Method for optimizing reactive power control capability of wind farm and related device

Abstract

This application discloses a method and related apparatus for optimizing the reactive power control capability of a wind farm. The method includes: if a reactive power step command is received and the current first reactive power capability evaluation value of the entire station is greater than or equal to a threshold, allocating and controlling each wind turbine to output reactive power according to the corresponding reactive power step amount based on the total reactive power step and the current second reactive power capability evaluation value of each wind turbine; determining the station's adjustment time, steady-state adjustment accuracy, overshoot, third reactive power capability evaluation value, and fourth reactive power capability evaluation value of each wind turbine based on the step response result information of the reactive power adjustment; if the steady-state adjustment accuracy is greater than or equal to an error threshold or the adjustment time is greater than or equal to a time threshold, updating the first reactive power capability evaluation value and the second reactive power capability evaluation value of each wind turbine to the third reactive power capability evaluation value and the corresponding fourth reactive power capability evaluation value, thereby obtaining the second reactive power capability evaluation information. This application can improve the reactive power regulation capability of the entire station.

Description

Technical Field

[0001] This application relates to the field of new energy technology, and in particular to a method and related device for optimizing the reactive power control capability of wind farms. Background Technology

[0002] In recent years, wind power, photovoltaic (PV) and other new energy power plants have been continuously connected to the grid, enabling these new energy sources to gradually evolve from supplementary power sources to primary power sources. However, the dynamic behavior of new energy power generation equipment, with power electronic converters as the core interface, differs fundamentally from that of synchronous generators. This leads to a reduction in the system's frequency (active power) and voltage (reactive power) regulation capabilities, and an increasingly narrow stability boundary. Therefore, the power grid urgently needs new energy power generation equipment that can not only be connected to the grid but also withstand its load, meaning it must possess strong regulation capabilities.

[0003] For grid-connected wind farms and photovoltaic power stations, the operating conditions and maintenance status of each wind turbine vary, resulting in different power regulation performances. Currently, most energy management platforms operate on an average strategy, leading to substandard reactive power regulation capabilities across the entire station. To improve the reactive power regulation capabilities of wind farms, SVC or SVG dynamic reactive power compensation equipment is typically used. This method requires significant investment by modifying multiple hardware and software systems. Summary of the Invention

[0004] This application provides a method and related device for optimizing the reactive power control capability of a wind farm. Based on the method described in this application, the reactive power regulation capability of the entire station can be improved without modifying multiple sets of hardware equipment and software systems, thus saving costs.

[0005] In a first aspect, this application provides a method for optimizing the reactive power control capability of a wind farm. The method includes: in response to receiving a first reactive power step command, acquiring first reactive power capability evaluation information; the first reactive power capability evaluation information includes the current first reactive power capability evaluation value of the entire station and the current second reactive power capability evaluation value corresponding to each wind turbine in the station; the first reactive power step command indicates the total first reactive power step of the entire station; if the first reactive power capability evaluation value is greater than or equal to a first threshold, based on the total first reactive power step and the current second reactive power capability evaluation value corresponding to each wind turbine, allocating the reactive power step amount corresponding to each wind turbine in proportion; controlling each wind turbine to output reactive power according to the corresponding reactive power step amount; simultaneously acquiring first electrical data during the reactive power adjustment process, and generating first step response result information based on the first electrical data, wherein the first electrical data includes the electrical data of the wind farm grid connection point. The data includes electrical data of each wind turbine; based on the first step response result information, a first index is determined, which includes the first settling time, first steady-state settling accuracy, first overshoot, third reactive power evaluation value, and fourth reactive power evaluation value corresponding to each wind turbine; wherein, the third reactive power evaluation value is determined based on the first settling time, first steady-state settling accuracy, and first overshoot; if the first steady-state settling accuracy is greater than or equal to the error threshold and the first settling time is greater than or equal to the time threshold, the first reactive power evaluation value in the first reactive power evaluation information is updated to the third reactive power evaluation value, and the current second reactive power evaluation value corresponding to each wind turbine is updated to the fourth reactive power evaluation value corresponding to each wind turbine, thus obtaining the second reactive power evaluation information; the second reactive power evaluation information is used for subsequent reactive power step command allocation optimization.

[0006] In conjunction with the first aspect, in one possible approach, determining the reactive power step amount corresponding to each wind turbine based on the first total reactive power step and the second reactive power capacity evaluation value corresponding to each wind turbine includes performing the following operations sequentially for the second reactive power capacity evaluation value corresponding to each wind turbine to determine the reactive power step amount corresponding to each wind turbine: determining the reactive power step amount corresponding to the currently processed wind turbine based on the product of the second reactive power capacity evaluation value corresponding to the currently processed wind turbine and the first total reactive power step; wherein the sum of the second reactive power capacity evaluation values ​​corresponding to each wind turbine is 1.

[0007] In conjunction with the first aspect, in one possible manner, the first indicator includes the first adjustment time of the entire station; the first step response result information includes a first time and a second time, the first time being the time when the step command corresponding to each wind turbine is sent; the second time being the initial time when the reactive power of the entire station reaches a steady-state value in the current step test; determining the first indicator based on the first step response result information includes: determining the first adjustment time of the entire station based on the difference between the second time and the first time.

[0008] In conjunction with the first aspect, in one possible approach, the filter parameter information includes a first sum and a second sum; the first sum refers to the sum of multiple filter coefficient values ​​in the first time unit; the second sum refers to the sum of multiple filter coefficient change values ​​in the first time unit; the filter coefficient change value refers to the difference between adjacent filter coefficient values; the determination of the first loss parameter based on the filter parameter information and / or filter result information includes: smoothing the first sum to obtain a first smoothed value; smoothing the second sum to obtain a second smoothed value; and determining the first loss parameter based on the ratio between the first smoothed value and the second smoothed value.

[0009] In conjunction with the first aspect, in one possible approach, the first step response result information includes a first difference; the first difference refers to the difference between the actual output of the second step quantity and the total second reactive power step quantity when the reactive power of the entire station reaches a steady-state value in the current step test at the second time; the first index also includes the first overshoot of the entire station; determining the first index based on the first step response result information and the first total reactive power step quantity includes: determining the first steady-state regulation accuracy of the entire station based on the ratio between the second difference and the first total reactive power step quantity.

[0010] In conjunction with the first aspect, in one possible approach, the first indicator includes a third functional capability evaluation value for the entire station; the method further includes: in response to determining the first settling time, the first steady-state adjustment accuracy, and the first overshoot, obtaining a first weighting coefficient, a second weighting coefficient, and a third weighting coefficient; wherein the sum of the values ​​of the first weighting coefficient, the second weighting coefficient, and the third weighting coefficient is 1; the first weighting coefficient indicates the importance of dynamic response speed, the second weighting coefficient indicates the importance of response stability, and the third weighting coefficient indicates the importance of steady-state adjustment accuracy; and based on the first weighting coefficient, the second weighting coefficient, the third weighting coefficient, the first settling time, the first steady-state adjustment accuracy, and the first overshoot, determining a third functional capability evaluation value for the entire station.

[0011] In conjunction with the first aspect, in one possible approach, the method further includes: deactivating the first reactive power step instruction when the first reactive power capability evaluation value is less than a first threshold, and / or outputting a first alarm message, the first alarm message being used to indicate that the reactive power control capability of the entire station cannot meet the current reactive power control requirements and that immediate shutdown for maintenance is required.

[0012] Secondly, this application provides a device for optimizing the reactive power control capability of a wind farm, the device comprising:

[0013] The response unit is used to respond to receiving a first reactive power step command and obtain first reactive power capacity evaluation information; the first reactive power capacity evaluation information includes the current first reactive power capacity evaluation value of the entire station and the current second reactive power capacity evaluation value of each wind turbine in the station; the first reactive power step command indicates the total first reactive power step of the entire station.

[0014] The reactive power step allocation unit is used to allocate the reactive power step corresponding to each wind turbine according to a ratio based on the first reactive power step total and the second reactive power capability evaluation value currently corresponding to each wind turbine when the first reactive power capability evaluation value is greater than or equal to the first threshold.

[0015] The step response result information acquisition unit is used to control each wind turbine to generate reactive power according to the corresponding reactive power step amount, and at the same time, acquire the first electrical data in the reactive power adjustment process, and generate the first step response result information based on the first electrical data. The first electrical data includes the electrical data of the wind farm grid connection point and the electrical data of each wind turbine.

[0016] The indicator determination unit is used to determine a first indicator based on the first step response result information. The first indicator includes the first adjustment time, the first steady-state adjustment accuracy, the first overshoot, the third non-functional capacity evaluation value of the entire station, and the fourth non-functional capacity evaluation value corresponding to each wind turbine. The third non-functional capacity evaluation value is determined based on the first adjustment time, the first steady-state adjustment accuracy, and the first overshoot.

[0017] The information update unit is used to update the first reactive power evaluation value in the first reactive power evaluation information to the third reactive power evaluation value, and update the current second reactive power evaluation value corresponding to each wind turbine to the fourth reactive power evaluation value corresponding to each wind turbine, when the first steady-state adjustment accuracy is greater than or equal to the error threshold, or the first adjustment time is greater than or equal to the time threshold, to obtain the second reactive power evaluation information; the second reactive power evaluation information is used for subsequent reactive power step command allocation optimization.

[0018] Thirdly, the application provides an electronic device including a processor, a memory, and a computer program or instructions stored in the memory, wherein the processor executes the computer program or instructions to implement the steps of any of the methods described in the above method embodiments.

[0019] Fourthly, the application provides a computer-readable storage medium storing a computer program or instructions that, when executed, implement the steps of any of the methods described in the above method embodiments. Attached Figure Description

[0020] Figure 1A This is a schematic diagram of a wind farm topology provided in an embodiment of this application;

[0021] Figure 1B This is a schematic diagram of a reactive power regulation process provided in the application embodiment;

[0022] Figure 2 This is a flowchart illustrating a method for optimizing the reactive power control capability of a wind farm, as provided in an embodiment of this application.

[0023] Figure 3 This is a flowchart illustrating another method for optimizing the reactive power control capability of a wind farm provided in an embodiment of this application;

[0024] Figure 4 This is the reactive power control capability test curve of the grid connection point before the optimization of the reactive power control capability of the power station provided in the embodiments of this application.

[0025] Figure 5 This is the reactive power control capability test curve corresponding to the grid connection point after the optimization of the reactive power control capability of the power station provided in the embodiments of this application. Detailed Implementation

[0026] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the figures. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressive forms “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressive forms as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0028] It should be noted that the terms "first," "second," "third," etc., used in the specification, claims, and figures of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data used in this way can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the term "comprising" and any variations thereof are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices.

[0029] To facilitate understanding of the embodiments of this application, the sub-wind farm architecture involved in the embodiments of this application will be introduced first below.

[0030] Please see Figure 1A , Figure 1A This is a schematic diagram of a wind farm topology using an embodiment of this application. For example... Figure 1A As shown, the wind farm topology includes a scheduling module, an energy management module, and N wind turbine units.

[0031] The energy management module can obtain the first reactive power capacity evaluation information upon receiving the first reactive power step instruction from the scheduling module.

[0032] The first reactive power capacity evaluation information includes the current first reactive power capacity evaluation value of the entire station and the current second reactive power capacity evaluation value of each wind turbine in the station. The first reactive power step command indicates the total first reactive power step of the entire station. The first reactive power capacity evaluation information can be the reactive power capacity evaluation information determined based on the previous step test of the current reactive power step test (hereinafter referred to as the step test). It should be noted that when the current step test is the first step test, the reactive power capacity evaluation information can be the default value, the current reactive power capacity evaluation value of each wind turbine in the station can be the average value, and the reactive power capacity evaluation value of the entire station is greater than the first threshold by default, for example, set to 1.

[0033] The first reactive power capability evaluation information can be a reactive power control capability evaluation table, such as the reactive power control capability evaluation table shown in Appendix 1:

[0034] Appendix 1 Reactive Power Control Capability Evaluation Table (Sample)

[0035]

[0036] Optionally, the first reactive power step instruction may include the total first reactive power step of the entire station (hereinafter referred to as the total first reactive power step). In this case, after receiving the first reactive power step instruction, the total first reactive power step is directly read.

[0037] Optionally, the first reactive power step command may also include the reactive power value that the entire station needs to output. In this case, the reactive power output of each wind turbine in the field can be obtained separately in the following way, and the first sum of the reactive power output of each wind turbine can be calculated. The first sum is then used as the reactive power output of the station. The difference between the reactive power value that the entire station needs to output and the first sum is calculated. The sum is then the total amount of the first reactive power step.

[0038] The first sum can be calculated using the following formula:

[0039]

[0040] Among them, Q wind0 Q is the first sum. i0 Let N be the reactive power output of the i-th wind turbine, and N be the total number of wind turbines in the site.

[0041] The total amount of the first reactive step jump can be calculated using the following formula:

[0042]

[0043] Where, ΔQ T_ref Q represents the total reactive power step change. z This represents the reactive power output required for the entire power station.

[0044] After receiving the first functional capacity assessment information, the energy management module will determine whether the first functional capacity assessment value is less than a first threshold. The first threshold is the minimum reference value for the entire station's functional capacity to meet the step demand.

[0045] If the first reactive power evaluation value is greater than or equal to the first threshold, it means that the reactive power of the entire station can meet the step demand. The energy management module can allocate the reactive power step amount corresponding to each wind turbine according to the ratio based on the first reactive power step amount and the second reactive power evaluation value corresponding to each wind turbine.

[0046] Specifically, the following operations can be performed sequentially for the second reactive power evaluation value corresponding to each wind turbine to determine the reactive power step amount corresponding to each wind turbine: Based on the product of the second reactive power evaluation value corresponding to the currently processed wind turbine and the total first reactive power step amount, the reactive power step amount corresponding to the currently processed wind turbine is determined; wherein, the sum of the second reactive power evaluation values ​​corresponding to each wind turbine is 1.

[0047] The first threshold can be an empirical value obtained from experiments, and this first threshold can be 0.7.

[0048] In other words, the reactive power step change corresponding to each wind turbine can be calculated based on the following formula:

[0049]

[0050] in, Let E be the reactive power step value corresponding to the i-th wind turbine. i Let be the current regulation capability evaluation value of the i-th wind turbine, and satisfy . N represents the total number of wind turbine units at the wind farm.

[0051] After determining the reactive power step value corresponding to each wind turbine, the energy management module can control each wind turbine to generate reactive power according to the corresponding reactive power step value.

[0052] In one implementation, the energy management module controls each wind turbine to output reactive power according to its corresponding reactive power step. Specifically, the energy management module generates a reactive power step instruction for each wind turbine based on its corresponding reactive power step. This instruction indicates the reactive power step of the corresponding wind turbine. The energy management module then synchronously distributes these instructions to the main control systems of each wind turbine. Upon receiving the reactive power step instruction from the energy management module, the main control system of each wind turbine controls the corresponding wind turbine to output reactive power.

[0053] The energy management module can synchronously acquire the first electrical data during the reactive power regulation process and generate the first step response result information based on the first electrical data. The first electrical data includes the electrical data of the wind farm grid connection point and the electrical data of each wind turbine. Based on the first step response result information, the energy management module determines the first indicators, which include the first adjustment time, first steady-state adjustment accuracy, first overshoot, third reactive power capacity evaluation value of the entire station, and the fourth reactive power capacity evaluation value corresponding to each wind turbine. The third reactive power capacity evaluation value is determined based on the first adjustment time, first steady-state adjustment accuracy, and first overshoot. The fourth reactive power capacity evaluation value is determined based on the adjustment time, steady-state adjustment accuracy, and overshoot of the corresponding wind turbine, and the determination method is the same as that of the third reactive power capacity evaluation value.

[0054] The reactive power adjustment process, also known as the step test process, refers to the time period from when the energy management module issues a reactive power step command to the object to be adjusted until the reactive power of the object to be adjusted reaches the steady-state value for the first time. This time period can also be called the adjustment time. Reaching the steady-state value means that the actual output power of the object to be adjusted is between 95% and 105% of the target output power. The target output power is the reactive power of the object to be adjusted after adding the reactive power step amount to the actual reactive power value of the object before the energy management module issues the reactive power step command (i.e., the actual reactive power before reactive power adjustment).

[0055] Below, taking a wind turbine as an example, we will combine... Figure 1B The relevant concepts will be introduced. Figure 1B The application embodiment provides a schematic diagram of a reactive power regulation process. The regulation time for each wind turbine is from the time the energy management module issues the command t0 until the actual reactive power reaches the steady-state value t. x_i Until then. Here, "reaching steady-state value" means that the actual reactive power output of the i-th wind turbine unit reaches 95%Q for the first time. i_ref Up to 105%Q i_ref Within the interval, Q i_ref It refers to the reactive power after adding the reactive power step amount to the actual reactive power before the i-th wind turbine unit performs reactive power adjustment.

[0056] As a specific implementation method, the first indicator includes the first adjustment time of the entire station; the first step response result information includes the first time and the second time, the first time being the time when the step command corresponding to each wind turbine is sent; the second time being the initial time when the reactive power of the entire station reaches the steady state value in the current step test; based on the first step response result information, the first indicator is determined, including: based on the difference between the second time and the first time, the first adjustment time of the entire station is determined.

[0057] Below, taking various wind turbine units as examples, the overshoot can be calculated based on the following formula (1):

[0058] (1)

[0059] in, Let ΔQ be the overshoot of the i-th wind turbine in the current sub-step test. i_max It represents the maximum step size of the i-th wind turbine in the current step test.

[0060] For the entire station, the overshoot σ is... z The calculation method refers to formula (1). That is to say, the first indicator also includes the first overshoot of the whole station; the first step response result information includes the first difference; the first difference refers to the difference between the largest first step in the current step test of the whole station and the first reactive step total (including the reactive step command value allocated to each wind turbine); based on the first step response result information and the first reactive step total, the first indicator is determined, including: based on the ratio between the first difference and the first reactive step total, the first overshoot of the whole station is determined.

[0061] Below, taking various wind turbine units as examples, the calculation method for steady-state regulation accuracy can be obtained based on the following formula (2):

[0062] (2)

[0063] in, Let be the steady-state adjustment accuracy of the i-th wind turbine unit in the current sub-step test. This refers to the actual step output when the reactive power of the entire station reaches a steady-state value in the current step test and the reactive power is output stably.

[0064] For the entire station, the steady-state regulation accuracy ε z The calculation method refers to formula (2). That is to say, the first index also includes the first steady-state regulation accuracy of the whole station; the first step response result information includes the second difference; the second difference refers to the difference between the actual output second step amount and the second reactive step amount when the reactive power of the whole station reaches the steady-state value in the current step test at the second time; based on the first step response result information and the first reactive step amount, the first index is determined, including: based on the ratio between the second difference and the first reactive step amount, the first steady-state regulation accuracy of the whole station is determined. The second step amount refers to the reactive power corresponding to the stable output of the reactive power of the whole station.

[0065] Below, taking each wind turbine as an example, the non-functional capacity evaluation value can be calculated based on the following formulas (3), (4), and (5):

[0066] The initial nonfunctional capacity assessment value can be calculated based on the following formula (3):

[0067] (3)

[0068] Where T is the baseline value for response time, which can be taken as 30s according to the standard requirements.

[0069] Where k1, k2, and k3 are evaluation coefficients, i.e., weighting coefficients for the settling time, overshoot, and steady-state control accuracy indicators, satisfying the following relationship:

[0070] (4)

[0071] The specific values ​​of the evaluation coefficients k1, k2, and k3 can be determined based on actual testing experience. For example, if testing reveals that steady-state regulation accuracy is the weak point of the power station's reactive power regulation capability, then k3 can be set to a larger value, such as k1=0.4, k2=0.1, and k3=0.5.

[0072] The initial non-functional capacity evaluation value is normalized to obtain the target non-functional capacity evaluation value, which can be calculated based on the following formula (3):

[0073] (5)

[0074] For the entire site, the overall site capability evaluation value E z Calculated according to formulas (3) and (4), since there is only one non-functional capacity evaluation value index, the non-functional capacity evaluation value of the whole station does not need to be normalized. That is to say, the first index includes the third non-functional capacity evaluation value of the whole station; the method also includes: in response to determining the first adjustment time, the first steady-state adjustment accuracy and the first overshoot, obtaining the first weight coefficient, the second weight coefficient and the third weight coefficient; wherein, the sum of the values ​​of the first weight coefficient, the second weight coefficient and the third weight coefficient is 1; the first weight coefficient indicates the importance of dynamic response speed, the second weight coefficient indicates the importance of response stability and the third weight coefficient indicates the importance of steady-state adjustment accuracy; based on the first weight coefficient, the second weight coefficient, the third weight coefficient, the first adjustment time, the first steady-state adjustment accuracy and the first overshoot, the third non-functional capacity evaluation value of the whole station is determined.

[0075] When the first steady-state adjustment accuracy is greater than or equal to the error threshold and the first adjustment time is greater than or equal to the time threshold, the energy management module can update the first reactive power evaluation value in the first reactive power evaluation information to the third reactive power evaluation value, and update the current second reactive power evaluation value corresponding to each wind turbine to the fourth reactive power evaluation value corresponding to each wind turbine, thus obtaining the second reactive power evaluation information; the second reactive power evaluation information is used for the allocation optimization of subsequent reactive power step commands.

[0076] The error threshold can be 5%, and the time threshold can be 30 seconds, without specific limitations.

[0077] When the first reactive power capacity evaluation value is less than the first threshold, the energy management module deactivates the first reactive power step command and / or outputs a first alarm message. The first alarm message indicates that the reactive power control capability of the entire station cannot meet the current reactive power control requirements, and immediate shutdown for maintenance is necessary. Deactivating the first reactive power step command means rendering the first reactive power step command in an invalid state.

[0078] Furthermore, after each step test experiment, the number of tests can be accumulated. If the results of m consecutive tests show that the updated steady-state adjustment accuracy of the entire station is greater than or equal to the error threshold, or the updated adjustment time of the entire station is greater than or equal to the time threshold, then the test is successful. m is an integer greater than or equal to 2, for example, m can be 3, 4, 5, 6, etc.

[0079] Based on the above wind farm topology, the following describes the implementation method for optimizing the reactive power control capability of wind farms provided by the embodiments of the present invention.

[0080] Please see Figure 2 , Figure 2 A flowchart of a method for optimizing the reactive power control capability of a wind farm, as provided in this application embodiment, is shown below. Figure 2 As shown, this method for optimizing reactive power control in wind farms can be applied to applications such as... Figure 1A The energy management module shown includes, but is not limited to, the following S201~S205 methods for optimizing the reactive power control capability of the wind farm.

[0081] S201. Upon receiving the first reactive power step command, the energy management module obtains the first reactive power capacity evaluation information. The first reactive power capacity evaluation information includes the current first reactive power capacity evaluation value of the entire station and the current second reactive power capacity evaluation value of each wind turbine in the station. The first reactive power step command indicates the total first reactive power step of the entire station, which can also be called the first reactive power step command value.

[0082] S202. When the first reactive power evaluation value is greater than or equal to the first threshold, the energy management module allocates the reactive power step amount corresponding to each wind turbine according to the ratio based on the first reactive power step amount and the second reactive power evaluation value corresponding to each wind turbine.

[0083] S203. The energy management module controls each wind turbine to generate reactive power according to the corresponding reactive power step amount. At the same time, it acquires the first electrical data during the reactive power adjustment process and generates the first step response result information based on the first electrical data. The first electrical data includes the electrical data of the wind farm grid connection point and the electrical data of each wind turbine.

[0084] S204. Based on the first step response result information, the energy management module determines the first indicator, which includes the first adjustment time, the first steady-state adjustment accuracy, the first overshoot, the third non-functional capacity evaluation value, and the fourth non-functional capacity evaluation value corresponding to each wind turbine.

[0085] The third non-functional capacity evaluation value is determined based on the first settling time, the first steady-state settling accuracy, and the first overshoot. The fourth non-functional capacity evaluation value is determined based on the settling time, steady-state settling accuracy, and overshoot of the corresponding wind turbine. The third and fourth non-functional capacity evaluation values ​​are determined in the same way.

[0086] S205. When the first steady-state adjustment accuracy is greater than or equal to the error threshold, or the first adjustment time is greater than or equal to the time threshold, the energy management module updates the first reactive power evaluation value in the first reactive power evaluation information to the third reactive power evaluation value, and updates the current second reactive power evaluation value corresponding to each wind turbine to the fourth reactive power evaluation value corresponding to each wind turbine, thereby obtaining the second reactive power evaluation information; the second reactive power evaluation information is used for the allocation optimization of subsequent reactive power step commands.

[0087] Both the error threshold and the time threshold are set based on experimental data or empirical values. If the first steady-state adjustment accuracy is less than the error threshold and the first adjustment time is less than the time threshold, it indicates that the results of the step test meet the testing requirements, meaning that the reactive power regulation capability of the wind farm meets the reactive power regulation requirements.

[0088] It should be noted that, Figure 2 The corresponding wind farm reactive power control capability optimization method is based on the same concept as the aforementioned energy management module, and the resulting technical effects are also the same. For the specific principles, please refer to the detailed description of the aforementioned energy management module, which will not be repeated here.

[0089] The following example illustrates the implementation of this application scheme in a real wind farm.

[0090] The wind farm has a total capacity of 50MW, consisting of 20 2.5MW wind turbine units, and is equipped with one ±10Mvar dynamic reactive power compensation device. Reactive power regulation capability tests were conducted on the wind turbine units at this station. During the test, the reactive power output of the SVG (Static Var Generator) was locked. The test range for reactive power control capability was set to -10 to 5Mvar. The test process was conducted using the dispatch module mode, setting the reactive power at the grid connection point to be adjusted in 5Mvar increments from 0Mvar to -10Mvar (maximum inductive reactive power output), and then gradually adjusted from -10Mvar back to 5Mvar. During the test, because the reactive power regulation amount was much smaller than the SVG reactive power capacity, the reactive power control at the grid connection point only reflected the reactive power regulation performance of the SVG. The waveform of the reactive power regulation capability test at the grid connection point is as follows: Figure 4 As shown in Appendix 2, the calculation results of the reactive power regulation index are as follows. Appendix 2 shows the test results of the main reactive power control index of the grid connection point before the optimization of the reactive power control capability of the power station. The steady-state regulation accuracy is 7.4% and the regulation time is 12s. The reactive power regulation capability is relatively poor among power stations of the same type and capacity, and the steady-state regulation accuracy exceeds 5%, so it needs to be upgraded.

[0091] Appendix 2 is as follows:

[0092]

[0093] Please see Figure 3 , Figure 3 This is a flowchart illustrating another method for optimizing the reactive power control capability of a wind farm provided in an embodiment of this application; as shown... Figure 3 As shown, in this method, the energy management module waits to receive a reactive power step command from the scheduling module; upon receiving the reactive power step command from the scheduling module, the energy management module determines the reactive power capacity evaluation value E of the entire station. z-p Is it less than 0.7? If E z-p If the value is less than 0.7, the reactive power step command will be deactivated, and an alarm will be issued, indicating that the station's reactive power control capability cannot meet the current demand, and immediate shutdown and maintenance are required; if E z-p If the value is greater than or equal to 0.7, the energy management module calculates the step command allocated to each wind turbine based on the reactive power control capability evaluation table and the corresponding formula; among which, the reactive power step command indicates ΔQ. T_ref =-5Mvar, the required additional issuance ΔQ T_ref =-5Mvar is entirely borne by the wind turbine, i.e., ΔQ wind =-5Mvar.

[0094] Since this is the first step test, the no-function rating of this wind turbine is taken as the average value, that is: .

[0095] Specifically, the energy management module can calculate the reactive power step command value allocated to each wind turbine according to the following formula:

[0096]

[0097] Then, the energy management module distributes each reactive power step command to the main control system of each wind turbine. The main control system of the wind turbine controls the output reactive power of the wind turbine. At the same time, the energy management module calculates and evaluates the reactive power regulation index of each wind turbine and the whole station based on the three-phase voltage and three-phase current at the turbine terminals of each wind turbine. This includes the regulation time, overshoot, steady-state regulation accuracy, and comprehensive evaluation value of reactive power regulation capability. Specifically, the energy management module calculates the reactive power regulation index of the wind turbine in this operation according to formulas (1), (2), (3), (4), and (5) based on the three-phase voltage and three-phase current at the turbine terminals of each wind turbine. The results are shown in Appendix Table 3.

[0098] Appendix 3: Evaluation Table of Reactive Power Control Capability (First Step Test)

[0099]

[0100] The evaluation table of reactive power regulation capability of wind turbine units shows that the overall reactive power regulation capability of wind turbine units #3, #4, #9, #10, and #11 is relatively low. Therefore, when the whole station participates in reactive power regulation next time, the reactive power share of these 5 wind turbine units should be shared by other wind turbine units with stronger overall regulation capability in order to improve the reactive power regulation capability of the whole station.

[0101] As shown in Appendix 3, during the initial reactive power regulation, each wind turbine unit shared the same reactive power of 0.05 pu. After one reactive power step regulation and comprehensive evaluation, the comprehensive evaluation value of the regulation capability of wind turbine units #3, #4, #9, #10, and #11 decreased from 0.05 to approximately 0.044. This means that the reactive power share borne by the wind turbine units with poorer regulation capability was "relinquished" to the wind turbine units with stronger regulation capability.

[0102] The reactive power control capability evaluation table is dynamically updated. The updated reactive power control capability evaluation table is shown in Appendix 4:

[0103] Appendix 4 Reactive Power Control Capability Evaluation Table (First Update)

[0104]

[0105] Return to step 1 and wait for the scheduling module to issue another reactive power step command to optimize the reactive power regulation capability of each wind turbine.

[0106] The current reactive power output of the entire station was calculated. Since this test primarily focused on optimizing the reactive power control capabilities of the wind turbine units within the station, the reactive power output of the SVG (Static Var Generator) was locked throughout the entire test, i.e., Q. svg0 =0 Mvar. The reactive power of the wind turbines is in a dynamically adjusted state. The sum of the reactive power of all wind turbines is currently Q. wind0 =-5.45Mvar.

[0107] Next, after superimposing the step reactive power, the total reactive power output of the station is calculated as Qz = -5.45 - 5 = -10.45 Mva. Since Q... z <25%S N Then, ΔQ needs to be issued. T_ref =-5Mvar is entirely borne by the wind turbine, i.e., ΔQ wind =-5Mvar.

[0108] Since the SVG does not participate in the adjustment in this test, step 3 will be executed next according to the method steps of this invention. The energy management module calculates the reactive power step command allocated to each wind turbine according to formula (3), and the results are shown in Appendix Table 5:

[0109] Appendix 5: Reactive power commands allocated to each wind turbine during this reactive power step test.

[0110]

[0111] Then ΔQ i_ref The reactive power output of each wind turbine is distributed to its main control system. The main control system controls the reactive power output of the wind turbines. Simultaneously, the energy management module calculates the reactive power regulation index of each wind turbine based on its terminal voltage and current, according to formulas (1), (2), (3), (4), and (5). The results are shown in Appendix Table 6.

[0112] Appendix 6 Reactive Power Control Capability Evaluation Table (Second Step Test)

[0113]

[0114] Since the reactive power adjustment time of the entire station is 4.4s, which is less than 30s, and the steady-state adjustment accuracy is 95.8%, which is greater than 95%, the adjustment capability evaluation value does not need to be updated. Return to step 1 and wait for the reactive power step command from the dispatch module. If the reactive power adjustment time of the entire station is greater than or equal to 30s, or the steady-state adjustment accuracy is greater than or equal to 5%, then increment the test count by 1 and check if the cumulative test count is greater than 5. If it is greater than 5, then deactivate the reactive power step command and issue an alarm, indicating that the reactive power control capability of the station cannot meet the current requirements, and request immediate shutdown for maintenance; if it is less than or equal to 5, return to waiting to receive the reactive power step command from the dispatch module and conduct the next step test.

[0115] The steady-state regulation accuracy and regulation time obtained from the subsequent four consecutive reactive power step tests all met the requirements, as detailed in Appendix 7 and... Figure 5 As shown, the maximum reactive power control response time of the entire station is 4.8s, and the control accuracy is 95.8%, which fully meets the requirements of the regulations.

[0116] Appendix 7: Test Results of Key Indicators of Reactive Power Control Capability at Grid Connection Points (After Optimization)

[0117]

[0118] This application embodiment also provides a wind farm reactive power control capability optimization device, the device comprising:

[0119] The response unit is used to respond to receiving the first reactive power step command and obtain the first reactive power capacity evaluation information; the first reactive power capacity evaluation information includes the current first reactive power capacity evaluation value of the entire station and the current second reactive power capacity evaluation value of each wind turbine in the station; the first reactive power step command indicates the total first reactive power step of the entire station.

[0120] The reactive power step allocation unit is used to allocate the reactive power step corresponding to each wind turbine according to the ratio based on the first reactive power step total and the second reactive power capability evaluation value corresponding to each wind turbine when the first reactive power capability evaluation value is greater than or equal to the first threshold.

[0121] The step response result information acquisition unit is used to control each wind turbine to generate reactive power according to the corresponding reactive power step amount. At the same time, it acquires the first electrical data during the reactive power adjustment process and generates the first step response result information based on the first electrical data. The first electrical data includes the electrical data of the wind farm grid connection point and the electrical data of each wind turbine.

[0122] The index determination unit is used to determine the first index based on the first step response result information. The first index includes the first settling time, the first steady-state settling accuracy, the first overshoot, the third non-functional capacity evaluation value of the whole station, and the fourth non-functional capacity evaluation value corresponding to each wind turbine. The third non-functional capacity evaluation value is determined based on the first settling time, the first steady-state settling accuracy, and the first overshoot.

[0123] The information update unit is used to update the first reactive power evaluation value in the first reactive power evaluation information to the third reactive power evaluation value, and update the current second reactive power evaluation value corresponding to each wind turbine to the fourth reactive power evaluation value corresponding to each wind turbine, when the first steady-state adjustment accuracy is greater than or equal to the error threshold, or the first adjustment time is greater than or equal to the time threshold, to obtain the second reactive power evaluation information; the second reactive power evaluation information is used for the subsequent allocation optimization of reactive power step commands.

[0124] The application also provides an electronic device, including a processor, a memory, and a computer program or instructions stored in the memory, wherein the processor executes the computer program or instructions to implement the steps of any of the methods described in the above method embodiments.

[0125] The application also provides a computer-readable storage medium storing a computer program or instructions that, when executed, implement the steps of any of the methods described in the above method embodiments.

[0126] It should be noted that for details not mentioned regarding the wind farm reactive power control optimization device, electronic equipment, and computer-readable storage medium, as well as the specific implementation methods of each step, please refer to [link to relevant documentation]. Figure 1A The embodiments and the foregoing content will not be repeated here.

[0127] While this application discloses the above information, it is not limited thereto. Any person skilled in the art can easily conceive of variations or substitutions without departing from the spirit and scope of this application, and can make various alterations and modifications, including combinations of the different functions and implementation steps described above, as well as software and hardware implementation methods, all of which are within the protection scope of this application.

Claims

1. A method for optimizing the reactive power control capability of a wind farm, characterized in that, The method includes: In response to receiving the first reactive power step command, the first reactive power capacity evaluation information is obtained; the first reactive power capacity evaluation information includes the current first reactive power capacity evaluation value of the entire station and the current second reactive power capacity evaluation value of each wind turbine in the station; the first reactive power step command indicates the total first reactive power step of the entire station. If the first reactive power performance evaluation value is greater than or equal to the first threshold, the reactive power step amount corresponding to each wind turbine is allocated proportionally based on the first reactive power step amount and the second reactive power performance evaluation value corresponding to each wind turbine. The system controls each wind turbine to generate reactive power according to the corresponding reactive power step amount. At the same time, it acquires the first electrical data during the reactive power adjustment process and generates the first step response result information based on the first electrical data. The first electrical data includes the electrical data of the wind farm grid connection point and the electrical data of each wind turbine. Based on the first step response result information, a first indicator is determined; or, based on the first step response result information and the first reactive power step total, a first indicator is determined. The first indicator includes the first adjustment time, the first steady-state adjustment accuracy, the first overshoot, the third reactive power capacity evaluation value of the entire station, and the fourth reactive power capacity evaluation value corresponding to each wind turbine. The third reactive power capacity evaluation value is determined based on the first adjustment time, the first steady-state adjustment accuracy, and the first overshoot. If the first steady-state adjustment accuracy is greater than or equal to the error threshold, or the first adjustment time is greater than or equal to the time threshold, the first reactive power evaluation value in the first reactive power evaluation information is updated to the third reactive power evaluation value, and the current second reactive power evaluation value corresponding to each wind turbine is updated to the fourth reactive power evaluation value corresponding to each wind turbine, thus obtaining the second reactive power evaluation information; the second reactive power evaluation information is used for the subsequent allocation optimization of reactive power step commands.

2. The method according to claim 1, characterized in that, The step of determining the reactive power step amount corresponding to each wind turbine based on the first reactive power step amount and the second reactive power capacity evaluation value corresponding to each wind turbine includes performing the following operations sequentially for the second reactive power capacity evaluation value corresponding to each wind turbine to determine the reactive power step amount corresponding to each wind turbine: The reactive power step value corresponding to the wind turbine unit being processed is determined by multiplying the second reactive power capacity evaluation value corresponding to the wind turbine unit being processed with the first reactive power step value; wherein, the sum of the second reactive power capacity evaluation values ​​corresponding to each wind turbine unit is 1.

3. The method according to claim 1, characterized in that, The first indicator includes the first adjustment time of the entire station; the first step response result information includes a first time and a second time, wherein the first time is the time when the step command corresponding to each wind turbine is sent; and the second time is the initial time when the reactive power of the entire station reaches the steady-state value in the current step test. The step of determining the first index based on the first step response result information includes: The first adjustment time of the entire station is determined based on the difference between the second time and the first time.

4. The method according to claim 1, characterized in that, The first step response result information includes a first difference; the first difference refers to the difference between the maximum first step amount and the total first reactive step amount in the current step test of the entire station; the first index also includes the first overshoot of the entire station; The determination of the first indicator based on the first step response result information and the first reactive power step quantity includes: The first overshoot of the entire station is determined based on the ratio between the first difference and the first reactive power step amount.

5. The method according to claim 1, characterized in that, The first step response result information includes a second difference; the second difference is the difference between the actual second step amount output by the reactive power of the entire station when it reaches the steady-state value in the current step test and the total reactive power step amount; the first index also includes the first steady-state regulation accuracy of the entire station; The determination of the first indicator based on the first step response result information and the first reactive power step quantity includes: The first steady-state regulation accuracy of the entire station is determined based on the ratio between the second difference and the first reactive power step amount.

6. The method according to claim 1, characterized in that, The first indicator includes the third functional impairment evaluation value of the entire station; the method further includes: In response to determining the first adjustment time, the first steady-state adjustment accuracy, and the first overshoot, a first weighting coefficient, a second weighting coefficient, and a third weighting coefficient are obtained; wherein the sum of the values ​​of the first weighting coefficient, the second weighting coefficient, and the third weighting coefficient is 1; the first weighting coefficient indicates the importance of dynamic response speed, the second weighting coefficient indicates the importance of response stability, and the third weighting coefficient indicates the importance of steady-state adjustment accuracy. Based on the first weighting coefficient, the second weighting coefficient, the third weighting coefficient, the first adjustment time, the first steady-state adjustment accuracy, and the first overshoot, the third non-functionality evaluation value of the entire station is determined.

7. The method according to claim 1, characterized in that, The method further includes: If the first reactive power capability evaluation value is less than the first threshold, the first reactive power step instruction is deactivated, and / or the first alarm information is output. The first alarm information is used to indicate that the reactive power control capability of the entire station cannot meet the current reactive power control requirements and that it needs to be shut down for maintenance immediately.

8. A device for optimizing reactive power control in wind farms, characterized in that, The device includes: The response unit is used to respond to receiving a first reactive power step command and obtain first reactive power capacity evaluation information; the first reactive power capacity evaluation information includes the current first reactive power capacity evaluation value of the entire station and the current second reactive power capacity evaluation value of each wind turbine in the station; the first reactive power step command indicates the total first reactive power step of the entire station. The reactive power step allocation unit is used to allocate the reactive power step corresponding to each wind turbine according to a ratio based on the first reactive power step total and the second reactive power capability evaluation value currently corresponding to each wind turbine when the first reactive power capability evaluation value is greater than or equal to the first threshold. The step response result information acquisition unit is used to control each wind turbine to generate reactive power according to the corresponding reactive power step amount, and at the same time, acquire the first electrical data in the reactive power adjustment process, and generate the first step response result information based on the first electrical data. The first electrical data includes the electrical data of the wind farm grid connection point and the electrical data of each wind turbine. The indicator determination unit is used to determine a first indicator based on the first step response result information, or to determine a first indicator based on the first step response result information and the first reactive power step total amount. The first indicator includes the first adjustment time, the first steady-state adjustment accuracy, the first overshoot, the third reactive power capacity evaluation value of the entire station, and the fourth reactive power capacity evaluation value corresponding to each wind turbine. The third reactive power capacity evaluation value is determined based on the first adjustment time, the first steady-state adjustment accuracy, and the first overshoot. The information update unit is used to update the first reactive power evaluation value in the first reactive power evaluation information to the third reactive power evaluation value, and update the current second reactive power evaluation value corresponding to each wind turbine to the fourth reactive power evaluation value corresponding to each wind turbine, when the first steady-state adjustment accuracy is greater than or equal to the error threshold, or the first adjustment time is greater than or equal to the time threshold, to obtain the second reactive power evaluation information; the second reactive power evaluation information is used for subsequent reactive power step command allocation optimization.

9. An electronic device comprising a processor, a memory, and a computer program or instructions stored in the memory, characterized in that, The processor executes the computer program or instructions to implement the steps of the method according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, It stores a computer program or instructions that, when executed, implement the steps of the method described in any one of claims 1-7.

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