Flexible dynamic low-frequency wind power system multi-agent coordination fault ride-through method and system

Abstract

The invention discloses a flexible dynamic low-frequency wind power system multi-body coordination ride-through control method and system, and the method comprises the steps: obtaining the voltage of a power frequency system, and inputting a power-matched low-frequency AC energy consumption device according to the power of the power frequency system before a fault when the fault of the power frequency system is judged according to the voltage of the power frequency system. According to the method, overvoltage and overcurrent in the flexible dynamic low-frequency wind power system can be effectively reduced, and the fault ride-through performance of the system is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible AC and DC power transmission in electric power systems, and in particular relates to a multi-agent coordinated ride-through control method and system for a flexible dynamic low-frequency wind power system. Background Art

[0002] Offshore wind power has the characteristics of high utilization hours, no greenhouse gas emissions, and suitability for large-scale development. In recent years, it has become an important direction for the development of wind power in coastal countries and regions. Judging from the development trend of global offshore wind power projects, the LCOE (levelized cost of electricity) of offshore wind power projects will continue to decline in the future, the capacity of single wind turbines is gradually increasing, and the choice of sites is constantly moving towards the deep sea. The farther from the shore, as the transmission distance increases, conventional transmission methods can no longer meet the demand, and new transmission methods such as flexible direct current transmission and flexible low-frequency transmission are gradually emerging.

[0003] The existing medium and long-distance offshore wind power generally adopts the variable speed constant frequency wind farm through flexible direct current transmission scheme. There are four levels of AC-DC (or DC-AC) converters from the generator to the onshore power grid, including the wind turbine side converter and the grid side converter, and the HVDC sending end converter station and receiving end converter station. This kind of scheme requires multi-level converters, which has the advantages of good controllability, but also has the disadvantages of large equipment investment and complex construction and operation and maintenance.

[0004] The dynamic low-frequency wind power system collects the fixed-speed wind turbines through the low-frequency power grid, converts the electric energy into industrial frequency through a large-capacity low-frequency converter and then sends it to the power grid. Only one level of AC / AC converter is required from the generator to the power grid, which greatly reduces the level and number of power electronic equipment. However, since the dynamic low-frequency transmission cancels the back-to-back converter of the unit, the controllability of the unit is poor. It is necessary to use the dynamic adjustable frequency of the low-frequency power grid to realize variable-speed MPPT of the wind turbine group to improve the utilization rate of wind energy.

[0005] When a fault occurs in the industrial frequency system, the inverter's ability to transmit power to the AC grid will be limited, and the wind turbine needs to adjust the pitch angle to reduce the transmitted active power. There is a problem of active power surplus in the dynamic low-frequency system, which will cause overvoltage in equipment such as the inverter, resulting in the system being unable to achieve fault ride-through and thus exiting operation. Summary of the invention

[0006] The purpose of the present invention is to provide a flexible dynamic low-frequency wind power system multi-agent coordinated ride-through control method and system, which can effectively reduce overvoltage and overcurrent in the flexible dynamic low-frequency wind power system and improve the fault ride-through performance of the system.

[0007] In order to achieve the above object, the solution of the present invention is:

[0008] A multi-agent coordinated ride-through control method for a flexible dynamic low-frequency wind power system, comprising:

[0009] The power frequency system voltage is obtained, and when it is determined that a power frequency system fault occurs according to the power frequency system voltage, a low-frequency AC energy consumption device with power matching is put into operation according to the power frequency system power before the fault.

[0010] Wherein, judging that a power frequency system fails according to the power frequency system voltage includes:

[0011] Get the positive sequence voltage U of the power frequency system pos , the power frequency system positive sequence voltage U pos With fault voltage setting value U set For comparison, if the positive sequence voltage U pos Less than the fault voltage setting value U set , it is judged that the power frequency system is faulty.

[0012] Among them, the low-frequency AC energy consumption device with power matching is put into use according to the power frequency system power before the fault, including:

[0013] Obtain the active power P of the AC / AC converter in the power frequency system before the fault all ;

[0014] N1 groups of low-frequency AC energy-consuming devices are put into the power frequency system; wherein, P one It is the capacity of a group of low-frequency AC energy consuming devices.

[0015] Among them, after the low-frequency AC energy consumption device with power matching is put into use, it also includes:

[0016] Get the capacitor voltage in the AC / AC converter and get the average capacitor voltage U of all converter modules in the AC / AC converter. c ;

[0017] According to the average value of capacitor voltage U c , calculate the current power regulation value ΔP; where the average capacitor voltage U c The capacitor voltage setting value U during the fault period cset Make the difference, and then perform PI regulation to obtain the current power regulation amount ΔP;

[0018] N2 groups of low-frequency AC energy-consuming devices are put into the power frequency system; wherein, P one is the capacity of a group of low-frequency AC energy consumption devices, P all is the active power of the AC / AC converter in the power frequency system before the fault.

[0019] Wherein, the method further comprises:

[0020] During a fault, the capacitor voltage setting value U during the fault is increased.cset , so that the converter module capacitor absorbs more active power.

[0021] Wherein, when judging that a power frequency system fails according to the power frequency system voltage, it also includes:

[0022] According to the power frequency system voltage, obtain the AC / AC converter low frequency side voltage command value F LFref ; Among them, F LFref =F LFrated -k×(U pos -U rated ), F LFrated is the rated voltage on the low-frequency side, k is the voltage-frequency conversion coefficient, U rated is the rated value of power frequency voltage, U pos is the positive sequence voltage of the power frequency system;

[0023] The AC / AC converter low frequency side voltage command value F LFref Controls the voltage frequency output on the low-frequency side of the AC / AC inverter.

[0024] Wherein, when judging that a power frequency system fails according to the power frequency system voltage, it also includes:

[0025] Get the AC / AC inverter low frequency F LFwind ;

[0026] If F LFwind -F LFrated >ΔF set , then the pitch angle is increased by adjusting the speed upper limit with the pitch angle, where ΔF set Set the value for frequency deviation.

[0027] A flexible dynamic low-frequency wind power system multi-agent coordinated ride-through control system, comprising:

[0028] A power frequency system voltage acquisition module is configured to acquire the power frequency system voltage;

[0029] a power frequency system fault judgment module, configured to judge whether a power frequency system fault occurs according to the power frequency system voltage; and

[0030] The energy consumption device input module is configured to input a low-frequency AC energy consumption device with power matching according to the power frequency system power before the failure when the power frequency system fault judgment module determines that the power frequency system has a fault.

[0031] The power frequency system fault judgment module judges that a power frequency system fault occurs according to the power frequency system voltage, including:

[0032] Get the positive sequence voltage U of the power frequency system pos , the power frequency system positive sequence voltage Upos With the fault voltage setting value U set For comparison, if the positive sequence voltage U pos Less than the fault voltage setting value U set , it is judged that the power frequency system is faulty.

[0033] Among them, the energy consumption device input module inputs a low-frequency AC energy consumption device with power matching according to the power frequency system power before the fault, including:

[0034] Obtain the active power P of the AC / AC converter in the power frequency system before the fault all ;

[0035] N1 groups of low-frequency AC energy-consuming devices are put into the power frequency system; wherein, P one It is the capacity of a group of low-frequency AC energy consuming devices.

[0036] The system further includes an energy consumption device input adjustment module, which is configured to:

[0037] Get the capacitor voltage in the AC / AC converter and get the average capacitor voltage U of all converter modules in the AC / AC converter. c ;

[0038] According to the average value of capacitor voltage U c , calculate the current power regulation value ΔP; where the average capacitor voltage U c The capacitor voltage setting value U during the fault period cset Make the difference, and then perform PI regulation to obtain the current power regulation amount ΔP;

[0039]

[0040] is the capacity of a group of low-frequency AC energy-consuming devices, P all is the active power of the AC / AC converter in the power frequency system before the fault.

[0041] Wherein, the system further comprises:

[0042] The capacitor voltage setting value adjustment module is configured to increase the capacitor voltage setting value U during the fault period. cset , so that the converter module capacitor absorbs more active power.

[0043] Wherein, the system further comprises a low-frequency side voltage frequency output control module, which is configured to:

[0044] According to the power frequency system voltage, obtain the AC / AC converter low frequency side voltage command value F LFref Among them, F LFref =F LFrated-k×(U pos -U rated ), F LFrated is the rated voltage on the low-frequency side, k is the voltage-frequency conversion coefficient, U rated is the rated value of power frequency voltage, U pos is the positive sequence voltage of the power frequency system;

[0045] The AC / AC converter low frequency side voltage command value F LFref Controls the voltage frequency output on the low-frequency side of the AC / AC inverter.

[0046] Wherein, the system further comprises a pitch angle control module, which is configured to:

[0047] Get the AC / AC inverter low frequency F LFwind ;

[0048] If F LFwind -F LFrated >ΔF set , then the pitch angle is increased by adjusting the speed upper limit with the pitch angle, where ΔF set Set the value for frequency deviation.

[0049] A computer device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor; when the processor executes the computer program, the steps of the flexible dynamic low-frequency wind power system multi-agent coordinated ride-through control method as described above are implemented.

[0050] A computer-readable storage medium stores a computer program; when the computer program is executed by a processor, the steps of the flexible dynamic low-frequency wind power system multi-agent coordinated ride-through control method as described above are implemented.

[0051] After adopting the above scheme, the beneficial effects of the present invention are:

[0052] In a dynamic low-frequency offshore wind system, when an AC fault occurs on the power frequency side resulting in surplus active power, the converter, energy consumption, and wind turbine in the system can be coordinated and controlled. By triggering the energy consumption device, quickly adjusting the pitch angle of the wind turbine, and modulating the converter control strategy, the surplus power of the wind turbine can be quickly reduced and absorbed, thereby suppressing system overvoltage. Through coordinated control of multiple devices, the capacity of energy-consuming equipment can be reduced, and equipment costs can be reduced. In addition, there is no need for communication between the wind turbine and the converter station, which has strong engineering feasibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a structural diagram of the dynamic low-frequency system;

[0054] Figure 2 It is a flow chart of the steps of the present invention. DETAILED DESCRIPTION

[0055] The present invention provides a flexible dynamic low-frequency wind power system multi-agent coordinated ride-through control method, comprising:

[0056] The power frequency system voltage is obtained, and when it is determined that a power frequency system fault occurs according to the power frequency system voltage, a low-frequency AC energy consumption device with power matching is put into operation according to the power frequency system power before the fault.

[0057] Wherein, judging that a power frequency system fails according to the power frequency system voltage includes:

[0058] Get the positive sequence voltage U of the power frequency system pos , the power frequency system positive sequence voltage U pos With fault voltage setting value U set For comparison, if the positive sequence voltage U pos Less than the fault voltage setting value U set , it is judged that the power frequency system is faulty.

[0059] Among them, the low-frequency AC energy consumption device with power matching is put into use according to the power frequency system power before the fault, including:

[0060] Obtain the active power P of the AC / AC converter in the power frequency system before the fault all ;

[0061] N1 groups of low-frequency AC energy-consuming devices are put into the power frequency system; wherein, P one It is the capacity of a group of low-frequency AC energy consuming devices.

[0062] Among them, after the low-frequency AC energy consumption device with power matching is put into use, it also includes:

[0063] Get the capacitor voltage in the AC / AC converter and get the average capacitor voltage U of all converter modules in the AC / AC converter. c ;

[0064] According to the average value of capacitor voltage U c , calculate the current power regulation value ΔP; where the average capacitor voltage U c The capacitor voltage setting value U during the fault period cset Make the difference, and then perform PI regulation to obtain the current power regulation amount ΔP;

[0065] N2 groups of low-frequency AC energy-consuming devices are put into the power frequency system; wherein, P one is the capacity of a group of low-frequency AC energy consumption devices, P all is the active power of the AC / AC converter in the power frequency system before the fault.

[0066] Wherein, the method further comprises:

[0067] During a fault, the capacitor voltage setting value U during the fault is increased. cset , so that the converter module capacitor absorbs more active power.

[0068] Wherein, when judging that a power frequency system fails according to the power frequency system voltage, it also includes:

[0069] According to the power frequency system voltage, obtain the AC / AC converter low frequency side voltage command value F LFref ; Among them, F LFref =F LFrated -k×(U pos -U rated ), F LFrated is the rated voltage on the low-frequency side, k is the voltage-frequency conversion coefficient, U rated is the rated value of power frequency voltage, U pos is the positive sequence voltage of the power frequency system;

[0070] The AC / AC converter low frequency side voltage command value F LFref Controls the voltage frequency output on the low-frequency side of the AC / AC inverter.

[0071] Wherein, when judging that a power frequency system fails according to the power frequency system voltage, it also includes:

[0072] Get the AC / AC inverter low frequency F LFwind ;

[0073] If F LFwind -F LFrated >ΔF set , then the pitch angle is increased by adjusting the speed upper limit with the pitch angle, where ΔF set Set the value for frequency deviation.

[0074] A flexible dynamic low-frequency wind power system multi-agent coordinated ride-through control system, comprising:

[0075] A power frequency system voltage acquisition module is configured to acquire the power frequency system voltage;

[0076] a power frequency system fault judgment module, configured to judge whether a power frequency system fault occurs according to the power frequency system voltage; and

[0077] The energy consumption device input module is configured to input a low-frequency AC energy consumption device with power matching according to the power frequency system power before the failure when the power frequency system fault judgment module determines that the power frequency system has a fault.

[0078] The power frequency system fault judgment module judges that a power frequency system fault occurs according to the power frequency system voltage, including:

[0079] Get the positive sequence voltage U of the power frequency system pos , the power frequency system positive sequence voltage U pos With fault voltage setting value U set For comparison, if the positive sequence voltage U pos Less than the fault voltage setting value U set , it is judged that the power frequency system is faulty.

[0080] Among them, the energy consumption device input module inputs a low-frequency AC energy consumption device with power matching according to the power frequency system power before the fault, including:

[0081] Obtain the active power P of the AC / AC converter in the power frequency system before the fault all ;

[0082] N1 groups of low-frequency AC energy-consuming devices are put into the power frequency system; wherein, P one It is the capacity of a group of low-frequency AC energy consuming devices.

[0083] Among them, it also includes an energy consumption device input adjustment module, which is configured to:

[0084] Get the capacitor voltage in the AC / AC converter and get the average capacitor voltage U of all converter modules in the AC / AC converter. c ;

[0085] According to the average value of capacitor voltage U c , calculate the current power regulation value ΔP; where the average capacitor voltage U c The capacitor voltage setting value U during the fault period cset Make the difference, and then perform PI regulation to obtain the current power regulation amount ΔP;

[0086] N2 groups of low-frequency AC energy-consuming devices are put into the power frequency system; wherein, P one is the capacity of a group of low-frequency AC energy consumption devices, P all is the active power of the AC / AC converter in the power frequency system before the fault.

[0087] Wherein, the system further comprises:

[0088] The capacitor voltage setting value adjustment module is configured to increase the capacitor voltage setting value U during the fault period. cset , so that the converter module capacitor absorbs more active power.

[0089] Among them, it also includes a low-frequency side voltage frequency output control module, which is configured as follows:

[0090] According to the power frequency system voltage, obtain the AC / AC converter low frequency side voltage command value F LFref Among them, F LFref =F LFrated -k×(U pos -U rated ), F LFrated is the rated voltage on the low-frequency side, k is the voltage-frequency conversion coefficient, U rated is the rated value of power frequency voltage, U pos is the positive sequence voltage of the power frequency system;

[0091] The AC / AC converter low frequency side voltage command value F LFref Controls the voltage frequency output on the low-frequency side of the AC / AC inverter.

[0092] Among them, it also includes a pitch angle control module, which is configured as follows:

[0093] Get the AC / AC inverter low frequency F LFwind ;

[0094] If F LFwind -F LFrated >ΔF set , then the pitch angle is increased by adjusting the speed upper limit with the pitch angle, where ΔF set Set the value for frequency deviation.

[0095] The following will be Figure 1 Taking the flexible dynamic low-frequency wind power system shown as an example, the multi-agent coordinated ride-through control method of the flexible dynamic low-frequency wind power system provided by the present invention is introduced.

[0096] The flexible dynamic low-frequency wind power system mainly includes a low-frequency converter station, an offshore platform low-frequency collection station and a low-frequency offshore wind turbine cluster, wherein the low-frequency offshore wind turbine cluster without a machine-side converter is connected to the offshore platform low-frequency collection station, and the electric energy is low-frequency transformed and then sent to the low-frequency converter station through a low-frequency line; the low-frequency converter station includes a low-frequency transformer, an AC / AC converter and an industrial frequency transformer, wherein one end of the low-frequency transformer is connected to the low-frequency line, and the other end is connected to one end of the industrial frequency transformer through an AC / AC converter, and the other end of the industrial frequency transformer is connected to the power grid to realize electric energy transmission.

[0097] In this embodiment, the rated frequency of the low-frequency wind power system is typically 20 Hz. The voltage, current, and power mentioned below are all per unit values.

[0098] like Figure 2 As shown, a flexible dynamic low-frequency wind power system multi-agent coordinated ride-through control method according to an embodiment of the present invention comprises the following steps:

[0099] Step S1, obtaining the power frequency system voltage, and determining whether the power frequency system has a fault by detecting the power frequency system voltage;

[0100] The method to determine whether the power frequency system has a fault is to compare the positive sequence voltage U pos And the fault voltage setting value U set , such as U pos Less than U set , then there is a power frequency system fault, otherwise it does not appear; U set The typical value is 0.85. Assuming that the positive sequence voltage drops to 0.5 pu in this embodiment, it is considered that a fault occurs in the power frequency system.

[0101] Step S2: if it is determined that a power frequency system fault occurs, a corresponding number of low-frequency AC energy consuming devices are put into operation according to the power of the power frequency system before the fault;

[0102] The calculation formula for the number of low-frequency AC energy-consuming devices is: Among them, N1 is the number of groups with energy consumption initially calculated, P all is the active power of the AC / AC converter before the fault, P one is the capacity of a group of energy consumption; is the absolute value, To round down.

[0103] Step S3, according to the size of the capacitor voltage in the AC / AC converter, correspondingly increase or decrease the number of groups of low-frequency AC energy consuming devices;

[0104] The method for increasing or decreasing the number of low-frequency energy-consuming devices is as follows: c and U cset The difference is used by the pi regulator to generate the adjustment amount ΔP, and the number of energy consumption input groups after increase or decrease is calculated by the formula Among them U c is the average capacitor voltage of all converter modules in the AC / AC converter, U cset It is the capacitor voltage setting value during fault period, which can be set to 1.4pu.

[0105] Preferably, U can be increased during a fault cset This allows the module capacitor to absorb more active power, which can reduce the capacity of the energy-consuming device.

[0106] Step S4, increasing the frequency of the low-frequency system voltage according to the drop amplitude of the power frequency voltage;

[0107] The low frequency adjustment method is: F LFref =F LFrated -k×(U pos -U rated ), where F LFrefis the voltage command value of the low-frequency side of the AC / AC converter, F LFrated is the rated value of the low-frequency side voltage, k is the voltage-frequency conversion coefficient, which can be selected as 5, U rated is the rated value of the industrial frequency voltage, and when the voltage drops to 0.5pu, the low frequency is dynamically adjusted to 22.5Hz.

[0108] Step S5: The wind turbine detects an increase in the frequency of the low-frequency system and quickly reduces power through pitch angle control.

[0109] The pitch angle control method is: LFwind -F LFrated >ΔF set , then the pitch angle is used to adjust the speed upper limit to increase the pitch angle to reduce the active power of the wind turbine, where F LFwind is the low frequency detected on the fan side, ΔF set It is the frequency deviation setting value, and the typical value is 0.3Hz.

[0110] Through the above control method, the energy-consuming device is quickly put into operation, the capacitor voltage of the converter rises to 1.4pu, the wind turbine quickly adjusts the pitch angle to reduce the active power, and the whole system achieves a new active power balance. After the AC fault is removed by protection, the flexible dynamic low-frequency wind power system can restore the original power and continue to operate.

[0111] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0112] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0113] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0114] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0115] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0116] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A flexible dynamic low-frequency wind power system multi-agent coordinated ride-through control method, characterized by: include, The power frequency system voltage is obtained, and when it is determined that a power frequency system fault occurs according to the power frequency system voltage, a low-frequency AC energy consumption device with power matching is put into operation according to the power frequency system power before the fault.

2. The method according to claim 1, characterized in that: Determining whether a power frequency system fails according to the power frequency system voltage includes: Get the positive sequence voltage U of the power frequency system pos , the power frequency system positive sequence voltage U pos With fault voltage setting value U set For comparison, if the positive sequence voltage U pos Less than the fault voltage setting value U set , it is judged that the power frequency system is faulty.

3. The method according to claim 1, characterized in that: According to the power of the power frequency system before the fault, low-frequency AC energy consuming devices with matching power are put into use, including: Obtain the active power P of the AC / AC converter in the power frequency system before the fault all ; N1 groups of low-frequency AC energy-consuming devices are put into the power frequency system; wherein, P one It is the capacity of a group of low-frequency AC energy consuming devices.

4. The method according to claim 1, characterized in that: After the low-frequency AC energy consumption device with power matching is put into use, it also includes: Get the capacitor voltage in the AC / AC converter and get the average capacitor voltage U of all converter modules in the AC / AC converter. c ; According to the average value of capacitor voltage U c , calculate the current power regulation value ΔP; where the average capacitor voltage U c The capacitor voltage setting value U during the fault period cset Make the difference, and then perform PI regulation to obtain the current power regulation amount ΔP; N2 groups of low-frequency AC energy-consuming devices are put into the power frequency system; wherein, P one is the capacity of a group of low-frequency AC energy consumption devices, P all is the active power of the AC / AC converter in the power frequency system before the fault.

5. The method according to claim 1, characterized in that: Also includes, During a fault, the capacitor voltage setting value U during the fault is increased. cset , so that the converter module capacitor absorbs more active power.

6. The method according to claim 1, characterized in that: When judging that a power frequency system fails according to the power frequency system voltage, the method further includes: According to the power frequency system voltage, obtain the AC / AC converter low frequency side voltage command value F LFref ; Among them, F LFref =F LFrated -k×(U pos -U rated ), F LFrated is the rated voltage on the low-frequency side, k is the voltage-frequency conversion coefficient, U rated is the rated value of power frequency voltage, U pos is the positive sequence voltage of the power frequency system; The AC / AC converter low frequency side voltage command value F LFref Controls the voltage frequency output on the low-frequency side of the AC / AC inverter.

7. The method according to claim 6, characterized in that: When judging that a power frequency system fails according to the power frequency system voltage, the method further includes: Get the AC / AC inverter low frequency F LFwind ; If F LFwind -F LFrated >ΔF set , then the pitch angle is increased by adjusting the speed upper limit with the pitch angle, where ΔF set Set the value for frequency deviation.

8. A flexible dynamic low-frequency wind power system multi-agent coordinated ride-through control system, characterized by: include, A power frequency system voltage acquisition module is configured to acquire the power frequency system voltage; a power frequency system fault judgment module, configured to judge whether a power frequency system fault occurs according to the power frequency system voltage; and The energy consumption device input module is configured to input a low-frequency AC energy consumption device with power matching according to the power frequency system power before the failure when the power frequency system fault judgment module determines that the power frequency system has a fault.

9. The system according to claim 8, characterized in that: The power frequency system fault judgment module judges that a power frequency system fault occurs according to the power frequency system voltage, including: Get the positive sequence voltage U of the power frequency system pos , the power frequency system positive sequence voltage U pos With fault voltage setting value U set For comparison, if the positive sequence voltage U pos Less than the fault voltage setting value U set , it is judged that the power frequency system is faulty.

10. The system according to claim 8, characterized in that: The energy consumption device input module inputs a low-frequency AC energy consumption device with power matching according to the power frequency system power before the fault, including: Obtain the active power P of the AC / AC converter in the power frequency system before the fault all ; N1 groups of low-frequency AC energy-consuming devices are put into the power frequency system; wherein, P one It is the capacity of a group of low-frequency AC energy consuming devices.

11. The system according to claim 8, characterized in that: It also includes an energy consumption device input adjustment module, which is configured to: Get the capacitor voltage in the AC / AC converter and get the average capacitor voltage U of all converter modules in the AC / AC converter. c ; According to the average value of capacitor voltage U c , calculate the current power regulation value ΔP; where the average capacitor voltage U c The capacitor voltage setting value U during the fault period cset Make the difference, and then perform PI regulation to obtain the current power regulation amount ΔP; N2 groups of low-frequency AC energy-consuming devices are put into the power frequency system; wherein, P one is the capacity of a group of low-frequency AC energy consumption devices, P all is the active power of the AC / AC converter in the power frequency system before the fault.

12. The system of claim 8, wherein: Also includes, The capacitor voltage setting value adjustment module is configured to increase the capacitor voltage setting value U during the fault period. cset , so that the converter module capacitor absorbs more active power.

13. The system of claim 8, wherein: It also includes a low-frequency side voltage frequency output control module, which is configured to: According to the power frequency system voltage, obtain the AC / AC converter low frequency side voltage command value F LFref ; Among them, F LFref =F LFrated -k×(U pos -U rated ), F LFrated is the rated voltage on the low-frequency side, k is the voltage-frequency conversion coefficient, U rated is the rated value of power frequency voltage, U pos is the positive sequence voltage of the power frequency system; The AC / AC converter low frequency side voltage command value F LFref Controls the voltage frequency output on the low-frequency side of the AC / AC inverter.

14. The system of claim 13, wherein: Also included is a pitch angle control module configured to: Get the AC / AC inverter low frequency F LFwind ; If F LFwind -F LFrated >ΔF set , then the pitch angle is increased by adjusting the speed upper limit with the pitch angle, where ΔF set Set the value for frequency deviation.

15. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor; characterized in that: When the processor executes the computer program, the steps of the flexible dynamic low-frequency wind power system multi-agent coordinated ride-through control method as described in any one of claims 1 to 7 are implemented.

16. A computer-readable storage medium storing a computer program; characterized in that: When the computer program is executed by a processor, the steps of the flexible dynamic low-frequency wind power system multi-agent coordinated ride-through control method as described in any one of claims 1 to 7 are implemented.

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