Method and apparatus for evaluating frequency modulation capability

Abstract

The specification provides a primary frequency modulation capability evaluation method and device. The method comprises: determining the system frequency variation type based on the real-time voltage frequency of the wind farm grid connection point; determining the target frequency modulation standby power and target rotor kinetic energy of the matching wind turbine according to the system frequency variation type; determining the effective frequency modulation standby power of the wind farm according to the target frequency modulation standby power of the wind turbine; determining the effective utilization kinetic energy of the wind farm according to the target rotor kinetic energy of the wind turbine; calculating the standby power reliability parameter of the wind farm based on the wind speed variation amount, the effective frequency modulation standby power of the wind farm; and performing primary frequency modulation on the wind farm according to the effective frequency modulation standby power of the wind farm, the effective utilization kinetic energy of the wind farm, and the standby power reliability parameter of the wind farm. The above method can solve the problem that the existing method cannot accurately evaluate the primary frequency modulation capability of the wind farm from the time and space dimensions.

Description

Technical Field

[0001] This manual pertains to the field of wind power generation technology, and in particular relates to a method and apparatus for evaluating primary frequency regulation capability. Background Technology

[0002] In recent years, the rapid development of new energy power generation technologies has continuously squeezed the space occupied by conventional hydropower and thermal power units, resulting in significant changes to the power supply structure. Consequently, the primary frequency regulation response resources available to the power grid based on conventional hydropower and thermal power units are gradually decreasing. At the same time, when new energy generating units reach their maximum daily output, the entire grid's thermal power or hydropower units are operating at deep peak shaving capacity, unable to provide the capability for subsequent primary frequency regulation, further increasing the frequency security risks to the power grid. Therefore, the need for new energy generating units to participate in the primary frequency regulation of the power grid is becoming increasingly urgent.

[0003] New energy generator sets can specifically include wind turbines and photovoltaic units. Currently, wind turbines participate in grid frequency regulation through various mechanisms, which can be categorized into rotor kinetic energy control (including virtual inertia control, droop control, and integrated inertia control) and power reserve control (including pitch angle control and rotor overspeed control). Rotor kinetic energy control of wind turbines involves introducing an auxiliary frequency regulation component into the active power control system, enabling a temporary conversion between the turbine rotor's kinetic energy and output power. However, rotor kinetic energy control can only provide short-term support for the system frequency and cannot reduce the steady-state frequency deviation. To achieve true primary frequency regulation, wind turbines must reserve power during steady-state operation. While conventional rotor overspeed control can reserve power, it typically only performs spatial calculations from the perspective of the wind turbine rotor kinetic energy, making it difficult to accurately assess the primary frequency regulation capability of a wind farm.

[0004] Therefore, there is an urgent need for a method that can accurately assess the primary frequency regulation capability of wind farms by comprehensively considering both time and space dimensions. Summary of the Invention

[0005] This specification provides a method and apparatus for evaluating primary frequency regulation capability, which can solve the problem that existing methods cannot accurately evaluate the primary frequency regulation capability of wind farms from both time and space dimensions, so as to achieve accurate and efficient primary frequency regulation of wind farms.

[0006] The purpose of the embodiments in this specification is to provide a method for evaluating primary frequency modulation capability, including:

[0007] Based on the real-time voltage frequency at the wind farm's grid connection point, determine the type of system frequency change.

[0008] Based on the type of system frequency change, determine the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine units;

[0009] Based on the target frequency regulation reserve power of the wind turbine generators, determine the effective frequency regulation reserve power of the wind farm; based on the target rotor kinetic energy of the wind turbine generators, determine the effective utilization kinetic energy of the wind farm.

[0010] Based on wind speed variation and the effective frequency regulation reserve power of the wind farm, calculate the reserve power reliability parameters of the wind farm.

[0011] Based on the wind farm's effective frequency regulation reserve power, effective utilization kinetic energy, and reserve power reliability parameters, the wind farm is subjected to primary frequency regulation.

[0012] Furthermore, in another embodiment of the method, determining the system frequency change type based on the real-time voltage frequency at the wind farm grid connection point includes:

[0013] Calculate the difference between the real-time voltage frequency at the grid connection point of the wind farm and the reference voltage frequency at the grid connection point of the wind farm;

[0014] Check if the difference is greater than the upper limit of the frequency change dead zone; if it is determined that the difference is greater than the upper limit of the frequency change dead zone, determine that the system frequency change type is a system frequency increase.

[0015] Check if the difference is less than the lower limit of the frequency change dead zone; if the difference is determined to be less than the lower limit of the frequency change dead zone, determine the system frequency change type as a system frequency decrease.

[0016] Furthermore, in another embodiment of the method, determining the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine based on the system frequency change type includes:

[0017] When the system frequency change type is determined to be a system frequency decrease, the releaseable frequency regulation reserve power and releaseable rotor kinetic energy of the wind turbine are calculated as the target frequency regulation reserve power and target rotor kinetic energy.

[0018] When the system frequency change type is determined to be a system frequency rise, the absorbable frequency regulation reserve power and absorbable rotor kinetic energy of the wind turbine are calculated as the target frequency regulation reserve power and target rotor kinetic energy.

[0019] Furthermore, in another embodiment of the method, when determining that the system frequency change type is a system frequency decrease, calculating the releaseable frequency regulation reserve power and releaseable rotor kinetic energy of the wind turbine includes:

[0020] When the system frequency change type is determined to be a decrease in system frequency, the nodal wind speeds in the decrease state wind speed range are determined.

[0021] Based on the nodal wind speeds within the descending wind speed range, the descending wind speed range is obtained;

[0022] Based on the decreasing wind speed range, calculate the releaseable frequency-regulating reserve power and releaseable rotor kinetic energy of the wind turbine.

[0023] Furthermore, in another embodiment of the method, determining the nodal wind speed within the descending wind speed range includes:

[0024] Based on the wind turbine operating data, the wind turbine parameters are obtained;

[0025] Based on the wind turbine parameters, the first optimal tip speed ratio is calculated;

[0026] The maximum wind energy utilization coefficient is obtained based on the first optimal tip speed ratio;

[0027] Determine the first wind energy utilization factor after the wind turbine is unloaded based on the maximum wind energy utilization factor;

[0028] The first tip speed ratio of the wind turbine after load reduction is determined based on the first wind energy utilization coefficient of the wind turbine after load reduction.

[0029] Based on the first optimal tip speed ratio and the first tip speed ratio after the wind turbine is unloaded, calculate the nodal wind speed in the descent wind speed range.

[0030] Furthermore, in another embodiment of the method, when determining that the system frequency change type is a system frequency rise, calculating the absorbable frequency regulation reserve power and absorbable rotor kinetic energy of the wind turbine includes:

[0031] When the system frequency change type is determined to be an upward trend, the nodal wind speeds in the upward trend wind speed range are determined.

[0032] Based on the nodal wind speeds within the updraft wind speed range, the updraft wind speed range is obtained.

[0033] Based on the wind speed range during the rising state, calculate the absorbable frequency regulation reserve power and absorbable rotor kinetic energy of the wind turbine.

[0034] Furthermore, in another embodiment of the method, determining the nodal wind speed within the updraft wind speed range includes:

[0035] Determine the second wind energy utilization factor after wind turbine unloading based on the maximum wind energy utilization factor;

[0036] The second tip speed ratio of the wind turbine after unloading is determined based on the second wind energy utilization coefficient after unloading.

[0037] Calculate the wind speed at the fourth node based on the tip speed ratio of the second blade after the wind turbine is unloaded;

[0038] Based on the wind speed at the fourth node and the node wind speeds in the descending wind speed range, determine the node wind speeds in the ascending wind speed range.

[0039] Furthermore, in another embodiment of the method, the calculation of the wind farm's reserve power reliability parameters based on wind speed variation and the wind farm's effective frequency regulation reserve power includes:

[0040] Based on the wind speed change, determine the joint probability density model of wind speed and wind speed change.

[0041] The wind speed fluctuation is obtained based on the joint probability density model of wind speed and wind speed change.

[0042] Wind speed is obtained based on the amount of wind speed fluctuation;

[0043] Calculate the reliability parameters of the wind farm's reserve power based on wind speed and the wind farm's effective frequency regulation reserve power.

[0044] On the other hand, this application provides a primary frequency modulation capability evaluation device, comprising:

[0045] The detection module is used to determine the type of system frequency change based on the real-time voltage frequency at the wind farm's grid connection point;

[0046] The first calculation module is used to determine the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine based on the type of system frequency change.

[0047] The second calculation module is used to determine the effective frequency regulation reserve power of the wind farm based on the target frequency regulation reserve power of the wind turbine; and to determine the effective utilization kinetic energy of the wind farm based on the target rotor kinetic energy of the wind turbine.

[0048] The third calculation module is used to calculate the reliability parameters of the wind farm's reserve power based on wind speed changes and the wind farm's effective frequency regulation reserve power.

[0049] The primary frequency regulation module is used to perform primary frequency regulation on the wind farm based on the wind farm's effective frequency regulation reserve power, the wind farm's effective utilization kinetic energy, and the wind farm's reserve power reliability parameters.

[0050] In another aspect, this application also provides a computer-readable storage medium storing computer instructions thereon, wherein the computer-readable storage medium implements the above-described primary frequency modulation capability assessment method when executing the instructions.

[0051] This specification provides a method and apparatus for assessing primary frequency regulation capability. It determines the system frequency variation type based on the real-time voltage and frequency at the wind farm's grid connection point; determines the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine generators based on the system frequency variation type; determines the effective frequency regulation reserve power of the wind farm based on the target frequency regulation reserve power of the wind turbine generators; determines the effective utilization kinetic energy of the wind farm based on the target rotor kinetic energy of the wind turbine generators; calculates the reserve power reliability parameters of the wind farm based on wind speed variation and the effective frequency regulation reserve power of the wind farm; and performs primary frequency regulation on the wind farm based on the effective frequency regulation reserve power, the effective utilization kinetic energy of the wind farm, and the reserve power reliability parameters of the wind farm.

[0052] Furthermore, when determining the system frequency change type based on the real-time voltage frequency at the wind farm's grid connection point, the difference between the real-time voltage frequency at the wind farm's grid connection point and the voltage reference frequency at the wind farm's grid connection point is calculated; it is then checked whether this difference is greater than the upper limit of the frequency change dead zone; if it is determined that the difference is greater than the upper limit of the frequency change dead zone, the system frequency change type is determined to be a system frequency increase; next, it is checked whether this difference is less than the lower limit of the frequency change dead zone; if it is determined that the difference is less than the lower limit of the frequency change dead zone, the system frequency change type is determined to be a system frequency decrease.

[0053] Furthermore, when determining the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine based on the system frequency change type, if the system frequency change type is determined to be a system frequency decrease, the releaseable frequency regulation reserve power and releaseable rotor kinetic energy of the wind turbine are calculated as the target frequency regulation reserve power and target rotor kinetic energy; if the system frequency change type is determined to be a system frequency increase, the absorbable frequency regulation reserve power and absorbable rotor kinetic energy of the wind turbine are calculated as the target frequency regulation reserve power and target rotor kinetic energy. Attached Figure Description

[0054] To more clearly illustrate the embodiments of this specification, the accompanying drawings used in the embodiments will be briefly introduced below. The drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a flowchart illustrating an embodiment of a primary frequency modulation capability evaluation method provided in this specification;

[0056] Figure 2 This is a schematic diagram of the wind turbine operating status in one embodiment of this specification when the system frequency change type is determined to be a system frequency decrease.

[0057] Figure 3This is a schematic diagram of the wind turbine operating state in one embodiment of this specification when the system frequency change type is determined to be a system frequency rise.

[0058] Figure 4 This is a schematic diagram of the module structure of one embodiment of a primary frequency modulation capability evaluation device provided in this specification;

[0059] Figure 5 This is a schematic diagram of the structural composition of a server provided in this manual. Detailed Implementation

[0060] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0061] Based on the mechanism of wind turbine participation in grid frequency regulation, the methods can be divided into rotor kinetic energy control and power reserve control (including pitch angle control and rotor overspeed control). Rotor kinetic energy control of wind turbines involves introducing an auxiliary frequency regulation stage into the active power control system of the wind turbine, enabling a brief conversion between the rotor's kinetic energy and output power. However, rotor kinetic energy control can only provide short-term support for the system frequency and cannot reduce the steady-state frequency deviation. To achieve true primary frequency regulation, wind turbines must reserve power during steady-state operation.

[0062] Furthermore, it is also considered that although conventional rotor overspeed control can reserve backup power, it usually only performs a single spatial calculation from the perspective of the rotor kinetic energy of the wind turbine, making it difficult to accurately assess the primary frequency regulation capability of the wind farm.

[0063] In view of the above-mentioned problems of existing methods and the specific reasons for these problems, this application considers to accurately assess the primary frequency regulation capability of wind farms from both time and space dimensions, so as to achieve accurate and efficient primary frequency regulation control of wind farms.

[0064] Based on the above approach, this specification proposes a method for assessing primary frequency regulation capability. First, based on the real-time voltage frequency at the wind farm's grid connection point, the type of system frequency variation is determined. Then, based on the type of system frequency variation, the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine units are determined. Next, based on the target frequency regulation reserve power of the wind turbine units, the effective frequency regulation reserve power of the wind farm is determined. Based on the target rotor kinetic energy of the wind turbine units, the effective utilization kinetic energy of the wind farm is determined. Based on wind speed variations and the effective frequency regulation reserve power of the wind farm, the reserve power reliability parameters of the wind farm are calculated. Finally, based on the effective frequency regulation reserve power, the effective utilization kinetic energy, and the reserve power reliability parameters of the wind farm, primary frequency regulation of the wind farm is performed.

[0065] See Figure 1 As shown in the embodiments of this specification, a method for evaluating primary frequency modulation capability is provided. In specific implementation, this method may include the following:

[0066] S101: Determine the type of system frequency change based on the real-time voltage frequency at the wind farm's grid connection point.

[0067] In some embodiments, the above-mentioned determination of the system frequency change type based on the real-time voltage frequency at the wind farm grid connection point may specifically include:

[0068] S1: Calculate the difference between the real-time voltage frequency at the grid connection point of the wind farm and the reference voltage frequency at the grid connection point of the wind farm;

[0069] S2: Detect whether the difference is greater than the upper limit of the frequency change dead zone; if it is determined that the difference is greater than the upper limit of the frequency change dead zone, determine that the system frequency change type is a system frequency increase.

[0070] S3: Detect whether the difference is less than the lower limit of the frequency change dead zone; if the difference is determined to be less than the lower limit of the frequency change dead zone, determine the system frequency change type as a system frequency decrease.

[0071] In some embodiments, the aforementioned frequency change dead zone specifically refers to the frequency difference set to prevent unnecessary operation of the turbine control valve when the grid frequency difference changes within a small range. When the difference between the real-time voltage frequency at the wind farm grid connection point and the voltage reference frequency at the wind farm grid connection point is within the frequency change dead zone range, primary frequency regulation of the wind farm is not required.

[0072] Based on the above embodiments, the system frequency change type is divided into rising state and falling state, and the effective frequency regulation reserve power and rotor kinetic energy that the generator set can absorb or release can be calculated separately under different system frequency change types; and the phenomenon of wind turbine sets frequently participating in primary frequency regulation when the system frequency change is small is avoided.

[0073] S102: Determine the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine based on the type of system frequency change.

[0074] In some embodiments, a wind farm includes multiple wind turbine units as described above, which are used for wind power generation.

[0075] In some embodiments, determining the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine based on the system frequency change type may, in specific implementation, include:

[0076] S1: When the system frequency change type is determined to be a system frequency decrease, calculate the releaseable frequency regulation reserve power and releaseable rotor kinetic energy of the wind turbine, and use them as the target frequency regulation reserve power and target rotor kinetic energy.

[0077] S2: When the system frequency change type is determined to be a system frequency rise, calculate the absorbable frequency regulation reserve power and absorbable rotor kinetic energy of the wind turbine, and use them as the target frequency regulation reserve power and target rotor kinetic energy.

[0078] In some embodiments, when determining that the system frequency change type is a system frequency decrease, calculating the releaseable frequency regulation reserve power and releaseable rotor kinetic energy of the wind turbine can, in specific implementation, include:

[0079] S1: When the system frequency change type is determined to be a decrease in system frequency, determine the nodal wind speed in the decrease state wind speed range;

[0080] S2: Based on the nodal wind speeds of the descending wind speed range, the descending wind speed range is obtained;

[0081] S3: Based on the wind speed range during the descent state, calculate the releaseable frequency-regulating reserve power and releaseable rotor kinetic energy of the wind turbine.

[0082] In some embodiments, the nodal wind speeds for determining the descending wind speed range described above may, in specific implementation, include:

[0083] S1: Obtain wind turbine parameters based on wind turbine operating data;

[0084] S2: Calculate the first optimal tip speed ratio based on wind turbine parameters;

[0085] S3: Obtain the maximum wind energy utilization coefficient based on the first optimal tip speed ratio;

[0086] S4: Determine the first wind energy utilization factor after the wind turbine is unloaded based on the maximum wind energy utilization factor;

[0087] S5: Determine the first tip speed ratio of the wind turbine after load reduction based on the first wind energy utilization coefficient of the wind turbine after load reduction;

[0088] S6: Calculate the nodal wind speed in the descent wind speed range based on the first optimal tip speed ratio and the first tip speed ratio after the wind turbine is unloaded.

[0089] In some embodiments, the aforementioned wind turbine operating data may specifically include wind speed, blade pitch angle, rotor radius, rotor speed, motor speed, and motor output power.

[0090] In some embodiments, the method for obtaining wind turbine parameters described above can be implemented using the least squares method. Other methods can also be used to calculate wind turbine parameters in the embodiments of this specification, and no limitation is made thereto.

[0091] In some embodiments, the node wind speeds in the aforementioned descending wind speed range may specifically include: the cut-in wind speed, the first node wind speed, the second node wind speed, and the third node wind speed.

[0092] In some embodiments, the calculation of the first optimal tip speed ratio based on wind turbine parameters may, in specific implementation, include:

[0093] The maximum value of formula (1) is taken as the first optimal tip speed ratio:

[0094]

[0095]

[0096] Where c1~c8 are wind turbine parameters, β is the blade pitch angle, Λ is an intermediate parameter, λ is the tip speed ratio, and C P This is the wind energy utilization coefficient.

[0097] In some embodiments, obtaining the maximum wind energy utilization coefficient based on the first optimal tip speed ratio can, in specific implementation, include: obtaining the maximum wind energy utilization coefficient based on the first optimal tip speed ratio and formula (1); wherein, the first optimal tip speed ratio can be denoted as λ. opt The maximum wind energy utilization coefficient can be denoted as C. P_max .

[0098] In some embodiments, determining the first wind energy utilization factor after load reduction of the wind turbine based on the maximum wind energy utilization factor may specifically include:

[0099] Calculate the first wind energy utilization coefficient of the wind turbine after load reduction using the following formula:

[0100] C P_DEL =(1-d%)C P_max (3)

[0101] Where d% represents the percentage of power reduction of the wind turbine, and C P_DEI This represents the first wind energy utilization coefficient.

[0102] In some embodiments, the determination of the first tip speed ratio of the wind turbine after load reduction based on the first wind energy utilization coefficient after load reduction can, in specific implementation, include: calculating the first tip speed ratio according to formula (1) and the first wind energy utilization coefficient after load reduction of the wind turbine; wherein, the first tip speed ratio can be denoted as λ. DEL .

[0103] In some embodiments, the calculation of the nodal wind speed in the descending wind speed range based on the first optimal tip speed ratio and the first tip speed ratio of the wind turbine after load reduction may, in specific implementation, include:

[0104] Calculate the nodal wind speeds in the descending wind speed range using the following formula:

[0105]

[0106] Where v1 is the wind speed at the first node, v2 is the wind speed at the second node, v3 is the wind speed at the third node, and w min This indicates the minimum speed limit for primary frequency regulation of the wind turbine, where R represents the rotor radius, and w N This indicates the rated speed limit for primary frequency regulation of the wind turbine.

[0107] In some embodiments, the first node wind speed represents the wind speed corresponding to the minimum speed limit of the wind turbine's primary frequency regulation when the power-speed curve of the wind turbine is reduced by d%; the second node wind speed represents the wind speed corresponding to the minimum speed limit of the wind turbine's primary frequency regulation when the maximum wind energy tracking curve of the wind turbine is affected; and the third node wind speed represents the wind speed corresponding to the rated speed of the wind turbine when the power-speed curve of the wind turbine is reduced by d%. The power-speed curve of the wind turbine after reducing its load by d% can be denoted as P. DEL The maximum wind energy tracking curve of the wind turbine can be denoted as P. MPPT .

[0108] In some embodiments, the aforementioned descent wind speed range may specifically include: a first entry zone, a first low wind speed zone, a first medium wind speed zone, and a first high wind speed zone.

[0109] In some embodiments, the above-mentioned method of obtaining the descending wind speed range based on the nodal wind speeds within the descending wind speed range may, in specific implementation, include:

[0110] S1: The first entry zone is obtained based on the wind speed of the wind turbine and the wind speed at the first node;

[0111] S2: Based on the wind speed at the first node and the wind speed at the second node, the first low wind speed zone is obtained;

[0112] S3: Based on the wind speed at the second node and the wind speed at the third node, the first medium wind speed zone is obtained;

[0113] S4: Based on the wind speed at the third node and the rated wind speed of the wind turbine, the first high wind speed zone is obtained.

[0114] In some embodiments, the cut-in wind speed and rated wind speed of the wind turbine can be determined based on the background data of the wind farm.

[0115] In some embodiments, the cut-in wind speed of the aforementioned wind turbine can be denoted as v. cut_in The rated wind speed of the aforementioned wind turbine can be denoted as v. N The range of the first entry zone mentioned above can be denoted as [v cut_in The range of the first low wind speed zone can be denoted as [v1, v2]; the range of the first medium wind speed zone can be denoted as [v2, v3]; the range of the first high wind speed zone can be denoted as [v3, v1]; N ].

[0116] In some embodiments, the calculation of the releaseable frequency-regulating reserve power and releaseable rotor kinetic energy of the wind turbine based on the decreasing wind speed range may, in specific implementation, include:

[0117] Calculate the releaseable frequency-regulating reserve power of wind turbines in the first low-wind-speed zone using the following formula:

[0118]

[0119] Where n1 represents the number of wind turbines in the first low wind speed zone, i represents the wind turbine number, and v i C represents the wind speed at the hub of the i-th wind turbine in the first low-wind-speed zone. P_i_1 P represents the wind energy utilization coefficient of the i-th wind turbine in the first low wind speed zone. MPPT_i_1 ΔP represents the maximum wind energy tracking curve value of the i-th wind turbine in the first low wind speed zone. i_1 Let f1 represent the releaseable frequency-regulating reserve power of the i-th wind turbine in the first low wind speed zone, and let f1 represent the functional relationship between wind speed, wind energy utilization coefficient, and minimum speed limit for primary frequency regulation.

[0120] Calculate the releaseable rotor kinetic energy of the wind turbine in the first low-wind-speed zone using the following formula:

[0121]

[0122] Where, ΔE K_i_1 Let J represent the releaseable rotor kinetic energy of the i-th wind turbine in the first low wind speed zone, and let w represent the moment of inertia of the wind turbine. i_1This represents the rotational speed of the i-th wind turbine in the first low wind speed zone.

[0123] Calculate the releaseable frequency-regulating reserve power of wind turbines in the first medium wind speed zone using the following formula:

[0124] ΔP i_2 =d%×P MPPT_i_2 (i = 1, 2, ..., n²) (7)

[0125] Where n2 represents the number of wind turbines in the first wind speed zone, ΔP i_2 P represents the releaseable frequency-regulating reserve power of the i-th wind turbine in the first medium wind speed zone. MPPT_i_2 This represents the maximum wind energy tracking curve value of the i-th wind turbine in the first medium wind speed zone.

[0126] Calculate the releaseable rotor kinetic energy of the wind turbine in the first medium wind speed zone using the following formula:

[0127]

[0128] Where, ΔE K_i_2 Let w represent the releaseable rotor kinetic energy of the i-th wind turbine in the first medium wind speed zone. i_2 Let w represent the rotational speed of the i-th wind turbine in the first medium wind speed zone. opt This indicates the optimal speed of the wind turbine.

[0129] Calculate the releaseable frequency-regulating reserve power of wind turbines in the first high-wind-speed zone using the following formula:

[0130]

[0131] Where n3 represents the number of wind turbines in the first high wind speed zone, w max Indicates the maximum speed limit of a wind turbine under primary frequency regulation, C P_i_3 P represents the wind energy utilization coefficient of the i-th wind turbine in the first high wind speed zone. MPPT_i_3 ΔP represents the maximum wind energy tracking curve value of the i-th wind turbine in the first high wind speed zone. i_3 f1 represents the releaseable frequency-regulating reserve power of the i-th wind turbine in the first high wind speed zone, and f2 represents the functional relationship between wind speed, wind energy utilization coefficient, and the maximum speed limit of primary frequency regulation.

[0132] Calculate the releaseable rotor kinetic energy of the wind turbine in the first high wind speed zone using the following formula:

[0133]

[0134] Where, ΔE K_i_3 This represents the releaseable rotor kinetic energy of the i-th wind turbine in the first high wind speed zone.

[0135] In some embodiments, wind turbines operating in the first cut-in zone operate in maximum wind energy tracking mode and therefore do not participate in the primary frequency regulation of the wind farm; when the speed of wind turbines operating in the first low wind speed zone decreases to the minimum speed limit for primary frequency regulation, they no longer generate additional active power and the speed is no longer reduced; when wind turbines operating in the first medium wind speed zone maximize the mechanical power input of the generator and the rotor speed decreases to the optimal speed, they no longer reduce the rotor speed; the load reduction capacity of wind turbines operating in the first high wind speed zone is determined by the rated speed and wind speed of the wind turbine.

[0136] In some embodiments, when determining that the system frequency change type is a system frequency rise, calculating the absorbable frequency regulation reserve power and absorbable rotor kinetic energy of the wind turbine can specifically include:

[0137] S1: When the system frequency change type is determined to be an increase in system frequency, determine the nodal wind speed in the wind speed range of the increase state;

[0138] S2: Based on the nodal wind speeds of the rising wind speed range, the rising wind speed range is obtained.

[0139] S3: Based on the wind speed range in the rising state, calculate the absorbable frequency regulation reserve power and absorbable rotor kinetic energy of the wind turbine.

[0140] In some embodiments, the aforementioned rising wind speed range may specifically include: a second entry zone, a second low wind speed zone, and a second medium wind speed zone.

[0141] In some embodiments, the nodal wind speeds for determining the updraft wind speed range described above may, in specific implementation, include:

[0142] S1: Determine the second wind energy utilization coefficient after the wind turbine is unloaded based on the maximum wind energy utilization coefficient;

[0143] S2: Determine the second tip speed ratio of the wind turbine after unloading based on the second wind energy utilization coefficient after unloading;

[0144] S3: Calculate the wind speed at the fourth node based on the tip speed ratio of the second blade after the wind turbine is unloaded;

[0145] S4: Determine the node wind speed in the rising state based on the fourth node wind speed and the node wind speed in the falling state wind speed range.

[0146] In some embodiments, determining the second wind energy utilization coefficient after wind turbine unloading based on the maximum wind energy utilization coefficient may, in specific implementation, include:

[0147] Calculate the second wind energy utilization coefficient after wind turbine unloading using the following formula:

[0148] C P_DEL' =(1-2d%)C P_max (11)

[0149] Where 2d% represents the percentage of power reduction of the wind turbine, C P_DEL' This represents the second wind energy utilization coefficient.

[0150] In some embodiments, determining the second tip speed ratio of the wind turbine after load reduction based on the second wind energy utilization coefficient after turbine load reduction may, in specific implementations, include:

[0151] Calculate the tip speed ratio of the second blade using the following formula:

[0152] C P_DEL' =f3(λ DEL′ (12)

[0153] Where, λ DEL′ f3 represents the tip speed ratio of the second blade and the functional relationship between the tip speed ratio of the second blade and the second wind energy utilization coefficient.

[0154] In some embodiments, the calculation of the fourth node wind speed based on the second blade tip speed ratio after wind turbine unloading may, in specific implementation, include:

[0155] Calculate the wind speed at the fourth node using the following formula:

[0156]

[0157] Here, v4 represents the wind speed at the fourth node.

[0158] In some embodiments, the fourth node wind speed represents the wind speed at the rated speed of the wind turbine corresponding to the operating curve of the wind turbine after a 2d% load reduction; wherein, the operating curve of the wind turbine after a 2d% load reduction can be denoted as P. DEL' .

[0159] In some embodiments, the node wind speeds in the aforementioned rising wind speed range may specifically include: the cut-in wind speed, the first node wind speed, the third node wind speed, and the fourth node wind speed.

[0160] In some embodiments, the above-mentioned method of obtaining the upswing wind speed range based on the nodal wind speed of the upswing wind speed range may, in specific implementation, include:

[0161] S1: The second entry zone is obtained based on the wind turbine's entry wind speed and the first node wind speed;

[0162] S2: Based on the wind speed at the first node and the wind speed at the fourth node, the second low wind speed zone is obtained;

[0163] S3: Based on the wind speed at the fourth node and the wind speed at the third node, the second medium wind speed zone is obtained.

[0164] In some embodiments, the range of the second entry area described above can be denoted as [v cut_in The range of the second low wind speed zone can be denoted as [v1, v4]; the range of the second medium wind speed zone can be denoted as [v4, v3].

[0165] In some embodiments, the calculation of the absorbable frequency-regulating reserve power and absorbable rotor kinetic energy of the wind turbine based on the rising wind speed range may, in specific implementation, include:

[0166] Calculate the absorbable frequency-regulating reserve power of wind turbines in the second low-wind-speed zone using the following formula:

[0167] ΔP i_4 =d%×P MPPT_i_4 (i = 1, 2, ..., n4) (14)

[0168] Where, ΔP i_4 P represents the absorbable frequency-regulating reserve power of the i-th wind turbine in the second low-wind-speed zone, n4 represents the number of wind turbines in the second low-wind-speed zone, and P represents the number of wind turbines in the second low-wind-speed zone. MPPT_i_4 This represents the maximum wind energy tracking curve value of the i-th wind turbine in the second low wind speed zone.

[0169] Calculate the absorbable rotor kinetic energy of the wind turbine in the second low wind speed zone using the following formula:

[0170]

[0171] Where, ΔE k_i_4 w represents the absorbable rotor kinetic energy of the i-th wind turbine in the second low wind speed zone. del The rotational speed before rotor acceleration is represented by w. del' This indicates the rotational speed of the rotor after acceleration.

[0172] Calculate the absorbable frequency-regulating reserve power of wind turbines in the second wind speed zone using the following formula:

[0173]

[0174] Where n5 represents the number of wind turbines in the second wind speed zone, f4 represents the functional relationship between wind speed, primary frequency regulation rated speed limit, and wind energy utilization coefficient, and C P_i_5 P represents the wind energy utilization coefficient of the i-th wind turbine in the second wind speed zone. MPPT_i_5 ΔP represents the maximum wind energy tracking curve value of the i-th wind turbine in the second wind speed zone. i_5 This represents the absorbable frequency-regulating reserve power of the i-th wind turbine in the second medium wind speed zone.

[0175] Calculate the absorbable rotor kinetic energy of the wind turbine in the second wind speed zone using the following formula:

[0176]

[0177] Where, ΔE k_i_5 This represents the absorbable rotor kinetic energy of the i-th wind turbine in the second medium wind speed zone.

[0178] In some embodiments, wind turbines operating in the second cut-in zone operate in maximum wind energy tracking mode and therefore do not participate in the primary frequency regulation of the system; wind turbines operating in the second low wind speed zone have their load reduction power changed from d% to 2d, and the rotor speed changes from the speed before acceleration to the speed after acceleration, which reduces the input mechanical power of the wind turbine while increasing the rotor kinetic energy to support the rise in system frequency; wind turbines operating in the second medium wind speed zone cannot continue to reduce the load by d% when the operating point is transferred, and the amount of power that can be reduced is determined by the wind speed and the maximum rotor speed.

[0179] Based on the above embodiments, the operating states of wind turbines with different system frequency change types can be divided from a spatial perspective, resulting in multiple wind speed ranges, as well as the target frequency regulation reserve power and target rotor kinetic energy of the wind turbines corresponding to the multiple wind speed ranges.

[0180] S103: Determine the effective frequency regulation reserve power of the wind farm based on the target frequency regulation reserve power of the wind turbine generator; determine the effective utilization kinetic energy of the wind farm based on the target rotor kinetic energy of the wind turbine generator.

[0181] In some embodiments, determining the effective frequency regulation reserve power of the wind farm based on the target frequency regulation reserve power of the wind turbine generators may, in specific implementations, include:

[0182] When the system frequency change is determined to be a system frequency decrease, the effective frequency regulation reserve power of the wind farm is calculated according to the following formula:

[0183]

[0184] Where j represents the wind farm number, This represents the effective frequency regulation reserve power that wind farm j can generate.

[0185] When the system frequency change type is determined to be a system frequency rise, the effective frequency regulation reserve power of the wind farm is calculated according to the following formula:

[0186]

[0187] in, This represents the effective frequency regulation reserve power that wind farm j can generate.

[0188] Calculate the effective frequency regulation reserve power of a wind farm using the following formula:

[0189]

[0190] Where, ΔP WP_j This represents the effective frequency regulation reserve power of wind farm j.

[0191] In some embodiments, the determination of the effective utilization kinetic energy of the wind farm based on the target rotor kinetic energy of the wind turbine can, in specific implementation, include:

[0192] S1: Calculate the inertial time constant of the wind turbine;

[0193] S2: Calculate the maximum value of the rotor kinetic energy of the wind turbine;

[0194] S3: Calculate the effective kinetic energy evaluation index of the wind turbine based on the target rotor kinetic energy and the maximum value of the rotor kinetic energy;

[0195] S4: Determine the effective kinetic energy utilization of the wind farm based on the effective kinetic energy evaluation index and the inertial time constant.

[0196] In some embodiments, the calculation of the inertial time constant of the wind turbine generator described above may specifically include:

[0197] Calculate the inertial time constant of the wind turbine using the following formula:

[0198]

[0199] Among them, H WT_i Let ΔE represent the inertial time constant of the i-th wind turbine. k_i This represents the absorbable or releaseable rotor kinetic energy of the i-th wind turbine. This represents the releaseable rotor kinetic energy of the i-th wind turbine. S represents the absorbable rotor kinetic energy of the i-th wind turbine. N Indicates the rated capacity, n j ΔE represents the number of wind turbines in wind farm j. k_i_0 Let ni represent the absorbable rotor kinetic energy of the i-th wind turbine in the first entry zone, n0 represent the number of wind turbines in the first entry zone, and ΔE represent the total absorbable rotor kinetic energy. k_i_0' n0' represents the releaseable rotor kinetic energy of the i-th wind turbine in the second entry zone, and n0' represents the number of wind turbines in the second entry zone.

[0200] Specifically, in some implementation scenarios, the lower limit for safe operation of the power system frequency is set at 48Hz. At this frequency, the rotor speed of the wind turbine will decrease by 4%. After the corresponding speed changes from 1pu to 0.96pu, the rotor kinetic energy released by the wind turbine reaches its maximum value.

[0201] In some embodiments, the calculation of the maximum value of the rotor kinetic energy of the wind turbine generator described above may specifically include:

[0202] Calculate the maximum value of the rotor kinetic energy using the following formula:

[0203]

[0204] Where, ΔE k_max_i This represents the maximum value of the rotor kinetic energy of the i-th wind turbine.

[0205] In some embodiments, the above-mentioned calculation of the effective kinetic energy evaluation index of the wind turbine based on the target rotor kinetic energy and the maximum value of the rotor kinetic energy may specifically include:

[0206] Calculate the effective kinetic energy evaluation index of the wind turbine according to the following formula:

[0207]

[0208] in, This represents the evaluation index of the effective kinetic energy that the i-th wind turbine can release. This represents the evaluation index of the effective kinetic energy that the i-th wind turbine can absorb.

[0209] In some embodiments, the determination of the effective kinetic energy utilization of the wind farm based on the effective kinetic energy evaluation index and the inertial time constant may, in specific implementation, include:

[0210] Calculate the effective kinetic energy of a wind farm using the following formula:

[0211]

[0212] Where, k WP_j This indicates the effective utilization of kinetic energy in wind farm j. This indicates the effective kinetic energy that wind farm j can release. P represents the effective kinetic energy that wind farm j can absorb and utilize. WT_i H represents the rated power of the i-th wind turbine. WP_j P represents the equivalent inertial constant of the wind farm j. WP_j This represents the rated power of wind farm j;

[0213] The equivalent inertial constant of wind farm j is calculated using the following formula:

[0214]

[0215] Based on the above embodiments, the target frequency regulation reserve power and target rotor kinetic energy of the wind turbine are comprehensively considered, and the effective frequency regulation reserve power and effective utilization kinetic energy of the wind farm are obtained from a spatial perspective, which increases the accuracy of the primary frequency regulation capability assessment of the wind farm.

[0216] S104: Calculate the reliability parameters of the wind farm's reserve power based on wind speed variation and the wind farm's effective frequency regulation reserve power.

[0217] In some embodiments, the calculation of the wind farm's reserve power reliability parameters based on wind speed variation and the wind farm's effective frequency regulation reserve power may, in specific implementations, include:

[0218] S1: Based on the wind speed change, determine the joint probability density model of wind speed and wind speed change;

[0219] S2: Based on the joint probability density model of wind speed and wind speed change, the wind speed fluctuation is obtained;

[0220] S3: Obtain wind speed based on wind speed fluctuation;

[0221] S4: Calculate the reliability parameters of the wind farm's reserve power based on wind speed and the wind farm's effective frequency regulation reserve power.

[0222] In some embodiments, before determining the joint probability density model of wind speed-wind speed change based on the wind speed change, the method further includes: acquiring wind speed data at multiple time points; subtracting the wind speed data at adjacent time points to obtain the wind speed change.

[0223] In some embodiments, the above-described method for determining the joint probability density model of wind speed and wind speed change based on wind speed change may, in specific implementation, include:

[0224] S1: Wind speed data at multiple time points are divided into intervals to obtain wind speed intervals;

[0225] S2: Obtain the number of identical wind speed changes in each wind speed range; based on the number of identical wind speed changes in each wind speed range, obtain the frequency distribution histogram and frequency distribution line graph of wind speed changes;

[0226] S3: Based on the frequency distribution histogram and frequency distribution line graph of wind speed change, obtain the distribution model of wind speed change in each wind speed interval; and fit the distribution model of wind speed change to obtain the probability density function of wind speed change.

[0227] S4: Fit the probability density function of wind speed change to determine the joint probability density model of wind speed and wind speed change.

[0228] In some embodiments, the model used to fit the probability density function of wind speed change can be a power function model. Other models may also be used to fit the probability density function of wind speed change in these embodiments, and no limitation is made thereto.

[0229] In some embodiments, the wind speed fluctuation is obtained from the joint probability density model of wind speed and wind speed change. In specific implementation, this may include: randomly sampling the probability density function of wind speed change in the joint probability density model of wind speed and wind speed change based on Monte Carlo simulation to obtain the wind speed fluctuation of the next time step from the current time step.

[0230] In some embodiments, obtaining wind speed based on wind speed fluctuation can, in specific implementation, include:

[0231] Calculate the wind speed using the following formula:

[0232]

[0233] in, This represents the wind speed at time t in wind farm j. This represents the wind speed fluctuation at time t+1 in wind farm j. Let represent the wind speed at time t+1 in wind farm j.

[0234] In some embodiments, the calculation of the wind farm's reserve power reliability parameters based on wind speed and the wind farm's effective frequency regulation reserve power may, in specific implementations, include:

[0235] Calculate the standby power reliability parameters of the wind farm using the following formula:

[0236]

[0237] in, This represents the backup power reliability parameter of wind farm j at time t. This represents the effective frequency regulation reserve power of wind farm j at time t. This represents the effective frequency regulation reserve power of wind farm j at time t+1.

[0238] Based on the above embodiments, the reliability parameters of wind farm reserve power at different times can be obtained from a time perspective, which increases the accuracy of the wind farm's primary frequency regulation capability assessment.

[0239] S105: Based on the wind farm's effective frequency regulation reserve power, effective utilization kinetic energy of the wind farm, and wind farm reserve power reliability parameters, perform primary frequency regulation on the wind farm.

[0240] In some embodiments, the aforementioned primary frequency regulation specifically refers to the automatic control process in which the wind turbine control system automatically controls the increase or decrease of the active power of the wind turbine to limit the change in grid frequency and maintain the grid frequency stability once the grid frequency deviates from the rated value.

[0241] In some embodiments, the above-mentioned primary frequency regulation of the wind farm based on the effective frequency regulation reserve power of the wind farm, the effective utilization kinetic energy of the wind farm, and the reserve power reliability parameters of the wind farm may specifically include: controlling the wind turbine to quickly release or absorb rotor kinetic energy based on the effective utilization kinetic energy of the wind farm to provide inertial response for the wind farm, so as to realize the inertial support of the wind turbine to the power grid; and controlling the wind turbine to release or absorb the effective frequency regulation reserve power of the wind farm to participate in the primary frequency regulation of the system when the reserve power reliability parameters of the wind farm are greater than a first preset reliability value.

[0242] In a specific scenario example, the primary frequency regulation capability assessment method provided in this manual can be applied to control the primary frequency regulation of a wind farm. The wind turbine operating status when the system frequency change type is determined to be a system frequency decrease is as follows: Figure 2 As shown, curve P DEL This represents the power-speed curve of the wind turbine after a load reduction of d%, curve P MPPT This represents the maximum wind energy tracking curve of the wind turbine, curve v s This represents the power-speed curves obtained when the wind speed of the wind turbine is within the interval (v2, v3). Curve v1 represents the power-speed curve obtained when the wind speed is v1, curve v2 represents the power-speed curve obtained when the wind speed is v2, and curve v3 represents the power-speed curve obtained when the wind speed is v3. cut_in The wind speed of the wind turbine is v. cut_in The power-speed curve obtained at that time, curve v N The wind speed of the wind turbine is v. N The power-speed curve obtained at that time, w3 represents curve P MPPT The rotational speed corresponding to the value of curve v3 is shown in the shaded area, which represents the effective frequency regulation reserve power that the wind farm can generate. The operating status of the wind turbine when the system frequency change type is determined to be a system frequency rise is as follows: Figure 3 As shown, curve P represents the current power-speed curve of the wind turbine. DEL' represents the power-speed curve of the wind turbine after a 2d% load reduction. Curve v4 represents the power-speed curve obtained when the wind speed of the wind turbine is v4. The shaded area represents the effective frequency regulation reserve power that the wind farm can reduce.

[0243] Based on the above-described primary frequency modulation capability assessment method, this specification also provides an embodiment of a primary frequency modulation capability assessment device, see reference. Figure 4 As shown, the primary frequency modulation capability evaluation device specifically includes the following modules:

[0244] Detection module 401 is used to determine the type of system frequency change based on the real-time voltage frequency at the wind farm grid connection point;

[0245] The first calculation module 402 is used to determine the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine based on the type of system frequency change.

[0246] The second calculation module 403 is used to determine the effective frequency regulation reserve power of the wind farm based on the target frequency regulation reserve power of the wind turbine; and to determine the effective utilization kinetic energy of the wind farm based on the target rotor kinetic energy of the wind turbine.

[0247] The third calculation module 404 is used to calculate the reliability parameters of the wind farm's reserve power based on wind speed variation and the wind farm's effective frequency regulation reserve power.

[0248] The primary frequency regulation module 405 is used to perform primary frequency regulation on the wind farm based on the wind farm's effective frequency regulation reserve power, the wind farm's effective utilization kinetic energy, and the wind farm's reserve power reliability parameters.

[0249] In some embodiments, the detection module 401 described above can be specifically used to calculate the difference between the real-time voltage frequency of the wind farm grid connection point and the voltage reference frequency of the wind farm grid connection point; detect whether the difference is greater than the upper limit of the frequency change dead zone; if the difference is greater than the upper limit of the frequency change dead zone, determine that the system frequency change type is a system frequency increase; detect whether the difference is less than the lower limit of the frequency change dead zone; if the difference is less than the lower limit of the frequency change dead zone, determine that the system frequency change type is a system frequency decrease.

[0250] In some embodiments, the first calculation module 402 described above can be specifically used to calculate the releaseable frequency regulation reserve power and releaseable rotor kinetic energy of the wind turbine when the system frequency change type is determined to be a system frequency decrease, as the target frequency regulation reserve power and target rotor kinetic energy; and to calculate the absorbable frequency regulation reserve power and absorbable rotor kinetic energy of the wind turbine when the system frequency change type is determined to be a system frequency increase, as the target frequency regulation reserve power and target rotor kinetic energy.

[0251] In some embodiments, the second computing module 403 described above can be specifically used for:

[0252] When the system frequency change is determined to be a system frequency decrease, the effective frequency regulation reserve power of the wind farm is calculated according to the following formula:

[0253]

[0254] in, This represents the effective frequency regulation reserve power that wind farm j can generate.

[0255] When the system frequency change type is determined to be a system frequency rise, the effective frequency regulation reserve power of the wind farm is calculated according to the following formula:

[0256]

[0257] in, This indicates the effective frequency regulation reserve power that wind farm j can reduce;

[0258] Calculate the effective frequency regulation reserve power of a wind farm using the following formula:

[0259]

[0260] Where, ΔP WP_j This represents the effective frequency regulation reserve power of wind farm j.

[0261] In some embodiments, the second calculation module 403 described above can also be used to: calculate the inertial time constant of the wind turbine; calculate the maximum value of the rotor kinetic energy of the wind turbine; calculate the effective kinetic energy evaluation index of the wind turbine based on the target rotor kinetic energy and the maximum value of the rotor kinetic energy; and determine the effective utilization kinetic energy of the wind farm based on the effective kinetic energy evaluation index and the inertial time constant.

[0262] In some embodiments, the third calculation module 404 described above can be specifically used to determine the joint probability density model of wind speed-wind speed change based on the wind speed change; obtain the wind speed fluctuation based on the joint probability density model of wind speed-wind speed change; obtain the wind speed based on the wind speed fluctuation; and calculate the backup power reliability parameters of the wind farm based on the wind speed and the effective frequency regulation backup power of the wind farm.

[0263] In some embodiments, the primary frequency regulation module 405 can be specifically used to control the wind turbine to quickly release or absorb rotor kinetic energy based on the effective utilization kinetic energy of the wind farm, so as to provide inertial response for the wind farm and realize the inertial support of the wind turbine to the power grid; when the backup power reliability parameter of the wind farm is greater than the first preset reliability value, the wind turbine is controlled to release or absorb the effective frequency regulation backup power of the wind farm to participate in the primary frequency regulation of the system.

[0264] It should be noted that the units, devices, or modules described in the above embodiments can be implemented by computer chips or physical entities, or by products with certain functions. For ease of description, the above devices are described by dividing them into various modules according to their functions. Of course, in implementing this specification, the functions of each module can be implemented in one or more software and / or hardware, or the module that implements the same function can be implemented by a combination of multiple sub-modules or sub-units, etc. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection between the devices or units shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0265] This specification also provides a computer storage medium for a primary frequency regulation capability assessment method. The computer storage medium stores computer program instructions that, when executed, implement the following: determining the system frequency change type based on the real-time voltage frequency at the wind farm's grid connection point; determining the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine generators according to the system frequency change type; determining the effective frequency regulation reserve power of the wind farm based on the target frequency regulation reserve power of the wind turbine generators; determining the effective utilization kinetic energy of the wind farm based on the target rotor kinetic energy of the wind turbine generators; calculating the reserve power reliability parameters of the wind farm based on wind speed changes and the effective frequency regulation reserve power of the wind farm; and performing primary frequency regulation on the wind farm based on the effective frequency regulation reserve power, the effective utilization kinetic energy of the wind farm, and the reserve power reliability parameters of the wind farm.

[0266] In this embodiment, the storage medium includes, but is not limited to, Random Access Memory (RAM), Read-Only Memory (ROM), cache, hard disk drive (HDD), or memory card. The memory can be used to store computer program instructions. The network communication unit can be an interface configured according to standards specified in the communication protocol for network connection communication.

[0267] In this embodiment, the specific functions and effects implemented by the program instructions stored in the computer storage medium can be explained in comparison with other implementation methods, and will not be repeated here.

[0268] This specification also provides a server, including a processor and a memory for storing processor-executable instructions. In specific implementations, the processor can perform the following steps according to the instructions: determining the system frequency change type based on the real-time voltage frequency at the wind farm's grid connection point; determining the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine generator set based on the system frequency change type; determining the effective frequency regulation reserve power of the wind farm based on the target frequency regulation reserve power of the wind turbine generator set; determining the effective utilization kinetic energy of the wind farm based on the target rotor kinetic energy of the wind turbine generator set; calculating the reserve power reliability parameters of the wind farm based on wind speed changes and the effective frequency regulation reserve power of the wind farm; and performing a first-stage frequency regulation on the wind farm based on the effective frequency regulation reserve power, the effective utilization kinetic energy of the wind farm, and the reserve power reliability parameters of the wind farm.

[0269] To execute the above instructions more accurately, please refer to... Figure 5 As shown in the embodiments of this specification, another specific server is also provided, wherein the server includes a network communication port 501, a processor 502 and a memory 503, and the above structures are connected by internal cables so that the various structures can perform specific data interaction.

[0270] Specifically, the network communication port 501 can be used to obtain the real-time voltage frequency of the wind farm's grid connection point.

[0271] The processor 502 can specifically be used to determine the system frequency change type based on the real-time voltage frequency at the wind farm's grid connection point; determine the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine generators according to the system frequency change type; determine the effective frequency regulation reserve power of the wind farm according to the target frequency regulation reserve power of the wind turbine generators; determine the effective utilization kinetic energy of the wind farm according to the target rotor kinetic energy of the wind turbine generators; calculate the reserve power reliability parameters of the wind farm based on wind speed changes and the effective frequency regulation reserve power of the wind farm; and perform primary frequency regulation on the wind farm based on the effective frequency regulation reserve power, the effective utilization kinetic energy of the wind farm, and the reserve power reliability parameters of the wind farm.

[0272] The memory 503 can be used to store the corresponding instruction program.

[0273] In this embodiment, the network communication port 501 can be a virtual port bound to different communication protocols, thereby enabling the sending or receiving of different data. For example, the network communication port can be a port responsible for web data communication, a port responsible for FTP data communication, or a port responsible for email data communication. Furthermore, the network communication port can also be a physical communication interface or communication chip. For example, it can be a wireless mobile network communication chip, such as GSM or CDMA; it can also be a Wi-Fi chip; or it can be a Bluetooth chip.

[0274] In this embodiment, the processor 502 can be implemented in any suitable manner. For example, the processor can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers, etc. This specification is not limiting.

[0275] In this embodiment, the memory 503 may include multiple layers. In a digital system, anything that can store binary data can be a memory. In an integrated circuit, a circuit with storage function but no physical form is also called a memory, such as RAM, FIFO, etc. In a system, a storage device with a physical form is also called a memory, such as a memory stick, TF card, etc.

[0276] While this specification provides the steps of operation for the methods described in the embodiments or flowcharts, more or fewer steps may be included based on conventional or non-inventive means. The order of steps listed in the embodiments is merely one possible order of execution among many steps and does not represent the only possible order. In actual device or client product execution, the methods shown in the embodiments or drawings may be executed sequentially or in parallel (e.g., in a parallel processor or multi-threaded processing environment, or even a distributed data processing environment). The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, product, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, product, or apparatus. Without further limitations, the presence of other identical or equivalent elements in a process, method, product, or apparatus that includes said elements is not excluded. The terms "first," "second," etc., are used to denote names and do not indicate any particular order.

[0277] Those skilled in the art will also know that, besides implementing the controller in the form of purely computer-readable program code, the same functions can be achieved by logically programming the method steps, making the controller take the form of logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers (PLCs), and embedded microcontrollers. Therefore, such a controller can be considered a hardware component, and the devices within it used to implement various functions can also be considered structures within that hardware component. Alternatively, the devices used to implement various functions can be considered as both software modules implementing the method and structures within a hardware component.

[0278] This specification can be described in the general context of computer-executable instructions that are executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc., that perform a specific task or implement a specific abstract data type. This specification can also be practiced in distributed computing environments, where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0279] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this specification can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solutions of this specification can essentially be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, mobile terminal, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments of this specification.

[0280] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. This specification can be used in numerous general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable electronic devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices, etc.

[0281] Although this specification has been described by way of examples, those skilled in the art will recognize that many variations and modifications are possible without departing from the spirit of this specification, and it is intended that the appended claims cover such variations and modifications without departing from the spirit of this specification.

Claims

1. A method for evaluating primary frequency modulation capability, characterized in that, include: Based on the real-time voltage frequency at the wind farm's grid connection point, determine the type of system frequency change. Based on the type of system frequency change, determine the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine units; Based on the target frequency regulation reserve power of the wind turbine generators, determine the effective frequency regulation reserve power of the wind farm; based on the target rotor kinetic energy of the wind turbine generators, determine the effective utilization kinetic energy of the wind farm. Based on wind speed variation and the effective frequency regulation reserve power of the wind farm, calculate the reserve power reliability parameters of the wind farm. Based on the wind farm's effective frequency regulation reserve power, effective utilization kinetic energy, and reserve power reliability parameters, the wind farm is subjected to primary frequency regulation. Among them, determining the effective frequency regulation reserve power of the wind farm based on the target frequency regulation reserve power of the wind turbine units includes: when the system frequency change type is determined to be a system frequency decrease, the effective frequency regulation reserve power of the wind farm is calculated according to the following formula: Where j represents the wind farm number, This represents the effective frequency regulation reserve power that wind farm j can generate. , , These represent the releaseable frequency-regulating reserve power of the i-th wind turbine in the first low-wind-speed zone, the first medium-wind-speed zone, and the first high-wind-speed zone, respectively. This refers to the number of wind turbines in the first low wind speed zone. This refers to the number of wind turbines in the first medium wind speed zone. The number of wind turbines in the highest wind speed zone; when the system frequency change type is determined to be a system frequency rise, the effective frequency regulation reserve power of the wind farm is calculated according to the following formula: ,in, This represents the effective frequency regulation reserve power of wind farm j. , Let represent the absorbable frequency-regulating reserve power of the i-th wind turbine in the second low-wind-speed zone and the second medium-wind-speed zone, respectively. The number of wind turbines in the second lowest wind speed zone. The number of wind turbines in the second medium wind speed zone; Based on the target rotor kinetic energy of the wind turbine, the effective utilization kinetic energy of the wind farm is determined, including: calculating the inertial time constant of the wind turbine; calculating the maximum value of the rotor kinetic energy of the wind turbine; calculating the effective kinetic energy evaluation index of the wind turbine based on the target rotor kinetic energy and the maximum value of the rotor kinetic energy; and determining the effective utilization kinetic energy of the wind farm based on the effective kinetic energy evaluation index and the inertial time constant.

2. The method according to claim 1, characterized in that, Based on the real-time voltage frequency at the wind farm's grid connection point, determine the types of system frequency changes, including: Calculate the difference between the real-time voltage frequency at the grid connection point of the wind farm and the reference voltage frequency at the grid connection point of the wind farm; Check if the difference is greater than the upper limit of the frequency change dead zone; if it is determined that the difference is greater than the upper limit of the frequency change dead zone, determine that the system frequency change type is a system frequency increase. Check if the difference is less than the lower limit of the frequency change dead zone; if the difference is determined to be less than the lower limit of the frequency change dead zone, determine the system frequency change type as a system frequency decrease.

3. The method according to claim 1, characterized in that, Based on the type of system frequency variation, determine the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine units, including: When the system frequency change type is determined to be a system frequency decrease, the releaseable frequency regulation reserve power and releaseable rotor kinetic energy of the wind turbine are calculated as the target frequency regulation reserve power and target rotor kinetic energy. When the system frequency change type is determined to be a system frequency rise, the absorbable frequency regulation reserve power and absorbable rotor kinetic energy of the wind turbine are calculated as the target frequency regulation reserve power and target rotor kinetic energy.

4. The method according to claim 3, characterized in that, When the system frequency change type is determined to be a system frequency decrease, the available frequency regulation reserve power and available rotor kinetic energy of the wind turbine are calculated, including: When the system frequency change type is determined to be a decrease in system frequency, the nodal wind speeds in the decrease state wind speed range are determined. Based on the nodal wind speeds within the descending wind speed range, the descending wind speed range is obtained; Based on the decreasing wind speed range, calculate the releaseable frequency-regulating reserve power and releaseable rotor kinetic energy of the wind turbine.

5. The method according to claim 4, characterized in that, Determine the nodal wind speeds within the descending wind speed range, including: Based on the wind turbine operating data, the wind turbine parameters are obtained; Based on the wind turbine parameters, the first optimal tip speed ratio is calculated; The maximum wind energy utilization coefficient is obtained based on the first optimal tip speed ratio; Determine the first wind energy utilization factor after the wind turbine is unloaded based on the maximum wind energy utilization factor; The first tip speed ratio of the wind turbine after load reduction is determined based on the first wind energy utilization coefficient of the wind turbine after load reduction. Based on the first optimal tip speed ratio and the first tip speed ratio after the wind turbine is unloaded, calculate the nodal wind speed in the descent wind speed range.

6. The method according to claim 3, characterized in that, When the system frequency change type is determined to be a system frequency rise, the absorbable frequency regulation reserve power and absorbable rotor kinetic energy of the wind turbine are calculated, including: When the system frequency change type is determined to be an upward trend, the nodal wind speeds in the upward trend wind speed range are determined. Based on the nodal wind speeds within the updraft wind speed range, the updraft wind speed range is obtained. Based on the wind speed range during the rising state, calculate the absorbable frequency regulation reserve power and absorbable rotor kinetic energy of the wind turbine.

7. The method according to claim 6, characterized in that, Determine the nodal wind speeds within the updraft wind speed range, including: Determine the second wind energy utilization factor after wind turbine unloading based on the maximum wind energy utilization factor; The second tip speed ratio of the wind turbine after unloading is determined based on the second wind energy utilization coefficient after unloading. Calculate the wind speed at the fourth node based on the tip speed ratio of the second blade after the wind turbine is unloaded; Based on the wind speed at the fourth node and the node wind speeds in the descending wind speed range, determine the node wind speeds in the ascending wind speed range.

8. The method according to claim 1, characterized in that, Based on wind speed variations and the effective frequency regulation reserve power of the wind farm, the reliability parameters of the wind farm's reserve power are calculated, including: Based on the wind speed change, determine the joint probability density model of wind speed and wind speed change. The wind speed fluctuation is obtained based on the joint probability density model of wind speed and wind speed change. Wind speed is obtained based on the amount of wind speed fluctuation; Calculate the reliability parameters of the wind farm's reserve power based on wind speed and the wind farm's effective frequency regulation reserve power.

9. A primary frequency modulation capability evaluation device, characterized in that, include: The detection module is used to determine the type of system frequency change based on the real-time voltage frequency at the wind farm's grid connection point; The first calculation module is used to determine the target frequency regulation reserve power and target rotor kinetic energy of the matching wind turbine based on the type of system frequency change. The second calculation module is used to determine the effective frequency regulation reserve power of the wind farm based on the target frequency regulation reserve power of the wind turbine; and to determine the effective utilization kinetic energy of the wind farm based on the target rotor kinetic energy of the wind turbine. The third calculation module is used to calculate the reliability parameters of the wind farm's reserve power based on wind speed changes and the wind farm's effective frequency regulation reserve power. The primary frequency regulation module is used to perform primary frequency regulation on the wind farm based on the wind farm's effective frequency regulation reserve power, the wind farm's effective utilization kinetic energy, and the wind farm's reserve power reliability parameters. Specifically, the second calculation module is used to: calculate the effective frequency regulation reserve power of the wind farm according to the following formula when the system frequency change type is determined to be a system frequency decrease: Where j represents the wind farm number, This represents the effective frequency regulation reserve power that wind farm j can generate. , , These represent the releaseable frequency-regulating reserve power of the i-th wind turbine in the first low-wind-speed zone, the first medium-wind-speed zone, and the first high-wind-speed zone, respectively. This refers to the number of wind turbines in the first low wind speed zone. This refers to the number of wind turbines in the first medium wind speed zone. The number of wind turbines in the highest wind speed zone; when the system frequency change type is determined to be a system frequency rise, the effective frequency regulation reserve power of the wind farm is calculated according to the following formula: ,in, This represents the effective frequency regulation reserve power of wind farm j. , Let represent the absorbable frequency-regulating reserve power of the i-th wind turbine in the second low-wind-speed zone and the second medium-wind-speed zone, respectively. The number of wind turbines in the second lowest wind speed zone. The number of wind turbine units in the second wind speed zone; and also used for: calculating the inertial time constant of the wind turbine units; calculating the maximum value of the rotor kinetic energy of the wind turbine units; calculating the effective kinetic energy evaluation index of the wind turbine units based on the target rotor kinetic energy and the maximum value of the rotor kinetic energy; and determining the effective utilization kinetic energy of the wind farm based on the effective kinetic energy evaluation index and the inertial time constant.

10. A computer-readable storage medium, characterized in that, It stores computer instructions that, when executed by a processor, implement the steps of the method according to any one of claims 1 to 8.

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