DC receiving end power grid voltage stability optimization method and system based on phase modifier control

Abstract

The application discloses a kind of based on phase modifier control DC receiving end power grid voltage stability optimization method and system, comprising: according to the different establishment of multiple groups of typical operating mode data of starting combination, load level and network structure;For any one group of typical operating mode data, respectively determine the first voltage of DC access point after the near-zone fault of converter station near-zone in the near-zone power grid of DC receiving end under different AC faults;For any one group of typical operating mode data, respectively according to the first voltage under different AC faults and the voltage segmented control optimization of phase modifier according to first preset comparison threshold, to obtain the voltage setting value corresponding to the any one group of typical operating mode data of the present application.The method of the present application adjusts the reference voltage of phase modifier in segments and arranges the fixed value;After DC near-zone AC fault, the reactive voltage support capability of DC receiving end near-zone phase modifier can be fully utilized, the voltage stability level of DC converter station is improved, and the voltage stability characteristics of DC receiving end power grid are optimized.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and more specifically, to a method and system for optimizing the voltage stability of a DC receiving-end power grid based on synchronous condenser control. Background Technology

[0002] The stability of the DC receiving-end near-field power grid is strongly coupled with the stable operation of the DC system. When there is an AC fault in the near-field of the DC receiving-end converter station, the DC converter station is prone to continuous commutation failure due to voltage fluctuations and low voltage problems, which threatens the safe and stable operation of the receiving-end power grid.

[0003] As a rotating device, the synchronous condenser, compared with dynamic reactive power compensation devices based on power electronics technology such as SVC and STATCOM, not only provides short-circuit capacity for the system but also has better reactive power output characteristics. It possesses unique advantages in reducing transient overvoltages at the DC sending end, suppressing commutation failures at the DC receiving end, and improving system stability through forced excitation. The ability of a synchronous condenser to provide dynamic reactive power support to the AC grid in response to voltage dips is determined by its voltage setting value, typically 1.0 pu. The larger this value, the stronger the dynamic reactive power support capability provided by the synchronous condenser when the AC system voltage deviates from its rated value.

[0004] Therefore, a method for optimizing the voltage stability of the DC receiving-end power grid based on synchronous condenser control is needed. Summary of the Invention

[0005] This invention proposes a method and system for optimizing the voltage stability of a DC receiving-end power grid based on synchronous condenser control, in order to solve the problem of how to optimize the voltage of a DC receiving-end power grid.

[0006] To address the aforementioned problems, according to one aspect of the present invention, a method for optimizing the voltage stability of a DC receiving-end power grid based on synchronous condenser control is provided, the method comprising:

[0007] Multiple sets of typical operating mode data were established based on different start-up combinations, load levels, and grid structures.

[0008] For any set of typical operating mode data, determine the first voltage of the DC connection point after the converter station near-area fault under different AC faults in the DC receiving-end near-area power grid.

[0009] For any set of typical operating mode data, the voltage segment control optimization of the synchronous condenser is performed according to the first voltage and the first preset comparison threshold under different AC faults, so as to obtain the voltage set value corresponding to the set of typical operating mode data.

[0010] The DC receiving-end grid voltage is stabilized and optimized based on the voltage setpoints corresponding to all typical operating mode data.

[0011] Preferably, the step of optimizing the voltage segmentation control of the synchronous condenser based on the first voltage and the first preset comparison threshold under different AC faults for any set of typical operating mode data, to obtain the voltage setpoint corresponding to the set of typical operating mode data, includes:

[0012] For any set of typical operating mode data, the voltage segment control optimization of the synchronous condenser is performed according to the first voltage and the first preset comparison threshold under different AC faults, the voltage setpoint under different AC faults is obtained, and the maximum value among the voltage setpoints under different AC faults is selected as the voltage setpoint corresponding to the set of typical operating mode data.

[0013] The voltage setpoint under any AC fault is determined using the following methods:

[0014] S301, determine whether the first voltage is less than or equal to a first preset comparison threshold;

[0015] S302, when it is determined that the first voltage is less than or equal to the first preset comparison threshold, it is determined whether the first voltage is less than or equal to the second preset comparison threshold;

[0016] S303, when the first voltage is less than or equal to the second preset comparison threshold, adjust the voltage setting value of the adjusting camera to the first preset adjustment value;

[0017] S304, obtain the second voltage of the DC access point after a near-field fault in the converter station, and determine whether the second voltage is less than or equal to the first preset comparison threshold;

[0018] S305, when it is determined that the second voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the second preset adjustment value.

[0019] Preferably, the method further includes:

[0020] S306, when it is determined that the first voltage is greater than the first preset comparison threshold, the voltage setting value of the adjusting phase is adjusted to the third preset adjustment value;

[0021] S307, Obtain the third voltage of the DC access point after a near-field fault in the converter station, and determine whether the third voltage is less than or equal to a first preset comparison threshold;

[0022] S308, when it is determined that the third voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value;

[0023] S309, obtain the fourth voltage of the DC access point after a near-field fault in the converter station, and determine whether the fourth voltage is less than or equal to the first preset comparison threshold.

[0024] S310, when it is determined that the fourth voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the first preset adjustment value, and the process proceeds to step S304.

[0025] Preferably, the method further includes:

[0026] S311, when it is determined that the first voltage is greater than the second preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value, and then the process proceeds to step S309.

[0027] Preferably, the first preset comparison threshold is 0.95 pu; the second preset comparison threshold is 0.9 pu; the first preset adjustment value is 1.05 pu; the second preset adjustment value is 1.07 pu; the third preset adjustment value is 1.0 pu; and the fourth preset adjustment value is 1.02 pu.

[0028] Preferably, the step of performing stable optimization control of the DC receiving-end grid voltage based on the voltage setpoint corresponding to all typical operating mode data includes:

[0029] The maximum value among the voltage setpoints corresponding to all typical operating mode data is selected as the target voltage value, and the DC receiving-end grid voltage is stabilized and optimized based on the target voltage value.

[0030] According to another aspect of the present invention, a DC receiving-end grid voltage stability optimization system based on synchronous condenser control is provided, the system comprising:

[0031] The typical operating mode data establishment unit is used to establish multiple sets of typical operating mode data based on different start-up combinations, load levels, and grid structures.

[0032] The first voltage acquisition unit is used to determine the first voltage of the DC connection point of the converter station after a fault in the near-area of ​​the DC receiving-end near-area power grid under different AC faults for any set of typical operating mode data.

[0033] The segmented control unit is used to optimize the voltage segmented control of the synchronous condenser based on the first voltage and the first preset comparison threshold under different AC faults for any set of typical operating mode data, so as to obtain the voltage set value corresponding to the set of typical operating mode data.

[0034] The stability optimization control unit is used to perform stability optimization control on the DC receiving-end grid voltage based on the voltage setpoints corresponding to all typical operating mode data.

[0035] Preferably, the segmented control unit, for any set of typical operating mode data, performs segmented voltage control optimization of the synchronous condenser based on the first voltage and the first preset comparison threshold under different AC faults, to obtain the voltage setpoint corresponding to the set of typical operating mode data, including:

[0036] For any set of typical operating mode data, the voltage segment control optimization of the synchronous condenser is performed according to the first voltage and the first preset comparison threshold under different AC faults, the voltage setpoint under different AC faults is obtained, and the maximum value among the voltage setpoints under different AC faults is selected as the voltage setpoint corresponding to the set of typical operating mode data.

[0037] The voltage setpoint under any AC fault is determined using the following methods:

[0038] S301, determine whether the first voltage is less than or equal to a first preset comparison threshold;

[0039] S302, when it is determined that the first voltage is less than or equal to the first preset comparison threshold, it is determined whether the first voltage is less than or equal to the second preset comparison threshold;

[0040] S303, when the first voltage is less than or equal to the second preset comparison threshold, adjust the voltage setting value of the adjusting camera to the first preset adjustment value;

[0041] S304, obtain the second voltage of the DC access point after a near-field fault in the converter station, and determine whether the second voltage is less than or equal to the first preset comparison threshold;

[0042] S305, when it is determined that the second voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the second preset adjustment value.

[0043] Preferably, the segmented control unit is further configured to:

[0044] S306, when it is determined that the first voltage is greater than the first preset comparison threshold, the voltage setting value of the adjusting phase is adjusted to the third preset adjustment value;

[0045] S307, Obtain the third voltage of the DC access point after a near-field fault in the converter station, and determine whether the third voltage is less than or equal to a first preset comparison threshold;

[0046] S308, when it is determined that the third voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value;

[0047] S309, obtain the fourth voltage of the DC access point after a near-field fault in the converter station, and determine whether the fourth voltage is less than or equal to the first preset comparison threshold.

[0048] S310, when it is determined that the fourth voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the first preset adjustment value, and the process proceeds to step S304.

[0049] Preferably, the segmented control unit is further configured to:

[0050] S311, when it is determined that the first voltage is greater than the second preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value, and then the process proceeds to step S309.

[0051] Preferably, the first preset comparison threshold is 0.95 pu; the second preset comparison threshold is 0.9 pu; the first preset adjustment value is 1.05 pu; the second preset adjustment value is 1.07 pu; the third preset adjustment value is 1.0 pu; and the fourth preset adjustment value is 1.02 pu.

[0052] Preferably, the stability optimization control unit performs stability optimization control on the DC receiving-end grid voltage based on the voltage setpoints corresponding to all typical operating mode data, including:

[0053] The maximum value among the voltage setpoints corresponding to all typical operating mode data is selected as the target voltage value, and the DC receiving-end grid voltage is stabilized and optimized based on the target voltage value.

[0054] This invention provides a method and system for optimizing the voltage stability of a DC receiving-end power grid based on synchronous condenser control. The method includes: establishing multiple sets of typical operating mode data based on different start-up combinations, load levels, and grid structures; for any set of typical operating mode data, determining the first voltage at the DC connection point of the converter station after a near-area fault in the DC receiving-end near-area power grid under different AC faults; for any set of typical operating mode data, performing segmented voltage control optimization of the synchronous condenser based on the first voltage under different AC faults and a first preset comparison threshold to obtain the voltage setpoint corresponding to that set of typical operating mode data; and performing stable optimization control of the DC receiving-end power grid voltage based on the voltage setpoints corresponding to all typical operating mode data. This method, by judging the degree of voltage drop at the converter station under a near-area AC fault in the DC region, adjusts the reference voltage arrangement setpoint of the synchronous condenser in segments; after a near-area AC fault in the DC region, it can fully utilize the reactive voltage support capability of the near-area synchronous condenser in the DC receiving end, improve the voltage stability level of the DC converter station, and optimize the voltage stability characteristics of the DC receiving-end power grid. Attached Figure Description

[0055] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures:

[0056] Figure 1This is a flowchart of a DC receiving-end grid voltage stability optimization method 100 based on synchronous condenser control according to an embodiment of the present invention;

[0057] Figure 2 This is an example diagram illustrating the optimization of DC receiving-end grid voltage stability according to an embodiment of the present invention;

[0058] Figure 3 (a) and (b) are schematic diagrams of the reactive power output of the pre- and post-modulation phase shifters configured according to the method of the present invention according to an embodiment of the present invention;

[0059] Figure 4 A comparison diagram of bus voltage before and after configuration according to the method of the present invention according to an embodiment of the present invention;

[0060] Figure 5 This is a schematic diagram of the structure of a DC receiving-end grid voltage stability optimization system 500 based on synchronous condenser control according to an embodiment of the present invention. Detailed Implementation

[0061] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0062] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0063] This invention proposes a method for optimizing the voltage stability of a DC receiving-end power grid based on the control optimization of a synchronous condenser. According to the degree of voltage drop of the DC converter station under AC fault, the voltage arrangement setting of the synchronous condenser is adjusted in stages, so that the synchronous condenser provides support for the voltage stability of the DC converter station during low-voltage ride-through, ensuring the stable operation of the DC system. This method can make full use of the reactive voltage support capability of the synchronous condenser in the near area of ​​the DC receiving-end power grid and optimize the voltage stability characteristics of the DC receiving-end power grid.

[0064] Figure 1 This is a flowchart of a DC receiving-end grid voltage stability optimization method 100 based on synchronous condenser control according to an embodiment of the present invention. Figure 1As shown, the DC receiving-end grid voltage stability optimization method based on synchronous condenser control provided by this invention determines the degree of voltage drop at the converter station under a near-area AC fault and adjusts the reference voltage setting of the synchronous condenser in stages. After a near-area AC fault, it can fully utilize the reactive voltage support capability of the near-area synchronous condenser at the DC receiving end, improve the voltage stability level of the DC converter station, and optimize the voltage stability characteristics of the DC receiving-end grid. The DC receiving-end grid voltage stability optimization method 100 based on synchronous condenser control provided by this invention starts from step 101. In step 101, multiple sets of typical operating mode data are established according to different start-up combinations, load levels, and grid structures.

[0065] In step 102, for any set of typical operating mode data, the first voltage of the DC connection point after the converter station near-area fault is determined under different AC faults in the DC receiving end near-area power grid.

[0066] Step 103: For any set of typical operating mode data, optimize the voltage segmented control of the synchronous condenser according to the first voltage and the first preset comparison threshold under different AC faults to obtain the voltage setpoint corresponding to the set of typical operating mode data. Preferably, the step of optimizing the voltage segmented control of the synchronous condenser according to the first voltage and the first preset comparison threshold under different AC faults to obtain the voltage setpoint corresponding to the set of typical operating mode data includes:

[0067] For any set of typical operating mode data, the voltage segment control optimization of the synchronous condenser is performed according to the first voltage and the first preset comparison threshold under different AC faults, the voltage setpoint under different AC faults is obtained, and the maximum value among the voltage setpoints under different AC faults is selected as the voltage setpoint corresponding to the set of typical operating mode data.

[0068] The voltage setpoint under any AC fault is determined using the following methods:

[0069] S301, determine whether the first voltage is less than or equal to a first preset comparison threshold;

[0070] S302, when it is determined that the first voltage is less than or equal to the first preset comparison threshold, it is determined whether the first voltage is less than or equal to the second preset comparison threshold;

[0071] S303, when the first voltage is less than or equal to the second preset comparison threshold, adjust the voltage setting value of the adjusting camera to the first preset adjustment value;

[0072] S304, obtain the second voltage of the DC access point after a near-field fault in the converter station, and determine whether the second voltage is less than or equal to the first preset comparison threshold;

[0073] S305, when it is determined that the second voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the second preset adjustment value.

[0074] Preferably, the method further includes:

[0075] S306, when it is determined that the first voltage is greater than the first preset comparison threshold, the voltage setting value of the adjusting phase is adjusted to the third preset adjustment value;

[0076] S307, Obtain the third voltage of the DC access point after a near-field fault in the converter station, and determine whether the third voltage is less than or equal to a first preset comparison threshold;

[0077] S308, when it is determined that the third voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value;

[0078] S309, obtain the fourth voltage of the DC access point after a near-field fault in the converter station, and determine whether the fourth voltage is less than or equal to the first preset comparison threshold.

[0079] S310, when it is determined that the fourth voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the first preset adjustment value, and the process proceeds to step S304.

[0080] Preferably, the method further includes:

[0081] S311, when it is determined that the first voltage is greater than the second preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value, and then the process proceeds to step S309.

[0082] Preferably, the first preset comparison threshold is 0.95 pu; the second preset comparison threshold is 0.9 pu; the first preset adjustment value is 1.05 pu; the second preset adjustment value is 1.07 pu; the third preset adjustment value is 1.0 pu; and the fourth preset adjustment value is 1.02 pu.

[0083] Step 104: Perform stable optimization control on the DC receiving-end grid voltage based on the voltage setpoints corresponding to all typical operating mode data.

[0084] Preferably, the step of performing stable optimization control of the DC receiving-end grid voltage based on the voltage setpoint corresponding to all typical operating mode data includes:

[0085] The maximum value among the voltage setpoints corresponding to all typical operating mode data is selected as the target voltage value, and the DC receiving-end grid voltage is stabilized and optimized based on the target voltage value.

[0086] Combination Figure 2 As shown, in this invention, the process of optimizing the DC receiving-end grid voltage stability includes:

[0087] Step 1: Establish multiple sets of typical operating mode data for the DC receiving-end power grid of the power grid to be studied under different start-up combinations, load levels, grid structure and other conditions.

[0088] Step 2: Select each operating mode established in Step 1 in sequence. For any operating mode, scan and calculate the voltage drop of the converter station under different AC faults in the DC receiving end near-area power grid, and obtain the first voltage under different AC faults.

[0089] Step 3: Sequentially determine the voltage drop of the DC receiving-end grid after a near-field short-circuit fault under each operating mode. If the voltage is less than or equal to 0.95pu (first preset comparison threshold), proceed to step 4; if it is higher than 0.95pu, proceed to step 5.

[0090] Step 4: Further determine whether the voltage drop is less than or equal to 0.90pu (second preset comparison threshold). If it is less than or equal to 0.90pu, proceed to step 7; if it is higher than 0.90pu, proceed to step 6.

[0091] Step 5: Adjust the camera voltage setting to keep the typical value 1.0 (third preset adjustment value) unchanged, and proceed to step 8.

[0092] Step 6: Adjust the camera voltage setting to 1.02pu (fourth preset adjustment value), and proceed to step 9.

[0093] Step 7: Adjust the camera voltage setting to 1.05pu (first preset adjustment value), and proceed to step 10.

[0094] Step 8: Determine whether the DC access point voltage after a near-field fault in the converter station is less than or equal to 0.95 pu. If it is less than or equal to 0.95 pu, proceed to step 6. If it is higher than 0.95 pu, proceed to step 12.

[0095] Step 9: Determine whether the DC access point voltage after a near-field fault in the converter station is less than or equal to 0.95 pu. If it is less than or equal to 0.95 pu, proceed to step 7; if it is higher than 0.95 pu, proceed to step 12.

[0096] Step 10: Determine whether the DC access point voltage after a near-field fault in the converter station is less than or equal to 0.95 pu. If it is less than or equal to 0.95 pu, proceed to step 11. If it is higher than 0.95 pu, proceed to step 12.

[0097] Step 11: Adjust the camera voltage setting to 1.07pu (second preset adjustment value).

[0098] Step 12: End of method.

[0099] Finally, the DC receiving-end grid voltage is stabilized and optimized based on the voltage setpoints corresponding to all typical operating mode data.

[0100] In this invention, based on the grid structure data of a certain region in China, BPA simulation is used to optimize the DC stable operation level by adopting the method proposed in this invention and utilizing the reactive voltage support capability of the synchronous condenser configured in the near area of ​​the DC receiving end, so as to verify the applicability of the method proposed in this invention.

[0101] Before adopting the method of this invention, the dynamic voltage support capability of the synchronous condenser after an AC fault in the near-area of ​​the DC converter station was as follows: Figure 3 As shown in (a), the peak value of the dynamic reactive power support capability after the fault is 362MVar, and the steady-state value is 182MVar.

[0102] Calculations show that after a three-phase short circuit on a busbar near the DC converter station, the AC voltage of the converter station drops to 0.94 Pu. Therefore, step 6 is initiated, and the synchronous condenser reference voltage setting is adjusted from the typical value of 1.0 to 1.02. After the reference voltage setting is adjusted, the dynamic reactive power support capability of the synchronous condenser is as follows: Figure 3 As shown in (b), the peak value of the dynamic reactive power support capability after the fault is 362MVar, and the steady-state value is 296MVar.

[0103] Then, calculate the AC bus voltage level of the converter station before / after the adjustment of the synchronous condenser reference voltage setting, and after a DC near-zone fault. For example... Figure 4 As shown, before adopting the method of this invention, the AC side voltage curve of the DC converter station after a three-phase short-circuit fault on the DC near-field bus is as shown in the lower curve. After adopting the method of this invention, under the same fault conditions, by adjusting the synchronous condenser reference voltage setting, the bus voltage curve is as shown in the upper curve. It can be seen that the voltage recovery level is significantly improved compared to before the method was adopted, optimizing the voltage stability level of the receiving-end DC under the impact of near-field AC faults.

[0104] Figure 5 This is a schematic diagram of a DC receiving-end grid voltage stability optimization system 500 based on synchronous condenser control according to an embodiment of the present invention. Figure 5 As shown, the DC receiving-end grid voltage stability optimization system 500 based on synchronous condenser control provided by the embodiment of the present invention includes: a typical operating mode data establishment unit 501, a first voltage acquisition unit 502, a segmented control unit 503, and a stability optimization control unit 504.

[0105] Preferably, the typical operation mode data establishment unit 501 is used to establish multiple sets of typical operation mode data according to different start-up combinations, load levels and grid structures.

[0106] Preferably, the first voltage acquisition unit 502 is used to determine the first voltage of the DC access point after the converter station near-area fault under different AC faults for any set of typical operating mode data.

[0107] Preferably, the segmented control unit 503 is used to optimize the voltage segmented control of the synchronous condenser based on the first voltage and the first preset comparison threshold under different AC faults for any set of typical operating mode data, so as to obtain the voltage set value corresponding to the set of typical operating mode data.

[0108] Preferably, the segmented control unit 503, for any set of typical operating mode data, performs segmented voltage control optimization of the synchronous condenser based on the first voltage and the first preset comparison threshold under different AC faults, to obtain the voltage setpoint corresponding to the set of typical operating mode data, including:

[0109] For any set of typical operating mode data, the voltage segment control optimization of the synchronous condenser is performed according to the first voltage and the first preset comparison threshold under different AC faults, the voltage setpoint under different AC faults is obtained, and the maximum value among the voltage setpoints under different AC faults is selected as the voltage setpoint corresponding to the set of typical operating mode data.

[0110] The voltage setpoint under any AC fault is determined using the following methods:

[0111] S301, determine whether the first voltage is less than or equal to a first preset comparison threshold;

[0112] S302, when it is determined that the first voltage is less than or equal to the first preset comparison threshold, it is determined whether the first voltage is less than or equal to the second preset comparison threshold;

[0113] S303, when the first voltage is less than or equal to the second preset comparison threshold, adjust the voltage setting value of the adjusting camera to the first preset adjustment value;

[0114] S304, obtain the second voltage of the DC access point after a near-field fault in the converter station, and determine whether the second voltage is less than or equal to the first preset comparison threshold;

[0115] S305, when it is determined that the second voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the second preset adjustment value.

[0116] Preferably, the segmented control unit 303 is further configured to:

[0117] S306, when it is determined that the first voltage is greater than the first preset comparison threshold, the voltage setting value of the adjusting phase is adjusted to the third preset adjustment value;

[0118] S307, Obtain the third voltage of the DC access point after a near-field fault in the converter station, and determine whether the third voltage is less than or equal to a first preset comparison threshold;

[0119] S308, when it is determined that the third voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value;

[0120] S309, obtain the fourth voltage of the DC access point after a near-field fault in the converter station, and determine whether the fourth voltage is less than or equal to the first preset comparison threshold.

[0121] S310, when it is determined that the fourth voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the first preset adjustment value, and the process proceeds to step S304.

[0122] Preferably, the segmented control unit 303 is further configured to:

[0123] S311, when it is determined that the first voltage is greater than the second preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value, and then the process proceeds to step S309.

[0124] Preferably, the first preset comparison threshold is 0.95 pu; the second preset comparison threshold is 0.9 pu; the first preset adjustment value is 1.05 pu; the second preset adjustment value is 1.07 pu; the third preset adjustment value is 1.0 pu; and the fourth preset adjustment value is 1.02 pu.

[0125] Preferably, the stability optimization control unit 504 performs stability optimization control on the DC receiving-end grid voltage based on the voltage setpoints corresponding to all typical operating mode data.

[0126] Preferably, the stability optimization control unit 504 performs stability optimization control on the DC receiving-end grid voltage based on the voltage setpoints corresponding to all typical operating mode data, including:

[0127] The maximum value among the voltage setpoints corresponding to all typical operating mode data is selected as the target voltage value, and the DC receiving-end grid voltage is stabilized and optimized based on the target voltage value.

[0128] The DC receiving-end grid voltage stability optimization system 500 based on synchronous condenser control in one embodiment of the present invention corresponds to the DC receiving-end grid voltage stability optimization method 100 based on synchronous condenser control in another embodiment of the present invention, and will not be described again here.

[0129] The invention has been described with reference to a few embodiments. However, as will be known to those skilled in the art, and as defined in the appended claims, other embodiments besides those disclosed above fall equivalently within the scope of the invention.

[0130] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the art, unless otherwise expressly defined herein. All references to “a / the / the [device, component, etc.]” ​​are openly interpreted as at least one instance of said device, component, etc., unless otherwise expressly stated. The steps of any method disclosed herein need not be performed in the exact order disclosed unless explicitly stated otherwise.

[0131] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0132] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0133] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0134] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for optimizing the voltage stability of a DC receiving-end power grid based on synchronous condenser control, characterized in that, The method includes: Multiple sets of typical operating mode data were established based on different start-up combinations, load levels, and grid structures. For any set of typical operating mode data, determine the first voltage of the DC connection point after the converter station near-area fault under different AC faults in the DC receiving-end near-area power grid. For any set of typical operating mode data, the voltage segment control optimization of the synchronous condenser is performed according to the first voltage and the first preset comparison threshold under different AC faults, so as to obtain the voltage set value corresponding to the set of typical operating mode data. The DC receiving-end grid voltage is optimized and controlled for stability based on the voltage setpoints corresponding to all typical operating mode data. Specifically, for any set of typical operating mode data, the voltage segmentation control optimization of the synchronous condenser is performed based on the first voltage and the first preset comparison threshold under different AC faults to obtain the voltage setpoint corresponding to the set of typical operating mode data, including: For any set of typical operating mode data, the voltage segment control optimization of the synchronous condenser is performed according to the first voltage and the first preset comparison threshold under different AC faults, the voltage setpoint under different AC faults is obtained, and the maximum value among the voltage setpoints under different AC faults is selected as the voltage setpoint corresponding to the set of typical operating mode data. The voltage setpoint under any AC fault is determined using the following methods: S301, determine whether the first voltage is less than or equal to a first preset comparison threshold; S302, when it is determined that the first voltage is less than or equal to the first preset comparison threshold, it is determined whether the first voltage is less than or equal to the second preset comparison threshold; S303, when the first voltage is less than or equal to the second preset comparison threshold, adjust the voltage setting value of the adjusting camera to the first preset adjustment value; S304, obtain the second voltage of the DC access point after a near-field fault in the converter station, and determine whether the second voltage is less than or equal to the first preset comparison threshold; S305, when it is determined that the second voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the second preset adjustment value.

2. The method according to claim 1, characterized in that, The method further includes: S306, when it is determined that the first voltage is greater than the first preset comparison threshold, the voltage setting value of the adjusting phase is adjusted to the third preset adjustment value; S307, Obtain the third voltage of the DC access point after a near-field fault in the converter station, and determine whether the third voltage is less than or equal to a first preset comparison threshold; S308, when it is determined that the third voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value; S309, obtain the fourth voltage of the DC access point after a near-field fault in the converter station, and determine whether the fourth voltage is less than or equal to the first preset comparison threshold. S310, when it is determined that the fourth voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the first preset adjustment value, and the process proceeds to step S304.

3. The method according to claim 2, characterized in that, The method further includes: S311, when it is determined that the first voltage is greater than the second preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value, and then the process proceeds to step S309.

4. The method according to claim 2, characterized in that, The first preset comparison threshold is 0.95 pu; the second preset comparison threshold is 0.9 pu; the first preset adjustment value is 1.05 pu; the second preset adjustment value is 1.07 pu; the third preset adjustment value is 1.0 pu; and the fourth preset adjustment value is 1.02 pu.

5. The method according to claim 1, characterized in that, The method of optimizing and controlling the DC receiving-end grid voltage based on the voltage setpoints corresponding to all typical operating mode data includes: The maximum value among the voltage setpoints corresponding to all typical operating mode data is selected as the target voltage value, and the DC receiving-end grid voltage is stabilized and optimized based on the target voltage value.

6. A DC receiving-end grid voltage stability optimization system based on synchronous condenser control, characterized in that, The system includes: The typical operating mode data establishment unit is used to establish multiple sets of typical operating mode data based on different start-up combinations, load levels, and grid structures. The first voltage acquisition unit is used to determine the first voltage of the DC connection point of the converter station after a fault in the near-area of ​​the DC receiving-end near-area power grid under different AC faults for any set of typical operating mode data. The segmented control unit is used to optimize the voltage segmented control of the synchronous condenser based on the first voltage and the first preset comparison threshold under different AC faults for any set of typical operating mode data, so as to obtain the voltage set value corresponding to the set of typical operating mode data. The stability optimization control unit is used to optimize the voltage of the DC receiving-end grid based on the voltage setpoint corresponding to all typical operating mode data. The segmented control unit, for any set of typical operating mode data, optimizes the voltage segmented control of the synchronous condenser based on the first voltage and the first preset comparison threshold under different AC faults, to obtain the voltage setpoint corresponding to the set of typical operating mode data, including: For any set of typical operating mode data, the voltage segment control optimization of the synchronous condenser is performed according to the first voltage and the first preset comparison threshold under different AC faults, the voltage setpoint under different AC faults is obtained, and the maximum value among the voltage setpoints under different AC faults is selected as the voltage setpoint corresponding to the set of typical operating mode data. The voltage setpoint under any AC fault is determined using the following methods: S301, determine whether the first voltage is less than or equal to a first preset comparison threshold; S302, when it is determined that the first voltage is less than or equal to the first preset comparison threshold, it is determined whether the first voltage is less than or equal to the second preset comparison threshold; S303, when the first voltage is less than or equal to the second preset comparison threshold, adjust the voltage setting value of the adjusting camera to the first preset adjustment value; S304, obtain the second voltage of the DC access point after a near-field fault in the converter station, and determine whether the second voltage is less than or equal to the first preset comparison threshold; S305, when it is determined that the second voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the second preset adjustment value.

7. The system according to claim 6, characterized in that, The segmented control unit is also used for: S306, when it is determined that the first voltage is greater than the first preset comparison threshold, the voltage setting value of the adjusting phase is adjusted to the third preset adjustment value; S307, Obtain the third voltage of the DC access point after a near-field fault in the converter station, and determine whether the third voltage is less than or equal to a first preset comparison threshold; S308, when it is determined that the third voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value; S309, obtain the fourth voltage of the DC access point after a near-field fault in the converter station, and determine whether the fourth voltage is less than or equal to the first preset comparison threshold. S310, when it is determined that the fourth voltage is less than or equal to the first preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the first preset adjustment value, and the process proceeds to step S304.

8. The system according to claim 7, characterized in that, The segmented control unit is also used for: S311, when it is determined that the first voltage is greater than the second preset comparison threshold, the voltage setting value of the adjusting camera is adjusted to the fourth preset adjustment value, and then the process proceeds to step S309.

9. The system according to claim 7, characterized in that, The first preset comparison threshold is 0.95 pu; the second preset comparison threshold is 0.9 pu; the first preset adjustment value is 1.05 pu; the second preset adjustment value is 1.07 pu; the third preset adjustment value is 1.0 pu; and the fourth preset adjustment value is 1.02 pu.

10. The system according to claim 6, characterized in that, The stability optimization control unit performs stability optimization control on the DC receiving-end grid voltage based on the voltage setpoints corresponding to all typical operating mode data, including: The maximum value among the voltage setpoints corresponding to all typical operating mode data is selected as the target voltage value, and the DC receiving-end grid voltage is stabilized and optimized based on the target voltage value.

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