Adaptive emergency control method and terminal for wind power considering frequency modulation capability of wind turbine generator

Abstract

The application discloses a wind power adaptive emergency control method and a terminal considering frequency modulation capacity of wind turbine generators, when the frequency of a power grid is lower than a starting threshold value of frequency modulation of a wind power plant, a virtual inertia collaborative control method is adopted to control the wind power plant group to participate in primary frequency modulation based on a frequency modulation capacity coefficient and a collaborative control coefficient of the wind power plant group, then when an estimated value of a maximum frequency drop estimated value is greater than a preset safety threshold value, the remaining adjustable capacity of the wind turbine generators in the wind power plant group is evaluated, the evaluation results are sorted, secondary regulation compensation power values of the wind turbine generators in each wind power plant are determined according to the sorting results and the evaluation results, and secondary regulation instructions are issued to each wind power plant according to the secondary regulation compensation power values, so that the surplus regulation capacity of the wind turbine generators is fully utilized, the capacity of the wind turbine generators in participating in system regulation in an emergency state is excavated from the perspective of the wind power plant group, the capacity of the system to cope with an emergency working condition is effectively improved, and the operation stability of the power grid is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine grid connection, and in particular to a wind power adaptive emergency control method and terminal taking into account the frequency regulation capability of the wind turbine. Background Art

[0002] In recent years, the scale of installed renewable energy capacity has grown rapidly, and the volatility and uncertainty of its output have become increasingly prominent. In particular, output fluctuations will cause the system frequency to fluctuate continuously, placing higher demands on the regulation capabilities and margins of conventional units. The current primary frequency regulation involving wind power is essentially passive, and does not fully consider the differences in the operating conditions of different units. In fact, by adopting methods such as rotor overspeed control and pitch angle control, wind turbines can retain a certain amount of reserve power within the unit, providing additional regulation capacity for system emergency control states, avoiding the direct use of safety and stability control measures such as machine and load shedding.

[0003] As new power systems are being developed and the scale of renewable energy installations continues to expand, it's important to consider leveraging wind power's inherent secondary regulation capabilities as a key supplement to power system regulation. By fully leveraging the overall regulation capabilities of wind farms, the regulation pressure on traditional units can be reduced to a certain extent. Furthermore, compared to conventional thermal power units with step-change in inertia, wind turbines offer adjustable virtual inertia, enabling second-level control and preventing drastic frequency fluctuations.

[0004] Therefore, how to utilize the frequency regulation capability of wind turbines to enhance the system's ability to cope with emergency conditions, and thereby improve the stability of grid operation, has become one of the issues that need to be considered. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a wind power adaptive emergency control method and terminal taking into account the frequency regulation capability of wind turbines, which can effectively improve the system's ability to cope with emergency conditions and improve the stability of power grid operation.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A wind power adaptive emergency control method considering the frequency regulation capability of a wind turbine generator system comprises the following steps:

[0008] Calculating a frequency regulation capability coefficient of a wind farm group and determining a coordinated control coefficient of the wind farm group;

[0009] If the grid frequency is lower than the starting threshold for the wind farm to participate in frequency regulation, a virtual inertia collaborative control method is used to control the wind farm group to participate in primary frequency regulation based on the frequency regulation capability coefficient of the wind farm group and the collaborative control coefficient, and a maximum frequency drop is estimated according to the power shortage size and the frequency regulation capability coefficient of the wind farm group to obtain an estimated value of the maximum frequency drop;

[0010] determining whether the estimated value of the maximum frequency drop is greater than a preset safety threshold; if so, evaluating the remaining adjustable capacity of the wind turbines in the wind farm group to obtain an evaluation result, and ranking the wind turbines according to the evaluation result to obtain a ranking result;

[0011] Determining a total power value required for compensation according to a preset secondary regulation ratio, and sending the total power value required for compensation to the wind farm group to obtain the power value required for compensation of each wind farm;

[0012] According to the power values ​​required to be compensated by the wind farms, the secondary adjustment compensation power values ​​of the wind turbines in the wind farms are determined according to the sorting results and the evaluation results, and secondary adjustment instructions are issued to the wind farms according to the secondary adjustment compensation power values.

[0013] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0014] A wind power adaptive emergency control terminal considering the frequency regulation capability of a wind turbine generator system includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented:

[0015] Calculating a frequency regulation capability coefficient of a wind farm group and determining a coordinated control coefficient of the wind farm group;

[0016] If the grid frequency is lower than the starting threshold for the wind farm to participate in frequency regulation, a virtual inertia collaborative control method is used to control the wind farm group to participate in primary frequency regulation based on the frequency regulation capability coefficient of the wind farm group and the collaborative control coefficient, and a maximum frequency drop is estimated according to the power shortage size and the frequency regulation capability coefficient of the wind farm group to obtain an estimated value of the maximum frequency drop;

[0017] determining whether the estimated value of the maximum frequency drop is greater than a preset safety threshold; if so, evaluating the remaining adjustable capacity of the wind turbines in the wind farm group to obtain an evaluation result, and ranking the wind turbines according to the evaluation result to obtain a ranking result;

[0018] Determining a total power value required for compensation according to a preset secondary regulation ratio, and sending the total power value required for compensation to the wind farm group to obtain the power value required for compensation of each wind farm;

[0019] According to the power values ​​required to be compensated for the wind farms, secondary adjustment compensation power values ​​of the wind turbines in the wind farms are determined according to the sorting results and the evaluation results, and secondary adjustment instructions are issued to the wind farms according to the secondary adjustment compensation power values.

[0020] The beneficial effect of the present invention is that: when the grid frequency is lower than the starting threshold for the wind farm to participate in frequency regulation, the virtual inertia cooperative control method is used to control the wind farm group to participate in the primary frequency regulation based on the frequency regulation capability coefficient and the cooperative control coefficient of the wind farm group. Then, when the estimated value of the maximum frequency drop is greater than the preset safety threshold, the residual adjustable capacity of the wind turbines in the wind farm group is evaluated, and the wind turbines are sorted according to the evaluation result to obtain the sorting result. The determined total power value required for compensation is sent to the wind farm group. According to the power value required for compensation of each wind farm, the secondary regulation compensation power value of the wind turbines in each wind farm is determined according to the sorting result and the evaluation result, and the secondary regulation instruction is sent to each wind farm based on the secondary regulation instruction. In this way, the virtual inertia cooperative control method is used to enable the wind farm group to participate in the primary frequency regulation, and then whether to perform secondary regulation is determined according to the actual situation after the primary frequency regulation. The surplus regulation capacity of the wind turbines is fully utilized, and the ability of the wind turbines to participate in system regulation in an emergency state is explored from the perspective of the wind farm group, thereby effectively improving the system's ability to cope with emergency conditions and improving the stability of grid operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a flow chart of the steps of a wind power adaptive emergency control method considering the frequency regulation capability of a wind turbine generator system according to an embodiment of the present invention;

[0022] Figure 2 This is a structural diagram of a wind power adaptive emergency control terminal taking into account the frequency regulation capability of a wind turbine generator system according to an embodiment of the present invention;

[0023] Figure 3 This is a control architecture diagram of a wind power participating system in a wind power adaptive emergency control method considering the frequency regulation capability of a wind turbine generator set according to an embodiment of the present invention;

[0024] Figure 4 This is a comparison diagram of frequency regulation results in different scenarios in a wind power adaptive emergency control method considering the frequency regulation capability of wind turbines according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] To illustrate the technical content, achieved objectives and effects of the present invention in detail, the following description is given in conjunction with the embodiments and accompanying drawings.

[0026] Please refer to Figure 1 A wind power adaptive emergency control method considering the frequency regulation capability of a wind turbine generator system comprises the following steps:

[0027] Calculating a frequency regulation capability coefficient of a wind farm group and determining a coordinated control coefficient of the wind farm group;

[0028] If the grid frequency is lower than the starting threshold for the wind farm to participate in frequency regulation, a virtual inertia collaborative control method is used to control the wind farm group to participate in primary frequency regulation based on the frequency regulation capability coefficient of the wind farm group and the collaborative control coefficient, and a maximum frequency drop is estimated according to the power shortage size and the frequency regulation capability coefficient of the wind farm group to obtain an estimated value of the maximum frequency drop;

[0029] determining whether the estimated value of the maximum frequency drop is greater than a preset safety threshold; if so, evaluating the remaining adjustable capacity of the wind turbines in the wind farm group to obtain an evaluation result, and ranking the wind turbines according to the evaluation result to obtain a ranking result;

[0030] Determining a total power value required for compensation according to a preset secondary regulation ratio, and sending the total power value required for compensation to the wind farm group to obtain the power value required for compensation of each wind farm;

[0031] According to the power values ​​required to be compensated for the wind farms, secondary adjustment compensation power values ​​of the wind turbines in the wind farms are determined according to the sorting results and the evaluation results, and secondary adjustment instructions are issued to the wind farms according to the secondary adjustment compensation power values.

[0032] As can be seen from the above description, the beneficial effects of the present invention are as follows: when the grid frequency is lower than the starting threshold for the wind farm to participate in frequency regulation, the virtual inertia collaborative control method is used to control the wind farm group to participate in primary frequency regulation based on the frequency regulation capability coefficient and collaborative control coefficient of the wind farm group; then, when the estimated value of the maximum frequency drop is greater than the preset safety threshold, the residual adjustable capacity of the wind turbines in the wind farm group is evaluated, and the wind turbines are sorted according to the evaluation result to obtain a sorting result. The determined total power value required for compensation is sent to the wind farm group; the secondary regulation compensation power value of the wind turbines in each wind farm is determined according to the sorting result and the evaluation result based on the power value required for compensation of each wind farm, and the secondary regulation compensation power value of the wind turbines in each wind farm is issued to each wind farm based on the secondary regulation instruction. In this way, the virtual inertia collaborative control method is used to enable the wind farm group to participate in primary frequency regulation, and then whether to perform secondary regulation is determined based on the actual situation after the primary frequency regulation. The surplus regulation capacity of the wind turbines is fully utilized, and the ability of the wind turbines to participate in system regulation in an emergency state is explored from the perspective of the wind farm group, thereby effectively improving the system's ability to cope with emergency conditions and improving the stability of grid operation.

[0033] Furthermore, the calculation of the frequency regulation capability coefficient of the wind farm group includes:

[0034] Obtaining a current speed and a rated speed of the wind turbine generator set, and calculating a frequency regulation capability coefficient of the wind turbine generator set based on the current speed and the rated speed;

[0035] Calculating a frequency regulation capability coefficient of a wind farm based on the frequency regulation capability coefficient of the wind turbine generator set;

[0036] The frequency regulation capability coefficient of the wind farm group is calculated based on the frequency regulation capability coefficient of the wind farm.

[0037] From the above description, it can be seen that the frequency regulation capability coefficient of the wind turbine is first calculated based on the current speed and rated speed of the wind turbine, then the frequency regulation capability coefficient of the wind farm is calculated based on the frequency regulation capability coefficient of the wind turbine, and finally the frequency regulation capability coefficient of the wind farm group is calculated based on the frequency regulation capability coefficient of the wind farm, so as to evaluate the primary frequency regulation capability of the wind farm group and ensure the subsequent primary frequency regulation effect.

[0038] Furthermore, the calculating of the frequency regulation capability coefficient of the wind farm based on the frequency regulation capability coefficient of the wind turbine generator system includes:

[0039] Equivalently dividing the wind farm into equivalent units, and determining the rated capacity of the equivalent units according to the rated capacity of each wind turbine in the wind farm;

[0040] The frequency regulation capability coefficient of the wind farm is calculated based on the principle of equal rotational kinetic energy according to the frequency regulation capability coefficient of the wind turbine generator set, the rated capacity of the wind turbine generator set, the inertia time constant of the wind turbine generator set and the rated capacity of the equivalent generator set.

[0041] From the above description, it can be seen that when evaluating the primary frequency regulation capability of a wind farm, the wind farm is evaluated as an equivalent unit, which makes the calculation of the frequency regulation capability coefficient of the wind farm simpler and more reliable.

[0042] Furthermore, the calculation of the frequency regulation capability coefficient of the wind farm based on the principle of equal rotational kinetic energy according to the frequency regulation capability coefficient of the wind turbine generator set, the rated capacity of the wind turbine generator set, the inertia time constant of the wind turbine generator set, and the rated capacity of the equivalent turbine generator set includes:

[0043]

[0044] Where k a_f Represents the frequency regulation capability coefficient of the wind farm, P fn Indicates the rated capacity of the equivalent unit, H f represents the equivalent inertia time constant of the equivalent unit, n represents the total number of wind turbines in a single wind farm, k a,jrepresents the frequency regulation capability coefficient of the j-th wind turbine in the wind farm, P wn,j represents the rated capacity of the jth wind turbine in the wind farm, H w,j It represents the inertia time constant of the j-th wind turbine in the wind farm.

[0045] From the above description, it can be seen that when calculating the frequency regulation capability coefficient of a wind farm, taking into account the frequency regulation capability coefficient, rated capacity, inertia time constant of the wind turbine and the rated capacity of the equivalent unit can more reliably reflect the frequency regulation capability of the wind farm.

[0046] Furthermore, determining the coordinated control coefficient of the wind farm group includes:

[0047] The coordinated control coefficient of the wind farm group is determined according to the inertia time constant of the wind turbine generator set of each wind farm in the wind farm group and the equivalent inertia time constant of the wind farm group.

[0048] From the above description, it can be seen that by introducing the coordinated control coefficient, the coordinated control of the wind farm group to participate in the primary frequency regulation is realized.

[0049] Furthermore, estimating the maximum value of the frequency drop according to the power shortage size and the frequency regulation capability coefficient of the wind farm group to obtain an estimated value of the maximum value of the frequency drop includes:

[0050]

[0051] Where, represents the estimated value of the maximum value of the frequency drop, represents the estimated value of the wind farm frequency regulation auxiliary power when the frequency drops to the maximum value, k a_fs represents the frequency regulation capability coefficient of the wind farm group, k p_fs represents the first virtual inertia control coefficient of the wind farm group, ΔP represents the power shortage of the power grid at the current moment, and α represents the proportional coefficient of the required wind power participating in frequency regulation.

[0052] From the above description, it can be seen that by estimating the maximum frequency drop based on the power shortage size and the frequency regulation capability coefficient of the wind farm group, it is measured whether emergency control is needed to ensure the stable operation of the power grid.

[0053] Furthermore, the residual adjustable capacity of the wind turbines in the wind farm group is evaluated to obtain an evaluation result including:

[0054] Calculating various evaluation indicators of the wind turbines in the wind farm group, the evaluation indicators including the wind turbine's scalable power value, the wind turbine's predicted power change trend, the wind turbine's tip speed ratio, the wind turbine's pitch angle, the wind turbine's wind power utilization rate, and the wind turbine's regulation rate;

[0055] Determining the weights of the various evaluation indicators of the wind turbine generator system using an entropy method;

[0056] Calculating an evaluation set of the wind turbine generator system under each evaluation index using a semi-trapezoidal distribution as a membership function;

[0057] Calculating an evaluation value of the wind turbine generator system using a weighted summation formula according to the weight and the evaluation set, and obtaining a comprehensive score according to the evaluation value;

[0058] The wind turbines are sorted according to the evaluation results to obtain a sorting result, which includes:

[0059] The wind turbines are sorted in descending order according to the comprehensive scores to obtain a sorting result.

[0060] From the above description, it can be seen that the evaluation indicators of wind turbines include the power value that can be increased by the wind turbines, the predicted power change trend of the wind turbines, the tip speed ratio of the wind turbines, the pitch angle of the wind turbines, the wind power utilization rate of the wind turbines and the adjustment rate of the wind turbines. This ensures that wind turbines that meet the adjustment response speed, adjustable capacity and higher operating reliability have priority in participating in secondary adjustment to ensure the best adjustment effect.

[0061] Furthermore, the sending of the total power value required for compensation to the wind farm group to obtain the power value required for compensation of each wind farm includes:

[0062]

[0063] Where, ΔP w2,i represents the power value required to be compensated for the i-th wind farm, k a_f,i represents the frequency regulation capability coefficient of the i-th wind farm, m represents the total number of wind farms participating in frequency regulation control, ΔP w2 Indicates the total power value required for compensation.

[0064] From the above description, it can be seen that sending the total power value required for compensation to the wind farm group and obtaining the power value required for compensation of each wind farm helps the wind turbines in each wind farm to participate in regulation according to the required power value for compensation.

[0065] Furthermore, determining the secondary regulation compensation power value of the wind turbines in each wind farm according to the power value required to be compensated for each wind farm according to the ranking result and the evaluation result includes:

[0066]

[0067] Where, ΔP i,jP represents the secondary regulation compensation power value of the j-th wind turbine participating in the regulation in the i-th wind farm, max,(i,j) Indicates the maximum power that the wind turbine can output at the current wind speed v, P VIC,(i,j) P represents the virtual inertia auxiliary power value of the j-th wind turbine in the i-th wind farm, w,j represents the active power output of the jth wind turbine when it was not participating in the frequency regulation before the accident, o represents the last wind turbine participating in the secondary regulation when the compensation power required for the secondary regulation is completed, n represents the total number of wind turbines in a single wind farm, P wn,j represents the rated power of the j-th wind turbine, P MPPT,j represents the output power of the jth wind turbine in the maximum power point tracking control mode at the current wind speed, v n Indicates the rated wind speed.

[0068] From the above description, it can be seen that the secondary regulation compensation power value of the wind turbines in each wind farm is determined according to the ranking results and evaluation results based on the power value required for compensation of each wind farm, thereby achieving an orderly distribution of the regulation power among different wind turbines and effectively improving the system's ability to cope with emergency conditions.

[0069] Please refer to Figure 2 Another embodiment of the present invention provides a wind power adaptive emergency control terminal that takes into account the frequency regulation capability of a wind turbine generator set, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, each step of the above-mentioned wind power adaptive emergency control method that takes into account the frequency regulation capability of a wind turbine generator set is implemented.

[0070] The wind power adaptive emergency control method and terminal considering the frequency regulation capability of wind turbines described above are applicable to power system frequency regulation scenarios in which wind turbines participate. The following is an explanation of the specific implementation methods:

[0071] Please refer to Figure 1 、 Figure 3 and Figure 4 , embodiment 1 of the present invention is:

[0072] A wind power adaptive emergency control method considering the frequency regulation capability of a wind turbine generator system comprises the following steps:

[0073] S1. Calculate the frequency regulation capability coefficient of the wind farm group and determine the coordinated control coefficient of the wind farm group, specifically including S11-S14:

[0074] S11. Obtain the current speed and rated speed of the wind turbine generator set, and calculate the frequency regulation capability coefficient of the wind turbine generator set based on the current speed and the rated speed, specifically:

[0075]

[0076] a=ω w / ω wn ;

[0077] Where k a represents the frequency regulation capability coefficient of the wind turbine, and a represents the current speed of the wind turbine ω w With rated speed ω wn ratio.

[0078] In an optional embodiment, the wind turbine generator set includes a direct-drive wind turbine. w1 Above, wind turbines participate in frequency regulation response, usually w1 Set to 0.6 times the rated speed.

[0079] S12, calculating the frequency regulation capability coefficient of the wind farm based on the frequency regulation capability coefficient of the wind turbine generator, specifically including S121-S122:

[0080] S121. Equivalently convert the wind farm into equivalent units, and determine the rated capacity of the equivalent units according to the rated capacity of each wind turbine in the wind farm, specifically:

[0081]

[0082] Where, P fn Indicates the rated capacity of the equivalent unit, P wn,j represents the rated capacity of the jth wind turbine in the wind farm, and n represents the total number of wind turbines in a single wind farm.

[0083] Since the product of the rated capacity of the unit and the inertia time constant is the rotational kinetic energy of the wind turbine at the rated speed, as shown in S122:

[0084] S122. Calculate the frequency regulation capability coefficient of the wind farm based on the principle of equal rotational kinetic energy according to the frequency regulation capability coefficient of the wind turbine generator set, the rated capacity of the wind turbine generator set, the inertia time constant of the wind turbine generator set, and the rated capacity of the equivalent turbine generator set, specifically:

[0085]

[0086] Where k a_f Represents the frequency regulation capability coefficient of the wind farm, P fn Indicates the rated capacity of the equivalent unit, H f represents the equivalent inertia time constant of the equivalent unit, k a,j represents the frequency regulation capability coefficient of the j-th wind turbine in the wind farm, P wn,j represents the rated capacity of the jth wind turbine in the wind farm, H w,jIt represents the inertia time constant of the j-th wind turbine in the wind farm.

[0087] S13. Calculating the frequency regulation capability coefficient of the wind farm group based on the frequency regulation capability coefficient of the wind farm, specifically including S131-S132:

[0088] S131. Equivalently convert the wind farm group into equivalent units, and determine the rated capacity of the equivalent units of the wind farm group based on the rated capacity of each wind farm in the wind farm group, specifically:

[0089]

[0090] Where, P fsn represents the rated capacity of the equivalent units of the wind farm group, m represents the total number of wind farms participating in frequency regulation control, P fn,i represents the rated capacity of the i-th wind farm.

[0091] S132. Calculate the frequency regulation capability coefficient of the wind farm group based on the principle of equal rotational kinetic energy according to the frequency regulation capability coefficient of the wind farm, the rated capacity of the wind farm, the equivalent inertia time constant of the wind farm, and the rated capacity of the equivalent units of the wind farm group, specifically:

[0092]

[0093] Where k a_fs Represents the frequency regulation capability coefficient of the wind farm group, H fs represents the equivalent inertia time constant of the wind farm group, k a_f,i represents the frequency regulation capability coefficient of the i-th wind farm, H f,i represents the equivalent inertia time constant of the i-th wind farm.

[0094] S14. Determine the coordinated control coefficient of the wind farm group.

[0095] Specifically, the coordinated control coefficient of the wind farm group is determined according to the inertia time constant of the wind turbine generator set of each wind farm in the wind farm group and the equivalent inertia time constant of the wind farm group.

[0096] χ fs,(i,j) =H w,(i,j) / H fs ;

[0097] Where, χ fs,(i,j) represents the coordinated control coefficient of the wind farm group, H w,(i,j) represents the inertia time constant of the j-th wind turbine in the i-th wind farm in the wind farm group.

[0098] The sending process takes into account the most ideal situation, assuming that there is no delay in each link from the step-by-step aggregation of wind turbine status to the step-by-step allocation of frequency modulation power. Therefore, in an optional embodiment, after S14, the following steps are further included:

[0099] Considering the frequency regulation capability of the wind farm group, the frequency regulation auxiliary power of the wind farm group is obtained as:

[0100]

[0101] Where, P VIC_fs represents the frequency regulation auxiliary power of the wind farm group, k p_fs represents the first virtual inertia control coefficient of the wind farm group, Δf represents the frequency drop, γ represents the virtual inertia coefficient, k d1_fs represents a second virtual inertia control coefficient of the wind farm group;

[0102] The virtual inertia auxiliary power value of the wind turbines in each wind farm is calculated based on the coordinated control coefficient of the wind farm group:

[0103]

[0104] Where, P VIC,(i,j) represents the virtual inertia auxiliary power value of the j-th wind turbine in the i-th wind farm, the frequency regulation capability coefficient of the j-th wind turbine in the i-th wind farm, k p,(i,j) represents the first virtual inertia control coefficient of the j-th wind turbine in the i-th wind farm, k d1,(i,j) It represents the second virtual inertia control coefficient of the j-th wind turbine in the i-th wind farm.

[0105] S2. If the grid frequency is lower than the starting threshold for the wind farm to participate in frequency regulation, a virtual inertia collaborative control method is used to control the wind farm group to participate in primary frequency regulation based on the frequency regulation capability coefficient of the wind farm group and the collaborative control coefficient, and the maximum value of the frequency drop is estimated according to the power shortage size and the frequency regulation capability coefficient of the wind farm group to obtain an estimated value of the maximum value of the frequency drop.

[0106] In an optional implementation, the primary frequency regulation dead zone of the wind turbine generator set is set to 0.1 Hz, and the starting threshold for the wind farm to participate in the frequency regulation is 49.9 Hz.

[0107] The step of estimating the maximum value of the frequency drop based on the power shortage size and the frequency regulation capability coefficient of the wind farm group to obtain an estimated value of the maximum value of the frequency drop includes:

[0108]

[0109] Where, represents the estimated value of the maximum value of the frequency drop, It represents the estimated value of the auxiliary power of the wind farm frequency regulation when the frequency drops to the maximum value, ΔP represents the power shortage of the power grid at the current moment, and α represents the proportional coefficient of the required wind power participating in the frequency regulation.

[0110] During the actual primary frequency regulation process, wind turbines don't proactively make additional adjustments based on the magnitude of the disturbance or their own status, resulting in some units not fully utilizing their reserve power. Therefore, based on an assessment of the units' remaining adjustable capacity, it's possible to further leverage the wind farm's excess capacity for emergency control, reducing the frequency deviation range. When the estimated grid frequency drops beyond a preset safety threshold, the grid dispatch center will issue an emergency control command for the wind farm's active power, ushering in the secondary regulation phase, as described below.

[0111] S3, determining whether the estimated value of the maximum frequency drop value is greater than a preset safety threshold; if so, evaluating the remaining adjustable capacity of the wind turbines in the wind farm group to obtain an evaluation result, and ranking the wind turbines according to the evaluation result to obtain a ranking result, specifically including S31-S35:

[0112] S31, determine whether the estimated value of the maximum frequency drop is greater than the preset safety threshold f s If yes, then calculate the various evaluation indicators of the wind turbines in the wind farm group, the evaluation indicators including the wind turbine power value that can be increased, the wind turbine power change trend that is predicted, the tip speed ratio of the wind turbine, the pitch angle of the wind turbine, the wind power utilization rate of the wind turbine, and the regulation rate of the wind turbine, specifically:

[0113]

[0114] Where, P * Indicates the power value that the wind turbine can increase, δ * Indicates the predicted power change trend of wind turbines, represents the tip speed ratio of the wind turbine. represents the pitch angle of the wind turbine, represents the wind power utilization rate of the wind turbine, Indicates the regulation rate of the wind turbine, P max,(i,j) Indicates the maximum power that wind turbine (i, j) can output under the current wind speed v, P w,(i,j) (t) represents the nominal active output value of wind turbine (i, j) measured in real time before participating in frequency regulation, P wp,(i,j) (t+1) represents the predicted output of wind turbine (i, j) at time t+1, P wp,(i,j) (t) represents the predicted output of wind turbine (i, j) at time t, P wn,(i,j) represents the rated power of wind turbine (i, j), λ optrepresents the optimal tip speed ratio, λ (i,j) represents the nominal value of the tip speed ratio of the wind turbine (i, j) measured in real time, β (i,j) It represents the nominal value of the pitch angle measured in real time by the wind turbine (i, j), Q (i,j) represents the cumulative power generation of wind turbine (i, j) during the statistical period, ΔT represents the corresponding statistical time length, l represents the total number of tests, ΔP (i,j),h Indicates the power change value of wind turbine (i, j) in the hth test, Δt h Indicates the time length corresponding to h tests.

[0115] S32: Determine the weight of each evaluation index of the wind turbine generator system using an entropy method.

[0116] Specifically, assuming that the object to be evaluated is n wind turbines in the i-th wind farm, and the measurement criteria are composed of the above six evaluation indicators, then the initial matrix X of the sample is n×6 for:

[0117]

[0118] Where x jk represents the value of the kth evaluation index corresponding to the jth wind turbine group, j = (1, 2, ..., n), k = (1, 2, ..., 6),

[0119] For the kth indicator, first calculate the information entropy value e k , and then calculate the information utility value g of each evaluation index k ,for:

[0120]

[0121] g k It represents the distance between the entropy value and 1. The larger the value, the greater the impact on the system.

[0122] Calculate the weight b of the kth evaluation index of the jth wind turbine group according to the information utility value of each evaluation index k for:

[0123]

[0124] According to the weight of the kth evaluation index of the jth wind turbine group, the weight coefficient matrix B of each evaluation index of the jth wind turbine group is obtained as B = [b1, b2, b3, b4, b5, b6].

[0125] S33. Calculate the evaluation set of the wind turbine generator system under each evaluation index using a semi-trapezoidal distribution as a membership function.

[0126] Specifically, assuming that the kth evaluation index is divided into three levels: "excellent", "good", and "poor", "excellent" means that the wind turbine has a very strong control capability, "good" means that the control capability is gradually weakening, and "poor" means that the wind turbine is not suitable as a control target. Assuming that the three level dividing points are a, b, and c, they are:

[0127]

[0128]

[0129] Where, represents the membership function of the k-th evaluation index with a grade of "excellent", represents the membership function of the k-th evaluation index with a grade of "good", represents the membership function of the k-th evaluation index with a grade of "poor";

[0130] Calculate the score f of the j-th wind turbine generator under the k-th evaluation index according to the membership function jk for:

[0131]

[0132] According to the score of the j-th wind turbine under the k-th evaluation index, the evaluation set F of the wind turbine under each evaluation index is obtained. j F j =[f j1 ,f j2 ,f j3 ,f j4 ,f j5 ,f j6 ].

[0133] S34: Calculate the evaluation value of the wind turbine generator system using a weighted summation formula based on the weight and the evaluation set, and obtain a comprehensive score based on the evaluation value, specifically:

[0134]

[0135] Where A j represents the evaluation value of the j-th wind turbine generator set, C j Represents the comprehensive score of the j-th wind turbine.

[0136] S35. Sort the wind turbines in descending order according to the comprehensive scores to obtain a sorting result.

[0137] S4. Determine a total power value required for compensation according to a preset secondary regulation ratio, and send the total power value required for compensation to the wind farm group to obtain a power value required for compensation of each wind farm.

[0138] The step of sending the total power value required for compensation to the wind farm group to obtain the power value required for compensation for each wind farm includes:

[0139]

[0140] Where, ΔP w2,i represents the power value required to be compensated for the i-th wind farm, k a_f,i represents the frequency regulation capability coefficient of the i-th wind farm, ΔP w2 Indicates the total power value required for compensation.

[0141] S5, according to the power value required to be compensated for each wind farm, determine the secondary adjustment compensation power value of the wind turbines in each wind farm according to the sorting result and the evaluation result, and issue a secondary adjustment instruction to each wind farm according to the secondary adjustment compensation power value, such as Figure 3 shown.

[0142] The step of determining the secondary adjustment compensation power value of the wind turbines in each wind farm according to the power value required to be compensated for each wind farm and the ranking result and the evaluation result includes:

[0143]

[0144] Where, ΔP i,j P represents the secondary regulation compensation power value of the j-th wind turbine participating in the regulation in the i-th wind farm, w,j represents the active power output of the jth wind turbine when it was not participating in the frequency regulation before the accident, o represents the last wind turbine participating in the secondary regulation when the compensation power required for the secondary regulation is completed, n represents the total number of wind turbines in a single wind farm, P wn,j represents the rated power of the j-th wind turbine, P MPPT,j represents the output power of the jth wind turbine in the maximum power point tracking control mode at the current wind speed, v n Indicates the rated wind speed.

[0145] Taking the operating data provided by the wind farm SACDA (Supervisory Control and Data Acquisition) system as an example, the numerical results of various evaluation indicators of the 20 wind turbines in the wind farm are calculated, as shown in Table 1. The results are valid in the next active power regulation cycle.

[0146] Table 1 Numerical calculation results of various evaluation indicators of wind turbines

[0147]

[0148]

[0149] For the convenience of solving, when δ * When it is negative, let it be an infinitesimal positive number. On this basis, the weight of each evaluation index in the process of active power regulation capability is determined as shown in Table 2.

[0150] Table 2 The weight of each evaluation index in the process of active power regulation capability

[0151]

[0152] Then, the quantified comprehensive score of the control capability of each wind turbine is calculated by combining the fuzzy membership function evaluation set, and the ranking is obtained as shown in Table 3.

[0153] Table 3 Ranking results of wind turbines

[0154] Wind turbine number score Sorting 1 3.1938 3 2 2.0020 12 3 1.7173 16 4 3.0317 4 5 3.2247 2 6 3.7870 1 7 2.7649 7 8 1.9291 13 9 1.3025 17 10 1.8278 14 11 2.5328 8 12 1.2713 19 13 2.8001 6 14 2.8678 5 15 2.4728 9 16 1.2944 18 17 1.7613 15 18 2.3763 10 19 1.1309 20 20 2.1056 11

[0155] The power allocation of wind turbines in secondary regulation is determined based on the evaluation results and ranking results.

[0156] Considering a system with a wind power penetration rate of 30%, a disturbance of a total amount of 0.08pu occurs at 2s. The wind farm issues an emergency control command 0.5s after the disturbance. Combining primary frequency regulation with secondary regulation, the frequency regulation results of the following three scenarios are compared: ① Emergency control without secondary regulation; ② Secondary regulation adopts the unit average control method, and all units are in action; ③ Secondary regulation adopts the adaptive allocation method of the present invention, and the action command is only issued to the first 16 units. The comparison results are as follows: Figure 4 As shown, it can be seen that the above method of the present invention fully utilizes the surplus adjustment capacity of the wind turbine generator set, and taps the ability of the wind turbine generator set to participate in system adjustment under emergency conditions from the perspective of the wind farm group, thereby effectively improving the system's ability to cope with emergency conditions and improving the stability of power grid operation.

[0157] Please refer to Figure 2 , the second embodiment of the present invention is:

[0158] A wind power adaptive emergency control terminal that takes into account the frequency regulation capability of a wind turbine generator set comprises a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, each step of the wind power adaptive emergency control method that takes into account the frequency regulation capability of the wind turbine generator set in Example 1 is implemented.

[0159] In summary, the present invention provides a wind power adaptive emergency control method and terminal that takes into account the frequency regulation capability of wind turbines. When the grid frequency is lower than the starting threshold for the wind farm to participate in frequency regulation, a virtual inertia collaborative control method is used to control the wind farm group to participate in primary frequency regulation based on the frequency regulation capability coefficient and collaborative control coefficient of the wind farm group. Then, when the estimated value of the maximum value of the estimated frequency drop is greater than the preset safety threshold, the remaining adjustable capacity of the wind turbines in the wind farm group is evaluated, and the wind turbines are sorted according to the evaluation results to obtain the sorting results. The determined total power value required for compensation is sent to the wind farm group, and the secondary regulation compensation power value of the wind turbines in each wind farm is determined according to the sorting results and the evaluation results according to the power value required for compensation of each wind farm. The secondary regulation instructions are sent to the wind farm group based on the power value required for compensation of each wind farm. Each wind farm adopts the virtual inertia collaborative control method to enable the wind farm group to participate in the primary frequency regulation, and then decides whether to conduct secondary regulation based on the actual situation after the primary frequency regulation. It fully utilizes the surplus regulation capacity of the wind turbines, and explores the ability of the wind turbines to participate in system regulation in emergency situations from the perspective of the wind farm group, thereby effectively improving the system's ability to cope with emergency conditions and improving the stability of the power grid operation. In addition, the evaluation indicators of the wind turbines include the wind turbine's boostable power value, the wind turbine's predicted power change trend, the wind turbine's tip speed ratio, the wind turbine's pitch angle, the wind power utilization rate of the wind turbine, and the wind turbine's regulation rate, thereby ensuring that wind turbines with higher regulation response speed, adjustable capacity and operational reliability participate in the secondary regulation first, ensuring the best regulation effect.

[0160] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A wind power adaptive emergency control method considering the frequency regulation capability of wind turbines, characterized in that: Including steps: Calculating a frequency regulation capability coefficient of a wind farm group and determining a coordinated control coefficient of the wind farm group; If the grid frequency is lower than the starting threshold for the wind farm to participate in frequency regulation, a virtual inertia collaborative control method is used to control the wind farm group to participate in primary frequency regulation based on the frequency regulation capability coefficient of the wind farm group and the collaborative control coefficient, and a maximum frequency drop is estimated according to the power shortage size and the frequency regulation capability coefficient of the wind farm group to obtain an estimated value of the maximum frequency drop; determining whether the estimated value of the maximum frequency drop is greater than a preset safety threshold; if so, evaluating the remaining adjustable capacity of the wind turbines in the wind farm group to obtain an evaluation result, and ranking the wind turbines according to the evaluation result to obtain a ranking result; Determining a total power value required for compensation according to a preset secondary regulation ratio, and sending the total power value required for compensation to the wind farm group to obtain the power value required for compensation of each wind farm; Determining, according to the power values ​​required to be compensated for the respective wind farms, secondary adjustment compensation power values ​​for the wind turbines in the respective wind farms in accordance with the ranking results and the evaluation results, and issuing secondary adjustment instructions to the respective wind farms according to the secondary adjustment compensation power values; The evaluation of the remaining adjustable capacity of the wind turbines in the wind farm group to obtain the evaluation result includes: Calculating various evaluation indicators of the wind turbines in the wind farm group, the evaluation indicators including the wind turbine's scalable power value, the wind turbine's predicted power change trend, the wind turbine's tip speed ratio, the wind turbine's pitch angle, the wind turbine's wind power utilization rate, and the wind turbine's regulation rate; Determining the weights of the various evaluation indicators of the wind turbine generator system using an entropy method; Calculating an evaluation set of the wind turbine generator system under each evaluation index using a semi-trapezoidal distribution as a membership function; Calculating an evaluation value of the wind turbine generator system using a weighted summation formula according to the weight and the evaluation set, and obtaining a comprehensive score according to the evaluation value; The wind turbines are sorted according to the evaluation results to obtain a sorting result, which includes: The wind turbines are sorted in descending order according to the comprehensive scores to obtain a sorting result.

2. A wind power adaptive emergency control method considering the frequency regulation capability of wind turbines according to claim 1, characterized in that: The calculation of the frequency regulation capability coefficient of the wind farm group includes: Obtaining a current speed and a rated speed of the wind turbine generator set, and calculating a frequency regulation capability coefficient of the wind turbine generator set based on the current speed and the rated speed; Calculating a frequency regulation capability coefficient of a wind farm based on the frequency regulation capability coefficient of the wind turbine generator set; The frequency regulation capability coefficient of the wind farm group is calculated based on the frequency regulation capability coefficient of the wind farm.

3. A wind power adaptive emergency control method considering the frequency regulation capability of wind turbines according to claim 2, characterized in that: The calculating of the frequency regulation capability coefficient of the wind farm based on the frequency regulation capability coefficient of the wind turbine generator includes: Equivalently dividing the wind farm into equivalent units, and determining the rated capacity of the equivalent units according to the rated capacity of each wind turbine in the wind farm; The frequency regulation capability coefficient of the wind farm is calculated based on the principle of equal rotational kinetic energy according to the frequency regulation capability coefficient of the wind turbine generator set, the rated capacity of the wind turbine generator set, the inertia time constant of the wind turbine generator set and the rated capacity of the equivalent generator set.

4. The wind power adaptive emergency control method considering the frequency regulation capability of wind turbines according to claim 3, characterized in that: The calculation of the frequency regulation capability coefficient of the wind farm based on the principle of equal rotational kinetic energy according to the frequency regulation capability coefficient of the wind turbine generator set, the rated capacity of the wind turbine generator set, the inertia time constant of the wind turbine generator set, and the rated capacity of the equivalent turbine generator set includes: ； Where, represents the frequency regulation capability coefficient of the wind farm, Indicates the rated capacity of the equivalent unit, represents the equivalent inertia time constant of the equivalent unit, n represents the total number of wind turbines in a single wind farm, represents the frequency regulation capability coefficient of the j-th wind turbine in the wind farm, represents the rated capacity of the j-th wind turbine in the wind farm, It represents the inertia time constant of the j-th wind turbine in the wind farm.

5. The wind power adaptive emergency control method considering the frequency regulation capability of wind turbines according to claim 1, characterized in that: Determining the coordinated control coefficient of the wind farm group includes: The coordinated control coefficient of the wind farm group is determined according to the inertia time constant of the wind turbine generator set of each wind farm in the wind farm group and the equivalent inertia time constant of the wind farm group.

6. The wind power adaptive emergency control method considering the frequency regulation capability of wind turbines according to claim 1, characterized in that: The estimating the maximum value of the frequency drop according to the power shortage size and the frequency regulation capability coefficient of the wind farm group to obtain the estimated value of the maximum value of the frequency drop includes: ； ； Where, represents the estimated value of the maximum value of the frequency drop, It represents the estimated value of the wind farm frequency regulation auxiliary power when the frequency drops to the maximum value. represents the frequency regulation capability coefficient of the wind farm group, represents the first virtual inertia control coefficient of the wind farm group, Indicates the power shortage of the power grid at the current moment, Indicates the proportional coefficient of wind power required to participate in frequency regulation.

7. The wind power adaptive emergency control method considering the frequency regulation capability of wind turbines according to claim 1, characterized in that: The step of sending the total power value required for compensation to the wind farm group to obtain the power value required for compensation for each wind farm includes: ； Where, represents the power value required to be compensated for the i-th wind farm, represents the frequency regulation capability coefficient of the i-th wind farm, m represents the total number of wind farms participating in frequency regulation control, Indicates the total power value required for compensation.

8. The wind power adaptive emergency control method considering the frequency regulation capability of wind turbines according to claim 7, characterized in that: The determining of the secondary adjustment compensation power value of the wind turbine generator set in each wind farm according to the power value required to be compensated by each wind farm according to the sorting result and the evaluation result includes: ； ； Where, represents the secondary regulation compensation power value of the j-th wind turbine participating in the regulation in the i-th wind farm, Indicates the maximum power that the wind turbine can output at the current wind speed v. represents the virtual inertia auxiliary power value of the j-th wind turbine in the i-th wind farm, represents the active power output of the jth wind turbine when it was not participating in the frequency regulation before the accident. o represents the last wind turbine participating in the secondary regulation when the compensation power required for the secondary regulation is completed. n represents the total number of wind turbines in a single wind farm. represents the rated power of the j-th wind turbine, represents the output power of the j-th wind turbine in the maximum power point tracking control mode at the current wind speed, Indicates the rated wind speed.

9. A wind power adaptive emergency control terminal considering the frequency regulation capability of a wind turbine generator system, 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, each step of the wind power adaptive emergency control method considering the frequency regulation capability of the wind turbine generator system according to any one of claims 1 to 8 is implemented.

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