A power stability control method and system for a wide-area AC-DC hybrid power system

Abstract

The present application relates to the technical field of power grid safety and stability control, and particularly relates to a power stability control method and system for a wide-area AC-DC hybrid power system. Through the coordinated control of the AC power grid, conventional UHVDC transmission and multi-terminal VSC-MTDC in the wide-area AC-DC hybrid power system, when a serious fault and active power imbalance occurs in the AC system power grid, the multi-terminal VSC-MTDC power is preferentially adjusted, the primary AC power source is cut off, and the conventional UHVDC transmission power is auxiliary adjusted, so as to realize power rapid transfer distribution and dynamic balance, improve the power grid fault response speed and control accuracy, significantly reduce the total amount of AC system generator tripping at the sending end, effectively reduce the risk of low-frequency operation of the power grid, and reduce the depth and frequency of multi-loop UHVDC cooperation in participating in the power reduction of the external DC power, so as to realize the optimal scheduling and utilization of power sources and power grid resources under the premise of ensuring the safety and stability of the whole system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power grid safety and stability control, and in particular to a power stability control method and system for a wide-area AC-DC hybrid power system. BACKGROUND

[0002] During power grid operation, various size fault disturbances and impacts will be encountered. In order to cope with the power grid operation risk under the N-2 fault mode of the power grid, ensure the safe and stable operation of the power grid (including transient stability, thermal stability, etc.), the entire system is configured with various types of AC-DC power grid safety and stability control systems (referred to as stability control systems) on important AC-DC transmission channels. Each stability control system is independent and coordinated, and takes corresponding stability control measures (referred to as stability control measures). The multiple AC-DC power grid safety and stability control systems configured in the power grid are divided into three categories, specifically: AC stability control system (multiple), conventional UHV DC stability control system (multiple) / multi-terminal flexible DC stability control system, AC-DC coordinated stability control system. The AC-DC coordinated stability control system is the highest level in the entire power grid.

[0003] At present, while meeting the needs of more hydropower and new energy for external transmission, under the serious fault mode of the main power grid (power grid N-2), in order to maintain the stability of the entire system (transient stability and thermal stability), the stability control strategy adopted by the existing AC-DC stability control system is: 1) the AC stability control system takes the stability control measure of cutting off a large number of power units (hydropower and new energy grid-connected lines) on the sending side, but the large amount of power unit cutting will cause the power grid to face a low frequency instability risk problem; 2) if the total amount of cutting on the sending side exceeds a certain threshold, the multi-loop UHV DC stability control system needs to take the DC power reduction measure, but this measure will affect the smooth operation of the UHV DC system.

[0004] How to meet the needs of large-capacity new energy power transmission in the future and at the same time cope with the risk problem faced by the power grid under the serious fault mode of AC-DC is a technical problem that needs to be considered and solved urgently in power grid planning.

[0005] How to improve and optimize the stability control strategy method based on the inherent technical advantages of the multi-terminal flexible DC system, the operation characteristics of the power grid, etc., at the technical level of the stability control strategy method of the multi-type, multi-level AC-DC stability control system in the entire system, in order to ultimately achieve effective improvement of the safe and stable operation level of the AC-DC system in the entire power grid, and improve the economic efficiency of the operation of the flexible DC system, is an important technical problem to solve the power grid operation risk problem faced by the present and future power grid, and promote the wider application and technical development of the flexible DC power transmission system. SUMMARY

[0006] To address the aforementioned technical problems, this invention provides a power stabilization and control method for a wide-area AC / DC hybrid power system, characterized by comprising the following steps:

[0007] S1. By acquiring multi-source data, obtain real-time operation data of AC power grid, conventional UHVDC power grid and multi-terminal flexible DC power grid within the wide-area AC / DC hybrid power system, and construct a real-time power grid operation data matrix;

[0008] S2. Calculate the DC adjustable power regulation margin data of the multi-terminal flexible DC grid based on the real-time operation data matrix of the power grid. ;

[0009] S3. When an N-2 or higher fault occurs in the AC transmission channel of a power source in a wide-area AC / DC hybrid power system, the total number of power source trips in the AC power grid is calculated based on the pre-set AC grid stability control strategy and the real-time grid operation data matrix. Data on the total number of power supply trips. With preset start-up threshold data for wide-area AC / DC hybrid power systems Perform data size judgment: when Data less than the gate valve threshold Then, based on the total number of power supply trips... Disconnect the power supply from the AC mains; otherwise, proceed to step S4.

[0010] S4. DC adjustable power regulation margin data for multi-terminal flexible DC grids Total data of the first power supply switching Perform data size determination:

[0011] When DC adjustable power adjustment margin data Greater than the total number of power supply trips At the same time, based on the pre-set stability control strategy, the adjustable DC power value of the multi-terminal flexible DC grid is increased. ;

[0012] When DC adjustable power adjustment margin data Less than or equal to the total number of power supply trips At the same time, based on the pre-set stability control strategy, the adjustable DC power value of the multi-terminal flexible DC grid is increased. And based on the improved DC adjustable power value of the multi-terminal flexible DC grid The total number of second power source trips in the AC power grid was calculated. ;

[0013] S5. Total data on the second power supply tripping. Valve threshold data Perform data size determination:

[0014] when the second power cut total amount data is less than the gate valve threshold data , then according to the second power cut total amount data , the power in the alternating current power grid is cut off;

[0015] when the second power cut total amount data is greater than or equal to the gate valve threshold data , then according to the second power cut total amount data , the power in the alternating current power grid is cut off, and the direct current output power value of the conventional ultra-high voltage direct current power grid is reduced .

[0016] Based on the above method, the application further provides a power stability control system for a wide-area AC / DC hybrid power system, which is realized based on any one of the above power stability control methods for a wide-area AC / DC hybrid power system, and comprises a multi-source data acquisition subsystem for acquiring real-time operation data of an alternating current power grid, a conventional ultra-high voltage direct current power grid and a multi-terminal flexible direct current power grid in the wide-area AC / DC hybrid power system through multi-source data acquisition, and constructing a power grid real-time operation data matrix;

[0017] an alternating current stability control subsystem for calculating power cut total amount data of the alternating current power grid according to a pre-set stability control strategy and the power grid real-time operation data matrix when an N-2 or more faults occur in a power transmission channel of the alternating current power grid in the wide-area AC / DC hybrid power system;

[0018] a multi-terminal flexible direct current stability control subsystem for calculating direct current adjustable power regulation margin data of the multi-terminal flexible direct current power grid according to the power grid real-time operation data matrix;

[0019] an AC / DC coordinated safety stability control subsystem for performing data judgment according to the power cut total amount data, the direct current adjustable power regulation margin data and start gate valve threshold data of the conventional ultra-high voltage direct current power grid, and transmitting stability control execution instructions to the alternating current stability control subsystem, the multi-terminal flexible direct current stability control subsystem and the direct current stability control subsystem according to the judgment results;

[0020] an ultra-high voltage direct current stability control subsystem for performing power reduction operation on the ultra-high voltage direct current power grid according to the stability control execution instructions.

[0021] A computer device comprises a memory, a processor and a computer program stored on the memory and executable on the processor, and the processor realizes the power stability control method for the wide-area AC / DC hybrid power system according to any one of the above methods when executing the computer program.

[0022] A storage medium has a computer program stored thereon, the computer program is executed by a processor to implement the power stability control method for a wide-area AC-DC hybrid power system.

[0023] The beneficial effects of the present application are that, through the coordinated control of the AC power grid, conventional UHVDC power transmission and multi-terminal flexible DC power transmission in the wide-area AC-DC hybrid power system, when a serious fault (grid N-2) or power imbalance occurs in the AC system power grid, the power is quickly transferred and balanced, and the response speed and control accuracy of the power grid are improved by preferentially adjusting the multi-terminal flexible DC power, secondarily removing the sending-end AC power supply, and auxiliary adjusting the conventional UHVDC power transmission power, thereby improving the ability of the power grid to resist serious fault risks and effectively reducing the risk of low-frequency operation of the power grid. At the same time, based on the technical level of the stability control strategy method of the multi-type and multi-level AC-DC stability control system in the whole grid, according to the inherent technical advantages of the multi-terminal flexible DC system and the operation characteristics of the power grid, the transient stability performance of the whole grid system and the overall security and stability level of the whole grid are effectively improved: the total amount of machine removal of the sending-end AC system is significantly reduced, the depth and frequency of multi-loop UHVDC cooperation in participating in the power reduction of the external DC power are reduced, the overall safety and stability of the system are improved, and the optimal scheduling and utilization of power sources and grid resources are realized under the premise of ensuring the safety and stability of the whole grid system. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A flowchart of a power stability control method for a wide-area AC-DC hybrid power system according to an embodiment of the present application.

[0025] Figure 2 A structural diagram of a power stability control system for a wide-area AC-DC hybrid power system according to an embodiment of the present application.

[0026] Figure 3 A power stability control judgment logic diagram for a wide-area AC-DC hybrid power system according to an embodiment of the present application.

[0027] Figure 4 A terminal device structure diagram of a power stability control method for a wide-area AC-DC hybrid power system according to an embodiment of the present application.

[0028] Figure 5 A computer-readable storage medium structure diagram of a power stability control method for a wide-area AC-DC hybrid power system according to an embodiment of the present application.

[0029] In the figure, 200 - terminal device, 210 - memory, 211 - RAM, 212 - cache memory, 213 - ROM, 214 - programs / utilities, 215 - program modules, 220 - processor, 230 - bus, 240 - external device, 250 - I / O interface, 260 - network adapter, 300 - program product. DETAILED DESCRIPTION

[0030] For the purposes of the present application, the technical solutions and advantages will be clearer. The present application will be further described in conjunction with the accompanying drawings and examples. It should be understood that the specific examples described herein are only intended to explain the present application and are not intended to limit the present application. That is, the described examples are only a part of the examples of the present application, but not all examples. The components of the embodiments of the present application generally described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. It should be noted that the relational terms such as "first" and "second" and the like are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations.

[0032] Moreover, the term "comprising", "containing" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or mechanical device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or mechanical device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of additional identical elements in the process, method, article or mechanical device including the element.

[0033] Example 1

[0034] As shown in Figure 1 Example 1 of the present application provides a power stability control method for a wide-area AC-DC hybrid power system, comprising the following steps:

[0035] S1. By multi-source data acquisition, real-time operation data of AC power grid, conventional UHV DC power grid and multi-terminal flexible DC power grid in the wide-area AC-DC hybrid power system are obtained, and a power grid real-time operation data matrix is constructed;

[0036] S2. Calculate the DC adjustable power regulation margin data of the multi-terminal flexible DC grid based on the real-time operation data matrix of the power grid. ;

[0037] S3. When an N-2 or higher fault occurs in the AC transmission channel of a power source in a wide-area AC / DC hybrid power system, the total number of power source trips in the AC power grid is calculated based on the pre-set AC grid stability control strategy and the real-time grid operation data matrix. Data on the total number of power supply trips. With preset start-up threshold data for wide-area AC / DC hybrid power systems Perform data size judgment: when Data less than the gate valve threshold Then, based on the total number of power supply trips... Disconnect the power supply from the AC mains; otherwise, proceed to step S4.

[0038] S4. DC adjustable power regulation margin data for multi-terminal flexible DC grids Total data of the first power supply switching Perform data size determination:

[0039] When DC adjustable power adjustment margin data Greater than the total number of power supply trips At the same time, based on the pre-set stability control strategy, the adjustable DC power value of the multi-terminal flexible DC grid is increased. ;

[0040] When DC adjustable power adjustment margin data Less than or equal to the total number of power supply trips At the same time, based on the pre-set stability control strategy, the adjustable DC power value of the multi-terminal flexible DC grid is increased. And based on the improved DC adjustable power value of the multi-terminal flexible DC grid The total number of second power source trips in the AC power grid was calculated. ;

[0041] S5. Total data on the second power supply tripping. Valve threshold data Perform data size determination:

[0042] When the total data of the second power supply switching Data less than the gate valve threshold Then, based on the total number of power supply trips... Disconnect the power source from the AC power grid;

[0043] When the total data of the second power supply switching Greater than or equal to the valve threshold data , then according to the second power cut total data cut off the power in the alternating current grid, and reduce the direct current output power value of the conventional ultra-high voltage direct current grid .

[0044] Further, the real-time operation data includes generator power angle data, alternating current grid voltage data, alternating current grid power data, alternating current grid frequency data, alternating current grid generator speed data, direct current power data and direct current voltage data of the conventional ultra-high voltage direct current grid and the multi-terminal flexible direct current grid.

[0045] Further, the stability control strategy includes cutting off the hydroelectric generator set at the sending end power source end side, cutting off the new energy grid-connected line at the sending end power source end side, and modulating the multi-terminal flexible direct current power and the multi-loop ultra-high voltage direct current power.

[0046] Further, in the step S2, according to the real-time operation data of the sending and receiving end side converter stations in the multi-terminal flexible direct current grid and the direct current grid, the adjustable direct current power adjustment margin data that meets the flexible direct current safety allowance in the multi-terminal flexible direct current grid in the current period is obtained by calculation .

[0047] Further, in the step S3, when the N-2 serious fault occurs in the power source sending alternating current channel in the wide-area alternating current and direct current hybrid power system, the power generator set in the alternating current grid is cut off according to the preset stability control strategy, and the first power cut total data and the data size relationship of the gate valve threshold value data is , if yes, execute step S4.

[0048] Specifically, the implementation process of each step of the above embodiment is as follows:

[0049] Step 1, in a wide-area complex alternating current and direct current hybrid power system containing multi-terminal flexible direct current and conventional ultra-high voltage direct current, in order to ensure the safe operation of the whole grid, three types of grid safety and stability control systems (referred to as stability control systems) are configured in the grid. According to the technical requirements of their own structure attributes, functional positioning and range, each stability control system respectively collects, monitors, summarizes, uploads or issues instructions, and implements the real-time signal information of the grid operation condition;

[0050] Step 2-A, each sending and receiving end side converter station in the multi-terminal flexible direct current stability control system is in networking operation mode with the synchronous alternating current grid. The multi-terminal flexible direct current transmission stability control system calculates, analyzes and confirms whether there is a direct current adjustable power margin space and value that meets the flexible direct current safety allowance in the multi-terminal flexible direct current transmission system in a period under the grid operation condition according to the real-time power operation condition of the sending and receiving end side converter stations and the direct current transmission line .

[0051] Step 2-B: If a severe N-2 fault occurs on a 500kV or higher main line of a major power transmission channel, the AC stability control system shall, according to the stability control strategy table, disconnect a certain capacity of power generating units on the sending end side. Stability control measures; determining the total amount of power to be cut off. (A threshold value for uploading certain startup information to the AC / DC co-control system).

[0052] Specifically, regarding the threshold data for starting the valve. And settings. Power systems, which contain numerous power components (generators, transformers, AC / DC transmission lines, motors, power electronic equipment components, etc.), will encounter various disturbances of different sizes during actual grid operation. Among them, the most serious fault is the grid N-2 (two components such as transmission lines and transformers fail simultaneously). In particular, the N-2 fault on the power source side, where power is transmitted through important AC transmission channels, is the most severe fault mode of the system. After this fault occurs, the transfer, impact, and power loss of a large capacity active power flow will have a serious impact on the system. If relevant stability control measures are not taken, the entire power grid will face the serious risk of losing stable operation (power angle instability, voltage instability, AC frequency instability) and system collapse. The direct consequence is a large-scale power outage in the receiving end area.

[0053] To address and prevent this serious fault, the power system is equipped with safety and stability control devices (functions include various safety and stability control systems and corresponding stability strategies). The main stability control strategy is: when a grid N-2 fault occurs, technical measures such as power source disconnection, load disconnection, and adjustment of conventional DC power are typically adopted. When a grid N-2 fault occurs, the degree of disturbance and damage to the system caused by faults in various N-2 components varies, resulting in different levels of disruption. Therefore, the number of power sources to be disconnected will also vary.

[0054] If the amount of generator tripping is small, the impact on the overall active power deficit (corresponding to the AC frequency) is minimal and falls within the allowable safe frequency difference range of the entire network. In this case, the system can be considered to be able to withstand the amount of generator tripping, and the AC stability control system will automatically implement the generator tripping measures. If the amount of generator tripping is large, the impact on the overall active power deficit (corresponding to the AC frequency) is significant, exceeding the allowable safe frequency difference range of the entire network. In this case, the power grid faces the risk of low-frequency operation. To address and avoid the risk of low-frequency operation of the power grid, a dedicated AC / DC coordination control system and related stability control strategies and early warning mechanisms are added to the power system (a safety early warning mechanism for uploading information on the total amount of generator tripping under severe fault conditions of the AC stability control system).

[0055] Specifically including: 1) the starting gate valve threshold data of the total amount of machine cut-off of the AC stability control system Set (the value is currently determined by the power dispatch department according to the total installed capacity of the power source of the regional power grid and the starting mode, and the value is dynamically adjusted according to the increasing scale of the power source in the power system. This value is also a numerical index for the power grid to judge the severity of the fault and the active power shortage that makes the whole network face the risk of low-frequency operation). 2) After the AC-DC system receives the first total amount of power source cut-off of the AC stability control system, and preliminarily judges that the fault is serious, in order to avoid the occurrence of low-frequency operation risk of the power grid due to large active power shortage, the AC-DC coordinated control system issues the stability control measures and instructions to the conventional DC stability control system to reduce one or more UHV DC export power; After the conventional UHV DC reduces the export DC power, the active power shortage of the whole network decreases, and the AC frequency returns to the safe operation range, maintaining the safe and stable operation of the whole network.

[0056] Step 3-A, the DC stability control system of the multi-terminal flexible DC uploads the operation condition related information of the multi-terminal flexible DC grid (including the allowed adjustable DC power margin value that can maintain the safe and stable operation of the power grid in a certain period of time

[0057] Step 3-B, the AC stability control system uploads the related information (including the total amount of power source to be cut off ) to the AC-DC coordinated control system master station under N-2 serious fault mode.

[0058] Step 4, after receiving the related information uploaded by the AC stability control system and the flexible DC stability control system, the AC-DC coordinated control system compares the related data of the pre-stored stability control strategy table of the coordinated control system and the numerical data of the adjustable DC power margin of the multi-terminal flexible DC, and judges: Whether the total amount of power source is within the safe allowable margin of the adjustable DC power of the multi-terminal flexible DC system at the sending end side of the converter station.

[0059] Step 5: The AC-DC coordinated control system adopts the stability control strategy of preferentially using the flexible DC system to improve the safe and stable level of the whole network: improving the adjustable DC power of the flexible DC part , and the AC stability control system does not need to take the stability control measures of cutting off the sending end power source. The AC-DC coordinated control system issues the stability control measures and specific DC power value instructions to the multi-terminal flexible DC system to improve the DC power.

[0060] Step 6: The AC-DC coordinated control system adopts the stability control strategy of preferentially using the flexible DC system to improve the safe and stable level of the whole network:

[0061] issues the stability control measures to the multi-terminal flexible DC system to improve part of the DC power​ ;

[0062] The cut-off part of the power supply unit capacity required to be issued to the alternating current stability control system , and simultaneously with the preset starting threshold value of the power reduction of the multi-loop DC external transmission project given by the power dispatching department Data comparison and judgment are performed: if , the AC-DC coordinated control system issues the cut-off part of the power supply unit capacity instruction to the alternating current stability control system .

[0063] Step 7: The AC-DC coordinated control system adopts the stability control strategy of preferentially utilizing the flexible DC system to improve the overall network security and stability level: if , the AC-DC coordinated control system adopts the stability control strategy of preferentially utilizing the flexible DC system to improve the overall network security and stability level: if

[0064] The AC-DC coordinated control system adopts the stability control strategy of preferentially utilizing the flexible DC system to improve the overall network security and stability level: if ;

[0065] The AC-DC coordinated control system adopts the stability control strategy of preferentially utilizing the flexible DC system to improve the overall network security and stability level: if .

[0066] Step 8, after receiving the relevant stability control instructions issued by the AC-DC coordinated control center, the alternating current stability control system, the multi-terminal flexible DC stability control system and the multi-loop ultra-high voltage DC stability control system execute the specific cut-off measures, the multi-terminal flexible DC system executes the flexible DC power improvement measures, and the ultra-high voltage DC stability control system executes the DC power reduction measures.

[0067] Embodiment 2

[0068] As shown in Figure 2 , on the basis of embodiment 1, the embodiment 2 of the application proposes a power stability control system for a wide-area AC-DC hybrid power system based on a power stability control method for a wide-area AC-DC hybrid power system.

[0069] Specifically, the system comprises a multi-source data acquisition subsystem for acquiring real-time operation data of an AC power grid, an ultra-high voltage DC power grid and a multi-terminal flexible DC power grid in a wide-area AC-DC hybrid power grid through multi-source data acquisition, and constructing a power grid real-time operation data matrix;

[0070] An alternating current stability control subsystem is configured to calculate the total power cut-off amount data of the AC power grid according to the pre-set stability control strategy and the power grid real-time operation data matrix when an N-2 or more faults occur in the power supply outgoing AC channel of the wide-area AC-DC hybrid power system.

[0071] The multi-terminal flexible DC stability control subsystem is used for calculating the DC adjustable power regulation margin data of the multi-terminal flexible DC power grid according to the real-time operation data matrix of the power grid.

[0072] The AC-DC coordinated safety and stability control subsystem is used for judging the data according to the total generator tripping amount data, the DC adjustable power regulation margin data and the gate valve threshold value data of the UHV DC power grid, and transmitting the stability control execution instructions to the AC stability control subsystem, the multi-terminal flexible DC stability control subsystem and the DC stability control subsystem according to the judgment results.

[0073] The conventional UHV DC stability control subsystem is used for performing power reduction operation on the UHV DC power grid according to the stability control execution instructions.

[0074] Specifically, the working process of the system is as follows:

[0075] Firstly, the multi-source data acquisition subsystem continuously acquires the frequency, voltage, active power, reactive power, unit speed and power angle and other information of the AC side, simultaneously acquires the DC power, voltage, port occupation degree, converter valve thermal stability margin and other information of the multi-terminal flexible DC side, and acquires the power, control mode and pole pair state of the conventional DC side, to form a complete real-time operation data matrix of the power grid.

[0076] Then, the AC stability control subsystem detects whether the N-2 and above serious faults occur in the key power transmission channel according to the data matrix and fault criterion, and calculates the total amount of the sending-end power to be cut off; at the same time, the multi-terminal flexible DC stability control subsystem calculates the available DC power regulation margin and performs safety boundary checking.

[0077] Next, the AC-DC coordinated safety and stability control subsystem comprehensively judges the AC side generator tripping demand, the multi-terminal flexible DC power regulation margin and the conventional UHV DC gate valve threshold value: if the flexible DC adjustable margin is sufficient to cover the generator tripping demand, the flexible DC power increasing instruction is directly issued and the AC side generator tripping is exempted; if it can only partially cover, the flexible DC power regulation is preferentially used, and the remaining insufficient part is realized through the AC side generator tripping; if the generator tripping demand still exceeds the flexible DC adjustable margin and reaches the threshold value, the power reduction instruction is issued to the conventional UHV DC side on the basis of the foregoing.

[0078] Then, each execution subsystem performs specific operation according to the instruction issued by the coordination subsystem: the multi-terminal flexible DC side rapidly increases the power, the AC side trips the generator according to the turn, the conventional DC side proportionally reduces the power, and the execution feedback is real-time returned.

[0079] Finally, the coordination subsystem performs closed-loop correction of frequency deviation and power imbalance based on measurement feedback. After the faulty component is restored, the stability control system withdraws the stability control measures in sequence according to the plan, including the flexible DC return to the set grid operating conditions, the gradual reconnection of the generating units, and the restoration of conventional UHVDC. The system also records the measurement and command logs throughout the process and feeds the data back into the strategy library for post-evaluation and strategy optimization.

[0080] Example 3

[0081] like Figure 4 As shown in the figure, based on Embodiment 1, Embodiment 3 proposes a terminal device for a power stabilization and control method for a wide-area AC / DC hybrid power system. The terminal device 200 includes at least one memory 210, at least one processor 220, and a bus 230 connecting different platform systems.

[0082] The memory 210 may include a readable medium in the form of volatile memory, such as RAM 211 and / or cache memory 212, and may further include ROM 213.

[0083] The memory 210 also stores a computer program, which can be executed by the processor 220, causing the processor 220 to execute any of the power stabilization methods for wide-area AC / DC hybrid power systems described in the embodiments of this application. The specific implementation and technical effects are consistent with those described in the embodiments of the above methods, and some details will not be repeated here. The memory 210 may also include a program / utility 214 having a set (at least one) of program modules 215. Such program modules include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment.

[0084] Accordingly, processor 220 can execute the aforementioned computer program, as well as executable program / utility 214.

[0085] Bus 230 can represent one or more of several types of bus structures, including a memory bus or memory controller, peripheral bus, graphics acceleration port, processor, or a local bus using any of the various bus structures.

[0086] Terminal device 200 can also communicate with one or more external devices 240, such as keyboards, pointing devices, Bluetooth devices, etc., and with one or more devices capable of interacting with it, and / or with any device that enables it to communicate with one or more other computing devices (e.g., routers, modems, etc.). This communication can be performed via I / O interface 250. Furthermore, terminal device 200 can communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via network adapter 260. Network adapter 260 can communicate with other modules of terminal device 200 via bus 230. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with terminal device 200, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms.

[0087] Example 4

[0088] like Figure 5 As shown, based on Embodiment 1, this embodiment proposes a computer-readable storage medium for a power stabilization and control method for a wide-area AC / DC hybrid power system. The computer-readable storage medium stores instructions that, when executed by a processor, implement any of the aforementioned power stabilization and control methods for a wide-area AC / DC hybrid power system. Its specific implementation method is consistent with the implementation methods and achieved technical effects described in the embodiments of the above methods, and some details will not be repeated.

[0089] Figure 5 The illustration shows a program product 300 for implementing the above-described method, which may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device, such as a personal computer. However, the program product 300 of the present invention is not limited thereto. In this embodiment, the readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device. The program product 300 may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0090] The computer readable storage medium can include a computer-readable medium in baseband or propagated as a carrier wave in a propagated signal, wherein the latter involves a propagating data signal. Such a propagated signal can take a wide variety of forms, including but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer-readable medium can also be any medium that can be read by a computer or a device or a machine, such as a computer-readable storage medium. A computer-readable storage medium can include a computer-readable storage medium or any medium that can store or transfer data for use by or in connection with an instruction execution system, apparatus, or device, such as a computer, or a machine. The computer-readable storage medium, media, or any such medium used in the execution of instructing the present disclosure can also be any pasteurizable medium that can be used to store or transfer data for use by or in connection with the instruction execution system, apparatus, or device. The program code embodied on the computer-readable storage medium can be transmitted using any appropriate medium, including but not limited to wireless, wired, optical fiber cable, RF, etc., or any suitable combination thereof. The program code for performing the operations of the present disclosure can be written in any combination of one or more programming languages, including an object-oriented programming language such as Java, C++, etc., or a conventional procedural programming languages such as the "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, as a standalone software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any kind of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (for example, using an Internet service provider to connect through the Internet).

[0091] The present application is described from the use purpose, the efficiency, the progress and the novelty, etc. The practical progress of the setting has met the function improvement and the use requirements emphasized by the patent law. The above description and drawings are only the preferred embodiments of the present application, and are not limited to the present application. Therefore, all the similar, similar, equivalent replacement or modification, etc. made within the scope of the patent application of the present application shall be within the scope of the patent application protection of the present application.

[0092] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and does not limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A power stability control method for a wide-area AC-DC hybrid power system, characterized by, The method comprises the following steps: S1. acquiring real-time operation data of an AC power grid, a conventional UHVDC power grid and a multi-terminal VSC-MTDC power grid in a wide-area AC / DC hybrid power system through multi-source data acquisition, and constructing a power grid real-time operation data matrix; S2. According to the real-time operation data matrix of the power grid, the DC adjustable power regulation margin data of the multi-terminal flexible DC power grid is calculated ; S3. When N-2 or more faults occur in the AC transmission channel of the wide-area AC-DC hybrid power system, the first total generator tripping data of the AC power grid is calculated according to the pre-set AC grid stability control strategy and the real-time operation data matrix of the power grid , and the first total generator tripping data is compared with the pre-set starting gate threshold data of the wide-area AC-DC hybrid power system . When the first total generator tripping data is less than the gate threshold data , the power sources in the AC power grid are tripped according to the first total generator tripping data , otherwise, step S4 is executed. S4. DC adjustable power regulation margin data of multi-terminal flexible DC power grid total amount of first power cut-off data Data size judgment: When DC adjustable power adjustment margin data Greater than the total number of power supply trips At the same time, based on the pre-set stability control strategy, the adjustable DC power value of the multi-terminal flexible DC grid is increased. ; When the direct-current adjustable power regulation margin data is less than or equal to the first total amount of generator tripping data , according to a pre-set stability control strategy, the direct-current adjustable power value of the multi-terminal flexible direct-current power grid is increased , and according to the increased direct-current adjustable power value of the multi-terminal flexible direct-current power grid , the second total amount of generator tripping data of the alternating-current power grid is calculated . S5. Total amount of data for second power cut AND gate valve threshold data Data size judgment is performed: when the second power cut total amount data is less than the gate valve threshold data then, according to the second power cut total amount data cut off the power supply in the alternating current network; When the second power cut total amount data is greater than or equal to the gate valve threshold data , then according to the second power cut total amount data , the power in the alternating current power grid is cut off, and the direct current output power value of the conventional extra-high voltage direct current power grid is reduced .

2. The power stability control method for wide-area AC / DC hybrid power system according to claim 1, characterized in that, The power grid real-time operation data comprises generator power angle data, AC power grid voltage data, AC power grid power data, AC power grid frequency data, DC power data and DC voltage data of the conventional UHVDC power grid and the multi-terminal VSC-MTDC power grid.

3. The power stability control method for wide-area AC / DC hybrid power system according to claim 1, characterized in that, The stability control strategy comprises cutting off a hydroelectric generator set at a sending end power source end side, cutting off a new energy grid-connected line at the sending end power source end side, and modulating multi-terminal VSC-MTDC power and multi-loop UHVDC power.

4. The power stability control method for wide-area AC / DC hybrid power system according to claim 1, characterized in that, In the step S2, according to the real-time operation data of the sending and receiving end side converter stations and the DC power grid in the multi-terminal flexible DC power grid, the DC adjustable power regulation margin data satisfying the DC safety allowance in the current period is obtained by calculation .

5. The power stability control method for wide-area AC / DC hybrid power system according to claim 1, characterized in that, In the step S3, when an N-2 serious fault occurs in the AC power grid of the wide-area AC-DC hybrid power system, the power units in the AC power grid are cut off according to the preset stability control strategy, and the total amount of the first power units cut off is judged The data size relationship between the gate valve threshold data is , and if yes, the step S4 is executed.

6. The power stability control method for wide-area AC / DC hybrid power system according to claim 1, characterized in that, In the step S4, when an N-2 serious fault occurs in the alternating current power grid of the wide-area AC-DC hybrid power system, a stable control strategy of increasing the DC adjustable power value of the multi-terminal flexible DC power grid is adopted preferentially, and the second total amount of generator tripping data of the alternating current power grid is calculated according to the increased DC adjustable power value of the multi-terminal flexible DC power grid. ​​​ 7. A power stability control system for a wide-area AC / DC hybrid power system, which is implemented based on the power stability control method for a wide-area AC / DC hybrid power system according to any one of claims 1-6, characterized in that, The method comprises the following steps: A multi-source data acquisition subsystem is configured to acquire real-time operation data of an AC power grid, a conventional UHVDC power grid and a multi-terminal VSC-MTDC power grid in a wide-area AC / DC hybrid power system through multi-source data acquisition, and construct a power grid real-time operation data matrix; An AC stability control subsystem is configured to, when an N-2 or more faults occur in a sending channel of an AC power source in the wide-area AC / DC hybrid power system, calculate total generator tripping data of the AC power grid according to a pre-set stability control strategy and the power grid real-time operation data matrix; A multi-terminal VSC-MTDC stability control subsystem is configured to calculate DC adjustable power regulation margin data of the multi-terminal VSC-MTDC power grid according to the power grid real-time operation data matrix; An AC / DC coordinated safety and stability control subsystem is configured to perform data judgment according to the total generator tripping data, the DC adjustable power regulation margin data and threshold data of a gate valve of the conventional UHVDC power grid, and transmit stability control execution instructions to the AC stability control subsystem, the multi-terminal VSC-MTDC stability control subsystem and a conventional UHVDC stability control subsystem according to a judgment result; A conventional UHVDC stability control subsystem is configured to perform power reduction operation on the UHVDC power grid according to the stability control execution instructions.

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