Consistent frequency support method and device for flexible system based on state factor

Abstract

The application discloses a consistency collaborative frequency support method and device for a flexible direct current system based on state factors, relates to the technical field of flexible direct current system collaborative frequency support, and comprises the following steps: acquiring multiple types of frequency modulation source related data, calculating state factors based on the multiple types of frequency modulation source related data, and obtaining the state factors of the multiple types of frequency modulation sources, wherein the multiple types of frequency modulation source related data comprises multiple types of frequency modulation source parameter data, safety upper and lower limit data of the multiple types of frequency modulation sources, and multiple types of frequency modulation source parameter data when a frequency event occurs; performing consistency control based on the state factors of the multiple types of frequency modulation sources, and controlling each frequency modulation source to make the state factor corresponding to the frequency modulation source consistent with a disturbed power grid through a consensus protocol, so that the frequency modulation sources are mutually bound, and the frequency modulation sources provide frequency support for the disturbed power grid according to their own frequency modulation capabilities, wherein the multiple types of frequency modulation sources comprise offshore wind turbine generators, a flexible direct current system, an asynchronous alternating current power grid and an energy storage system, and the frequency modulation energy of the whole system is reasonably called to participate in frequency support for the disturbed power grid, so that the safety and stability of the frequency modulation sources are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coordinated frequency support of flexible direct current systems, in particular to a state factor-based consistency coordinated frequency support method and device for flexible direct current systems. BACKGROUND

[0002] In recent years, offshore wind power has developed rapidly. Due to the long distance from the shore, large-capacity and long-distance power transmission is required, so that multi-terminal flexible direct current transmission has obvious advantages. However, the offshore wind farm connected to the multi-terminal flexible direct current transmission is decoupled from the onshore power grid and cannot directly provide frequency support. Therefore, it is of great significance to study the frequency support technology of the offshore wind farm connected to the multi-terminal flexible direct current transmission system.

[0003] Existing research usually calls on wind turbines, flexible direct current systems, non-disturbance power grids and energy storage to provide frequency support for the disturbed power grid, but this also brings certain risks, such as wind turbine stall cutting, too low DC voltage of the flexible direct current system and state of charge of the energy storage exceeding the safety range, and greater frequency fluctuations in the non-disturbance power grid than in the disturbed power grid, which will have a serious impact on the entire system. Therefore, the output of each frequency modulation source should be reasonably called to ensure its own safety and stability.

[0004] In response to this, the academic community has proposed various allocation strategies to reasonably allocate frequency modulation power. However, current researches mostly focus on the output allocation among the same type of frequency modulation sources, such as among wind turbines and among non-disturbance power grids, ignoring the coordinated control among different types of frequency modulation sources, failing to consider the overall system, which not only increases the control difficulty but also increases the safety risk of each frequency modulation source, which is not conducive to the stable operation of the overall system. SUMMARY

[0005] To solve the problems mentioned in the background, the purpose of the present application is to provide a state factor-based consistency coordinated frequency support method and device for flexible direct current systems, which reasonably calls on the frequency modulation energy of the overall system to participate in the frequency support of the disturbed power grid, ensuring the safety and stability of the frequency modulation source.

[0006] In the first aspect, the purpose of the present application can be realized by the following technical solution: a state factor-based consistency coordinated frequency support method for flexible direct current systems, the method comprising the following steps:

[0007] Obtaining multi-type frequency modulation source related data, calculating state factors based on the multi-type frequency modulation source related data to obtain state factors of the multi-type frequency modulation sources, wherein the multi-type frequency modulation source related data includes multi-type frequency modulation source parameter data, safety upper and lower limit data of the multi-type frequency modulation sources, and multi-type frequency modulation source parameter data at the time of a frequency event;

[0008] The state factors of the multiple types of frequency modulation sources are controlled in consistency, and the multiple types of frequency modulation sources are controlled through a consensus protocol, so that the state factors of the multiple types of frequency modulation sources are consistent with the disturbed power grid, and the multiple types of frequency modulation sources are bound to each other and provide frequency support for the disturbed power grid according to their frequency modulation capabilities, wherein the multiple types of frequency modulation sources include offshore wind turbines, flexible direct current systems, non-synchronous alternating current power grids and energy storage systems.

[0009] With reference to the first aspect, in some implementations of the first aspect, the method further includes that the multiple types of frequency modulation source parameter data includes: offshore wind turbine rotating speed ω ri , offshore alternating current power grid frequency f OWF , flexible direct current system direct current voltage U dc , non-synchronous alternating current power grid frequency f j and energy storage state of charge SOC es .

[0010] With reference to the first aspect, in some implementations of the first aspect, the method further includes that the safety upper and lower limit data of the multiple types of frequency modulation sources includes: offshore wind turbine rotating speed ω ri_max , ω ri_min ; offshore alternating current power grid frequency f OWF_max , f OWF_min ; flexible direct current system direct current voltage U dc_max , U dc_min ; non-synchronous alternating current power grid frequency f j_max , f j_min ; energy storage state of charge SOC es_max , SOC es_min , and offshore alternating current power grid frequency reference value f OWF_ref needs to be determined.

[0011] With reference to the first aspect, in some implementations of the first aspect, the method further includes that the multiple types of frequency modulation source parameter data when the frequency event occurs includes: offshore wind turbine rotating speed ω ri0 , flexible direct current system voltage U dc0 , non-synchronous alternating current power grid frequency f j0 , and energy storage state of charge SOC es0 when the frequency event occurs.

[0012] With reference to the first aspect, in some implementations of the first aspect, the method further includes that the process of calculating the state factors based on the related data of the multiple types of frequency modulation sources includes:

[0013] The calculation formula of the wind turbine state factor is:

[0014]

[0015] In the formula, J i is the rotational inertia of the wind turbine.

[0016] The frequency modulation energy of the HVDC system comes from the DC support capacitor thereon, and thus the calculation formula of the state factor is:

[0017]

[0018] In the formula, C eq is the equivalent support capacitor of the HVDC system;

[0019] For the non-synchronous AC power grid, an equivalent synchronous unit can be equivalent, and the calculation formula of the state factor is:

[0020]

[0021] In the formula, J jeq is the equivalent synchronous unit inertia, ω jeq is the real-time rotor speed of the equivalent unit, ω jeq0 is the initial speed of the equivalent unit when the frequency event occurs, ω jeq_max and ω jeq_min are the safe upper and lower limits of the rotor speed of the equivalent unit;

[0022] The relationship between the rotor speed of the synchronous generator and the frequency is:

[0023]

[0024] In the formula, ω and p are the rotor speed and the number of pole pairs of the synchronous generator, f syn is the output AC frequency of the generator, and the modified state factor of the non-synchronous AC power grid is:

[0025]

[0026] Finally, the calculation formula of the state factor of the energy storage system is as follows:

[0027]

[0028] In combination with the first aspect, in some implementations of the first aspect, the method further includes: the state factor based on the multiple types of frequency modulation sources and the consistency control are performed through a consensus protocol, and the consensus protocol controlled through the consensus protocol is as follows:

[0029] x i =y=z j =s es .

[0030] In combination with the first aspect, in some implementations of the first aspect, the method further includes: in the process of the state factor based on the multiple types of frequency modulation sources and the consistency control,

[0031] The offshore wind farm is decoupled from the onshore non-synchronous power grid due to the flexible direct system, and cannot directly perceive the frequency change of the disturbed power grid, so it is necessary to map the frequency of the disturbed power grid to the offshore alternating current grid through the change of the direct current voltage of the flexible direct system, so as to avoid the use of communication equipment and improve the transmission speed of frequency information, wherein the flexible direct system is consistent with the state factor of the disturbed power grid due to the consensus protocol of response consistency, so that the frequency of the offshore alternating current grid is controlled to satisfy the following formula:

[0032]

[0033] In a second aspect, to achieve the above object, the application discloses a state factor-based consistency collaborative frequency support device of a flexible direct system, comprising:

[0034] A state factor calculation module is configured to obtain multi-type frequency modulation source related data, calculate the state factor based on the multi-type frequency modulation source related data, and obtain the state factor of the multi-type frequency modulation source, wherein the multi-type frequency modulation source related data comprises multi-type frequency modulation source parameter data, safety upper and lower limit data of the multi-type frequency modulation source, and multi-type frequency modulation source parameter data when a frequency event occurs.

[0035] A collaborative frequency support module is configured to control the state factor of the multi-type frequency modulation source based on the state factor of the multi-type frequency modulation source and perform consistency control, regulate and control through a consensus protocol, control the corresponding state factor of each frequency modulation source to be consistent with the disturbed power grid, bind each other, and provide frequency support for the disturbed power grid according to the frequency modulation capability of each frequency modulation source, wherein the multi-type frequency modulation source comprises offshore wind turbine, flexible direct system, non-synchronous alternating current grid and energy storage system.

[0036] In another aspect of the application, to achieve the above object, a terminal device is disclosed, comprising a memory, a processor and a computer program stored in the memory and capable of running on the processor, the memory stores a computer program capable of running on the processor, and when the processor loads and executes the computer program, the state factor-based consistency collaborative frequency support method of the flexible direct system is adopted.

[0037] In still another aspect of the application, to achieve the above object, a computer readable storage medium is disclosed, the computer readable storage medium stores a computer program, and when the computer program is loaded and executed by the processor, the state factor-based consistency collaborative frequency support method of the flexible direct system is adopted.

[0038] The application has the following beneficial effects:

[0039] The frequency modulation capability of each frequency modulation source is quantitatively evaluated, so that the frequency modulation power can be reasonably distributed; the present application does not require communication equipment, and each frequency modulation source only needs to collect local information to provide frequency support for the disturbed power grid, which not only improves the frequency modulation reliability, but also speeds up the system response speed; the present application breaks through the traditional technology which is mainly focused on the output distribution among the same type of frequency modulation sources, and starts from the whole system, coordinates all potential frequency modulation sources in the system to participate in the frequency support of the disturbed power grid, improves the frequency modulation energy utilization rate, and ensures the safety and stability of the frequency modulation source itself. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0041] Figure 1 is a method flowchart of the present application;

[0042] Figure 2 is a control block diagram of the present application for the state factor-based consistency collaborative frequency support method of the multi-terminal flexible system;

[0043] Figure 3 is a control flowchart of the present application for the state factor-based consistency collaborative frequency support method of the multi-terminal flexible system;

[0044] Figure 4 is a simulation model topology structure diagram of the offshore wind power through the multi-terminal flexible system;

[0045] Figure 5 is a simulation result of the state factor-based consistency collaborative frequency support method of the multi-terminal flexible system on the simulation model;

[0046] Figure 6 is a device structure schematic diagram of the present application. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort are within the scope of protection of the present application.

[0048] Embodiment one:

[0049] As shown in the drawings, Figure 1 the state factor-based consistency collaborative frequency support method of the flexible system, the method comprises the following steps:

[0050] S101: Obtain multi-class frequency modulation source related data, and calculate a state factor based on the multi-class frequency modulation source related data to obtain a state factor of the multi-class frequency modulation source, wherein the multi-class frequency modulation source related data includes multi-class frequency modulation source parameter data, safety upper and lower limit data of the multi-class frequency modulation source, and multi-class frequency modulation source parameter data at the time of a frequency event;

[0051] Specifically, the safety upper and lower limit data of the multi-class frequency modulation source includes a sea wind turbine speed upper and lower limit ω ri_max , ω ri_min ; a sea alternating current grid frequency upper and lower limit f OWF_max , f OWF_min ; a flexible direct current system direct current voltage upper and lower limit U dc_max , U dc_min ; an asynchronous alternating current grid frequency upper and lower limit f j_max , f j_min ; and an energy storage state of charge upper and lower limit SOC es_max , SOC es_min . In addition, a sea alternating current grid frequency reference value f OWF_ref is also determined.

[0052] Real-time collection is performed on a sea wind turbine speed ω ri , a sea alternating current grid frequency f OWF , a flexible direct current system direct current voltage U dc , an asynchronous alternating current grid frequency f j , and an energy storage state of charge SOC es .

[0053] A sea wind turbine speed ω ri0 , a flexible direct current system voltage U dc0 , an asynchronous alternating current grid frequency f j0 , and an energy storage state of charge SOC es0 at the time of a frequency event are recorded.

[0054] State factors of the sea wind turbine, the flexible direct current system, the asynchronous alternating current grid, and the energy storage system are calculated, and are respectively denoted as x i , y, z j , and s es , to evaluate frequency modulation capabilities of the frequency modulation sources in the same standard system.

[0055] The calculation formula of the wind turbine state factor is as follows:

[0056]

[0057] In the formula, J i is the rotational inertia of the wind turbine.

[0058] The frequency modulation energy of the HVDC system comes from the DC support capacitor thereon, and therefore the calculation formula of the state factor thereof is:

[0059]

[0060] In the formula, C eq is the equivalent support capacitor of the HVDC system.

[0061] For the asynchronous AC power grid, it can be equivalent to a synchronous generator unit, and therefore the calculation formula of the state factor thereof is:

[0062]

[0063] In the formula, J jeq is the equivalent inertia of the synchronous generator unit, ω jeq is the real-time rotor speed of the equivalent generator unit, ω jeq0 is the initial rotor speed of the equivalent generator unit when the frequency event occurs, ω jeq_max , ω jeq_min are the safe upper and lower limits of the rotor speed of the equivalent generator unit.

[0064] According to the knowledge of motor, the relationship between the rotor speed of the synchronous generator and the frequency is:

[0065]

[0066] In the formula, ω, p are the rotor speed of the synchronous generator and the pole pair number, f syn is the frequency of the AC power output by the generator, and therefore the modified state factor of the asynchronous AC power grid is:

[0067]

[0068] Finally, the calculation formula of the state factor of the energy storage system is as follows:

[0069]

[0070] S102: Based on the state factors of the multiple types of frequency modulation sources, consistency control is performed, the frequency modulation sources control their corresponding state factors to be consistent with the disturbed power grid through a consensus protocol, so that the frequency modulation sources are mutually bound, and the frequency modulation sources provide frequency support for the disturbed power grid according to their own frequency modulation capabilities, wherein the multiple types of frequency modulation sources include offshore wind turbine generators, HVDC systems, asynchronous AC power grids, and energy storage systems.

[0071] Specifically, consistency control is adopted, the frequency modulation sources control their state factors to be consistent with the disturbed power grid through a consensus protocol, so that the frequency modulation sources are mutually bound, and the frequency modulation sources provide frequency support for the disturbed power grid according to their own frequency modulation capabilities.

[0072] The consensus protocol in the consistency control is as follows:

[0073] x i = y = z j = s es

[0074] Under consistency control, the offshore wind farm is decoupled from the onshore non-synchronous grid due to the flexible system, and cannot directly perceive the frequency change of the disturbed grid, so it is necessary to map the frequency of the disturbed grid to the offshore alternating current grid through the change of the direct current voltage of the flexible system, so as to avoid the communication equipment and improve the transmission speed of the frequency information. Wherein, the state factor of the flexible system is consistent with the disturbed grid due to the response of the consistency consensus protocol, so the frequency of the offshore alternating current grid can be controlled to satisfy the following formula:

[0075]

[0076] Specifically, the scheme of the application is further described through the following embodiments:

[0077] The topological structure of the offshore wind power through the multi-terminal flexible grid-connected system simulation model is shown in Figure 4 Among them, the energy storage system adopts power type energy storage-super capacitor to provide fast frequency support for the disturbed grid.

[0078] The system is mainly composed of 1 offshore wind farm, 1 offshore converter station, 3 onshore converter stations, 3 non-connected onshore alternating current grids and 50 parallel super capacitors. Among them, the wind farm contains 3 aggregated wind turbines, the wind speed of which is 8 m / s, 8.5 m / s and 9 m / s (1-3) respectively, each aggregated wind turbine is aggregated by 20 5MW permanent magnet direct drive wind turbines, and the wind turbine model parameters are shown in Table 1. The capacitance of the super capacitor is 100F, and the rated voltage is 160V. For the non-synchronous alternating current grid, because this paper mainly studies its frequency response, it is equivalent to a synchronous unit, and the inertia time constant of the equivalent unit is set to 4.5s, 4s and 3.5s (1-3) respectively, the rated capacity is 500MVA, 333MVA and 166MVA respectively, and the equivalent load power is 525MW, 350MW and 175MW respectively. The other parameters of the offshore wind power through the multi-terminal flexible grid-connected system are as follows: the capacity of the sea-land converter station is 300MVA, the direct current side voltage is ±300kV, the alternating current side voltage of the offshore converter station is 220kV, the alternating current side voltage of the onshore converter station is 150kV, the direct current support capacitor of the flexible system is 7.5mF, the distance from the offshore converter station to the three onshore converter stations is 100km, 150km and 200km respectively, and the distance between the energy storage system and the non-synchronous grid 3 is 20km.

[0079] Table 1 5MW wind turbine model parameters

[0080]

[0081] The simulation verification is carried out below, and is compared and analyzed with the traditional frequency support method. The comparison simulation example is set as follows:

[0082] Case 1 (method of the invention, MOI): the consistency collaborative frequency support method of the multi-terminal flexible system based on state factors of the application is adopted;

[0083] Case 2 (traditional method, TDM): the offshore wind farm adopts centralized control, and the multi-terminal flexible system and the energy storage system both adopt droop control.

[0084] The safety lower limit of the offshore wind turbine speed, the flexible system DC voltage, the energy storage system state of charge, the offshore AC power grid and the non-synchronous AC power grid frequency is respectively set as 0.7pu, 0.9pu, 0.2pu, 49.8Hz and 49.8Hz. At 5s, 120MW load surge occurs in the non-synchronous AC power grid 1, the frequency drops, and the simulation results of the comparison example are as shown in Figure 5 It can be seen that, under the traditional method, because the multi-terminal flexible system adopts droop control, the land converter station output power is affected by the droop coefficient, the frequency regulation stability is poor, and once the droop coefficient is set improperly, the non-disturbance power grid may even produce greater frequency fluctuation than the disturbed power grid, as shown in Figure 5 (B-a), the frequency fluctuation of the non-synchronous power grid 3 even exceeds that of the disturbed power grid 1. In contrast, the method of the application coordinates all frequency regulation sources of the whole system to participate in the frequency support of the disturbed power grid through consistency control, the frequency regulation capacity of which is strong, and the frequency regulation capacity of which is weak, which realizes good frequency regulation effect while ensuring the safety and stability of the frequency regulation source, as shown in Figure 5 (A-b), the higher the speed of the aggregated wind turbine, the more energy it releases, and the greater the speed drop. In addition, under the consistency collaborative frequency support method of the multi-terminal flexible system based on state factors of the application, the system does not need to install communication equipment, and each frequency regulation source only needs to collect local information to realize global consistency control, which reduces the communication delay and improves the frequency regulation reliability.

[0085] It should be noted that the specific embodiment is based on a frequency drop event, which is only an example and does not limit the application scenarios of the application. The same applies to the frequency surge event.

[0086] Embodiment two: as shown in Figure 6 To achieve the above object, the application discloses a consistency collaborative frequency support device of a flexible system based on state factors, which comprises:

[0087] The state factor calculation module 11 is configured to acquire multi-type frequency modulation source related data, and calculate state factors of the multi-type frequency modulation sources based on the multi-type frequency modulation source related data, wherein the multi-type frequency modulation source related data comprises multi-type frequency modulation source parameter data, safety upper and lower limit data of the multi-type frequency modulation sources, and multi-type frequency modulation source parameter data when a frequency event occurs.

[0088] The cooperative frequency support module 12 is configured to control consistency based on the state factors of the multi-type frequency modulation sources, and control each frequency modulation source to be consistent with the disturbed power grid by using a consensus protocol, so that the frequency modulation sources are mutually bound and provide frequency support for the disturbed power grid according to their own frequency modulation capabilities, wherein the multi-type frequency modulation sources comprise offshore wind turbine generators, flexible direct current systems, non-synchronous alternating current power grids, and energy storage systems.

[0089] Based on the same inventive concept, the application further provides a computer device, which comprises one or more processors and a memory for storing one or more computer programs; the program comprises program instructions, and the processor is configured to execute the program instructions stored in the memory. The processor can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The processor is the computing core and control core of the terminal, and is configured to implement one or more instructions, and is specifically configured to load and execute one or more instructions in the computer storage medium to implement the above method.

[0090] It should be further noted that based on the same inventive concept, the present application further provides a computer storage medium, which stores a computer program, and the computer program is run by a processor to execute the above method. The storage medium can adopt any combination of one or more computer readable media. The computer readable medium can be a computer readable signal medium or a computer readable storage medium. The computer readable storage medium may, for example, but is not limited to, an electrical, magnetic, optical, electrical, magnetic, infrared, or semiconductor system, device or apparatus, or any combination thereof. More specific examples (non-exhaustive list) of the computer readable storage medium include: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, the computer readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device or apparatus.

[0091] In the description of the present application, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0092] The above shows and describes the basic principles, main features and advantages of the present disclosure. It should be understood by those skilled in the art that the present disclosure is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present disclosure. Without departing from the spirit and scope of the present disclosure, various changes and improvements can be made to the present disclosure, and all these changes and improvements fall within the scope of the present disclosure.

Claims

1. A consistent cooperative frequency support method for a flexible system based on state factors, characterized in that, The method includes the following steps: Acquire relevant data of multiple types of frequency modulation sources, calculate state factors based on the relevant data of multiple types of frequency modulation sources, and obtain state factors of multiple types of frequency modulation sources. The relevant data of multiple types of frequency modulation sources includes parameter data of multiple types of frequency modulation sources, safety upper and lower limit data of multiple types of frequency modulation sources, and parameter data of multiple types of frequency modulation sources when frequency events occur. The process of calculating the state factor based on correlation data from multiple frequency modulation sources includes: The formula for calculating the state factor of a wind turbine is: wherein is the moment of inertia of the wind turbine; is the offshore wind turbine speed, is the offshore wind turbine speed safety upper limit, is the offshore wind turbine speed safety lower limit, is the offshore wind turbine speed at the time of the frequency event; The frequency modulation energy of the flexible DC system comes from its DC support capacitor, therefore the formula for calculating the state factor is: wherein is the equivalent supporting capacitance of the HVDC system, is the DC voltage of the HVDC system, is the upper limit of the DC voltage of the HVDC system, is the lower limit of the DC voltage of the HVDC system, is the voltage of the HVDC system when the frequency event occurs. For asynchronous AC power grids, they can be equivalent to a synchronous generator unit, and the formula for calculating the state factor is: wherein, is the equivalent inertia of the synchronous machine, is the real-time rotor speed of the equivalent machine, is the initial rotor speed of the equivalent machine at the time of the frequency event, , are the safe upper and lower limits of the rotor speed of the equivalent machine. The relationship between the rotor speed and frequency of a synchronous generator is as follows: wherein , is the synchronous generator rotor speed and the number of pole pairs, is the generator output AC frequency, the modified non-synchronous AC grid state factor is: is the non-synchronous AC grid frequency, is the non-synchronous AC grid frequency safety upper limit, is the non-synchronous AC grid frequency safety lower limit, is the non-synchronous AC grid frequency at the time of the frequency event; Finally, the formula for calculating the state factor of an energy storage system is as follows: ； is the energy storage state of charge, is the energy storage state of charge safety upper limit, is the energy storage state of charge safety lower limit, is the energy storage state of charge at the time of the frequency event; Based on the state factors of multiple frequency regulation sources and consistent control, through consensus protocol regulation, each frequency regulation source controls its corresponding state factor to be consistent with the disturbed power grid, so that they are mutually bound and jointly provide frequency support for the disturbed power grid according to their own frequency regulation capabilities. The multiple frequency regulation sources include offshore wind turbines, flexible DC systems, asynchronous AC power grids and energy storage systems. The consensus protocol, which is based on state factors from multiple frequency modulation sources and performs consistency control, and is regulated by a consensus protocol, is as follows: 。 2. The state factor based consistent co-ordinated frequency support method for a flexible system according to claim 1, wherein, In the process of consistency control based on state factors of multiple types of frequency modulation sources... Offshore wind farms are decoupled from the onshore asynchronous power grid due to the flexible DC system, making it impossible to directly sense changes in the frequency of the disturbed power grid. Therefore, it is necessary to map the frequency of the disturbed power grid to the offshore AC power grid through changes in the DC voltage of the flexible DC system. This eliminates the need for communication equipment and improves the frequency information transmission speed. Because the flexible DC system responds to a consensus protocol, its state factor is consistent with that of the disturbed power grid. Therefore, controlling the frequency of the offshore AC power grid satisfies the following equation: is the offshore AC grid frequency, is the offshore AC grid frequency reference value, is the offshore AC grid frequency safety upper limit, is the offshore AC grid frequency safety lower limit.

3. A state factor based HVDC system consistent cooperative frequency support apparatus, adopting the state factor based HVDC system consistent cooperative frequency support method of any one of claims 1 to 2, characterized in that, include: The state factor calculation module is used to acquire relevant data of multiple types of frequency modulation sources, calculate the state factors based on the relevant data of multiple types of frequency modulation sources, and obtain the state factors of multiple types of frequency modulation sources. The relevant data of multiple types of frequency modulation sources includes parameter data of multiple types of frequency modulation sources, safety upper and lower limit data of multiple types of frequency modulation sources, and parameter data of multiple types of frequency modulation sources when frequency events occur. The coordinated frequency support module is used to perform consistency control based on the state factors of multiple frequency regulation sources. Through consensus protocol regulation, each frequency regulation source controls its corresponding state factor to be consistent with the disturbed power grid, so that they are mutually bound and jointly provide frequency support for the disturbed power grid according to their own frequency regulation capabilities. The multiple frequency regulation sources include offshore wind turbines, flexible DC systems, asynchronous AC power grids and energy storage systems.

4. A terminal device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, The memory stores a computer program that can run on the processor. When the processor loads and executes the computer program, it employs the state factor-based consistent cooperative frequency support method for flexible direct current systems as described in any one of claims 1 to 2.

5. A computer-readable storage medium having stored therein a computer program, characterized in that, When the computer program is loaded and executed by the processor, it employs the state factor-based consistent cooperative frequency support method for flexible direct current systems as described in any one of claims 1 to 2.

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