A robustness evaluation method, device, equipment and medium for oscillation suppression strategy

Abstract

The oscillation suppression strategy robustness evaluation method, device, equipment and medium disclosed in the present invention extract the oscillation suppression frequency components of the voltage and current signals sampled under the current strategy of the power network based on signal decomposition technology, and calculate the active power according to the parameters of the power network; construct the oscillation scenario of the doubly-fed asynchronous wind turbine system, determine the active power peak output of each oscillation scenario; perform periodic analysis on the active power, and calculate the power characteristic index and robust characteristic index in combination with the active power peak output of each oscillation scenario. This scheme can realize the quantitative evaluation of the robustness of the suppression strategy, provide an index reference for the applicability optimization of the oscillation suppression strategy in a wide frequency band, and is conducive to oscillation suppression and improving system stability.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy grid-connected control, and in particular to a method, device, equipment and medium for evaluating the robustness of an oscillation suppression strategy. Background Art

[0002] With the large-scale grid connection of new energy, the formation of high-voltage direct current transmission networks and the commissioning of power electronic loads, modern power systems have shown the characteristics of a high proportion of renewable energy and a high proportion of power electronic equipment (referred to as "double high"). The interaction between power electronic equipment and the power grid in the "double high" power system will cause broadband oscillations with frequencies ranging from a few hertz to several thousand hertz. Broadband oscillations may damage power equipment, cause shutdown of new energy generators, etc., seriously affect equipment safety and threaten the stable operation of the system, becoming an important factor restricting the efficient consumption of new energy.

[0003] Most existing oscillation suppression strategies are designed for specific frequency bands. Although there are corresponding oscillation suppression strategies for multiple frequency bands, there is a lack of quantitative evaluation of the robustness of the provided suppression strategies, which is not conducive to the applicability and optimization of the suppression strategies. Summary of the invention

[0004] In view of the above-mentioned defects, the present invention provides an oscillation suppression strategy robustness evaluation method, device, equipment and medium, which can realize the quantitative evaluation of the robustness of the suppression strategy and provide an indicator reference for optimizing the applicability of the oscillation suppression strategy in a wide frequency band.

[0005] An embodiment of the present invention provides a method for evaluating the robustness of an oscillation suppression strategy, the method comprising:

[0006] Based on the signal decomposition technology, the voltage and current signals sampled under the current strategy of the power network are subjected to extraction of suppressed oscillation frequency components, and active power is calculated according to the parameters of the power network;

[0007] Construct oscillation scenarios of the doubly-fed asynchronous wind turbine generator system and determine the active power peak output of each oscillation scenario;

[0008] The active power is analyzed periodically, and the power characteristic index and the robust characteristic index are calculated in combination with the active power peak value output in each oscillation scenario.

[0009] Preferably, based on the signal decomposition technology, the voltage and current signals sampled under the current strategy of the power network are subjected to extraction of suppressed oscillation frequency components, and active power is calculated according to the parameters of the power network, including:

[0010] Acquire voltage and current signals sampled from the power network;

[0011] Extraction of suppressed oscillation frequency components of sampled voltage and current signals based on signal decomposition technology;

[0012] Determining a time domain waveform of active power according to the extracted frequency components and the parameters of the power network;

[0013] The active power at each moment is obtained according to the determined time domain waveform.

[0014] Preferably, constructing oscillation scenarios of a doubly-fed asynchronous wind turbine generator system and determining the active power peak output of each oscillation scenario include:

[0015] According to the parameters of the grid structure of the doubly-fed asynchronous wind turbine system, a sub-supersynchronous oscillation scenario of the doubly-fed wind turbine is constructed;

[0016] By adjusting the parameters of the offshore wind power grid-connected control system and the wind speed, two subsynchronous oscillation scenarios with different frequencies are constructed.

[0017] Building a medium and high frequency oscillation scenario according to the double-fed asynchronous wind turbine generator system;

[0018] By adjusting the parameters of the offshore wind power grid-connected control system and the capacitance of the equivalent cable, two medium and high frequency oscillation scenarios are constructed;

[0019] The active power peak value output in each oscillation scenario is determined according to each constructed oscillation scenario.

[0020] Preferably, the active power is periodically analyzed, and combined with the active power peak value output in each oscillation scenario, a power characteristic index and a robust characteristic index are calculated, including:

[0021] The value of the active power is periodically sampled in each resonance period to obtain an array of active power in each resonance period;

[0022] Normalizing the active power array to obtain a normalized array;

[0023] Calculate the change rate of the normalized array of two adjacent resonant periods to obtain the dynamic characteristic index;

[0024] Calculating the power characteristic index according to a preset power characteristic calculation model and the dynamic characteristic index;

[0025] Calculate the weight corresponding to each oscillation scenario according to the active power peak value output by each oscillation scenario;

[0026] Assign corresponding weights to the power characteristic indicators under each oscillation scenario to obtain the weighted power characteristic indicators of each oscillation scenario;

[0027] The robust characteristic index is calculated according to a preset robust characteristic calculation model and a weighted power characteristic index of each oscillation scenario.

[0028] Preferably, the dynamic characteristic index is ;

[0029] Among them, P s (n) represents the dynamic characteristic index of the nth resonance cycle, P sd (n) represents the normalized array of the nth resonance period, P sd (n+1) represents the normalized array of the n+1th resonance period, T h Indicates the duration of the oscillation cycle.

[0030] Preferably, the power characteristic calculation model is: ;

[0031] Among them, P si is the power characteristic index under the i-th oscillation scenario, P s (n) represents the dynamic characteristic index of the nth resonance period, and N is the total number of resonance periods.

[0032] Preferably, the robust characteristic calculation model is ;

[0033] Among them, E s is the robust characteristic index, is the weighted power characteristic index under the i-th oscillation scenario, , P Si is the power characteristic index under the i-th oscillation scenario, K i is the weight in the i-th oscillation scenario, , M is the number of scenes, is the peak active power output in the i-th oscillation scenario.

[0034] An embodiment of the present invention further provides an oscillation suppression strategy robustness evaluation device, the device comprising:

[0035] A decomposition module, used for extracting the suppressed oscillation frequency components of the voltage and current signals sampled under the current strategy of the power network based on the signal decomposition technology, and calculating the active power according to the parameters of the power network;

[0036] A scenario module is used to construct oscillation scenarios of a doubly-fed asynchronous wind turbine generator system and determine the active power peak output of each oscillation scenario;

[0037] The evaluation module is used to perform periodic analysis on the active power and calculate the power characteristic index and the robust characteristic index in combination with the active power peak value outputted in each oscillation scenario.

[0038] An embodiment of the present invention also provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the oscillation suppression strategy robustness evaluation method as described in any one of the above embodiments is implemented.

[0039] An embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the oscillation suppression strategy robustness evaluation method as described in any one of the above embodiments.

[0040] The oscillation suppression strategy robustness evaluation method, device, equipment and medium provided by the present invention extract the oscillation suppression frequency components of the voltage and current signals sampled under the current strategy of the power network based on signal decomposition technology, and calculate the active power according to the parameters of the power network; construct the oscillation scenario of the doubly-fed asynchronous wind turbine system, determine the active power peak output of each oscillation scenario; perform periodic analysis on the active power, and calculate the power characteristic index and the robust characteristic index in combination with the active power peak output of each oscillation scenario. This scheme can realize the quantitative evaluation of the robustness of the suppression strategy and provide an index reference for optimizing the applicability of the oscillation suppression strategy in a wide frequency band. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a flowchart of a method for evaluating the robustness of an oscillation suppression strategy provided by an embodiment of the present invention;

[0042] Figure 2 It is a schematic diagram of the structure of the grid structure of the doubly-fed wind turbine connected to the infinite power grid provided by an embodiment of the present invention;

[0043] Figure 3 It is an FFT analysis oscillation curve diagram of active power at a wind speed of 9.0 N / min provided by an embodiment of the present invention;

[0044] Figure 4 It is an FFT analysis oscillation curve diagram of the system active power at a wind speed of 10.0 N / min provided by an embodiment of the present invention;

[0045] Figure 5 Schematic diagram of the grid structure of a doubly-fed wind turbine grid-connected system via parallel compensation capacitors provided by an embodiment of the present invention;

[0046] Figure 6 It is an FFT analysis oscillation curve diagram of a parallel capacitance of 10 μF and an oscillation frequency of 490 Hz provided in an embodiment of the present invention;

[0047] Figure 7It is an FFT analysis oscillation curve diagram of a parallel capacitance of 20 μF and an oscillation frequency of 475 Hz provided in an embodiment of the present invention;

[0048] Figure 8 is a schematic diagram of the structure of an oscillation suppression strategy robustness evaluation device provided by an embodiment of the present invention;

[0049] Fig. 9 It is a structural diagram of a terminal device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] See also Figure 1 , is a flow chart of a method for evaluating the robustness of an oscillation suppression strategy provided by an embodiment of the present invention, the method comprising steps S1 to S3:

[0052] Step S1, based on signal decomposition technology, extracting the suppressed oscillation frequency components of the voltage and current signals sampled under the current strategy of the power network, and calculating the active power according to the parameters of the power network;

[0053] Step S2, constructing an oscillation scenario of a doubly-fed asynchronous wind turbine generator system, and determining the active power peak value outputted by each oscillation scenario;

[0054] Step S3, performing periodic analysis on the active power, and calculating a power characteristic index and a robust characteristic index in combination with the active power peak value output in each oscillation scenario.

[0055] In the specific implementation of this embodiment, the core idea of ​​defining the robustness evaluation index of the power network is used for reference, and based on the signal decomposition technology, the sampled voltage and current signals are subjected to extraction of the suppressed oscillation frequency components and parameter identification to calculate the active power.

[0056] In order to comprehensively evaluate the oscillation suppression effect of the oscillation suppression strategy, an oscillation scenario is constructed based on a doubly-fed asynchronous wind turbine generator system to meet the verification requirements, and the active power peak output of each oscillation scenario is determined;

[0057] The active power is analyzed periodically, and the power characteristic index and the robust characteristic index are calculated in combination with the active power peak value output in each oscillation scenario.

[0058] The present application scheme is based on a robustness evaluation method for oscillation suppression strategies based on electrical quantity response trajectory characteristics. Two oscillation scenarios are constructed based on the DFIG system, and then a power characteristic index is constructed. A weighted approach is adopted to comprehensively evaluate the oscillation suppression effects of multiple scenarios to construct a robustness evaluation index, so as to comprehensively evaluate the adaptability of different oscillation suppression strategies in a wide frequency band, that is, to quantify the oscillation suppression effect of the oscillation suppression strategy in a wide frequency band. By applying the parameter adaptive strategy and the design strategy for each scenario in different scenarios, the defined index calculation is performed, which verifies the effectiveness and feasibility of the constructed index, and provides an index reference for optimizing the applicability of the oscillation suppression strategy in a wide frequency band.

[0059] In another embodiment provided by the present invention, step S1 includes the following steps:

[0060] Most of the existing oscillation suppression strategies are designed for specific frequency bands. Although there are corresponding oscillation suppression strategies for multiple frequency bands, there is a lack of quantitative evaluation of the wide-band adaptability, i.e., robustness, of the proposed suppression strategies. In order to comprehensively evaluate the adaptability of different oscillation suppression strategies in a wide frequency band, i.e., to quantify the oscillation suppression effect of the oscillation suppression strategy in a wide frequency band, the changes in the time domain waveform of active power can well reflect the suppression effect of the oscillation suppression strategy. At the same time, for the analysis of traditional power frequency stability problems and low-frequency forced power oscillations, the use of the time domain waveform of active power for analysis is more in line with research habits and can enrich the indicator system to make the robustness evaluation results of the oscillation suppression strategy more credible. Therefore, the trajectory characteristics of the time domain waveform of active power P are selected to quantify the oscillation suppression effect.

[0061] Therefore, by acquiring the voltage and current signals sampled from the power network; extracting the suppressed oscillation frequency components of the sampled voltage and current signals based on signal decomposition technology; determining the time domain waveform of the active power according to the extracted frequency components and the parameters of the power network; and obtaining the active power at each moment according to the determined time domain waveform.

[0062] In another embodiment provided by the present invention, the step S2 specifically includes the following steps:

[0063] In order to comprehensively evaluate the oscillation suppression effect of the oscillation suppression strategy, an oscillation scenario is constructed based on the double-fed asynchronous wind turbine generator system DFIG to meet the verification requirements;

[0064] See also Figure 2 , is a schematic diagram of the structure of the grid structure of the doubly-fed wind turbine connected to the infinite power grid provided by an embodiment of the present invention. RSC and GSC are the machine-side converter and the grid-side converter, respectively. Referring to Table 1, is a schematic table of parameters of the grid structure, and a sub-supersynchronous oscillation scenario of the doubly-fed wind turbine is constructed based on the specific parameters in Table 1.

[0065] Table 1 Parameters of grid structure

[0066]

[0067] According to the parameters of the grid structure of the doubly-fed asynchronous wind turbine system, a sub-supersynchronous oscillation scenario of the doubly-fed wind turbine is constructed;

[0068] When the system is running stably, see Figure 3 , is an FFT analysis oscillation curve diagram of active power at a wind speed of 9.0 N / min provided by an embodiment of the present invention, that is, the oscillation amplitude at different frequencies, and the oscillation frequency of the peak value at this time is 27.5 Hz.

[0069] When the system is running stably, see Figure 4 , is an FFT analysis oscillation curve diagram of the system active power at a wind speed of 10.0 N / min provided in an embodiment of the present invention, where the peak oscillation frequency is 22.5 Hz.

[0070] By adjusting the parameters of the offshore wind power grid-connected control system and the wind speed, two subsynchronous oscillation scenarios with different frequencies are constructed.

[0071] Building a medium and high frequency oscillation scenario according to the double-fed asynchronous wind turbine generator system;

[0072] By adjusting the parameters of the offshore wind power grid-connected control system and the capacitance of the equivalent cable, two medium and high frequency oscillation scenarios are constructed;

[0073] In summary, by adjusting the parameters of the wind power grid-connected control system and the wind speed, subsynchronous oscillation scenarios with two frequencies of 27.5 Hz and 22.5 Hz can be constructed.

[0074] See also Figure 5 , is a schematic diagram of the grid structure of a doubly-fed wind turbine grid-connected system through parallel compensation capacitors provided by an embodiment of the present invention. See Table 2, which is the parameters of the generator and the converter.

[0075] Table 2 Parameters of generator and converter

[0076]

[0077] The high-frequency oscillation scenario of the doubly-fed wind turbine is constructed according to the generator and converter parameters in Table 2. Changes in the equivalent capacitance of the cable will affect the high-frequency resonance frequency of the doubly-fed wind power grid-connected system, see Figure 6 , is an FFT analysis oscillation curve diagram of a parallel capacitance of 10 μF and an oscillation frequency of 490 Hz provided by an embodiment of the present invention. Figure 7 , is an FFT analysis oscillation curve diagram of a parallel capacitance of 20μF and an oscillation frequency of 475Hz provided by an embodiment of the present invention. The FFT analysis oscillation curve of the active power of a double-fed wind power grid-connected system with different cable equivalent capacitance values ​​is used. The resonant frequency of the grid-connected system is offset due to the influence of the cable equivalent capacitance value.

[0078] By adjusting the parameters of the offshore wind power grid-connected control system and the capacitance of the equivalent cable, medium and high frequency oscillation scenarios with frequencies of 475 Hz and 490 Hz can be constructed.

[0079] The active power peak value output in each oscillation scenario is determined according to each constructed oscillation scenario.

[0080] In another embodiment provided by the present invention, the step S3 specifically includes the following steps:

[0081] The active power array P(n) within the analysis period is obtained by cyclically sampling the value of P with each resonance period Th as a period;

[0082] In order to eliminate the influence of different types of oscillation amplitudes on the accuracy of system active power evaluation, P(n) is normalized to obtain a normalized array;

[0083] Calculate the change rate of the normalized array of two adjacent resonant periods to obtain the dynamic characteristic index;

[0084] The power characteristic index is calculated according to a preset power characteristic calculation model and the dynamic characteristic index; the weight corresponding to each oscillation scenario is calculated according to the active power peak value output by each oscillation scenario;

[0085] Assign corresponding weights to the power characteristic indicators under each oscillation scenario to obtain the weighted power characteristic indicators of each oscillation scenario;

[0086] In order to eliminate the different active power amplitudes generated by different working conditions, sampling times, and scenarios, the robust characteristic index E s The influence of this strategy makes the indicator E s More reasonable and effective, giving different weights K to the power characteristic index Ps i And the weighted P s Named as weighted power characteristic index P di In order to meet the needs of robustness verification of the fixed parameter suppression strategy in multi-band oscillation scenarios, a robust characteristic index E is constructed. s , calculating the robust characteristic index according to a preset robust characteristic calculation model and a weighted power characteristic index of each oscillation scenario.

[0087] In another embodiment provided by the present invention, the active power array P(n) is normalized to obtain an expression of the active power array Psd(n): ;

[0088] Among them, P max is the maximum value of P(n) in the oscillation evaluation interval, P min is the minimum value of P(n) within the oscillation evaluation interval.

[0089] To quantify P sd (n) changes, and the P obtained from two adjacent oscillation cycles is sd The rate of change of (n) is defined as the dynamic characteristic index P s (n).

[0090] ;

[0091] Among them, P s (n) represents the dynamic characteristic index of the nth resonance cycle, P sd (n) represents the normalized array of the nth resonance period, P sd (n+1) represents the normalized array of the n+1th resonance period, T h Indicates the duration of the oscillation cycle.

[0092] So the resonant period T h P is calculated for the calculation period. sd (n), the growth and decay of the value calculated in each adjacent cycle and P s (n) corresponds to a positive or negative value, and the speed of growth or decay is determined by P s The value of (n) is reflected.

[0093] In another embodiment provided by the present invention, the power characteristic calculation model is defined as: ;

[0094] Among them, P si is the power characteristic index under the i-th oscillation scenario, P s (n) represents the dynamic characteristic index of the nth resonance period, and N is the total number of resonance periods.

[0095] That is, the power characteristic index under each oscillation scenario during calculation .

[0096] Based on the trend of active power amplitude growth and attenuation in the evaluation interval and the mapping relationship between the stability time, further analysis shows that the larger the power characteristic index of the complex power system, the greater its contribution to oscillation suppression, that is, the better the effect of the oscillation suppression strategy; the smaller the power characteristic index of the complex power system, the smaller its contribution to oscillation suppression, that is, the worse the effect of the oscillation suppression strategy. Therefore, through the relative size of the power characteristic index, the contribution of the oscillation suppression strategy to oscillation suppression in the "double high" power system in the wide frequency domain can be evaluated, thereby achieving the purpose of evaluating its robustness.

[0097] In another embodiment provided by the present invention, in order to meet the requirement of robustness verification of the suppression strategy of fixed parameters in multi-band oscillation scenarios, a robust characteristic index E is constructed. s .

[0098] The robust characteristic calculation model is: ;

[0099] Among them, E s is the robust characteristic index, is the weighted power characteristic index under the i-th oscillation scenario, , P Si is the power characteristic index under the i-th oscillation scenario, K i is the weight in the i-th oscillation scenario, , M is the number of scenes, is the peak active power output in the i-th oscillation scenario.

[0100] The empowerment idea is adopted to comprehensively consider the oscillation suppression effects in multiple scenarios to construct a robustness evaluation index, so as to comprehensively evaluate the adaptability of different oscillation suppression strategies in a wide frequency band, that is, to quantify the oscillation suppression effect of the oscillation suppression strategy in a wide frequency band. By applying the parameter adaptation strategy and the design strategy for each scenario in different scenarios, the defined indicator calculation is performed, which verifies the effectiveness and feasibility of the constructed indicator, and provides an indicator reference for optimizing the applicability of the oscillation suppression strategy in a wide frequency band.

[0101] The embodiment of the present invention also provides an oscillation suppression strategy robustness evaluation device, see Figure 8 , is a schematic diagram of the structure of an oscillation suppression strategy robustness evaluation device provided by an embodiment of the present invention, the device comprising:

[0102] A decomposition module, used for extracting the suppressed oscillation frequency components of the voltage and current signals sampled under the current strategy of the power network based on the signal decomposition technology, and calculating the active power according to the parameters of the power network;

[0103] A scenario module is used to construct oscillation scenarios of a doubly-fed asynchronous wind turbine generator system and determine the active power peak output of each oscillation scenario;

[0104] The evaluation module is used to perform periodic analysis on the active power and calculate the power characteristic index and the robust characteristic index in combination with the active power peak value outputted in each oscillation scenario.

[0105] It should be noted that the oscillation suppression strategy robustness evaluation device provided in the embodiment of the present invention can execute the oscillation suppression strategy robustness evaluation method described in any of the above embodiments, and the specific functions of the oscillation suppression strategy robustness evaluation device are not described in detail herein.

[0106] See also Fig. 9, is a schematic diagram of the structure of a terminal device provided in an embodiment of the present invention. The terminal device of this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor, such as an oscillation suppression strategy robustness evaluation program. When the processor executes the computer program, the steps in the above-mentioned oscillation suppression strategy robustness evaluation method embodiments are implemented, such as Figure 1 Steps S1 to S3 are shown. Or the processor implements the functions of each module in the above-mentioned device embodiments when executing the computer program.

[0107] Exemplarily, the computer program may be divided into one or more modules / units, and the one or more modules / units are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units may be a series of computer program instruction segments that can complete functions, and the instruction segments are used to describe the execution process of the computer program in the terminal device. For example, the computer program may be divided into various modules, and the specific functions of each module are not described again.

[0108] The terminal device may be a computing device such as a desktop computer, a notebook, a PDA, and a cloud server. The terminal device may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that the schematic diagram is merely an example of a terminal device and does not constitute a limitation on the terminal device. The terminal device may include more or fewer components than shown in the diagram, or may combine certain components, or different components. For example, the terminal device may also include an input / output device, a network access device, a bus, etc.

[0109] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the terminal device, and uses various interfaces and lines to connect various parts of the entire terminal device.

[0110] The memory can be used to store the computer program and / or module, and the processor realizes various functions of the terminal device by running or executing the computer program and / or module stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0111] Wherein, if the module / unit integrated in the terminal device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Wherein, the computer program includes computer program code, and the computer program code can be in code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0112] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A robustness evaluation method for an oscillation suppression strategy, characterized in that: The method comprises: Based on the signal decomposition technology, the voltage and current signals sampled under the current strategy of the power network are subjected to extraction of suppressed oscillation frequency components, and active power is calculated according to the parameters of the power network; Construct oscillation scenarios of the doubly-fed asynchronous wind turbine generator system and determine the active power peak output of each oscillation scenario; Performing periodic analysis on the active power, and calculating a power characteristic index and a robust characteristic index based on the active power peak value outputted in each oscillation scenario; Performing periodic analysis on the active power and calculating power characteristic index and robust characteristic index in combination with the active power peak value outputted in each oscillation scenario, including: The value of the active power is periodically sampled in each resonance period to obtain an array of active power in each resonance period; Normalizing the active power array to obtain a normalized array; Calculate the change rate of the normalized array of two adjacent resonant periods to obtain the dynamic characteristic index; Calculating the power characteristic index according to a preset power characteristic calculation model and the dynamic characteristic index; Calculate the weight corresponding to each oscillation scenario according to the active power peak value output by each oscillation scenario; Assign corresponding weights to the power characteristic indicators under each oscillation scenario to obtain the weighted power characteristic indicators of each oscillation scenario; The robust characteristic index is calculated according to a preset robust characteristic calculation model and a weighted power characteristic index of each oscillation scenario.

2. The oscillation suppression strategy robustness evaluation method according to claim 1, characterized in that: Based on the signal decomposition technology, the voltage and current signals sampled under the current strategy of the power network are subjected to extraction of suppressed oscillation frequency components, and active power is calculated according to the parameters of the power network, including: Acquire voltage and current signals sampled from the power network; Extraction of suppressed oscillation frequency components of sampled voltage and current signals based on signal decomposition technology; Determining a time domain waveform of active power according to the extracted frequency components and the parameters of the power network; The active power at each moment is obtained according to the determined time domain waveform.

3. The oscillation suppression strategy robustness evaluation method according to claim 1, characterized in that: Construct oscillation scenarios of the doubly-fed asynchronous wind turbine generator system and determine the active power peak output of each oscillation scenario, including: According to the parameters of the grid structure of the doubly-fed asynchronous wind turbine system, a sub-supersynchronous oscillation scenario of the doubly-fed wind turbine is constructed; By adjusting the parameters of the offshore wind power grid-connected control system and the wind speed, two subsynchronous oscillation scenarios with different frequencies are constructed. Building a medium and high frequency oscillation scenario according to the double-fed asynchronous wind turbine generator system; By adjusting the parameters of the offshore wind power grid-connected control system and the capacitance of the equivalent cable, two medium and high frequency oscillation scenarios are constructed; The active power peak value output in each oscillation scenario is determined according to each constructed oscillation scenario.

4. The oscillation suppression strategy robustness evaluation method according to claim 1, characterized in that: The dynamic characteristic index is ; Among them, P s (n) represents the dynamic characteristic index of the nth resonance cycle, P sd (n) represents the normalized array of the nth resonance period, P sd (n+1) represents the normalized array of the n+1th resonance period, T h Indicates the duration of the oscillation cycle.

5. The oscillation suppression strategy robustness evaluation method according to claim 1, characterized in that: The power characteristic calculation model is: ; Among them, P si is the power characteristic index under the i-th oscillation scenario, P s (n) represents the dynamic characteristic index of the nth resonance period, and N is the total number of resonance periods.

6. The oscillation suppression strategy robustness evaluation method according to claim 1, characterized in that: The robust characteristic calculation model is: ; Among them, E s is the robust characteristic index, is the weighted power characteristic index under the i-th oscillation scenario, , P Si is the power characteristic index under the i-th oscillation scenario, K i is the weight in the i-th oscillation scenario, , M is the number of scenes, is the peak active power output in the i-th oscillation scenario.

7. An oscillation suppression strategy robustness evaluation device, characterized in that: The device comprises: A decomposition module, used for extracting the suppressed oscillation frequency components of the voltage and current signals sampled under the current strategy of the power network based on the signal decomposition technology, and calculating the active power according to the parameters of the power network; A scenario module is used to construct oscillation scenarios of a doubly-fed asynchronous wind turbine generator system and determine the active power peak output of each oscillation scenario; An evaluation module, used to perform periodic analysis on the active power and calculate a power characteristic index and a robust characteristic index based on the active power peak value outputted in each oscillation scenario; Performing periodic analysis on the active power and calculating power characteristic index and robust characteristic index in combination with the active power peak value outputted in each oscillation scenario, including: The value of the active power is periodically sampled in each resonance period to obtain an array of active power in each resonance period; Normalizing the active power array to obtain a normalized array; Calculate the change rate of the normalized array of two adjacent resonant periods to obtain the dynamic characteristic index; Calculating the power characteristic index according to a preset power characteristic calculation model and the dynamic characteristic index; Calculate the weight corresponding to each oscillation scenario according to the active power peak value output by each oscillation scenario; Assign corresponding weights to the power characteristic indicators under each oscillation scenario to obtain the weighted power characteristic indicators of each oscillation scenario; The robust characteristic index is calculated according to a preset robust characteristic calculation model and a weighted power characteristic index of each oscillation scenario.

8. A terminal device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the method for evaluating the robustness of an oscillation suppression strategy according to any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the oscillation suppression strategy robustness evaluation method according to any one of claims 1 to 6.

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