An autonomous sensing method for the reactive power-voltage sensitivity at the grid connection point of a wind farm

Abstract

The present invention relates to the field of automatic control for new energy grid connection in power systems, and discloses a method for autonomously sensing the reactive power-voltage sensitivity at the grid connection point of a wind farm. The method includes reactive power-voltage measurement, setting up an operating condition construction module, a reactive power-voltage data window construction module, and a data screening module to screen the steady-state operation data at the grid connection point, calculate the reactive power-voltage sensitivity sequence, and iteratively update the reactive power-voltage sensitivity sequence. The AVC substation selects the corresponding reactive power-voltage sensitivity parameter from the reactive power-voltage sensitivity sequence according to the current operating condition and voltage control target to calculate the reactive power increment, thereby realizing the high-precision control function of the AVC substation. Without the need to add extra hardware, it is convenient for the upgrade of existing AVC substations. The high-precision reactive power-voltage sensitivity can reduce the action frequency of the AVC substation, and also reduce the probability of overshoot or undershoot of the voltage at the grid connection point of the wind farm, improving the qualified rate of the voltage at the grid connection point of the wind farm, and having good effects in both new energy power plants and areas with intensive new energy grid connection.

Description

Technical Field

[0001] The present invention relates to the field of automatic control for new energy grid connection in power systems, and particularly to a method for autonomously sensing the reactive voltage sensitivity at the grid connection point of a wind farm. Background Art

[0002] At present, the regional power grid adopts a hierarchical and graded automatic voltage control (AVC) system to achieve voltage control and optimization of the regional distribution network. The main station of the AVC system is deployed at the management main station, and the AVC sub-stations are deployed at substations and power plants. The AVC sub-stations obtain the bus voltages of substations and power plants, the switching signals of reactive power sources, and the reactive power source capacities through measuring devices by means of communication. The AVC main station aggregates the operating conditions of the voltage distribution of the regional distribution network, formulates the top-level reactive voltage optimization strategy in combination with power flow calculation, distributes the reactive power target values and operation strategies, and realizes the stable operation of the voltage of the regional distribution network. With the access of new energy power generation to the grid, corresponding capacity ratios of dynamic reactive power compensation sources and AVC sub-stations are built in new energy power stations, and they participate in the reactive voltage optimization of the grid together with traditional shunt capacitor banks.

[0003] With the continuous access of new energy power generation mainly based on wind power and photovoltaic power to the grid, the problem of voltage fluctuation in the local high-penetration new energy power grid is prominent. In particular, the problems of grid voltage over-limit and safe and stable operation caused by large-scale wind power grid connection are further highlighted. The traditional automatic voltage control (AVC) device with static configuration of control parameters does not have the function of sensing the change of grid operation state, and it is difficult to adapt to the complex working conditions of large fluctuations in new energy output and flexible operation modes of new power systems. Considering the voltage adaptive control of multiple wind farms in a wind power cluster has become an urgent technical requirement for accepting large-scale offshore wind power clusters. The traditional AVC system of new energy power stations cannot autonomously sense the change of the grid and cannot take into account both the adjustment speed and accuracy. Summary of the Invention

[0004] The present invention provides a method for autonomously sensing the reactive voltage sensitivity at the grid connection point of a wind farm, which can effectively solve the problems in the background art.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for autonomously sensing the reactive voltage sensitivity at the grid connection point of a wind farm includes the following steps:

[0007] Obtain the positive-sequence voltage, three-phase total active power, and three-phase total reactive power at the grid connection point;

[0008] Set up an operating condition construction module, a reactive voltage data window construction module, and a data screening module in the AVC sub-station system;

[0009] Obtain the steady-state operation data of the grid connection point of the wind farm according to the data screening module, and calculate the reactive voltage sensitivity sequence;

[0010] Iteratively update the calculated reactive voltage sensitivity sequence with the stored reactive voltage sensitivity sequence;

[0011] The AVC substation calculates the reactive power increment according to the current operating condition of the wind farm and the voltage control target and performs steady-state control;

[0012] Continue to iteratively update the reactive voltage sensitivity sequence calculated from the steady-state operation data obtained after the steady-state control of the AVC substation.

[0013] Furthermore, directly collect the three-phase voltage and current data on the secondary side of the grid connection point of the wind farm in real time, and calculate the real-time positive-sequence voltage U 1 , the three-phase total active power P PCC and the three-phase total reactive power Q PCC , where the sampling frequency is f s , and the calculation period is T.

[0014] Furthermore, set the reactive voltage sensitivity sequence SD 1 [N 1 in the operating condition construction module, where N 1 represents the number of operating condition intervals, and is specifically calculated using the following formula:

[0015] N 1 =P N / dP;

[0016] Among them, P N represents the rated grid connection capacity of the wind farm, and dP represents the operating condition interval size;

[0017] Set the reactive voltage data window QU[N 1 [N 2 in the reactive voltage data window construction module, where N 2 represents the size of the reactive voltage data window, and is specifically calculated using the following formula:

[0018] N 2 =(U H -U L ) / dU;

[0019] Among them, U H represents the upper limit value of the voltage control of the AVC substation, U L represents the lower limit value of the voltage control of the AVC substation, and dU represents the reactive voltage window size.

[0020] Further, the steady-state operation data of the grid connection point includes the positive-sequence voltage U of the grid connection point 1 and the reactive power Q PCC . When the grid connection point is in a steady state, the AVC substation does not operate, and the current positive-sequence voltage U 1 is within the upper and lower limits of the voltage control set by the AVC substation;

[0021] Storing the obtained steady-state operation data of the grid connection point in the corresponding reactive power-voltage data window includes the following steps:

[0022] Calculating the interval number j where the operating condition is located through the current active power P of the grid connection point PCC ;

[0023] Calculating the interval number j of the reactive power-voltage data window through the current positive-sequence voltage U of the grid connection point 1 ;

[0024] Storing the current steady-state operation data of the grid connection point in the corresponding reactive power-voltage data window, specifically using the following algorithm:

[0025]

[0026]

[0027] QU[i][j].U 1 = U 1 ,

[0028] QU[i][j].Q PCC = Q PCC .

[0029] Further, the calculation process of the reactive power-voltage sensitivity sequence includes the following steps:

[0030] Obtaining the fitting parameter sequence k 1 [N 2 from the reactive power-voltage data window QU[N N-1 , K N-2 ,......, K 1 , b through the polynomial fitting algorithm;

[0031] Storing the fitting parameter sequence k N-1 , K N-2 ,......, K 1 , b into the reactive power-voltage sensitivity sequence SD 1 [N 1 , and the specific storage method is as follows:

[0032]

[0033] where \(i = 0, 1, 2,\cdots, 9\).

[0034] Further, update the reactive power voltage sensitivity sequence \(SD 1 [N 1 and the stored reactive power voltage sensitivity sequence \(SD 0 [N 1 according to the weight algorithm, specifically using the following formula:

[0035] SD 0 [i].b=\(\alpha\times SD 0 [i].b+\(\beta\times SD 1 [i].b\(\vert i = 0, 1, 2,\cdots,N 1 -1,

[0036] SD 0 [i].k j =\(\alpha\times SD 0 [i].k j +\(\beta\times SD 1 [i].k j \(\vert i = 0, 1, 2,\cdots,N 1 -1; j = 0, 1, 2,\cdots,N 2-1 ;

[0037] where \(\alpha\) is the weight of the existing reactive power voltage sensitivity, \(\beta\) is the weight of the reactive power voltage sensitivity obtained during the training process, and the value ranges of \(\alpha\) and \(\beta\) weights are from 0 to 1. Set \(\alpha\gt\beta\) according to the principle that the existing reactive power voltage sensitivity weight is higher than the trained reactive power voltage sensitivity weight;

[0038] When the AVC substation is powered on for the first time, set the initial reactive power voltage sensitivity sequence \(SD 0 [N 1 according to the given parameters of the wind farm technical standard or the empirical values of on-site tests.

[0039] Further, when the AVC substation monitors that the positive sequence voltage at the grid connection point crosses the set voltage dead zone, select the corresponding reactive power voltage sensitivity sequence parameters according to the current operating condition \(P 0 , specifically using the following algorithm:

[0040]

[0041] Calculate the reactive power increment \(\Delta Q\) according to the current positive sequence voltage \(U 1 and the target voltage \(U t , specifically using the following algorithm:

[0042] \(\Delta U = U t -U 1 ,

[0043] ΔQ = k N-1 ×ΔU N-1 + k N-2 ×ΔU N-2 +...... + k 1 ×ΔU + b。

[0044] A reactive voltage sensitivity self - perception device at the grid connection point of a wind farm, using the above - mentioned method, includes:

[0045] A data acquisition unit, used to collect the three - phase voltage and current values on the secondary side of the grid connection point of the wind farm, and calculate the real - time positive - sequence voltage, three - phase total active power, and three - phase total reactive power;

[0046] A data processing unit, used to screen and merge the steady - state operation data of the grid connection point and store them, and calculate the reactive voltage sensitivity sequence under the current steady - state working condition according to the stored data;

[0047] An operating condition construction unit, used to iteratively update the newly obtained reactive voltage sensitivity sequence and the stored reactive voltage sensitivity sequence;

[0048] A regulation unit, used to calculate the reactive power increment according to the current operating condition and voltage control target and perform steady - state control.

[0049] A computer device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the above - mentioned method is implemented.

[0050] A storage medium stores a computer program, and when the computer program is executed by a processor, the above - mentioned method is implemented.

[0051] The beneficial effects of the present invention are:

[0052] Based on the dynamic change of voltage sensitivity in the existing reactive voltage control of wind farms and the differences in reactive voltage sensitivity under different working conditions, the present invention discloses a self - perception method for reactive voltage sensitivity at the grid connection point of a wind farm, which can track the reactive voltage sensitivity under different working conditions, and the polynomial fitting algorithm adopted improves the accuracy of reactive voltage sensitivity at the grid connection point of the wind farm;

[0053] The solution of the present invention can be upgraded in the existing AVC system, has good scalability, solves the problems of frequent voltage fluctuations caused by random wind power output and the reciprocating regulation problem caused by the fixed reactive voltage sensitivity parameters control of AVC. The adopted reactive voltage sensitivity sequence solves the problem of insufficient adaptability caused by the dynamic change of reactive voltage sensitivity in wind farms, and plays a promoting role in improving the power quality of wind power grid connection, and has good popularization significance. Description of the Drawings

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0055] Figure 1 It is a schematic flow diagram of the method for autonomously sensing the reactive power-voltage sensitivity at the grid connection point of the wind farm in the present invention;

[0056] Figure 2 It is a schematic diagram of the dynamic change of the reactive power-voltage sensitivity under different working conditions in the present invention. Specific embodiments

[0057] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0058] It should be noted that when an element is referred to as "fixed to" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation manner.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0060] The present invention discloses a method for autonomously sensing the reactive power-voltage sensitivity at the grid connection point of a wind farm, which relates to the field of automatic control of new energy grid connection in the power system. As Figure 1 shown, the process of autonomously sensing the reactive power-voltage sensitivity includes a training process and an application process. Among them, the training process involves reactive power-voltage measurement, data processing and reactive power-voltage sensitivity calculation, and the application process involves reactive power-voltage sensitivity update and reactive power-voltage sensitivity application.

[0061] Specifically, the method for autonomously perceiving the reactive power - voltage sensitivity at the grid - connection point of a wind farm includes the following steps: Obtain the positive - sequence voltage, three - phase total active power, and three - phase total reactive power at the grid - connection point; Set up an operating condition construction module, a reactive power - voltage data window construction module, and a data screening module in the AVC sub - station system; Obtain the steady - state operation data of the grid - connection point of the wind farm according to the data screening module, and calculate the reactive power - voltage sensitivity sequence; Iteratively update the calculated reactive power - voltage sensitivity sequence with the stored reactive power - voltage sensitivity sequence; The AVC sub - station calculates the reactive power increment according to the current operating condition of the wind farm and the voltage control target and performs steady - state control; Continue to iteratively update the reactive power - voltage sensitivity sequence calculated from the steady - state operation data obtained after the AVC sub - station's steady - state control.

[0062] The existing acquisition methods of the AVC sub - station include a communication acquisition method and a direct acquisition method. The communication acquisition method is more commonly used, but the data accuracy of the communication acquisition method is restricted by the measurement accuracy of the measurement and control device, and the acquisition accuracy is restricted by the communication delay.

[0063] Therefore, in the present invention, the three - phase voltage and current data on the secondary side of the grid - connection point of the wind farm are measured in real - time through the direct acquisition method, and the real - time positive - sequence voltage U 1 , three - phase total active power P PCC and three - phase total reactive power Q PCC of the grid - connection point are calculated. Among them, the sampling frequency is f s , and the calculation period is T. In this embodiment, the sampling frequency f s ≥2000Hz, and the calculation period is T≤5ms.

[0064] Furthermore, in the present invention, a reactive power - voltage sensitivity sequence SD 1 [N 1 is set in the operating condition construction module, where N 1 represents the number of operating condition intervals, and is specifically calculated using the following formula:

[0065] N 1 =P N / dP:

[0066] Among them, P N represents the rated grid - connection capacity of the wind farm, and dP represents the operating condition interval size; the larger dP is, the lower the accuracy of the reactive power - voltage sensitivity, but the shorter the time to obtain the reactive power - voltage sensitivity of the entire operating condition of the wind farm; the smaller dP is, the higher the accuracy of the reactive power - voltage sensitivity, but the longer the time to obtain the reactive power - voltage sensitivity of the entire operating condition of the wind farm. In this embodiment, P N =100MW, dP takes a value of 10MW, then N 1 =10.

[0067] Set the reactive power and voltage data window QU[N 1 [N 2 , where N 2 represents the size of the reactive power and voltage data window, and is specifically calculated using the following formula:

[0068] N 2 =(U H -U L ) / dU;

[0069] Among them, U H represents the upper limit value of the AVC substation voltage control, U L represents the lower limit value of the AVC substation voltage control, and dU represents the reactive power and voltage window size; the larger dU is, the smaller the calculation sample data of the reactive power and voltage sensitivity, and the lower the fitting accuracy of the reactive power and voltage sensitivity; the smaller dU is, the more calculation sample data of the reactive power and voltage sensitivity, and the higher the fitting accuracy of the reactive power and voltage sensitivity. In this embodiment, U H takes 235 kV, U L takes 222 kV, and dU takes 1 kV, then N 2 =13, and the created reactive power and voltage data window size is QU

[10]

[13] , occupying 130 floating-point memories.

[0070] Furthermore, in the present invention, the grid-connected point steady-state operation data includes the grid-connected point positive-sequence voltage U 1 and the reactive power Q PCC , when the AVC substation has no action at the grid-connected point steady state, and the current positive-sequence voltage U 1 is within the voltage control upper and lower limit values set by the AVC substation;

[0071] The obtained grid-connected point steady-state operation data is stored in the corresponding reactive power and voltage data window, including the following steps:

[0072] Calculate the interval number i where the operating condition is located through the grid-connected point current active power T PCC ;

[0073] Calculate the interval number j of the reactive power and voltage data window through the grid-connected point current positive-sequence voltage U 1 ;

[0074] Store the current grid-connected point steady-state operation data in the corresponding reactive power and voltage data window, and specifically use the following algorithm:

[0075]

[0076]

[0077] QU[i][j].U 1 =U 1 ,

[0078] QU[i][j].Q PCC = Q PCC 。

[0079] In this embodiment, the above calculation process is as follows:

[0080]

[0081]

[0082] QU[i][j].U 1 = U 1 ,

[0083] QU[i][j].Q PCC = Q PCC 。

[0084] Furthermore, in the present invention, the calculation process of the reactive power voltage sensitivity sequence includes the following steps:

[0085] The reactive power voltage data window QU[N 1 [N 2 is subjected to a polynomial fitting algorithm to obtain the fitting parameter sequence k N-1 , K N-2 ,......, K 1 , b; the more polynomial degrees are used, the higher the accuracy of the reactive power voltage sensitivity, but the greater the algorithm complexity, the higher the required processor performance, and the higher the hardware configuration requirements for the AVC substation; the fewer polynomial phases are used, the lower the accuracy of the reactive power voltage sensitivity, but the smaller the algorithm complexity, the lower the required processor performance, and the lower the hardware configuration requirements for the AVC substation. In this embodiment, taking the 3rd-degree polynomial fitting as an example, the fitting parameter sequence is K 2 , K 1 , b.

[0086] The fitting parameter sequence k N-1 , K N-2 ,......, K 1 , b is stored in the reactive power voltage sensitivity sequence SD 1 [N 1 , and the specific storage method is as follows:

[0087]

[0088] where i = 0, 1, 2,......, 9. In this embodiment, N 1 = 10.

[0089] The reactive power voltage sensitivity sequence SD 1 [N 1with the stored reactive voltage sensitivity sequence SD 0 [N 1 is updated according to the weight algorithm, and the following formula is specifically adopted:

[0090] SD 0 [i].b = α × SD 0 [i].b + β × SD 1 [i].b|i = 0, 1, 2,......N 1 -1,

[0091] SD 0 [i].k j = α × SD 0 [i].k j + β × SD 1 [i].k j |i = 0, 1, 2,......N 1 -1; j = 0, 1, 2,......N 2-1 ;

[0092] Among them, α is the existing reactive voltage sensitivity weight, β is the reactive voltage sensitivity weight obtained during the training process, and the value ranges of α and β weights are 0 to 1. According to the principle that the existing reactive voltage sensitivity weight is higher than the trained reactive voltage sensitivity weight, α > β is set. In this embodiment, α takes 0.7 and β takes 0.3.

[0093] When the AVC substation is powered on for the first time, the initial reactive voltage sensitivity sequence SD is set according to the given parameters of the wind farm technical standard or the empirical values of on-site tests 0 [N 1 . The SD 0 [N 1 has a memory function, and the given parameters of the technical standard or the empirical values of on-site tests are only valid when the AVC substation is powered on for the first time.

[0094] In the existing standard GB / T 40289-2021, it is clearly stipulated that the general value range of the reactive voltage sensitivity parameter is 2 to 15, and the typical value is 6. In this embodiment, the fitting parameter sequence is initialized as K 2 = 0, K 1 = 6, b = 0.

[0095] When the AVC substation monitors that the positive sequence voltage at the grid connection point crosses the set voltage dead zone, the corresponding reactive voltage sensitivity sequence parameters are selected according to the current operating condition P 0 Specifically, the following algorithm is adopted:

[0096]

[0097] According to the current positive sequence voltage U1 、Target voltage U t , calculate the reactive power increment ΔQ, and the specific algorithm is as follows:

[0098] ΔU = U t - U 1 ,

[0099] ΔQ = k N-1 ×ΔU N-1 + k N-2 ×ΔU N-2 +...... + k 1 ×ΔU + b.

[0100] According to the parameters set in this embodiment, the selection of the reactive power sensitivity parameters of the AVC substation during initialization is as follows:

[0101]

[0102] According to the current positive sequence voltage U 10 、Target voltage U t0 , calculate the reactive power increment ΔQ according to the following specific algorithm:

[0103] ΔU = U t0 - U 10 ,

[0104] ΔQ = k 10 ×ΔU = 6×ΔU;

[0105] The process of calculating the reactive power increment by the AVC substation during the above initialization is the same as that of the existing AVC substation. Under the same working condition P 0 , when the AVC substation completes one control, the reactive power-voltage parameter sequence of this working condition is updated to: K 21 , K 11 , b 1 , and the first reactive power-voltage sensitivity update is completed through weight calculation:

[0106]

[0107] The AVC substation calculates the reactive power increment ΔQ during the second control according to the current sequence voltage U 11 、Target voltage U t1 , as follows:

[0108] ΔU = U t1 - U 11 ,

[0109] ΔQ = k 2 ×ΔU 2 + k 1 ×ΔU + b = 0.3×k 21 + (0.3×k11 (+4.2)×ΔU + b 1 ;

[0110] After the AVC substation has been trained for W rounds, under the P 0 operating condition, the reactive power - voltage sensitivity sequence is trained to be K 2W , K 1W , b W . The AVC substation calculates the reactive power increment ΔQ according to the current sequence voltage U 1W and the target voltage U tW as follows:

[0111] ΔU = U tW - U 1W ,

[0112] ΔQ = k 2W ×ΔU 2 + k 1W ×ΔU + b w ;

[0113] Furthermore, the AVC substation trains, calculates, and updates the reactive power sensitivities for the operating conditions in N 1 according to the changes in the operating conditions of the wind farm. As shown in Figure 2 , the fitting curves of the reactive power - voltage sensitivities under the two operating conditions of operating condition i and j + 1.

[0114] Based on the same inventive concept, the embodiment of the present application also provides a device for autonomously sensing the reactive power - voltage sensitivity at the grid connection point of a wind farm, which can be used to implement the method described in the above - mentioned embodiment, as in the following embodiment. Since the principle of solving problems by the device for autonomously sensing the reactive power - voltage sensitivity at the grid connection point of a wind farm is similar to that of the method for autonomously sensing the reactive power - voltage sensitivity at the grid connection point of a wind farm, the implementation of the device for autonomously sensing the reactive power - voltage sensitivity at the grid connection point of a wind farm can refer to the implementation of the method for autonomously sensing the reactive power - voltage sensitivity at the grid connection point of a wind farm, and the repeated parts will not be elaborated. Hereinafter, the term "unit" or "module" may be a combination of software and / or hardware that can achieve a predetermined function. Although the systems described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0115] The embodiment of the present invention provides a device for autonomously sensing the reactive power - voltage sensitivity at the grid connection point of a wind farm, including:

[0116] A data acquisition unit, configured to collect the three - phase voltage and current values on the secondary side of the grid connection point of the wind farm, and calculate the real - time positive - sequence voltage, the total three - phase active power, and the total three - phase reactive power;

[0117] A data processing unit, configured to screen and merge the steady - state operation data of the grid connection point and store them, and calculate the reactive power - voltage sensitivity sequence under the current steady - state operating condition;

[0118] An operating condition construction unit for iteratively updating the newly obtained reactive power-voltage sensitivity sequence and the stored reactive power-voltage sensitivity sequence;

[0119] A regulation unit for calculating the reactive power increment according to the current operating condition and the voltage control target and performing steady-state control.

[0120] A computer device provided by an embodiment of the present application includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the above method is implemented.

[0121] An embodiment of the present application also provides a storage medium on which a computer program is stored. When the computer program is executed by a processor, the above method is implemented.

[0122] Among them, the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM for short), Electrically Erasable Programmable Read-Only Memory (EEPROM for short), Erasable Programmable Read Only Memory (EPROM for short), Programmable Red-Only Memory (PROM for short), Read-Only Memory (ROM for short), magnetic memory, flash memory, a magnetic disk or an optical disc.

[0123] In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. The meaning of "plurality" is two or more, unless otherwise specifically defined.

[0124] In the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0125] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0126] Any process or method description represented in a flowchart or described in other ways herein may be understood to represent a module, segment, or portion of code including one or more executable instructions for implementing a specific logical function or process, and the scope of the preferred embodiments of the present invention includes additional implementations, where the functions may be executed in a way that is not shown or discussed, including in a substantially simultaneous manner according to the functions involved or in a reverse order, which should be understood by those skilled in the art to which the embodiments of the present invention pertain.

[0127] The logic and / or steps represented in a flowchart or described in other ways herein, for example, can be considered as a sequenced list of executable instructions for implementing a logical function, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in connection with these instruction execution systems, apparatuses, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection portion having one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or, if necessary, other suitable processing, and then stored in a computer memory.

[0128] It should be understood that various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGAs), field programmable gate arrays (FPGAs), etc.

[0129] Those of ordinary skill in the art of this technology can understand that all or part of the steps carried by the method of the above embodiments can be completed by instructing relevant hardware through a program, and the said program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0130] The above-mentioned storage medium can be a read-only memory, a magnetic disk or an optical disc, etc. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

[0131] Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A method for autonomously sensing reactive voltage sensitivity at a wind farm grid connection point, characterized in that: The following steps are involved: Obtain the positive sequence voltage, three-phase total active power and three-phase total reactive power of the grid connection point; An operating condition building module, a reactive voltage data window building module and a data screening module are set in the AVC substation system; Obtaining the steady-state operation data of the wind farm grid connection point according to the data screening module, and calculating the reactive voltage sensitivity sequence; Iteratively updating the calculated reactive voltage sensitivity sequence and the stored reactive voltage sensitivity sequence; The AVC substation calculates reactive power increment and performs steady-state control according to the current operating conditions of the wind farm and the voltage control target; Continuing to iteratively update the reactive voltage sensitivity sequence calculated from the steady-state operation data obtained after the steady-state control of the AVC substation; The reactive voltage sensitivity sequence is set in the operating condition building module ,in Indicates the number of operating condition intervals, which is calculated using the following formula: ； in, Indicates the grid-connected rated capacity of the wind farm, Indicates the size of the operating condition interval; The reactive voltage data window is set in the reactive voltage data window construction module. ,in Indicates the size of the reactive voltage data window, which is calculated using the following formula: ； in, Indicates the upper limit of the voltage control of the AVC substation. Indicates the lower limit of the AVC substation voltage control. Indicates the reactive voltage window size; The grid-connected point steady-state operation data includes the grid-connected point positive sequence voltage and reactive power , when the grid connection point is in steady state, the AVC substation has no action, and the current positive sequence voltage It is within the voltage control upper and lower limits set by the AVC substation; Storing the obtained grid-connected point steady-state operation data in the corresponding reactive voltage data window comprises the following steps: The current active power at the grid connection point Calculate the interval number of the operating condition ; The positive sequence voltage at the grid connection point Calculate the interval number of the reactive voltage data window ; The current grid-connected point steady-state operation data is stored in the corresponding reactive voltage data window, specifically using the following algorithm: ， ， ， The calculation process of the reactive voltage sensitivity sequence comprises the following steps: The reactive voltage data window The fitting parameter sequence is obtained through the polynomial fitting algorithm ; The fitting parameter sequence The reactive voltage sensitivity sequence is stored in The specific storage method is as follows: ； in, .

2. The method for autonomously sensing reactive power voltage sensitivity of a wind farm grid connection point according to claim 1 is characterized in that: The three-phase voltage and current data of the secondary side of the wind farm grid connection point are measured in real time by direct acquisition, and the real-time positive sequence voltage of the grid connection point is calculated. , three-phase total active power And the three-phase total reactive power , where the sampling frequency is The calculation cycle is .

3. The method for autonomously sensing reactive power voltage sensitivity of a wind farm grid connection point according to claim 1, characterized in that: The reactive voltage sensitivity sequence With stored reactive voltage sensitivity sequence Update according to the weight algorithm, using the following formula: ， ； in, is the existing reactive voltage sensitivity weight, is the reactive voltage sensitivity weight obtained during the training process, and The value range of the weight is 0 to 1, and it is set according to the principle that the existing reactive voltage sensitivity weight is higher than the trained reactive voltage sensitivity weight. ; When the AVC substation is powered on for the first time, the initial reactive voltage sensitivity sequence is set according to the given parameters of the wind farm technical standards or the empirical values ​​of the field test. .

4. The method for autonomously sensing reactive voltage sensitivity of a wind farm grid connection point according to claim 3 is characterized in that: When the AVC substation detects that the positive sequence voltage at the grid connection point exceeds the set voltage dead zone, according to the current operating conditions Select the corresponding reactive voltage sensitivity sequence parameters, and use the following algorithm: ； According to the current positive sequence voltage , target voltage , calculate the reactive power increment , the specific algorithm is as follows: ， 。 5. An autonomous sensing device for reactive voltage sensitivity at a wind farm grid connection point, characterized in that: Using the method according to any one of claims 1 to 4, comprising: The data acquisition unit is used to collect the three-phase voltage and current values ​​on the secondary side of the wind farm grid connection point, and calculate the real-time positive sequence voltage, three-phase total active power and three-phase total reactive power; A data processing unit is used to screen and merge the steady-state operation data of the grid-connected point and store them, and calculate the reactive voltage sensitivity sequence under the current steady-state working condition based on the stored data; An operating condition construction unit, used for iteratively updating the newly obtained reactive voltage sensitivity sequence and the stored reactive voltage sensitivity sequence; The control unit is used to calculate the reactive power increment and perform steady-state control according to the current operating conditions and voltage control target.

6. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 4 is implemented.

7. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 4 is implemented.

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