerical marking method in power - system analysis and engineering calculations, representing the relative values of various physical quantities and parameters. U 1max = 1.05 pu, U 2max = 1.05 pu, then pu represents the per - unit values of the voltages of the DC sending - end commutation bus and the new - energy grid - connection point respectively.

[0040] S20. Use the DSP - EMTDC hybrid simulation software to simulate the three - phase AC short - circuit fault of the DC sending - end commutation bus of the transmission system, and obtain the first voltage parameters during the fault. The first voltage parameters include the first maximum bus voltage of the DC sending - end commutation bus and the first maximum grid - connection voltage of the new - energy grid - connection point.

[0041] It should be noted that in step S20, mainly use the DSP - EMTDC hybrid simulation software to simulate the three - phase AC short - circuit fault of the DC sending - end commutation bus of the transmission system with new energy connected to the DC sending - end, obtain the maximum voltage of the DC sending - end commutation bus during the fault as the first maximum bus voltage, and the maximum voltage of the new - energy grid - connection point during the fault as the first maximum grid - connection voltage. In this embodiment, the first maximum bus voltage U 1 obtained in step S20 is 1.13 pu, and the first maximum grid - connection voltage U 2 is 1.22 pu.

[0042] S30. If the first voltage parameters do not meet the voltage constraints, gradually adjust the new - energy reactive - power control parameters of the transmission system based on the initial value of the reactive - current recovery, and obtain the second voltage parameters during the fault corresponding to each adjustment of the new - energy reactive - power control parameters until the obtained second voltage parameters meet the voltage constraints, and then stop adjusting the new - energy reactive - power control parameters.

[0043] It should be noted that in step S30, mainly judge whether the first voltage parameters obtained in step S20 meet the voltage constraints. When the first voltage parameters obtained in step S20 do not meet the voltage constraints, on the DSP - EMTDC hybrid simulation software, based on the initial value of the reactive - current recovery, adjust the new - energy reactive - power control parameters of the transmission system according to I qn = I qn-1-ΔI is adjusted step by step to obtain the second voltage parameter during the fault corresponding to each adjustment of the new energy reactive power control parameter until the obtained second voltage parameter meets the voltage constraint, and then the adjustment of the new energy reactive power control parameter is stopped. In this embodiment, n is the number of adjustments, ΔI is the adjustment data, and I qn-1 is the previous new energy reactive power control parameter corresponding to the nth adjustment of the new energy reactive power control parameter; when n = 1, I qn-1 is the initial value of the reactive current recovery.

[0044] Furthermore, the adjustment data is 0.1 pu, where pu is the per-unit value of the reactive current. Both the first voltage parameter and the second voltage parameter include the highest bus voltage and the highest grid-connected voltage. The voltage constraint is that the highest bus voltage is less than the highest withstand bus voltage, and the highest grid-connected voltage is less than the highest withstand grid-connected voltage.

[0045] It should be noted that when the first voltage parameter does not meet the voltage constraint, the initial value I of the reactive current recovery q0 is gradually reduced to 0 pu according to I qn = I qn-1 -ΔI to obtain the second highest bus voltage U 1 ' of the DC sending-end commutation bus and the second highest grid-connected voltage U 2 ' of the new energy grid connection point during the fault when the new energy reactive power control parameter is 0. If U 1 ' = 1.08 pu and U 2 ' = 1.06 pu still do not meet the voltage constraint requirements, further reduce the new energy reactive power control parameter to -0.2 pu according to I qn = I qn-1 -ΔI to obtain the third highest bus voltage U 1 ″ of the DC sending-end commutation bus and the third highest grid-connected voltage U 2 ″ of the new energy grid connection point during the fault when the new energy reactive power control parameter is -0.2 pu. U 1 ″ = 1.04 pu and U 2 ″ = 1.02 pu, meeting the voltage constraint requirements.

[0046] S40. Obtain the new energy reactive power control parameter that meets the voltage constraint and record this new energy reactive power control parameter as the reactive power control optimization parameter.

[0047] It should be noted that the new energy reactive power control parameter that meets the voltage constraint is obtained through steps S10 to S30, and this new energy reactive power control parameter is the optimized parameter of the low-voltage ride-through reactive power control strategy for the power transmission system of the new energy grid-connected at the DC sending end.

[0048] The method for optimizing the parameters of the low-voltage ride-through reactive power control strategy for DC sending-end grid-connected new energy sources provided by this application includes obtaining the initial transmission parameters of the power transmission system of the DC sending-end grid-connected new energy sources; using DSP-EMTDC hybrid simulation software to simulate the three-phase AC short-circuit fault of the DC sending-end converter bus of the power transmission system to obtain the first voltage parameters during the fault, where the first voltage parameters include the first highest bus voltage of the DC sending-end converter bus and the first highest grid-connected voltage of the new energy grid connection point; if the first voltage parameters do not meet the voltage constraints, gradually adjust the new energy reactive power control parameters of the power transmission system based on the initial value of the reactive current recovery until the second voltage parameters during the fault corresponding to each adjustment of the new energy reactive power control parameters are obtained and meet the voltage constraints, and then stop adjusting the new energy reactive power control parameters; obtain the new energy reactive power control parameters that meet the voltage constraints and record these new energy reactive power control parameters as the optimized reactive power control parameters. This method for optimizing the parameters of the low-voltage ride-through reactive power control strategy for DC sending-end grid-connected new energy sources gradually adjusts the new energy reactive power control parameters according to whether the voltages of the DC sending-end converter bus and the new energy grid connection point meet the voltage constraints on the DSP-EMTDC hybrid simulation software, realizing the optimization of the low-voltage ride-through reactive power strategy control parameters for new energy sources in the DC sending-end new energy-intensive area. Applying the optimized optimized reactive power control parameters to this power transmission system can keep the voltages of the sending-end converter bus and the new energy grid connection point at a reasonable level after an AC fault occurs at the DC receiving-end, solving the technical problem that in the existing DC sending-end new energy-intensive area, overvoltage occurs at the DC sending-end after an AC fault occurs at the DC receiving-end, resulting in equipment damage or large-scale disconnection of new energy sources.

[0049] Figure 2 It is the reactive power curve graph of the new energy sources for the method for optimizing the parameters of the low-voltage ride-through reactive power control strategy for DC sending-end grid-connected new energy sources described in the embodiment of this application. Figure 3 It is the voltage parameter curve graph of the method for optimizing the parameters of the low-voltage ride-through reactive power control strategy for DC sending-end grid-connected new energy sources described in the embodiment of this application.

[0050] In an embodiment of this application, the method for optimizing the parameters of the low-voltage ride-through reactive power control strategy for DC sending-end grid-connected new energy sources applies the second voltage parameters and the optimized reactive power control parameters that meet the constraint conditions to the power transmission system of the DC sending-end grid-connected new energy sources, and based on the second voltage parameters and the optimized reactive power control parameters, simulates the typical N-1 fault at the sending-end on the DSP-EMTDC hybrid simulation software to obtain simulation results, such as Figure 2 and Figure 3 shown.

[0051] Embodiment 2:

[0052] Figure 4This is the framework diagram of the low-voltage ride-through reactive power control strategy parameter optimization system for DC sending-end grid-connected new energy in the embodiments of the present application.

[0053] As Figure 4 shown, the present application also provides a low-voltage ride-through reactive power control strategy parameter optimization system for DC sending-end grid-connected new energy, including a data acquisition module 10, a simulation module 20, an adjustment module 30, and an optimized parameter acquisition module 40;

[0054] The data acquisition module 10 is used to acquire the initial transmission parameters of the power transmission system of DC sending-end grid-connected new energy. The initial transmission parameters include the initial value of the reactive current recovery during the new energy low-voltage ride-through recovery process, the maximum tolerable bus voltage of the DC sending-end converter bus, and the maximum tolerable grid connection voltage of the new energy grid connection point;

[0055] The simulation module 20 is used to simulate the three-phase AC short-circuit fault of the DC sending-end converter bus of the power transmission system by using DSP-EMTDC hybrid simulation software, and acquire the first voltage parameters during the fault. The first voltage parameters include the first maximum bus voltage of the DC sending-end converter bus and the first maximum grid connection voltage of the new energy grid connection point;

[0056] The adjustment module 30 is used to gradually adjust the new energy reactive power control parameters of the power transmission system based on the initial value of the reactive current recovery when the first voltage parameters do not meet the voltage constraints, and acquire the second voltage parameters during the fault corresponding to each adjustment of the new energy reactive power control parameters until the acquired second voltage parameters meet the voltage constraints, and then stop adjusting the new energy reactive power control parameters;

[0057] The optimized parameter acquisition module 40 is used to acquire the new energy reactive power control parameters that meet the voltage constraints and record the new energy reactive power control parameters as reactive power control optimized parameters.

[0058] In the embodiments of the present application, the adjustment module 30 is also used to adjust the new energy reactive power control parameter I qn for each time based on the initial value of the reactive current recovery. The new energy reactive power control parameter I qn = I qn-1 -ΔI. In the formula, n is the number of adjustments, ΔI is the adjustment data, and I qn-1 is the previous new energy reactive power control parameter corresponding to the nth adjustment of the new energy reactive power control parameter; when n = 1, I qn-1 is the initial value of the reactive current recovery.

[0059] In the embodiments of the present application, the adjustment data is 0.1 pu, and pu is the per-unit value of the reactive current.

[0060] In the embodiments of the present application, both the first voltage parameter and the second voltage parameter include the highest bus voltage and the highest grid-connected voltage, and the voltage constraint is that the highest bus voltage is less than the highest tolerable bus voltage, and the highest grid-connected voltage is less than the highest tolerable grid-connected voltage.

[0061] It should be noted that the content of the modules in Embodiment 2 corresponds to the steps in the method of Embodiment 1. The content of the method steps in Embodiment 1 has been elaborated in detail in Embodiment 1, and the content of the modules in the system will not be repeated in Embodiment 2.

[0062] Embodiment 3:

[0063] The present application also provides a storage device, which stores multiple pieces of program codes. The program codes are suitable for being loaded and run by a processor to execute the above-mentioned method for optimizing the low-voltage ride-through reactive power control strategy parameters of new energy with a DC sending end connected to the grid.

[0064] Embodiment 4:

[0065] The present application also provides a terminal device, including a processor and a memory;

[0066] The memory is used to store program codes and transmit the program codes to the processor;

[0067] The processor is used to execute the above-mentioned method for optimizing the low-voltage ride-through reactive power control strategy parameters of new energy with a DC sending end connected to the grid according to the instructions in the program codes.

[0068] Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the above-described system, device, and unit can refer to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0069] In several embodiments provided by the present application, it should be understood that the disclosed system, device, and method can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and 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 displayed or discussed mutual coupling or direct coupling or communication connection can be through some interfaces, and the indirect coupling or communication connection of the device or unit can be in an electrical, mechanical, or other form.

[0070] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0071] In addition, each functional unit in various embodiments of the present application may be integrated into one processing unit, or each unit may exist physically alone, 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 a software functional unit.

[0072] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it may be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, may be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0073] As described above, the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of various embodiments of the present application.

Claims

1. A method for optimizing the parameters of a low-voltage ride-through reactive power control strategy for new energy integrated into the DC sending end grid, characterized in that, it includes the following steps: Obtain the initial transmission parameters of the power transmission system for new energy integrated into the DC sending end grid. The initial transmission parameters include the initial value of the reactive current recovery during the new energy low-voltage ride-through recovery process, the maximum tolerable bus voltage of the DC sending end converter bus, and the maximum tolerable grid connection voltage of the new energy grid connection point; Use DSP-EMTDC hybrid simulation software to simulate the three-phase AC short-circuit fault of the DC sending end converter bus of the power transmission system, and obtain the first voltage parameters during the fault. The first voltage parameters include the first maximum bus voltage of the DC sending end converter bus and the first maximum grid connection voltage of the new energy grid connection point; If the first voltage parameters do not meet the voltage constraints, gradually adjust the new energy reactive power control parameters of the power transmission system based on the initial value of the reactive current recovery, and obtain the second voltage parameters during the fault corresponding to each adjustment of the new energy reactive power control parameters until the obtained second voltage parameters meet the voltage constraints, and stop adjusting the new energy reactive power control parameters; Obtain the new energy reactive power control parameters that meet the voltage constraints and record the new energy reactive power control parameters as reactive power control optimization parameters; Gradually adjust the new energy reactive power control parameters of the transmission system based on the initial value of the reactive current recovery, and obtain the second voltage parameters during the fault corresponding to each adjustment of the new energy reactive power control parameters, including: the new energy reactive power control parameter I adjusted each time based on the initial value of the reactive current recovery qn is , where n is the number of adjustments, is the adjustment data, and I qn-1 is the previous new energy reactive power control parameter corresponding to the nth adjustment of the new energy reactive power control parameter; when n = 1, I qn-1 is the initial value of the reactive current recovery; Both the first voltage parameters and the second voltage parameters include the maximum bus voltage and the maximum grid connection voltage. The voltage constraint is that the maximum bus voltage is less than the maximum tolerable bus voltage, and the maximum grid connection voltage is less than the maximum tolerable grid connection voltage.

2. The method for optimizing the parameters of the low-voltage ride-through reactive power control strategy for new energy integrated into the DC sending end grid according to claim 1, characterized in that, The adjustment data is 0.1 pu, and pu is the per-unit value of the reactive current.

3. A system for optimizing the parameters of a low-voltage ride-through reactive power control strategy for new energy integrated into the DC sending end grid, characterized in that, it includes a data acquisition module, a simulation module, an adjustment module, and an optimization parameter acquisition module; The data acquisition module is used to obtain the initial transmission parameters of the power transmission system for new energy integrated into the DC sending end grid. The initial transmission parameters include the initial value of the reactive current recovery during the new energy low-voltage ride-through recovery process, the maximum tolerable bus voltage of the DC sending end converter bus, and the maximum tolerable grid connection voltage of the new energy grid connection point; The simulation module is used to use DSP-EMTDC hybrid simulation software to simulate the three-phase AC short-circuit fault of the DC sending end converter bus of the power transmission system, and obtain the first voltage parameters during the fault. The first voltage parameters include the first maximum bus voltage of the DC sending end converter bus and the first maximum grid connection voltage of the new energy grid connection point; The adjustment module is used to gradually adjust the new energy reactive power control parameters of the power transmission system based on the fact that the first voltage parameters do not meet the voltage constraints and based on the initial value of the reactive current recovery, and obtain the second voltage parameters during the fault corresponding to each adjustment of the new energy reactive power control parameters until the obtained second voltage parameters meet the voltage constraints, and stop adjusting the new energy reactive power control parameters; The optimization parameter acquisition module is configured to acquire new energy reactive power control parameters that satisfy voltage constraints and record the new energy reactive power control parameters as reactive power control optimization parameters; The adjustment module is further configured to adjust the new - energy reactive - power control parameter \(I\) each time based on the initial value of the reactive - current recovery qn is , where \(n\) is the number of adjustments, is the adjustment data, and \(I\) qn-1 is the previous new - energy reactive - power control parameter corresponding to the new - energy reactive - power control parameter adjusted for the \(n\)th time; when \(n = 1\), \(I\) qn-1 is the initial value of the reactive - current recovery; Both the first voltage parameter and the second voltage parameter include the highest bus voltage and the highest grid-connected voltage, and the voltage constraint is that the highest bus voltage is less than the highest tolerable bus voltage, and the highest grid-connected voltage is less than the highest tolerable grid-connected voltage.

4. The low-voltage ride-through reactive power control strategy parameter optimization system for a DC sending-end grid-connected new energy according to claim 3, characterized in that, The adjustment data is 0.1 pu, where pu is the per-unit value of reactive current.

5. A storage device, in which multiple program codes are stored, characterized in that, The program codes are adapted to be loaded and run by a processor to execute the low-voltage ride-through reactive power control strategy parameter optimization method for a DC sending-end grid-connected new energy according to claim 1 or 2.

6. A terminal device, characterized in that, comprises a processor and a memory; The memory is configured to store program codes and transmit the program codes to the processor; The processor is configured to execute the low-voltage ride-through reactive power control strategy parameter optimization method for a DC sending-end grid-connected new energy according to the instructions in the program codes as claimed in claim 1 or 2.

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