Method and device for suppressing subsynchronous oscillation of new energy unit and storage medium

Abstract

The application discloses a new energy unit subsynchronous oscillation suppression method and device and a storage medium. The method comprises the following steps: performing frequency spectrum analysis on the output oscillation current of the new energy unit according to a preset time interval, and obtaining the subsynchronous oscillation amplitude and frequency of the subsynchronous frequency band current; when the subsynchronous oscillation amplitude exceeds a preset amplitude threshold, performing adaptive filtering on the output oscillation current according to the subsynchronous oscillation frequency, and obtaining a subsynchronous oscillation waveform; according to the subsynchronous oscillation waveform, adding corresponding control to the excitation system of a phase modifier, so that the phase modifier generates a same-frequency opposite-phase suppression current for the new energy unit; according to the zero-crossing point of the subsynchronous oscillation waveform, correcting the suppression frequency and suppression phase of the suppression waveform of the suppression current, and determining the reverse suppression current. At each zero-crossing point of the oscillation waveform, the frequency and phase of the suppression waveform are corrected, and the optimization of oscillation suppression is realized.

Description

Technical Field

[0001] This invention relates to the field of new energy technology, and more specifically, to a method, apparatus, and storage medium for suppressing subsynchronous oscillations in new energy generating units. Background Technology

[0002] Under the dual-carbon context, with the continuous increase in the grid-connected capacity of new energy sources such as wind power and photovoltaics in my country, the problem of subsynchronous oscillations in new energy sources is becoming increasingly prominent, gradually becoming one of the issues restricting the stability of new energy transmission systems. Especially in new energy-rich areas such as western and northern my country, subsynchronous oscillations have become a huge potential risk threatening the safe and reliable operation of the power grid, posing a severe challenge to the stable control and consumption of new energy sources.

[0003] In complex power systems, various factors can trigger subsynchronous oscillations in renewable energy units. Taking wind turbines as an example, direct-drive wind turbines connected to a weak AC system via power electronic converters, and centralized doubly-fed wind power transmitted to external systems via AC series compensation systems, can all cause subsynchronous oscillations. Since renewable energy-rich areas typically connect to the power system via large power electronic devices, which have complex structures and are susceptible to numerous factors causing system oscillations, operators cannot anticipate the occurrence of unknown oscillations and cannot fully utilize the control and regulation capabilities of power electronic equipment. Often, they can only rely on temporary control measures such as directly disconnecting turbines or series compensation after the oscillation occurs to ensure the overall safety of the system.

[0004] The subsynchronous oscillations generated by new energy power units differ from the specific-frequency subsynchronous oscillations of conventional steam turbine units. Subsynchronous oscillations generated by systems such as direct-drive wind turbines or photovoltaic systems connected to a weak AC system via power electronic converters do not have a fixed frequency; their frequency drifts over a relatively wide frequency band. In contrast, the damping control strategies for conventional steam turbine units only target one or more fixed-frequency subsynchronous oscillations under fixed parameters of the unit, and cannot effectively suppress the subsynchronous oscillations of new energy power units.

[0005] Currently, there are various measures to address subsynchronous oscillations in renewable energy sources, but they all have certain limitations in terms of economic efficiency or applicability. For example, methods such as switching off generators or series compensation can change the system's operating mode to eliminate the oscillation source and prevent oscillation propagation, but this will significantly reduce the power output of the power plants and limit the transmission capacity of the lines. Strengthening power grid transformation is costly and only suitable for the power grid planning stage. While optimizing unit parameters has good economic benefits, there are too many power plants in renewable energy-rich areas, and their controller parameters are huge, resulting in a huge amount of computation for parameter optimization. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method, apparatus, and storage medium for suppressing subsynchronous oscillations in new energy generating units.

[0007] According to one aspect of the present invention, a method for suppressing subsynchronous oscillations in a new energy power unit is provided, comprising: The output oscillation current of the new energy unit is subjected to spectrum analysis at preset time intervals to obtain the subsynchronous oscillation amplitude and frequency of the subsynchronous frequency band current. When the amplitude of the subsynchronous oscillation exceeds the preset amplitude threshold, the output oscillation current is adaptively filtered according to the subsynchronous oscillation frequency to obtain the subsynchronous oscillation waveform. Based on the subsynchronous oscillation waveform, corresponding control is added to the excitation system of the synchronous condenser so that the synchronous condenser outputs a suppressor current with the same frequency and opposite phase to the new energy unit. The suppression frequency and suppression phase of the suppression waveform of the suppression current are corrected based on the zero-crossing point of the subsynchronous oscillation waveform to determine the reverse suppression current.

[0008] Optionally, based on the subsynchronous oscillation waveform, corresponding control is added to the excitation system of the synchronous condenser, enabling the synchronous condenser to operate on the same-frequency, opposite-phase suppression current output by the new energy unit, including: The parameter information of the output oscillation current is obtained based on the subsynchronous oscillation waveform; Based on the parameter information, the additional excitation damping control value is calculated; Based on the additional excitation damping control value, determine the suppression current of the synchronous condenser outputting the same frequency and opposite phase to the new energy unit.

[0009] Optionally, the suppression frequency and suppression phase of the suppression waveform of the suppression current are corrected based on the zero-crossing point of the subsynchronous oscillation waveform to determine the operation of the reverse suppression current, including: Based on the time difference between adjacent zero-crossing points of the subsynchronous oscillation waveform, the actual oscillation frequency of the subsynchronous oscillation waveform is determined, and the suppression frequency of the suppression waveform of the suppression current is corrected at the zero-crossing point based on the oscillation frequency to determine the frequency of the reverse suppression waveform. Based on each zero-crossing point of the subsynchronous oscillation waveform, the suppression phase of the suppression waveform of the suppression current is corrected at the zero-crossing point to determine the phase of the reverse suppression waveform; The reverse suppression current is determined based on the frequency and phase of the reverse suppression waveform.

[0010] According to another aspect of the present invention, a subsynchronous oscillation suppression device for a new energy unit is provided, comprising: The first acquisition module is used to perform spectrum analysis on the output oscillation current of the new energy unit according to a preset time interval, and to acquire the subsynchronous oscillation amplitude and frequency of the subsynchronous frequency band current. The second acquisition module is used to adaptively filter the output oscillation current according to the subsynchronous oscillation frequency and acquire the subsynchronous oscillation waveform when the amplitude of the subsynchronous oscillation exceeds the preset amplitude threshold. The output module is used to add corresponding control to the excitation system of the synchronous condenser according to the subsynchronous oscillation waveform, so that the synchronous condenser outputs a suppressor current with the same frequency and opposite phase to the new energy unit. The determination module is used to correct the suppression frequency and suppression phase of the suppression waveform of the suppression current based on the zero-crossing point of the subsynchronous oscillation waveform, and to determine the reverse suppression current.

[0011] According to another aspect of the present invention, a computer-readable storage medium is provided, the storage medium storing a computer program for performing the methods described in any of the above aspects of the present invention.

[0012] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising: a processor; a memory for storing executable instructions of the processor; the processor being configured to read the executable instructions from the memory and execute the instructions to implement the method described in any of the preceding aspects of the present invention.

[0013] Therefore, by utilizing the distributed synchronous condensers already installed in renewable energy power plants and adding appropriate control strategies to their excitation control systems, when the amplitude of the subsynchronous frequency band current exceeds a preset threshold, the subsynchronous oscillation current / voltage in the system is reverse-compensated in real time. This effectively suppresses the subsynchronous oscillation of the renewable energy units, demonstrating good economic efficiency. Attached Figure Description

[0014] Exemplary embodiments of the present invention can be more fully understood by referring to the following figures: Figure 1 This is a flowchart illustrating a method for suppressing subsynchronous oscillations in new energy generating units, provided in an exemplary embodiment of the present invention. Figure 2 This is another flowchart illustrating a method for suppressing subsynchronous oscillations in new energy generating units provided in an exemplary embodiment of the present invention; Figure 3 This is a schematic diagram of a synthesized waveform provided by an exemplary embodiment of the present invention, with an oscillation source frequency of 25Hz, a waveform frequency deviation of +0.1Hz, and an initial phase difference of 180°. Figure 4 This is a schematic diagram of the synthesized waveform after phase correction, provided by an exemplary embodiment of the present invention, with an oscillation source frequency of 25Hz, suppressing waveform frequency deviation of +5Hz. Figure 5 This is a schematic diagram of the structure of a subsynchronous oscillation suppression device for new energy generating units provided in an exemplary embodiment of the present invention; Figure 6 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. Detailed Implementation

[0015] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0016] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0017] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of the present invention are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0018] It should also be understood that in the embodiments of the present invention, "multiple" can refer to two or more, and "at least one" can refer to one, two or more.

[0019] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more unless explicitly defined or given contrary instructions in the context.

[0020] Furthermore, the term "and / or" in this invention is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this invention generally indicates that the preceding and following related objects have an "or" relationship.

[0021] It should also be understood that the description of the various embodiments in this invention emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0022] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0023] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0024] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0026] The embodiments of this invention can be applied to electronic devices such as terminal devices, computer systems, and servers, and can operate together with a wide range of other general-purpose or special-purpose computing system environments or configurations. Well-known examples of terminal devices, computing systems, environments, and / or configurations suitable for use with electronic devices such as terminal devices, computer systems, and servers include, but are not limited to: personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments including any of the above systems, etc.

[0027] Electronic devices such as terminal devices, computer systems, and servers can be described in the general context of computer system executable instructions (such as program modules) executed by a computer system. Typically, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in distributed cloud computing environments, where tasks are executed by remote processing devices linked through communication networks. In distributed cloud computing environments, program modules can reside on local or remote computing system storage media, including storage devices.

[0028] Exemplary methods Figure 1 This is a schematic flowchart of a method for suppressing subsynchronous oscillations in new energy power units provided by an exemplary embodiment of the present invention. This embodiment can be applied to electronic devices, such as... Figure 1 As shown, the subsynchronous oscillation suppression method 100 for new energy generating units includes the following steps: Step 101: Perform spectrum analysis on the output oscillation current of the new energy unit according to the preset time interval to obtain the subsynchronous oscillation amplitude and frequency of the subsynchronous frequency band current; Step 102: When the amplitude of the subsynchronous oscillation exceeds the preset amplitude threshold, the output oscillation current is adaptively filtered according to the subsynchronous oscillation frequency to obtain the subsynchronous oscillation waveform. Step 103: Based on the subsynchronous oscillation waveform, add corresponding control to the excitation system of the synchronous condenser so that the synchronous condenser outputs a suppressor current with the same frequency and opposite phase to the new energy unit.

[0029] Step 104: Based on the zero-crossing point of the subsynchronous oscillation waveform, correct the suppression frequency and suppression phase of the suppression waveform of the suppression current to determine the reverse suppression current.

[0030] Specifically, refer to Figure 1 and Figure 2As shown, when the new energy unit system is running, the output current of the new energy power station is monitored in real time. At certain time intervals, periodic spectrum analysis is performed to obtain the real-time amplitude of the subsynchronous frequency band current and determine whether the enabling criteria have been met. When the amplitude of the subsynchronous component in the system exceeds the limit, the additional control is activated. The preset amplitude depends on the specific circumstances of the new energy unit and is not specified here.

[0031] A synchronous condenser is a special type of synchronous motor, similar to a synchronous generator, but it lacks a prime mover and cannot output active power to the system. However, by adjusting the excitation system to change the excitation voltage / current, it can control the condenser to output reactive power to the external system. Synchronous condensers are characterized by fast adjustment and response speed, capable of responding to electrical quantities at the sub-synchronous frequency of the grid connection point. Distributed synchronous condensers are highly integrated, small-capacity synchronous phase-changing devices deployed within renewable energy power plants. They effectively strengthen voltage support in the sending-end near-field system. With their excellent transient and steady-state characteristics and reactive power regulation capabilities, they play a crucial role in maintaining power system voltage stability. Simultaneously, they can improve system short-circuit capacity and short-circuit ratio, strongly supporting large-scale long-distance transmission of renewable energy.

[0032] Therefore, by utilizing the distributed synchronous condensers already installed in the new energy power plants and adding appropriate control strategies to their excitation control systems, when the amplitude of the subsynchronous frequency band current exceeds the preset threshold, the subsynchronous oscillation current / voltage in the system is compensated in real time, thereby suppressing the subsynchronous oscillation of the new energy units and achieving good economic benefits.

[0033] Optionally, based on the subsynchronous oscillation waveform, corresponding control is added to the excitation system of the synchronous condenser, enabling the synchronous condenser to operate on the same-frequency, opposite-phase suppression current output by the new energy unit, including: The parameter information of the output oscillation current is obtained based on the subsynchronous oscillation waveform; Based on the parameter information, the additional excitation damping control value is calculated; Based on the additional excitation damping control value, determine the suppression current of the synchronous condenser outputting the same frequency and opposite phase to the new energy unit.

[0034] Specifically, adaptive filtering is applied to the system current to filter out the corresponding subsynchronous oscillation waveform. Based on the oscillation waveform, relevant information such as frequency, amplitude, phase, and zero-crossing point is obtained. Then, the additional excitation damping control value is calculated, controlling the synchronous condenser to output a suppressed waveform with the same frequency and opposite phase to the system, thus suppressing the subsynchronous oscillation. By utilizing the distributed synchronous condensers already installed in the renewable energy power plants and adding appropriate control strategies to their excitation control systems, real-time reverse compensation of the subsynchronous oscillation current / voltage in the system is achieved, thereby suppressing the subsynchronous oscillation of the renewable energy units, demonstrating good economic efficiency.

[0035] The additional excitation damping control value needs to be obtained through prior simulation. By applying voltages of different frequencies to the synchronous condenser's excitation voltage and observing the output voltage / current at the generator terminals, the corresponding relationship between the two is obtained, forming a feature library. When suppression is enabled, based on the amplitude, phase, frequency, and other information of the obtained oscillation waveform, combined with the feature library, the information of the control quantity added to the synchronous condenser's excitation voltage is obtained. Then, the control is applied, and the synchronous condenser will output a suppression waveform with the same frequency but opposite phase, thereby achieving suppression.

[0036] Optionally, the suppression frequency and suppression phase of the suppression waveform of the suppression current are corrected based on the zero-crossing point of the subsynchronous oscillation waveform to determine the operation of the reverse suppression current, including: Based on the time difference between adjacent zero-crossing points of the subsynchronous oscillation waveform, the oscillation frequency of the subsynchronous oscillation waveform is determined, and the suppression frequency of the suppression waveform of the suppression current is corrected at the zero-crossing point based on the oscillation frequency to determine the frequency of the reverse suppression waveform. Based on each zero-crossing point of the subsynchronous oscillation waveform, the suppression phase of the suppression waveform of the suppression current is corrected at the zero-crossing point to determine the phase of the reverse suppression waveform; The reverse suppression current is determined based on the frequency and phase of the reverse suppression waveform.

[0037] Specifically, considering signal measurement errors, in actual situations, there may be deviations in the frequency and phase of the suppressed waveform and the oscillation waveform, leading to the failure of subsynchronous oscillation suppression. Therefore, it is necessary to correct the frequency and waveform of the oscillation waveform.

[0038] By monitoring the zero-crossing points of the oscillation waveform, the phase of the suppression waveform is corrected at each zero-crossing point, ensuring that the suppression current waveform is completely out of phase with the oscillation waveform. Simultaneously, the frequency of the suppression waveform is corrected based on the time difference between the current zero-crossing point and the previous zero-crossing point. In other words, the time frequency of the oscillation waveform is calculated based on the time difference between two adjacent zero-crossing points of the oscillation waveform (current), and then the frequency of the suppression waveform is corrected based on this frequency.

[0039] The formula for calculating the frequency of the suppressed waveform obtained through zero-point monitoring is as follows: in It represents the time difference between two consecutive zero crossings.

[0040] The proposed method for suppressing subsynchronous oscillations in new energy generating units is based on the distributed synchronous condensers already installed at new energy collection stations. This method monitors the outgoing current of the new energy stations and performs timed spectrum analysis. When the oscillation amplitude reaches a preset threshold, the outgoing current is adaptively filtered to extract the oscillation waveform. Based on the amplitude, phase, and zero-crossing point of the oscillation waveform, compensation calculations are performed, and the synchronous condenser is controlled to output a suppression current of the same frequency but opposite phase to the system, thereby suppressing the subsynchronous oscillations.

[0041] For example, considering a subsynchronous oscillation at a frequency of 25Hz and an amplitude of 1A occurring at a new energy power station, an additional system generates a suppression current with an amplitude of 0.3 and a frequency of 25.1Hz (the initial phase difference between the two is 180°, i.e., completely out of phase). Observe the combined waveform of the two, such as... Figure 3 As shown. If there is a frequency difference between the suppressed waveform and the oscillating waveform, even if their initial phases are completely opposite, as time progresses, the phase difference gradually deviates, causing the amplitude of the synthesized waveform to be higher than that of the oscillating waveform. In this case, consider the following correction strategy: 1. Track each zero-crossing point of the oscillating waveform, and at each zero-crossing point, reset the phase of the suppressed waveform to π, so that the phases of the two waveforms are completely opposite at the zero-crossing point.

[0042] 2. Whenever a new zero-crossing point is encountered, the frequency of the oscillation waveform is calculated in real time based on the time difference with the previous zero-crossing point, and the frequency of the suppression waveform is corrected accordingly.

[0043] Figure 4 This is the synthesized waveform with a frequency deviation of +5Hz. The amplitude of the suppressed waveform is 0.3. It can be seen that even with a frequency deviation of 5Hz (i.e., 30Hz), phase correction alone can still reduce the oscillation amplitude to approximately 70% of the ideal value. Therefore, by tracking the zero-crossing point of the oscillation waveform and correcting the frequency and phase of the suppressed waveform, oscillation suppression can be achieved.

[0044] By employing an appropriate excitation damping control strategy in addition to distributed phase modulation, the subsynchronous oscillation of new energy sources can be suppressed. The main innovations of this invention include: (1) The damping control strategy proposed in this invention utilizes the distributed synchronous condensers already installed in the new energy power station to achieve subsynchronous oscillation suppression under the broadband of new energy. At the same time, considering the inconsistency between the suppression frequency and the oscillation frequency caused by measurement error, a zero-crossing tracking of the oscillation waveform is specifically proposed to further correct the frequency and phase of the compensation waveform, effectively avoiding the occurrence of suppression failure.

[0045] (2) The damping control strategy proposed in this invention is based on the distributed synchronous condensers already installed in the new energy power plants. It only requires the addition of a suitable damping control link to their excitation system, without increasing the investment in primary equipment, and has good economic efficiency. Moreover, it does not affect the function of the distributed synchronous condenser itself in providing or absorbing reactive power to the system under normal operating conditions.

[0046] Exemplary device Figure 5 This is a schematic diagram of the structure of a subsynchronous oscillation suppression device for new energy power units provided in an exemplary embodiment of the present invention. Figure 5 As shown, the device 500 includes: The first acquisition module 510 is used to perform spectrum analysis on the output oscillation current of the new energy unit according to a preset time interval, and to acquire the subsynchronous oscillation amplitude and frequency of the subsynchronous frequency band current. The second acquisition module 520 is used to adaptively filter the output oscillation current according to the subsynchronous oscillation frequency and acquire the subsynchronous oscillation waveform when the amplitude of the subsynchronous oscillation exceeds the preset amplitude threshold. The output module 530 is used to add corresponding control to the excitation system of the synchronous condenser according to the subsynchronous oscillation waveform, so that the synchronous condenser outputs a suppressor current with the same frequency and opposite phase to the new energy unit. The determination module 540 is used to correct the suppression frequency and suppression phase of the suppression waveform of the suppression current based on the zero crossing point of the subsynchronous oscillation waveform, and to determine the reverse suppression current.

[0047] Optionally, the output module 530 includes: The acquisition submodule is used to obtain parameter information of the output oscillation current based on the subsynchronous oscillation waveform; The calculation submodule is used to calculate the additional excitation damping control value based on the parameter information. The first determining submodule is used to determine the same-frequency, opposite-phase suppression current output by the synchronous condenser to the new energy unit based on the additional excitation damping control value.

[0048] Optionally, module 540 is defined, including: The second determining submodule is used to determine the oscillation frequency of the subsynchronous oscillation waveform based on the time difference between adjacent zero crossings of the subsynchronous oscillation waveform, and to correct the suppression frequency of the suppression waveform of the suppression current at the zero crossing based on the oscillation frequency, thereby determining the frequency of the reverse suppression waveform. The third determining submodule is used to correct the suppression phase of the suppression waveform of the suppression current at each zero crossing point of the subsynchronous oscillation waveform, and determine the phase of the reverse suppression waveform. The fourth determination submodule is used to determine the reverse suppression current based on the reverse suppression waveform frequency and the reverse suppression waveform phase.

[0049] Exemplary electronic devices Figure 6 This is the structure of an electronic device provided in an exemplary embodiment of the present invention. For example... Figure 6 As shown, the electronic device 60 includes one or more processors 61 and a memory 62.

[0050] The processor 61 may be a central processing unit (CPU) or other form of processing unit with data processing and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0051] The memory 62 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 61 may execute the program instructions to implement the methods of the software programs of the various embodiments of the present invention described above, and / or other desired functions. In one example, the electronic device may also include an input device 63 and an output device 64, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0052] In addition, the input device 63 may also include, for example, a keyboard, a mouse, etc.

[0053] The output device 64 can output various information to the outside. The output device 64 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0054] Of course, for the sake of simplicity, Figure 6 Only some of the components of the electronic device relevant to the present invention are shown, omitting components such as buses, input / output interfaces, etc. In addition, the electronic device may include any other suitable components depending on the specific application.

[0055] Exemplary computer program products and computer-readable storage media In addition to the methods and apparatus described above, embodiments of the present invention may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps in the methods according to various embodiments of the present invention described in the "Exemplary Methods" section above.

[0056] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of the present invention. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0057] Furthermore, embodiments of the present invention may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps of the methods for information mining of historical change records according to various embodiments of the present invention as described in the "Exemplary Methods" section above.

[0058] The computer-readable storage medium may be 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, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, system, 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 disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0059] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the aforementioned specific details.

[0060] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For system embodiments, since they largely correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0061] The block diagrams of devices, systems, devices, and systems involved in this invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, systems, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0062] The methods and systems of the present invention may be implemented in many ways. For example, they may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above-described order of steps for the methods is for illustrative purposes only, and the steps of the methods of the present invention are not limited to the order specifically described above unless otherwise specifically stated. Furthermore, in some embodiments, the present invention may also be implemented as a program recorded on a recording medium, the program comprising machine-readable instructions for implementing the methods according to the present invention. Thus, the present invention also covers recording media storing programs for performing the methods according to the present invention.

[0063] It should also be noted that in the systems, apparatus, and methods of the present invention, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered equivalents of the present invention. The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the invention. Therefore, the invention is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

[0064] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the invention to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.

Claims

1. A method for suppressing subsynchronous oscillations in new energy generating units, characterized in that, include: The output oscillation current of the new energy unit is subjected to spectrum analysis at preset time intervals to obtain the subsynchronous oscillation amplitude and frequency of the subsynchronous frequency band current. When the amplitude of the subsynchronous oscillation exceeds a preset amplitude threshold, the output oscillation current is adaptively filtered according to the subsynchronous oscillation frequency to obtain the subsynchronous oscillation waveform; Based on the subsynchronous oscillation waveform, corresponding control is added to the excitation system of the synchronous condenser so that the synchronous condenser outputs a suppressor current with the same frequency and opposite phase to the new energy unit. The suppression frequency and suppression phase of the suppression waveform of the suppression current are corrected based on the zero-crossing point of the subsynchronous oscillation waveform to determine the reverse suppression current; Based on the subsynchronous oscillation waveform, corresponding control is added to the excitation system of the synchronous condenser to enable the synchronous condenser to output a suppressor current of the same frequency but opposite phase to the new energy unit, including: The parameter information of the output oscillation current is obtained based on the subsynchronous oscillation waveform; Based on the parameter information, the additional excitation damping control value is calculated; Based on the additional excitation damping control value, determine the same-frequency, opposite-phase suppression current output by the synchronous condenser to the new energy unit; The operation of correcting the suppression frequency and suppression phase of the suppression waveform of the suppression current based on the zero-crossing point of the subsynchronous oscillation waveform, and determining the reverse suppression current, includes: Based on the time difference between adjacent zero-crossing points of the subsynchronous oscillation waveform, the actual oscillation frequency of the subsynchronous oscillation waveform is determined, and the suppression frequency of the suppression waveform of the suppression current is corrected at the zero-crossing point based on the oscillation frequency to determine the frequency of the reverse suppression waveform. Based on each zero-crossing point of the subsynchronous oscillation waveform, the suppression phase of the suppression waveform of the suppression current is corrected at the zero-crossing point to determine the phase of the reverse suppression waveform; The reverse suppression current is determined based on the frequency and phase of the reverse suppression waveform. The expression for the actual oscillation frequency is: in It is the time difference between two consecutive zero crossings; If there is a frequency difference between the suppressed waveform and the oscillation waveform, the following correction strategy is implemented: Track each zero-crossing point of the oscillating waveform, and at each zero-crossing point, reset the phase of the suppressed waveform to π, so that the phases of the two waveforms are completely opposite at the zero-crossing point; Whenever a new zero-crossing point is encountered, the actual oscillation frequency of the oscillation waveform is calculated in real time based on the time difference with the previous zero-crossing point, and the frequency of the suppressed waveform is corrected accordingly.

2. A subsynchronous oscillation suppression device for new energy generating units, used to implement the method of claim 1, characterized in that, include: The first acquisition module is used to perform spectrum analysis on the output oscillation current of the new energy unit according to a preset time interval, and to acquire the subsynchronous oscillation amplitude and frequency of the subsynchronous frequency band current. The second acquisition module is used to adaptively filter the output oscillation current according to the subsynchronous oscillation frequency and acquire the subsynchronous oscillation waveform when the amplitude of the subsynchronous oscillation exceeds a preset amplitude threshold. The output module is used to add corresponding control to the excitation system of the synchronous condenser according to the subsynchronous oscillation waveform, so that the synchronous condenser outputs a suppressor current with the same frequency and opposite phase to the new energy unit. The determination module is used to correct the suppression frequency and suppression phase of the suppression waveform of the suppression current based on the zero-crossing point of the subsynchronous oscillation waveform, and to determine the reverse suppression current. Output module, including: The acquisition submodule is used to acquire parameter information of the output oscillation current based on the subsynchronous oscillation waveform; The calculation submodule is used to calculate the additional excitation damping control value based on the parameter information. The first determining submodule is used to determine the same-frequency, opposite-phase suppression current output by the synchronous condenser to the new energy unit based on the additional excitation damping control value; The module to be determined includes: The second determining submodule is used to determine the actual oscillation frequency of the subsynchronous oscillation waveform based on the time difference between adjacent zero crossings of the subsynchronous oscillation waveform, and to correct the suppression frequency of the suppression waveform of the suppression current at the zero crossing based on the oscillation frequency to determine the frequency of the reverse suppression waveform. The third determining submodule is used to correct the suppression phase of the suppression waveform of the suppression current at each zero crossing point of the subsynchronous oscillation waveform, and determine the phase of the reverse suppression waveform. The fourth determining submodule is used to determine the reverse suppression current based on the frequency and phase of the reverse suppression waveform. The expression for the actual oscillation frequency is: in It is the time difference between two consecutive zero crossings; If there is a frequency difference between the suppressed waveform and the oscillation waveform, the following correction strategy is implemented: Track each zero-crossing point of the oscillating waveform, and at each zero-crossing point, reset the phase of the suppressed waveform to π, so that the phases of the two waveforms are completely opposite at the zero-crossing point; Whenever a new zero-crossing point is encountered, the actual oscillation frequency of the oscillation waveform is calculated in real time based on the time difference with the previous zero-crossing point, and the frequency of the suppressed waveform is corrected accordingly.

3. A computer-readable storage medium, characterized in that, The storage medium stores a computer program for executing the method described in claim 1.

4. An electronic device, characterized in that, The electronic device includes: processor; Memory used to store the processor's executable instructions; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method of claim 1.

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