Method and device for suppressing wind power oscillation based on digital filtering

Abstract

The application discloses a wind power oscillation suppression method and device based on digital filtering, wherein the method comprises the following steps: screening a target wind farm; determining wind power generators to be upgraded in the target wind farm according to utilization hours and a set proportion; generating digital filter parameters based on the frequency of historical oscillation events; enabling part of the digital filters, collecting voltage and current data of the wind power generators and the wind farm when the oscillation occurs, calculating and comparing the relative sizes of the oscillation frequency components of the impedances and currents of the wind power generators with the digital filters enabled and disabled, and adjusting the digital filter parameters until the filter suppression condition is reached; setting the adjusted digital filter parameters and enabling all the filters to complete the subsynchronous oscillation suppression. Thus, the problems in the prior art that with the increase of the scale of the wind farm, the upgrade time and economic cost required for applying the suppression measures increase, and the effectiveness of the wind power oscillation suppression method cannot be determined are solved.

Description

Technical Field

[0001] This application relates to the field of power system stability control technology, and in particular to a method and device for suppressing wind power oscillations based on digital filtering. Background Technology

[0002] In related technologies, oscillation suppression measures can be divided into grid-side measures and generator-side measures. Grid-side measures are usually based on FACTS (Flexible AC Transmission System) equipment or dedicated suppression converters. Generator-side measures include adjusting control parameters, replacing control structures, adding damping control, or embedding blocking filters. Adjusting control parameters, replacing control structures, and adding damping control require the establishment of a detailed model of the wind turbine for design. Embedding blocking filters can be designed according to the frequency of oscillation to achieve oscillation suppression.

[0003] However, the relevant technologies require the addition of secondary side equipment, which is inconvenient for on-site implementation. At the same time, as the scale of wind farms increases, the types and number of wind turbines also increase, leading to increased upgrade time and economic costs for implementing suppression measures. Furthermore, the effectiveness of wind power oscillation suppression methods cannot be determined, which urgently needs to be addressed. Summary of the Invention

[0004] This application is based on the inventor's understanding and insights into the following issues:

[0005] The new power system is developing towards a high proportion of renewable energy and power electronic equipment in all aspects of the "source-grid-load" chain. However, the interaction between power electronic equipment such as wind power, photovoltaics, and flexible DC transmission, as well as between them and the AC / DC power grid, can cause subsynchronous oscillations. For example, in 2012, oscillations occurred between a doubly-fed wind farm and a series-compensated electric field in Guyuan, China, and in 2020, oscillations occurred between a doubly-fed wind farm and a flexible DC transmission system in Zhangbei, China. These oscillations seriously threaten the safe and stable operation of the power system. Therefore, research on the suppression of subsynchronous oscillations has important practical significance.

[0006] Existing oscillation suppression measures can be divided into grid-side measures and turbine-side measures. Grid-side measures are usually based on FACTS equipment or dedicated suppression converters, which may require additional equipment investment. Upgrading grid-side equipment in an already operational power grid may require a long downtime. Turbine-side measures include adjusting control parameters, replacing control structures, adding damping control, or embedding blocking filters. Adjusting control parameters, replacing control structures, and adding damping control all require the establishment of detailed models of wind turbines for design. Embedding blocking filters can be designed according to the oscillation frequency, but some existing technologies require the addition of secondary-side equipment, which is not convenient for on-site implementation. At the same time, as the scale of wind farms increases, the types and number of wind turbines increase, and the time and economic cost of upgrading each converter is high. In addition, due to the extremely complex operating conditions in actual systems, existing technologies rarely propose specific methods for testing and verifying the effectiveness of suppression measures in actual power systems.

[0007] This application provides a method and apparatus for suppressing wind power oscillations based on digital filtering, which solves the problems in related technologies, such as the need to add secondary side equipment, which is inconvenient for on-site implementation; the need for upgrade time and economic cost to apply suppression measures as the scale of wind farms increases and the types and number of wind turbines increase; and the effectiveness of the wind power oscillation suppression method cannot be determined.

[0008] The first aspect of this application provides a wind power oscillation suppression method based on digital filtering, comprising the following steps: analyzing the oscillation frequency of each wind farm and obtaining the impedance characteristics of each wind farm at the oscillation frequency, screening at least one target wind farm, wherein each wind farm includes at least one wind turbine; determining wind turbines to be upgraded from the at least one target wind farm; generating digital filter parameters for the wind turbines to be upgraded based on the historical oscillation frequencies of the wind turbines to be upgraded; enabling some digital filters corresponding to the digital filter parameters of the wind turbines to be upgraded, and collecting voltage and current data of the wind turbines to be upgraded when oscillation occurs, calculating and comparing the relative magnitudes of the oscillation frequency components in the impedance and current of wind turbines with and without enabled digital filters, so as to adjust the parameters of the digital filters of the wind turbines to be upgraded according to the comparison results until the comparison results reach a preset filter suppression condition; enabling all digital filters corresponding to the digital filter parameters of the wind turbines to be upgraded based on the adjusted digital filter parameters of the wind turbines to be upgraded, thereby completing the suppression of subsynchronous oscillation.

[0009] Optionally, in one embodiment of this application, the screening of at least one target wind farm includes: selecting doubly-fed wind farms with negative real parts of impedance as target wind farms based on the impedance characteristics of each wind farm at the oscillation frequency.

[0010] Optionally, in one embodiment of this application, determining the wind turbines to be upgraded from the at least one target wind farm includes: determining the wind turbines to be upgraded based on the utilization hours of the wind turbines in the at least one target wind farm and a preset proportion of wind turbines to be upgraded.

[0011] Optionally, in one embodiment of this application, the analysis of the oscillation frequency of each wind farm includes: collecting voltage and current waveform data of each wind farm collection station when oscillation occurs; performing frequency domain transformation processing on the voltage and current waveform data to obtain data to be analyzed; and obtaining the oscillation frequency of each wind farm based on the data to be analyzed.

[0012] A second aspect of this application provides a wind power oscillation suppression device based on digital filtering, comprising: an analysis module for analyzing the oscillation frequency of each wind farm and obtaining the impedance characteristics of each wind farm at the oscillation frequency, and screening at least one target wind farm, wherein each wind farm includes at least one wind turbine; a determination module for determining wind turbines to be upgraded from the at least one target wind farm; a generation module for generating digital filter parameters for the wind turbines to be upgraded based on historically occurring oscillation frequencies of the wind turbines to be upgraded; and a processing module for enabling the digital filter parameters of the wind turbines to be upgraded. The system collects voltage and current data of the wind turbine to be upgraded during oscillations, and calculates and compares the relative magnitudes of the oscillation frequency components in the impedance and current of the wind turbine with and without enabled digital filters. Based on the comparison results, the parameters of the digital filters of the wind turbine to be upgraded are adjusted until the comparison results meet the preset filter suppression conditions. A setting module is used to enable all digital filters corresponding to the digital filter parameters of the wind turbine to be upgraded based on the adjusted digital filter parameters, thereby suppressing the subsynchronous oscillations.

[0013] Optionally, in one embodiment of this application, the analysis module is further configured to identify doubly-fed wind farms with negative real parts of impedance as target wind farms based on the impedance characteristics of each wind farm at the oscillation frequency.

[0014] Optionally, in one embodiment of this application, the determining module is further configured to determine the wind turbines to be upgraded based on the utilization hours of the wind turbines in the at least one target wind farm and a preset proportion of wind turbines to be upgraded.

[0015] Optionally, in one embodiment of this application, the analysis module includes: a data acquisition unit for acquiring voltage and current waveform data of each wind farm collection station when oscillation occurs; a processing unit for performing frequency domain transformation processing on the voltage and current waveform data to obtain data to be analyzed; and an acquisition unit for obtaining the oscillation frequency of each wind farm based on the data to be analyzed.

[0016] A third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the wind power oscillation suppression method based on digital filtering as described in the above embodiments.

[0017] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for suppressing wind power oscillations based on digital filtering.

[0018] This application's embodiments can analyze the oscillation frequency of each wind farm and obtain the impedance characteristics of each wind farm at the oscillation frequency, screen target wind farms, and thus determine the wind turbines to be upgraded. Based on the frequency of historical oscillation events, digital filter parameters for the wind turbines to be upgraded are generated. Partial digital filters corresponding to the digital filter parameters of the wind turbines to be upgraded are enabled. Voltage and current data of the wind turbines to be upgraded are collected during oscillation. The relative magnitudes of the oscillation frequency components in the impedance and current of wind turbines with and without enabled digital filters are calculated and compared. The digital filter parameters are adjusted until the filter suppression condition is met. The adjusted digital filter parameters are set and all filters are enabled, completing the subsynchronous oscillation suppression. This eliminates the need for additional equipment or devices, reducing workload, effectively saving time and cost, ensuring the effectiveness of the suppression measures, and is simple and easy to implement. Therefore, it solves the problems in related technologies, such as the need to add secondary-side equipment, which is inconvenient for on-site implementation; the increased upgrade time and economic cost required for applying suppression measures as the scale of wind farms and the types and number of wind turbines increase; and the inability to determine the effectiveness of wind power oscillation suppression methods.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0021] Figure 1This is a flowchart of a wind power oscillation suppression method based on digital filtering according to an embodiment of this application;

[0022] Figure 2 This is a schematic diagram of the structure of an oscillation suppression system based on a digital filter according to a specific embodiment of this application;

[0023] Figure 3 This is a schematic diagram of a typical RSC (Rotor-side Converter) control structure with additional digital filtering provided according to an embodiment of this application;

[0024] Figure 4 This is a schematic diagram illustrating the filter suppression effect of a specific embodiment of this application;

[0025] Figure 5 A flowchart illustrating a specific embodiment of a wind power oscillation suppression method based on digital filtering according to this application;

[0026] Figure 6 This is a schematic diagram of the structure of a wind power oscillation suppression device based on digital filtering according to an embodiment of this application;

[0027] Figure 7 This is a schematic diagram of the structure of an electronic device according to an embodiment of this application. Detailed Implementation

[0028] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0029] The following description, with reference to the accompanying drawings, describes a method and apparatus according to embodiments of this application. Addressing the issues mentioned in the background section regarding the need for secondary-side equipment in related technologies, which is inconvenient for on-site implementation, and the increasing scale and number of wind turbines in wind farms leading to increased upgrade time and economic costs for implementing suppression measures, as well as the inability to determine the effectiveness of wind power oscillation suppression methods, this application provides a method according to embodiments of this application. In this method, the oscillation frequency of each wind farm can be analyzed, and the impedance characteristics of each wind farm at the oscillation frequency can be obtained. Target wind farms are screened to determine the wind turbines to be upgraded. Based on the frequency of historical oscillation events, a list of wind turbines to be upgraded is generated. The system enables the corresponding digital filters of the wind turbines to be upgraded, and collects voltage and current data of the wind turbines to be upgraded when oscillations occur. It calculates and compares the relative magnitudes of the oscillation frequency components in the impedance and current of the wind turbines with and without enabled digital filters, and adjusts the digital filter parameters until the filter suppression conditions are met. The adjusted digital filter parameters are then set, and all filters are enabled, completing the subsynchronous oscillation suppression. This eliminates the need for additional equipment or devices, reducing workload, effectively saving time and costs, and ensuring the effectiveness of the suppression measures. It is simple and easy to implement. This solves the problems of related technologies that require the addition of secondary-side equipment, making on-site implementation inconvenient. Furthermore, as the scale of wind farms increases, the types and number of wind turbines increase, leading to increased upgrade time and economic costs for applying suppression measures, and the inability to determine the effectiveness of wind power oscillation suppression methods.

[0030] Specifically, Figure 1 This is a flowchart illustrating a method according to an embodiment of this application.

[0031] like Figure 1 As shown, the method according to an embodiment of this application includes the following steps:

[0032] In step S101, the oscillation frequency of each wind farm is analyzed, and the impedance characteristics of each wind farm at the oscillation frequency are obtained to screen at least one target wind farm, wherein each wind farm includes at least one wind turbine.

[0033] It is understood that the embodiments of this application can analyze the oscillation frequency of each wind farm in the following steps, obtain the impedance characteristics of each wind farm at the oscillation frequency, and screen at least one target wind farm in the following steps, wherein each wind farm includes at least one wind turbine, thereby effectively improving the feasibility of the wind power oscillation suppression method.

[0034] In one embodiment of this application, analyzing the oscillation frequency of each wind farm includes: collecting voltage and current waveform data of each wind farm collection station when oscillation occurs; performing frequency domain transformation processing on the voltage and current waveform data to obtain the data to be analyzed; and obtaining the oscillation frequency of each wind farm based on the data to be analyzed.

[0035] In some embodiments, the present application can collect the three-phase voltage and current flowing into each wind farm substation when oscillation occurs, perform frequency domain transformation processing on the voltage and current waveform data to obtain the data to be analyzed, and obtain the oscillation frequency of each wind farm based on the data to be analyzed, thereby improving the feasibility of the wind power oscillation suppression method.

[0036] In one embodiment of this application, screening at least one target wind farm includes: selecting doubly-fed wind farms with negative real parts of impedance as target wind farms based on the impedance characteristics of each wind farm at the oscillation frequency.

[0037] As one possible implementation, embodiments of this application can collect the three-phase voltage and current flowing into each wind farm substation when oscillation occurs, and obtain the subsynchronous oscillation phasors of voltage and current through frequency domain transformation, such as DFT (Discrete Fourier Transform), and calculate the subsynchronous impedance. There are various ways to calculate the subsynchronous impedance, which are not specifically limited here. When the real part of the subsynchronous impedance of the doubly-fed wind farm is negative, the wind farm provides negative damping for the oscillation, and it is necessary to add a digital filter to enhance the damping and achieve oscillation suppression. The impedance of all wind farms is calculated, and the doubly-fed wind farms with negative real parts of subsynchronous impedance are recorded as target wind farms.

[0038] In step S102, wind turbines to be upgraded are determined from at least one target wind farm.

[0039] It is understood that the embodiments of this application can determine the wind turbines to be upgraded from at least one target wind farm in the following steps, thereby requiring only software upgrades without the need for additional equipment or devices, reducing workload and effectively saving time and costs.

[0040] In one embodiment of this application, determining the wind turbines to be upgraded from at least one target wind farm includes: determining the wind turbines to be upgraded based on the utilization hours of the wind turbines in the at least one target wind farm and a preset proportion of wind turbines to be upgraded.

[0041] In some embodiments, the present application embodiments can determine the wind turbines to be upgraded based on the utilization hours of wind turbines in at least one target wind farm and a certain proportion of upgraded wind turbines. This enables the addition of digital filters to more than a certain proportion of the operating wind turbines. The digital filters can make the wind turbines exhibit positive resistance within a specific frequency range. Upgrading only some of the wind turbines can change the impedance characteristics of the entire wind farm and suppress oscillations.

[0042] It should be noted that the preset upgrade wind turbine units are set by those skilled in the art according to the actual situation, and no specific limitations are made here.

[0043] For example, embodiments of this application can be used to locate n wind farms within the i-th wind farm. i The typhoon turbine generators are sorted from highest to lowest based on their annual utilization hours or wind resource level to obtain a set {WTG1……WTGn}. i The number of wind turbine units that need to be upgraded is:

[0044] n si =[k×n i +1

[0045] Where k represents the proportion of wind turbine units being upgraded, with a typical value of 0.5.

[0046] Furthermore, we can further define {WTG1……WTGn} i The first n in} si Upgrading the system allows more than a certain percentage of operating wind turbines to be equipped with digital filters in most cases, providing positive damping for the wind farm as a whole in oscillation mode, improving the adaptability of oscillation suppression measures, and is simple and easy to implement.

[0047] In step S103, digital filter parameters for the wind turbine to be upgraded are generated based on the historical oscillation frequencies of the wind turbine to be upgraded.

[0048] It is understood that the embodiments of this application can statistically analyze the historical oscillation frequencies of all wind turbines to be upgraded, design the digital filter parameters of the wind turbines to be upgraded, and update the wind turbine control program. During the period when the target wind turbine is shut down due to low wind speed, the converter control software can be upgraded to avoid power loss.

[0049] In actual implementation, such as Figure 2 The diagram shows a schematic of an oscillation suppression system based on a digital filter. For a selected target wind turbine, when the wind speed is less than the cut-in wind speed, the original converter control software can be replaced with the control software after adding the digital filter. Figure 2This mainly includes multiple wind turbines with upgraded digital filters and the monitoring center at the wind farm substation. After receiving the enable signal and filtering parameters issued by the monitoring center, the wind turbines with upgraded digital filters have oscillation suppression function, and the suppression effect can be verified by the test methods in the following steps, which effectively improves the feasibility and effectiveness of the oscillation suppression method.

[0050] In step S104, the digital filter corresponding to the digital filter parameters of the wind turbine to be upgraded is enabled, and the voltage and current data of the wind turbine to be upgraded are collected when oscillation occurs. The relative magnitudes of the oscillation frequency components in the impedance and current of the wind turbine with and without the digital filter enabled are calculated and compared. The parameters of the digital filter of the wind turbine to be upgraded are adjusted according to the comparison results until the comparison results reach the preset filter suppression conditions.

[0051] It is understood that the embodiments of this application can enable a small number of digital filters corresponding to the digital filter parameters of the wind turbine to be upgraded. The digital filter of a wind turbine or a wind turbine on a collector line can be enabled according to the number of wind turbines in the wind farm. When oscillation occurs, the voltage and current recording data of the wind turbine and the collector line in the wind farm are collected, and the magnitude of the oscillation current component of the wind turbine impedance and the collector line connected to it is analyzed when oscillation occurs.

[0052] Furthermore, when the wind turbine with the filter enabled exhibits positive resistance or the oscillation current component of the connected collector line is smaller than that of other collector lines without the filter enabled, the oscillation suppression measures are considered effective. Otherwise, the filter parameters are readjusted according to the current oscillation frequency until the filter suppression condition is met. This can be used to verify the suppression effect in the actual system, ensuring the effectiveness of the suppression measures. It can also be used to verify other turbine-side oscillation suppression measures.

[0053] Furthermore, adding a digital filter only requires adding corresponding code to the existing converter control program, without the need for additional equipment, saving time and cost, and the filter parameter ω c f B and enable signal k f It can be transmitted through the existing communication network between the substation and the wind turbine, which facilitates subsequent commissioning and testing.

[0054] It should be noted that the preset filter is set by those skilled in the art according to the actual situation, and no specific limitation is made here.

[0055] In step S105, based on the adjusted digital filter parameters of the wind turbine to be upgraded, all digital filters corresponding to the digital filter parameters of the wind turbine to be upgraded are enabled to suppress the subsynchronous oscillation.

[0056] It is understood that the embodiments of this application can suppress subsynchronous oscillations based on the adjusted digital filter parameters of the wind turbine to be upgraded and enable all filters corresponding to the digital filter parameters of the wind turbine to be upgraded. Thus, the doubly fed wind turbine can have oscillation suppression function by upgrading the converter control software without adding additional equipment or devices, reducing workload. At the same time, it can avoid software upgrades for all wind turbines, saving time and costs. It is simple and easy to implement, and can be used to verify the suppression effect in actual systems, ensuring the effectiveness of the suppression measures. It can also be used to test other similar suppression measures.

[0057] For example, such as Figure 3 The diagram shows a typical RSC control structure with an added digital filter. By adding a digital filter to the d-axis control within the RSC inner loop, the amplitude gain within a specific frequency range is reduced, causing the doubly-fed induction generator (DFIG) to exhibit positive resistance. This provides positive damping for oscillation modes, preventing oscillations. Furthermore, adding the digital filter only requires adding corresponding code to the existing converter control program, without requiring additional equipment. The filter parameter ω... c f B and enable signal k f It can be transmitted through the existing communication network between the substation and the wind turbine. The discrete transfer function of the digital filter is shown in the following equation:

[0058]

[0059] in,

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066] Where, ω c f B These represent the filter center frequency and stopband width, respectively. s The sampling time should be consistent with the existing settings for the converter control.

[0067] Furthermore, ω c and f BThe design should be based on the oscillation frequency range of the current scenario, collecting current waveform data when oscillation occurs, and analyzing the frequency set {f1,……,f} of existing oscillation events. n The center frequency is set as the average of all frequencies. Since the additional filter is in the dq coordinate system, the oscillation frequency in the abc coordinate system needs to be transformed to the dq coordinate system. Therefore, the center frequency ω... c for:

[0068]

[0069] The minimum frequency in the frequency set is f. min Maximum frequency f max Therefore, the stopband width should cover the possible oscillation frequency range while allowing for a certain margin. The stopband width f B The following conditions must be met:

[0070] f B ≥f max -f min

[0071] In summary, the embodiments of this application can reduce the amplitude gain within a specific frequency range by adding a digital filter to the d-axis of the RSC inner loop control, thereby making the doubly-fed wind turbine exhibit positive resistance, providing positive damping for the oscillation mode, and preventing oscillation. Furthermore, adding the digital filter only requires adding corresponding code to the existing converter control program, without requiring additional equipment. The filter parameter ω... c f B and enable signal k f It can be transmitted through the existing communication network between the substation and the wind turbine, which facilitates subsequent commissioning and testing.

[0072] For example, such as Figure 4 The diagram shown is a schematic of filter suppression in a specific embodiment of this application. In a real wind farm, a wind power oscillation suppression method based on digital filtering is applied. The digital filter of one wind turbine is enabled, and the waveform data of three wind turbines when oscillation occurs at 2.1Hz are obtained. Filter No. 1 is enabled, while filters No. 2 and No. 3 are disabled. It can be seen that wind turbine No. 1 exhibits positive resistance and the amplitude of the oscillation component is relatively small, thus achieving the suppression effect. Therefore, no additional equipment or device is needed, reducing the workload, effectively saving time and cost, ensuring the effectiveness of the suppression measures, and making it simple and easy to implement.

[0073] like Figure 5 As shown, the working principle of this application will be explained in detail below with a specific embodiment.

[0074] Step S501: Collect voltage and current data of the wind farm substation when oscillation occurs, perform frequency domain transformation, obtain the oscillation frequency and subsynchronous phasor, and effectively improve the feasibility of the wind power oscillation suppression method.

[0075] Step S502: Calculate the subsynchronous impedance of each wind farm. The result for the i-th wind farm is:

[0076]

[0077] Among them, Z Wi This represents the equivalent impedance at the subsynchronous frequency. A voltage phasor representing the oscillation frequency. The current phasor representing the oscillation frequency, R i X represents the real part of the impedance. i This represents the imaginary part of the impedance, and we select doubly-fed wind farms with negative real parts as target wind farms.

[0078] Step S503: In R i When the number of wind turbines is less than 0, the target wind turbines are sorted by utilization hours and selected according to a set ratio, and the number of wind turbines that need to be upgraded is:

[0079] n si =[k×n i +1.

[0080] Step S504: Statistically analyze the frequency of oscillation events and design filter parameters, where the center frequency is:

[0081]

[0082] And the stopband width f B The following conditions must be met:

[0083] f B ≥f max -f min .

[0084] Step S505: Upgrade the wind turbine converter control software, which effectively improves the feasibility and effectiveness of the oscillation suppression method.

[0085] Step S506: Set the filter parameters, enable some filters and monitor the occurrence of oscillations.

[0086] Step S507: Analyze the impedance characteristics of the wind turbine or the magnitude of the oscillation component in the current when oscillation occurs, and verify the oscillation suppression effect. If negative resistance is present or the oscillation component does not decrease significantly, proceed to step S506; otherwise, proceed to step S508.

[0087] Step S508: Enable the filter to complete oscillation suppression, thus eliminating the need for additional equipment or devices, reducing workload, saving time and cost, and making it simple and easy to implement.

[0088] The method proposed in this application can analyze the oscillation frequency of each wind farm and obtain the impedance characteristics of each wind farm at the oscillation frequency. Target wind farms are screened to determine the wind turbines to be upgraded. Based on the frequency of historical oscillation events, digital filter parameters for the wind turbines to be upgraded are generated. Some digital filters corresponding to the digital filter parameters of the wind turbines to be upgraded are enabled. Voltage and current data of the wind turbines to be upgraded are collected when oscillation occurs. The relative magnitudes of the oscillation frequency components in the impedance and current of wind turbines with and without enabled digital filters are calculated and compared. The digital filter parameters are adjusted until the filter suppression condition is met. The adjusted digital filter parameters are set and all filters are enabled, completing the subsynchronous oscillation suppression. This eliminates the need for additional equipment or devices, reducing workload, effectively saving time and cost, ensuring the effectiveness of the suppression measures, and is simple and easy to implement. Therefore, it solves the problems in related technologies, such as the need to add secondary-side equipment, which is inconvenient for on-site implementation. Furthermore, as the scale of wind farms increases, the types and number of wind turbines increase, leading to increased upgrade time and economic costs for applying suppression measures, and the inability to determine the effectiveness of wind power oscillation suppression methods.

[0089] Next, with reference to the accompanying drawings, an apparatus according to an embodiment of this application is described.

[0090] Figure 6 This is a block diagram of an apparatus according to an embodiment of this application.

[0091] like Figure 6 As shown, the apparatus 10 according to an embodiment of this application includes: an analysis module 100, a determination module 200, a generation module 300, a processing module 400, and a setting module 500.

[0092] Specifically, the analysis module 100 is used to analyze the oscillation frequency of each wind farm and obtain the impedance characteristics of each wind farm at the oscillation frequency, and screen at least one target wind farm, wherein each wind farm includes at least one wind turbine.

[0093] The determination module 200 is used to determine the wind turbine units to be upgraded from at least one target wind farm.

[0094] The generation module 300 is used to generate digital filter parameters for the wind turbine to be upgraded based on the historical oscillation frequencies of the wind turbine to be upgraded.

[0095] The processing module 400 is used to enable a portion of the digital filters corresponding to the digital filter parameters of the wind turbine to be upgraded, and to collect the voltage and current data of the wind turbine to be upgraded when oscillation occurs. It calculates and compares the relative magnitudes of the oscillation frequency components in the impedance and current of the wind turbine with and without the digital filters enabled, so as to adjust the parameters of the digital filters of the wind turbine to be upgraded according to the comparison results until the comparison results reach the preset filter suppression conditions.

[0096] The setting module 500 is used to enable all digital filters corresponding to the digital filter parameters of the wind turbine to be upgraded based on the adjusted digital filter parameters of the wind turbine to be upgraded, so as to complete the suppression of subsynchronous oscillation.

[0097] Optionally, in one embodiment of this application, the analysis module 100 is further configured to select doubly-fed wind farms with negative real parts of impedance as target wind farms based on the impedance characteristics of each wind farm at the oscillation frequency.

[0098] Optionally, in one embodiment of this application, the determining module 200 is further configured to determine the wind turbines to be upgraded based on the utilization hours of wind turbines in at least one target wind farm and a preset ratio of wind turbines to be upgraded.

[0099] Optionally, in one embodiment of this application, the analysis module 100 includes: a data acquisition unit, a processing unit, and an acquisition unit.

[0100] The acquisition unit is used to collect voltage and current waveform data from each wind farm's collection station when oscillations occur.

[0101] The processing unit is used to perform frequency domain transformation on the voltage and current waveform data to obtain the data to be analyzed.

[0102] The acquisition unit is used to obtain the oscillation frequency of each wind farm based on the data to be analyzed.

[0103] It should be noted that the foregoing explanation of the method embodiments according to the present application also applies to the apparatus embodiments according to the present application, and will not be repeated here.

[0104] The apparatus proposed in this application can analyze the oscillation frequency of each wind farm and obtain the impedance characteristics of each wind farm at the oscillation frequency. It can then screen target wind farms to determine the wind turbines to be upgraded. Based on the frequency of historical oscillation events, it generates digital filter parameters for the wind turbines to be upgraded, enables some digital filters corresponding to these parameters, and collects voltage and current data of the wind turbines to be upgraded during oscillation. It calculates and compares the relative magnitudes of the oscillation frequency components in the impedance and current of wind turbines with and without enabled digital filters, adjusts the digital filter parameters until the filter suppression condition is met, sets the adjusted digital filter parameters, and enables all filters to complete the subsynchronous oscillation suppression. This eliminates the need for additional equipment or devices, reducing workload, effectively saving time and cost, ensuring the effectiveness of the suppression measures, and is simple and easy to implement. Therefore, it solves the problems in related technologies, such as the need to add secondary-side equipment, which is inconvenient for on-site implementation; the increased upgrade time and economic cost required for applying suppression measures as the scale of wind farms and the types and number of wind turbines increase; and the inability to determine the effectiveness of wind power oscillation suppression methods.

[0105] Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include:

[0106] The memory 701, the processor 702, and the computer program stored on the memory 701 and capable of running on the processor 702.

[0107] When the processor 702 executes the program, it implements the method provided in the above embodiments according to the embodiments of this application.

[0108] Furthermore, electronic devices also include:

[0109] Communication interface 703 is used for communication between memory 701 and processor 702.

[0110] The memory 701 is used to store computer programs that can run on the processor 702.

[0111] The memory 701 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0112] If the memory 701, processor 702, and communication interface 703 are implemented independently, then the communication interface 703, memory 701, and processor 702 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, Figure 7 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0113] Optionally, in a specific implementation, if the memory 701, processor 702, and communication interface 703 are integrated on a single chip, then the memory 701, processor 702, and communication interface 703 can communicate with each other through an internal interface.

[0114] The processor 702 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0115] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the method described above according to the embodiments of this application.

[0116] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0117] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0118] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0119] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0120] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0121] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0122] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0123] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A wind power oscillation suppression method based on digital filtering, characterized in that, Includes the following steps: Analyze the oscillation frequency of each wind farm and obtain the impedance characteristics of each wind farm at the oscillation frequency to screen at least one target wind farm, wherein each wind farm includes at least one wind turbine. Identify the wind turbine units to be upgraded from the at least one target wind farm; Based on the historical oscillation frequencies of the wind turbine to be upgraded, digital filter parameters for the wind turbine to be upgraded are generated. Enable a portion of the digital filters corresponding to the digital filter parameters of the wind turbine to be upgraded, and collect voltage and current data of the wind turbine to be upgraded when oscillation occurs. Calculate and compare the relative magnitudes of the oscillation frequency components in the impedance and current of the wind turbine with and without the digital filters enabled, and adjust the parameters of the digital filters of the wind turbine to be upgraded according to the comparison results until the comparison results reach the preset filter suppression conditions; and Based on the adjusted digital filter parameters of the wind turbine to be upgraded, all digital filters corresponding to the digital filter parameters of the wind turbine to be upgraded are enabled to suppress subsynchronous oscillations.

2. The method according to claim 1, characterized in that, The screening of at least one target wind farm includes: Based on the impedance characteristics of each wind farm at the oscillation frequency, the doubly fed wind farm with a negative real part of impedance is taken as the target wind farm.

3. The method according to claim 1, characterized in that, The step of identifying the wind turbines to be upgraded from the at least one target wind farm includes: The wind turbines to be upgraded are determined based on the utilization hours of the wind turbines in the at least one target wind farm and the preset proportion of wind turbines to be upgraded.

4. The method according to claim 1, characterized in that, The analysis of the oscillation frequency of each wind farm includes: Collect voltage and current waveform data from each wind farm's collection station when oscillations occur; The voltage and current waveform data are subjected to frequency domain transformation to obtain the data to be analyzed; The oscillation frequency of each wind farm is obtained based on the data to be analyzed.

5. A wind power oscillation suppression device based on digital filtering, characterized in that, include: An analysis module is used to analyze the oscillation frequency of each wind farm and obtain the impedance characteristics of each wind farm at the oscillation frequency, and screen at least one target wind farm, wherein each wind farm includes at least one wind turbine. A determination module is used to determine the wind turbine units to be upgraded from the at least one target wind farm; The generation module is used to generate digital filter parameters for the wind turbine to be upgraded based on the historical oscillation frequencies of the wind turbine to be upgraded. The processing module is used to enable a portion of the digital filters corresponding to the digital filter parameters of the wind turbine to be upgraded, and to collect voltage and current data of the wind turbine to be upgraded when oscillation occurs. It calculates and compares the relative magnitudes of the oscillation frequency components in the impedance and current of the wind turbine with and without the digital filters enabled, and adjusts the parameters of the digital filters of the wind turbine to be upgraded based on the comparison results until the comparison results meet a preset filter suppression condition. The setting module is used to enable all digital filters corresponding to the adjusted digital filter parameters of the wind turbine to be upgraded, thereby suppressing subsynchronous oscillations.

6. The apparatus according to claim 5, characterized in that, The analysis module is further used to identify doubly-fed wind farms with negative real parts of impedance as target wind farms based on the impedance characteristics of each wind farm at the oscillation frequency.

7. The apparatus according to claim 5, characterized in that, The determining module is further configured to determine the wind turbine to be upgraded based on the utilization hours of the wind turbines in the at least one target wind farm and the preset proportion of wind turbines to be upgraded.

8. The apparatus according to claim 5, characterized in that, The analysis module includes: The acquisition unit is used to collect voltage and current waveform data from each wind farm collection station when oscillations occur. The processing unit is used to perform frequency domain transformation processing on the voltage and current waveform data to obtain the data to be analyzed; The acquisition unit is used to obtain the oscillation frequency of each wind farm based on the data to be analyzed.

9. An electronic device, characterized in that, include: The memory, the processor, and the computer program stored in the memory and executable on the processor, the processor executing the program to implement the wind power oscillation suppression method based on digital filtering as described in any one of claims 1-4.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the wind power oscillation suppression method based on digital filtering as described in any one of claims 1-4.

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