Frequency modulation control method and device for mixed pumped storage system and electronic equipment

Abstract

The invention belongs to the technical field of pumped storage control, and particularly discloses a frequency modulation control method and device for a mixed pumped storage system and electronic equipment. The method is applied to the hybrid pumped storage system, the hybrid pumped storage system comprises a constant-speed pumped storage unit, a variable-speed pumped storage unit and a frequency modulation system, and the method comprises the steps that when frequency fluctuation occurs in the hybrid pumped storage system, the frequency adjustment range output by the frequency modulation system is obtained; the frequency adjustment range is obtained by performing frequency adjustment on the constant-speed pumped storage unit and the variable-speed pumped storage unit; performing frequency division processing on the frequency adjustment range based on the amplitude-frequency response characteristics of the constant-speed pumped storage unit and the variable-speed pumped storage unit, and determining a frequency division result; and frequency modulation is carried out on the constant-speed pumped storage unit and the variable-speed pumped storage unit based on the frequency division result until frequency fluctuation of the hybrid pumped storage system is eliminated. According to the invention, the comprehensive regulation capability and the operation stability of the mixed pumped storage system can be greatly improved.

Description

Technical Field

[0001] The present application belongs to the field of pumped storage control technology, and more specifically, to a frequency modulation control method, device and electronic equipment for a hybrid pumped storage system. Background Art

[0002] With the continuous increase in the total installed capacity of distributed energy sources such as wind power and solar power, the intermittent and volatile output of these energy sources has brought great challenges to the safe and stable operation of the power grid. These distributed energy sources are generally connected to the grid through power electronic converters, lacking the damping and inertia of traditional generators when connected to the grid, which limits the penetration rate of new energy in the power grid. In order to solve the above problems, it is necessary to configure a certain capacity of energy storage in the power grid to participate in the frequency regulation of the power grid, provide power and energy auxiliary services for the power grid, and increase the inertia and damping of the power grid.

[0003] As a widely adopted large-scale energy storage technology, pumped storage plays an important role in balancing power fluctuations in the power grid and ensuring energy security. At present, a hybrid pumped storage system consisting of fixed-speed pumped storage units and variable-speed pumped storage units is usually used for power grid energy storage. However, the frequency regulation method of variable-speed pumped storage units mostly adopts the virtual inertia control method, which directly tracks the load fluctuations and independently adjusts the fixed-speed pumped storage units. This method does not consider the frequency regulation response characteristics and coordination problems of the two types of pumped storage units themselves during the frequency regulation process, resulting in the frequency regulation control effect of the hybrid pumped storage system is not ideal, and the comprehensive regulation capability of the system needs to be improved urgently.

[0004] Therefore, how to better realize the frequency control of hybrid pumped storage systems has become a technical problem that needs to be solved urgently in the industry. Summary of the invention

[0005] In view of the defects of the prior art, the purpose of this application is to better realize the frequency regulation control of the hybrid pumped storage system, aiming to solve the problem that the frequency regulation control effect of the existing hybrid pumped storage system is not ideal and the comprehensive regulation capability of the system needs to be improved urgently.

[0006] To achieve the above objectives, in a first aspect, the present application provides a frequency modulation control method for a hybrid pumped storage system, which is applied to a hybrid pumped storage system, wherein the hybrid pumped storage system includes a fixed-speed pumped storage unit, a variable-speed pumped storage unit and a frequency modulation system, including:

[0007] When frequency fluctuation occurs in the hybrid pumped storage system, obtaining a frequency regulation range output by the frequency regulation system;

[0008] Performing frequency division processing on the frequency adjustment range based on the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit, and determining a frequency division result;

[0009] The fixed-speed pumped-storage unit and the variable-speed pumped-storage unit are frequency-adjusted based on the frequency division result until the frequency fluctuation of the hybrid pumped-storage system is eliminated.

[0010] Optionally, the frequency adjustment range is subjected to frequency division processing based on the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit to determine the frequency division result, including:

[0011] Analyzing the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit to determine the target operating frequency of the variable-speed pumped-storage unit at the resonance peak;

[0012] Based on the target operating frequency of the variable-speed pumped-storage unit at the resonance peak, the frequency adjustment range is divided to determine a first frequency range component greater than the target operating frequency and a second frequency range component not greater than the target operating frequency; the frequency division result includes the first frequency range component and the second frequency range component.

[0013] Optionally, the frequency of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit is adjusted based on the frequency division result until the frequency fluctuation of the hybrid pumped-storage system is eliminated, including:

[0014] Step S1, using the first frequency range component and the second frequency range component to perform frequency modulation on the variable speed pumped storage unit and the fixed speed pumped storage unit to determine an updated frequency adjustment range output by the frequency modulation system;

[0015] Step S2, performing frequency division processing on the updated frequency adjustment range to determine an updated first frequency range component and an updated second frequency range component;

[0016] Step S3, using the updated first frequency range component and the updated second frequency range component to perform frequency modulation on the variable speed pumped storage unit and the fixed speed pumped storage unit;

[0017] When it is determined that the hybrid pumped storage system still has frequency fluctuations, an updated frequency adjustment range is determined, and steps S2 to S3 are repeated until the frequency fluctuations of the hybrid pumped storage system are eliminated.

[0018] Optionally, the step of frequency-modulating the variable-speed pumped-storage unit and the fixed-speed pumped-storage unit by using the first frequency range component and the second frequency range component comprises:

[0019] Determine a first power deviation corresponding to the first frequency range component and a second power deviation corresponding to the second frequency range component;

[0020] Performing power output limitation processing on the second power deviation to determine a second power adjustment amount and a corresponding second power adjustment margin of the constant-speed pumped-storage unit;

[0021] Perform power output limitation processing based on the first power deviation and the second power adjustment margin to determine a first power adjustment amount and a corresponding first power adjustment margin of the variable-speed pumped-storage unit; the first power adjustment margin is used to iteratively update the frequency adjustment range;

[0022] The variable-speed pumped-storage unit is frequency-regulated using the first power regulation amount, and the fixed-speed pumped-storage unit is frequency-regulated using the second power regulation amount.

[0023] Optionally, after the variable-speed pumped-storage unit is frequency-regulated by using the first power regulation amount, and the fixed-speed pumped-storage unit is frequency-regulated by using the second power regulation amount, the method further includes:

[0024] Acquire a first operating power of the variable-speed pumped-storage unit after frequency modulation and a second operating power of the fixed-speed pumped-storage unit after frequency modulation;

[0025] Performing a primary frequency regulation calculation and a secondary frequency regulation calculation based on the current power fluctuation deviation of the external wind turbine generator set, the first operating power, and the second operating power, respectively, to determine a first frequency regulation range after the primary frequency regulation calculation and a second frequency regulation range after the secondary frequency regulation calculation;

[0026] Determining a frequency adjustment amount corresponding to the first power adjustment margin;

[0027] The first frequency adjustment range, the second frequency adjustment range and the frequency adjustment amount are superimposed to determine an updated frequency adjustment range output by the frequency modulation system.

[0028] Optionally, the analyzing the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit to determine the target operating frequency of the variable-speed pumped-storage unit at the resonance peak includes:

[0029] Perform power spectrum density analysis on the historical power fluctuation time series data of external wind turbines to determine the target power fluctuation frequency range;

[0030] An amplitude-frequency response characteristic difference analysis is performed on the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit within the target power fluctuation frequency range, and a target operating frequency of the variable-speed pumped-storage unit at a resonance peak is determined based on the analysis result.

[0031] Optionally, performing power spectrum density analysis on historical power fluctuation time series data of the external wind turbine generator set to determine the target power fluctuation frequency range includes:

[0032] Acquire multiple types of wind power fluctuation time series data from the historical power fluctuation time series data of the external wind turbine generator set;

[0033] Performing power spectrum density analysis on each type of wind power fluctuation time series data to determine a statistical average of wind power spectrum density corresponding to each type of wind power fluctuation time series data;

[0034] The target power fluctuation frequency range is determined based on the frequency distribution of the statistical average values ​​of the power spectrum densities of various types of wind power.

[0035] In a second aspect, the present application provides a hybrid pumped storage system frequency modulation control device, which is applied to a hybrid pumped storage system, wherein the hybrid pumped storage system includes a fixed-speed pumped storage unit, a variable-speed pumped storage unit and a frequency modulation system, including:

[0036] An acquisition module, used for acquiring a frequency regulation range output by the frequency modulation system when frequency fluctuation occurs in the hybrid pumped storage system;

[0037] A frequency division module, used to perform frequency division processing on the frequency adjustment range based on the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit, and determine a frequency division result;

[0038] A frequency modulation module is used to modulate the frequency of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit based on the frequency division result until the frequency fluctuation of the hybrid pumped-storage system is eliminated.

[0039] In a third aspect, the present application provides an electronic device comprising: at least one memory for storing programs; and at least one processor for executing the programs stored in the memory. When the program stored in the memory is executed, the processor is used to execute the method described in the first aspect or any possible implementation of the first aspect.

[0040] In a fourth aspect, the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method described in the first aspect or any possible implementation of the first aspect.

[0041] In a fifth aspect, the present application provides a computer program product. When the computer program product runs on a processor, the processor executes the method described in the first aspect or any possible implementation of the first aspect.

[0042] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the prior art:

[0043] The present application provides a frequency regulation control method, device and electronic equipment for a hybrid pumped storage system. By considering the difference in amplitude-frequency response characteristics between a fixed-speed pumped-storage unit and a variable-speed pumped-storage unit during the regulation process, the frequency regulation range of the initial output of the frequency regulation system is obtained when frequency fluctuations occur in the hybrid pumped-storage system, and then the frequency regulation range is targetedly divided to divide the load fluctuation response frequency band. The divided frequency division results are used to perform targeted regulation instruction allocation and frequency regulation control on the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit until the frequency fluctuations of the hybrid pumped-storage system are eliminated, thereby realizing joint frequency regulation control that takes into account the respective regulation advantages of the two types of units, and greatly improving the comprehensive regulation capability and operation stability of the hybrid pumped-storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is one of the flow charts of the frequency modulation control method of the hybrid pumped storage system provided in the embodiment of the present application;

[0045] Figure 2 (a) is a schematic diagram of the frequency distribution of the statistical average value of the wind power spectrum density under the single-mode wind power fluctuation provided in the embodiment of the present application, (b) is a schematic diagram of the frequency distribution of the statistical average value of the wind power spectrum density under the positively skewed wind power fluctuation provided in the embodiment of the present application, (c) is a schematic diagram of the frequency distribution of the statistical average value of the wind power spectrum density under the negatively skewed wind power fluctuation provided in the embodiment of the present application, (d) is a schematic diagram of the frequency distribution of the statistical average value of the wind power spectrum density under the bimodal wind power fluctuation provided in the embodiment of the present application;

[0046] Figure 3 This is one of the control flow diagrams of the frequency modulation system of the hybrid pumped storage system provided in the embodiment of the present application;

[0047] Figure 4 (a) is a schematic diagram of the frequency response amplitude-frequency characteristics of the fixed-speed / variable-speed pumped-storage unit provided in an embodiment of the present application, and (b) is a schematic diagram of the power response amplitude-frequency characteristics of the fixed-speed / variable-speed pumped-storage unit provided in an embodiment of the present application;

[0048] Figure 5 This is the second schematic diagram of the frequency modulation system control flow of the hybrid pumped storage system provided in the embodiment of the present application;

[0049] Figure 6 (a) is a schematic diagram of a global root locus curve of a conventional hybrid pumped storage system as the speed governor control parameters change, and (b) is a schematic diagram of a global root locus curve of a hybrid pumped storage system provided by an embodiment of the present application as the speed governor control parameters change;

[0050] Figure 7 is a schematic diagram of a spectral density distribution curve of frequency fluctuations of a hybrid pumped storage system provided in an embodiment of the present application;

[0051] Figure 8 (a) is a schematic diagram of a time domain curve of a frequency response of a conventional hybrid pumped storage system under frequency fluctuations, and (b) is a schematic diagram of a time domain curve of a frequency response of a hybrid pumped storage system under frequency fluctuations provided in an embodiment of the present application;

[0052] Fig. 9 It is a structural schematic diagram of a frequency modulation control device for a hybrid pumped storage system provided by the present application;

[0053] Fig.10 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0055] The terms "first" and "second" and the like in the specification and claims herein are used to distinguish different objects, rather than to describe a specific order of the objects. For example, the first frequency range component and the second frequency range component are used to distinguish frequency range components of different functions, rather than to describe a specific order of the frequency range components; the first power deviation and the second power deviation are used to distinguish power deviations corresponding to different objects, rather than to describe a specific order of the power deviations.

[0056] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0057] In the description of the embodiments of the present application, unless otherwise specified, "multiple categories" means two or more categories. For example, multiple categories of wind power fluctuation time series data refer to two or more categories of wind power fluctuation time series data.

[0058] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0059] Figure 1is one of the flow charts of the frequency modulation control method of the hybrid pumped storage system provided in the embodiment of the present application. The method can be applied to the hybrid pumped storage system, which includes a fixed-speed pumped storage unit, a variable-speed pumped storage unit and a frequency modulation system, such as Figure 1 As shown, the method includes:

[0060] Step S10, when the frequency fluctuation occurs in the hybrid pumped storage system, obtaining the frequency regulation range output by the frequency regulation system;

[0061] Step S20, performing frequency division processing on the frequency adjustment range based on the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit, and determining a frequency division result;

[0062] Step S30, frequency-adjusting the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit based on the frequency division result until the frequency fluctuation of the hybrid pumped-storage system is eliminated.

[0063] Specifically, the frequency modulation system described in the embodiment of the present application may include a primary frequency modulation system and a secondary frequency modulation system. The primary frequency modulation system is applicable to the system frequency deviation caused by load changes with small fluctuation amplitude and short fluctuation period; the secondary frequency modulation system is applicable to the system frequency deviation caused by load changes with large fluctuation amplitude and long fluctuation period.

[0064] It should be noted that, in the embodiments of the present application, the fluctuation of wind power generation may be taken into account, and the frequency fluctuation of the hybrid pumped storage system may be caused by the frequency / power fluctuation of the wind turbine.

[0065] The frequency regulation range described in the embodiment of the present application refers to the initial frequency regulation result obtained by the frequency regulation system according to the operating frequencies of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit and the fluctuating frequency of the external wind turbine unit when frequency fluctuations occur in the hybrid pumped-storage system. The frequency regulation range is used to further perform frequency regulation control on the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit.

[0066] The amplitude-frequency response characteristics of the constant-speed pumped-storage unit and the variable-speed pumped-storage unit described in the embodiments of the present application refer to the power response amplitude-frequency characteristics and frequency response amplitude-frequency characteristics exhibited by the constant-speed pumped-storage unit and the variable-speed pumped-storage unit during the historical frequency modulation control process of the hybrid pumped-storage system.

[0067] In an embodiment of the present application, in step S10, when frequency fluctuation occurs in the hybrid pumped-storage system, the fluctuation frequency of the external wind turbine is obtained, and then the frequency regulation system performs frequency regulation calculation according to the fluctuation frequency, the operating frequency of the fixed-speed pumped-storage unit at this time, and the current operating frequency of the variable-speed pumped-storage unit to obtain an initial frequency regulation range for the frequency regulation control of the pumped-storage unit, thereby obtaining the frequency regulation range output by the frequency regulation system.

[0068] In an embodiment of the present application, in step S20, by acquiring historical frequency modulation data of the hybrid pumped-storage system, the difference in amplitude-frequency response of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit in different frequency bands is analyzed when the frequency fluctuation of the external wind turbine unit occurs, and the respective regulation characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit for multi-band signals are determined.

[0069] The analysis found that the variable-speed pumped-storage unit has a significant inhibitory effect on frequency fluctuations in the medium and high frequency bands. The multi-band regulation rapidity of the variable-speed pumped-storage unit and the large inertia stable regulation characteristics of the fixed-speed pumped-storage unit were determined. This provides a scientific basis for the coordinated control of the subsequent hybrid control system and is conducive to the rational allocation of the regulation tasks of the hybrid pumped-storage system.

[0070] Furthermore, in this step, according to the analysis results of the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit, the frequency regulation range obtained by the above-mentioned initial frequency modulation is divided to obtain a frequency division result, thereby determining the frequency regulation ranges corresponding to the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit respectively, and performing joint frequency regulation control while taking into account the respective regulation advantages of the two types of units.

[0071] Further, in an embodiment of the present application, in step S30, the above-mentioned frequency division result is used to perform frequency modulation control on the fixed-speed pumped storage unit and the variable-speed pumped storage unit respectively according to the frequency modulation range corresponding to each unit. If the frequency fluctuation of the hybrid pumped storage system is still not eliminated after the frequency modulation, it is necessary to continue to perform iterative frequency division processing according to the frequency adjustment range output by the frequency modulation system, and repeat the frequency modulation of the fixed-speed pumped storage unit and the variable-speed pumped storage unit until the frequency fluctuation of the hybrid pumped storage system is eliminated.

[0072] The frequency regulation control method for a hybrid pumped storage system of the embodiment of the present application considers the difference in amplitude-frequency response characteristics between a fixed-speed pumped-storage unit and a variable-speed pumped-storage unit during the regulation process, obtains the frequency regulation range of the initial output of the frequency regulation system when frequency fluctuations occur in the hybrid pumped-storage system, and then performs targeted frequency division processing on the frequency regulation range to divide the load fluctuation response frequency bands. The divided frequency division results are used to perform targeted regulation instruction allocation and frequency regulation control on the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit until the frequency fluctuations of the hybrid pumped-storage system are eliminated, thereby realizing joint frequency regulation control that takes into account the respective regulation advantages of the two types of units, and greatly improving the comprehensive regulation capability and operation stability of the hybrid pumped-storage system.

[0073] Based on the content of the above embodiment, as an optional embodiment, the frequency adjustment range is divided based on the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit to determine the frequency division result, including:

[0074] The amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit are analyzed to determine the target operating frequency of the variable-speed pumped-storage unit at the resonance peak.

[0075] Based on the target operating frequency of the variable-speed pumped-storage unit at the resonance peak, the frequency adjustment range is divided to determine a first frequency range component greater than the target operating frequency and a second frequency range component not greater than the target operating frequency; the frequency division result includes the first frequency range component and the second frequency range component.

[0076] Specifically, in the embodiment of the present application, the specific implementation method of frequency division processing of the frequency adjustment range based on the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit is as follows:

[0077] First, by obtaining the historical frequency fluctuation data of external wind turbines, the amplitude-frequency response characteristics of fixed-speed pumped storage units and variable-speed pumped storage units are analyzed. Through the analysis, the target operating frequency of the variable-speed pumped storage unit at the resonance peak can be determined.

[0078] Based on the content of the above embodiment, as an optional embodiment, the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit are analyzed to determine the target operating frequency of the variable-speed pumped-storage unit at the resonance peak, including:

[0079] Perform power spectrum density analysis on the historical power fluctuation time series data of external wind turbines to determine the target power fluctuation frequency range;

[0080] The difference in amplitude-frequency response characteristics of fixed-speed pumped-storage units and variable-speed pumped-storage units in the target power fluctuation frequency range is analyzed, and the target operating frequency of the variable-speed pumped-storage unit at the resonance peak is determined based on the analysis results.

[0081] Specifically, the target power fluctuation frequency range described in the embodiment of the present application refers to the distribution range of the power fluctuation spectrum density of the external wind turbine generator set.

[0082] In an embodiment of the present application, multiple types of fluctuation data are extracted from the historical power fluctuation time series data of the external wind turbine generator set, and power spectrum density analysis is performed based on different fluctuation data to obtain the distribution range of the power fluctuation spectrum density of the external wind turbine generator set, that is, the target power fluctuation frequency range.

[0083] Based on the content of the above embodiment, as an optional embodiment, a power spectrum density analysis is performed on the historical power fluctuation time series data of the external wind turbine generator set to determine the target power fluctuation frequency range, including:

[0084] Obtain multiple types of wind power fluctuation time series data from historical power fluctuation time series data of external wind turbines;

[0085] Perform power spectrum density analysis on various wind power fluctuation time series data to determine the statistical average of wind power spectrum density corresponding to various wind power fluctuation time series data;

[0086] Based on the frequency distribution of the statistical average values ​​of the power spectrum density of various types of wind power, the target power fluctuation frequency range is determined.

[0087] Specifically, in the embodiment of the present application, for the fluctuation of wind power generation, a wind power generation turbulence model provided by the National Renewable Energy Laboratory (NREL) through Turbsim, namely, the IEC Kaimal model (IECKAI), is used. The wind power turbulence model satisfies:

[0088]

[0089] Where f is the cycle frequency, L K represents the integral scale parameter, u hub represents the wind speed at the hub (m / s), σ k Represents the turbulence standard deviation of the Normal Turbulence Model (NTM) wind spectrum.

[0090] Based on the above wind power turbulence model, the historical power fluctuation time series data of external wind turbines are used to generate four types of wind power fluctuation time series with typical time distribution, namely single peak, positive skewness, negative skewness and bimodal. The simulation duration is set to 1800 seconds and the sampling frequency is 1s. Thus, multiple types of wind power fluctuation time series data are obtained.

[0091] Furthermore, power spectrum density analysis is performed on various types of wind power fluctuation time series data to determine the statistical average of wind power spectrum density corresponding to various types of wind power fluctuation time series data. The calculation formula for the statistical average of wind power spectrum density is as follows:

[0092]

[0093] In the formula, E(*) is the expected value, S x (f) represents the statistical average of the Fourier transformed power spectral density.

[0094] Combined with the Wiener-Khinchin theorem, the window Fourier transform is used to correspond the time domain and frequency domain fluctuation characteristics of wind power. The transformation equation can be expressed as follows:

[0095]

[0096] Then, the power spectrum density is discretized, where T is the sampling time, T s is the sampling interval, f s =1 / T s is the sampling frequency. The first sampling point of load fluctuation within a certain period of time is defined as:

[0097] x T [i] = ΔP(t i )

[0098] The sampling data length of each sampling point is recorded as N, N = T / T s Therefore, the kth wind power fluctuation point can be expressed as:

[0099]

[0100] It can be further deduced that the statistical average value of the discretized wind power spectrum density is:

[0101]

[0102] Furthermore, the statistical average value of the above discretized wind power spectrum density is used for data sampling to obtain the distribution characteristics of the above four types of wind power fluctuations, and then the power spectrum density analysis is performed, and the results can be obtained as follows: Figure 2 shown. Figure 2 In the figure, (a) is a schematic diagram of the frequency distribution of the statistical mean value of wind power spectrum density under unimodal wind power fluctuation, (b) is a schematic diagram of the frequency distribution of the statistical mean value of wind power spectrum density under positively skewed wind power fluctuation, (c) is a schematic diagram of the frequency distribution of the statistical mean value of wind power spectrum density under negatively skewed wind power fluctuation, and (d) is a schematic diagram of the frequency distribution of the statistical mean value of wind power spectrum density under bimodal wind power fluctuation.

[0103] from Figure 2 It can be seen that the multi-scale frequency response range of the four types of wind power fluctuations is 0.005Hz to 0.5Hz, and they have different energy distributions in different frequency bands, thus the target power fluctuation frequency range can be obtained.

[0104] It should be noted that the unimodal, positively skewed, negatively skewed and bimodal distribution characteristics of wind power fluctuations are important indicators for describing the characteristics of wind power fluctuations. Unimodal means that the distribution of wind power fluctuations is mainly concentrated near a peak value, that is, the fluctuation characteristics are relatively simple, without obvious multi-peak or dispersion phenomena; positive skewness (or right skewness) means that in the distribution of wind power fluctuations, larger values ​​(i.e., positive values ​​that deviate from the average value) appear more frequently, while smaller values ​​(i.e., negative values ​​that deviate from the average value) appear less frequently; negative skewness (or left skewness) is the opposite of positive skewness, which means that in the distribution of wind power fluctuations, smaller values ​​(i.e., negative values ​​that deviate from the average value) appear more frequently, while larger values ​​(i.e., positive values ​​that deviate from the average value) appear less frequently; bimodal distribution means that there are two obvious peaks in the distribution of wind power fluctuations, that is, the fluctuation characteristics present a bimodal state.

[0105] in, Figure 2 Specifically, the power spectrum density value gradually decreases from low frequency to high frequency. The low-frequency region shows a higher energy density, while the energy distribution in the medium-frequency and high-frequency regions is more dispersed. This is due to the low-pass filtering effect caused by the physical and electrical inertia of wind turbines in the high-frequency region, which makes the amplitude of the wind power spectrum show a downward trend. In addition, the maximum power output constraint of the wind turbine also limits the growth of the power spectrum amplitude in the low-frequency region. According to the distribution range and characteristics of the power spectrum density of wind power fluctuations, it can be divided into three frequency bands from left to right in the frequency domain, which are recorded as low frequency band (0.005Hz~0.01Hz), medium frequency band (0.01Hz~0.1Hz) and high frequency band (0.1Hz~0.5Hz).

[0106] The method of the embodiment of the present application can effectively determine the distribution range of the power fluctuation spectral density by utilizing the historical power fluctuation time series data of the external wind turbine set to perform power spectral density analysis of multiple types of wind power fluctuations, thereby providing a reliable analysis range for the subsequent differences in the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit, and helping to improve the accuracy of the frequency regulation range division processing.

[0107] Furthermore, in an embodiment of the present application, by establishing a frequency response model of a hybrid pumped-storage system with a variable-speed pumped-storage unit, the difference in amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit is analyzed within the target power fluctuation frequency range.

[0108] It should be noted that fixed-speed pumped storage units and variable-speed pumped storage units have the same hydraulic mechanical regulation system structure and parameter properties. The only difference is their respective electrical structures and the way they participate in frequency regulation.

[0109] Figure 3 This is one of the control flow diagrams of the frequency modulation system of the hybrid pumped storage system provided in the embodiment of the present application, such as Figure 3 As shown in FIG. 1 , the hybrid pumped storage system includes a primary frequency regulation system and a secondary frequency regulation system, wherein the linearized model of the hydraulic mechanical regulation system in the hybrid pumped storage system can be expressed as follows:

[0110]

[0111] In the formula, G g1 (s) and G g2 (s) represent the transfer functions of the primary frequency modulation system and the secondary frequency modulation system, G′(s) represents the transfer function of the servo system, K p , K i are the speed controller parameters of the hybrid pumped storage system, T tg 、T g Respectively represent the response constant and reset time constant of the servo system, R and R T They represent the droop and transient regulation coefficient of the speed regulator, B i Represents the system frequency deviation coefficient, T w Represents the water flow inertia time constant.

[0112] Furthermore, the amplitude-frequency response characteristics of the fixed-speed pumped storage unit and the variable-speed pumped storage unit in the regulation process are analyzed. Based on the classical control theory and the frequency domain stability analysis method, the frequency response Bode diagram of the fixed-speed / variable-speed pumped storage unit is drawn, as shown in Figure 2. Figure 4 As shown, Figure 4 (a) is a schematic diagram of the frequency response amplitude-frequency characteristics of a fixed-speed / variable-speed pumped storage unit, where f F / pw,f V / pw represent the frequency response curves of the fixed-speed pumped storage unit and the variable-speed pumped storage unit in the frequency domain; (b) is a schematic diagram of the power response amplitude-frequency characteristics of the fixed-speed / variable-speed pumped storage unit, where P F / pw、P V / pw represent the power response curves of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit in the frequency domain respectively.

[0113] Continue to refer to Figure 4In terms of frequency response, compared with fixed-speed pumped storage units, variable-speed pumped storage units have a strong suppression effect on power fluctuations in the medium and partial high frequency ranges, and the frequency response amplitude at the resonance peak is reduced by 61.3%. However, there is no obvious difference in the response of the two types of units to the low frequency band, which indicates that the regulation advantage of variable-speed pumped storage units on a long time scale is not prominent.

[0114] Similarly, at the power response level, the power response amplitude of the fixed-speed pumped-storage unit first increases and then decreases, while the power response amplitude of the variable-speed pumped-storage unit shows an overall downward trend.

[0115] It is worth noting that in Figure 4 In the amplitude-frequency characteristics of the two types of units shown, there is an obvious turning point near the frequency of 0.077Hz. This key transition effectively eliminates the resonant peak of the power response of the fixed-speed pumped-storage unit, which shows that the two types of units have their own adjustment characteristics for multi-band signals, especially the variable-speed pumped-storage unit has a significant inhibitory effect in the medium and high frequency bands. Therefore, based on the above analysis results, it is determined that the target operating frequency of the variable-speed pumped-storage unit at the resonant peak can be 0.077Hz.

[0116] The method of the embodiment of the present application obtains the target power fluctuation frequency range by performing power spectral density analysis on the historical power fluctuation time series data of the external wind turbine set, and then analyzes the difference in amplitude-frequency response characteristics of the fixed-speed pumped-storage set and the variable-speed pumped-storage set in this frequency range. The resonant frequency of the variable-speed pumped-storage set can be effectively determined, which provides a scientific basis for the coordinated frequency division control of the subsequent hybrid pumped-storage system and contributes to the rational allocation of system regulation tasks.

[0117] Furthermore, in an embodiment of the present application, based on the resonant frequency of the variable-speed pumped-storage unit obtained by the above analysis, that is, the target operating frequency, the frequency adjustment range output by the frequency modulation system is divided into frequency bands, and a first frequency range component greater than the target operating frequency and a second frequency range component not greater than the target operating frequency can be obtained, thereby obtaining a frequency division result for setting the frequency modulation instruction.

[0118] The method of the embodiment of the present application, by considering the difference analysis of the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit, obtains the target operating frequency of the variable-speed pumped-storage unit at the resonance peak, fully exploits the large inertia regulation reliability of the fixed-speed pumped-storage unit and the fast load supporting capability of the variable-speed pumped-storage unit, provides a scientific basis for the targeted allocation of subsequent frequency regulation system regulation instructions, and is conducive to achieving joint frequency regulation control that takes into account the regulation advantages of the two types of units.

[0119] Based on the content of the above embodiment, as an optional embodiment, the frequency of the fixed-speed pumped storage unit and the variable-speed pumped storage unit is adjusted based on the frequency division result until the frequency fluctuation of the hybrid pumped storage system is eliminated, including:

[0120] Step S1, using the first frequency range component and the second frequency range component to perform frequency modulation on the variable speed pumped storage unit and the fixed speed pumped storage unit to determine an updated frequency adjustment range output by the frequency modulation system;

[0121] Step S2, performing frequency division processing on the updated frequency adjustment range to determine an updated first frequency range component and an updated second frequency range component;

[0122] Step S3, using the updated first frequency range component and the updated second frequency range component to perform frequency modulation on the variable speed pumped storage unit and the fixed speed pumped storage unit;

[0123] When it is determined that the hybrid pumped storage system still has frequency fluctuations, an updated frequency adjustment range is determined, and steps S2 to S3 are repeated until the frequency fluctuations in the hybrid pumped storage system are eliminated.

[0124] Specifically, in the embodiment of the present application, the frequency division results obtained above are used to modulate the frequencies of the fixed-speed pumped-storage units and the variable-speed pumped-storage units. By adopting an iterative frequency division control method, the frequency adjustment range of each frequency modulation system output is continuously divided, and then the frequency modulation control is performed on the two types of units until the frequency fluctuations occurring in the hybrid pumped-storage system are eliminated.

[0125] Figure 5 This is the second schematic diagram of the frequency modulation system control flow of the hybrid pumped storage system provided in the embodiment of the present application, such as Figure 5 As shown, in the embodiment of the present application, the cutoff frequency of the Butterworth filter in the adjustment instruction frequency division control module is pre-set to the operating frequency at the resonance peak of the variable speed pumped storage unit. Therefore, when the frequency fluctuation of the hybrid pumped storage system causes the system frequency deviation, the frequency deviation is sent to the frequency modulation system (including the primary frequency modulation system and the secondary frequency modulation system) through the action of the internal inertial parameter system, and the frequency modulation system performs corresponding frequency modulation control according to the frequency fluctuation characteristics, and finally outputs the frequency adjustment range.

[0126] Among them, the equivalent inertia constant of the inertia parameter system in the hybrid pumped storage system is determined by the capacity ratio and reference value of each system. The transfer function of the inertia parameter system can be expressed as follows:

[0127]

[0128] in,

[0129]

[0130] In the formula, H ∑ , H F , H V They represent the inertia time constants of the fixed-speed pumped storage unit, the variable-speed pumped storage unit and the equivalent system, respectively, and p fs 、p vs They represent the capacity ratio reference values ​​of fixed-speed and variable-speed pumped-storage units in the hybrid pumped-storage system, α ∑ , D1 represent the equivalent value and reference value of the system load damping coefficient respectively.

[0131] Then, the frequency adjustment range is divided into a first frequency range component and a second frequency range component through a frequency division control module.

[0132] Further, in an embodiment of the present application, in step S1, the variable speed pumped storage unit and the fixed speed pumped storage unit are frequency modulated using the first frequency range component and the second frequency range component to determine an updated frequency regulation range output by the frequency modulation system.

[0133] Continue to refer to Figure 5 As an optional embodiment, the step of frequency-modulating the variable-speed pumped-storage unit and the fixed-speed pumped-storage unit using the first frequency range component and the second frequency range component includes:

[0134] Determine a first power deviation corresponding to a first frequency range component and a second power deviation corresponding to a second frequency range component;

[0135] Performing power output limitation processing on the second power deviation to determine a second power adjustment amount and a corresponding second power adjustment margin of the constant-speed pumped-storage unit;

[0136] Perform power output limitation processing based on the first power deviation and the second power adjustment margin to determine the first power adjustment amount and the corresponding first power adjustment margin of the variable speed pumped storage unit; the first power adjustment margin is used to iteratively update the frequency adjustment range;

[0137] The variable speed pumped storage unit is frequency-regulated using the first power regulation amount, and the fixed speed pumped storage unit is frequency-regulated using the second power regulation amount.

[0138] Specifically, the power output limitation processing described in the embodiments of the present application refers to the power output limitation processing performed by a system preset power regulation rate limiting module.

[0139] The process of power output limitation processing by the power regulation rate limiting module can be expressed as follows:

[0140]

[0141] Among them, △P GV0 Indicates the change in the unit speed governor's output power before adjusting the speed limit, S G Represents the system unit capacity, R Gmax Indicates the maximum regulation rate of the system unit, R Gmin Indicates the minimum regulation rate of the system unit.

[0142] Further, in an embodiment of the present application, based on the relationship between the unit operating frequency and power, the first power deviation ΔP corresponding to the first frequency range component is determined. High The second power deviation △P corresponding to the second frequency range component Low , and then the second power deviation △P Low The △P is input to the power regulation rate limiting module for power output limiting processing. Low As △P GV0 Substituting into the above limiting formula, the second power regulation value △P of the fixed speed pumped storage unit is obtained: GV and the corresponding second power adjustment margin (△P GV0 -△P GV ).

[0143] By comprehensively considering the capacity and regulation capability of the fixed-speed pumped storage unit and the variable-speed pumped storage unit, the variable-speed pumped storage unit can quickly compensate for the margin (△P GV0 -△P GV ), so that the first power deviation △P High and the second power adjustment margin (△P GV0 -△P GV ) are superimposed to generate △P V , and △P V The power output is limited in the same way as the power regulation rate limiting module, and the first power regulation amount △P of the variable speed pumped storage unit is obtained. VPSS and the corresponding first power adjustment margin (△P V -△P VPSS ).

[0144] Furthermore, using the first power adjustment amount ΔP VPSS The variable speed pumped storage unit is frequency modulated and the second power adjustment amount △P is used GV The fixed-speed pumped storage unit is frequency-regulated. For the variable-speed pumped storage unit, when the system frequency fluctuates, the frequency is regulated by the internal frequency regulator to generate a frequency deviation signal, which is then compared with the first power regulation amount △P VPSSThe superposition processing is performed, and then under the action of the superposition signal, the power of the double-fed generator is adjusted by the internal power regulator, so as to realize the use of the first power adjustment amount △P VPSS The process of frequency modulation of a variable speed pumped storage unit.

[0145] The method of the embodiment of the present application introduces power output restrictions by simultaneously considering the capacity and regulation capability of the two types of units, thereby designing an adaptive additional compensation action mode of the system, taking the regulation margin of the fixed-speed pumped-storage unit as the additional compensation amount of the variable-speed pumped-storage unit, and realizing adaptive coordinated control of the hybrid pumped-storage system in terms of regulation action constraints.

[0146] Based on the content of the above embodiment, as an optional embodiment, after the variable speed pumped storage unit is frequency-regulated by using the first power regulation amount, and the fixed speed pumped storage unit is frequency-regulated by using the second power regulation amount, the method further includes:

[0147] Obtaining a first operating power of the variable-speed pumped-storage unit after frequency modulation and a second operating power of the fixed-speed pumped-storage unit after frequency modulation;

[0148] Performing a primary frequency regulation calculation and a secondary frequency regulation calculation based on the current power fluctuation deviation, the first operating power, and the second operating power of the external wind turbine generator set, respectively, to determine a first frequency regulation range after the primary frequency regulation calculation and a second frequency regulation range after the secondary frequency regulation calculation;

[0149] Determining a frequency adjustment amount corresponding to a first power adjustment margin;

[0150] The first frequency adjustment range, the second frequency adjustment range and the frequency adjustment amount are superimposed to determine an updated frequency adjustment range output by the frequency modulation system.

[0151] Specifically, continue to refer to Figure 5 In an embodiment of the present application, after the variable-speed pumped-storage unit is frequency-regulated by the first power regulation amount, and the fixed-speed pumped-storage unit is frequency-regulated by the second power regulation amount, the first operating power of the variable-speed pumped-storage unit after frequency regulation and the second operating power of the fixed-speed pumped-storage unit after frequency regulation can be further obtained. Thus, the system superimposes the current power fluctuation deviation, the first operating power and the second operating power of the external wind turbine unit, and then inputs the superimposed signal into the frequency regulation system for frequency regulation calculation, thereby determining the first frequency regulation range after the primary frequency regulation calculation of the primary frequency regulation system, and the second frequency regulation range after the secondary frequency regulation calculation of the secondary frequency regulation system.

[0152] Furthermore, in the embodiment of the present application, the power regulation margin (ΔP V -△PVPSS ) will be returned to the control loop of the hybrid pumped storage system and re-perform frequency division control. Specifically, the first power adjustment margin (△P V -△P VPSS ) and returns the frequency adjustment amount to the system control loop, and performs superposition operation on the first frequency adjustment range output by the primary frequency modulation system, the second frequency adjustment range output by the secondary frequency modulation system and the frequency adjustment amount, so as to update the frequency adjustment range output by the frequency modulation system before, thereby determining the updated frequency adjustment range output by the frequency modulation system to perform re-frequency division control on it.

[0153] The method of the embodiment of the present application, after frequency modulation of the variable-speed pumped-storage unit and the fixed-speed pumped-storage unit, further utilizes the current power fluctuation deviation of the external wind turbine unit and the power after the unit frequency modulation to input into the frequency modulation system again for frequency modulation calculation, completes the update of the frequency adjustment range previously output by the frequency modulation system, prepares for subsequent iterative frequency division and frequency modulation control, and realizes the system's adaptive additional compensation frequency modulation mode.

[0154] Further, continue to refer to Figure 5 In an embodiment of the present application, in step S2, after being processed by the frequency division control module, the updated frequency adjustment range is divided again to obtain an updated first frequency range component and an updated second frequency range component.

[0155] Furthermore, in an embodiment of the present application, in step S3, the variable speed pumped storage unit and the constant speed pumped storage unit are frequency-regulated again by utilizing the above-mentioned updated first frequency range component and the updated second frequency range component, in accordance with the above-mentioned frequency modulation control process, an adaptive compensation frequency modulation method based on rate regulation limitation is used.

[0156] Finally, when it is determined that the hybrid pumped storage system still has frequency fluctuations, the frequency adjustment range after the current update is determined, and the process from step S2 to step S3 is repeated, and iterative frequency division and frequency modulation control are continuously performed until the frequency fluctuations in the hybrid pumped storage system are eliminated.

[0157] The method of the embodiment of the present application designs an adaptive compensating frequency regulation mechanism based on regulation restrictions, utilizes the amplitude-frequency response difference between the fixed-speed and variable-speed pumped-storage units to continuously coordinate the regulation status of each unit, gives full play to the variable-speed pumped-storage unit's ability to quickly regulate high-frequency load fluctuations, reduces the amount of action of the fixed-speed pumped-storage unit, and further improves the overall regulation performance of the hybrid regulation system.

[0158] In a specific embodiment of the present application, a hybrid pumped storage system is provided with 12 units, including 10 fixed-speed pumped storage units and 2 variable-speed pumped storage units, with a total installed capacity of 3000MW. The cutoff frequency in the hybrid pumped storage system using the frequency modulation control method of the present application is set to 0.1Hz, and the stability analysis and verification of the proposed coordinated control method are carried out.

[0159] By drawing the global root locus curve of the hybrid pumped storage system without and with the frequency modulation control method of the present application as the governor control parameter K changes, as shown in FIG. Figure 6 As shown. Figure 6 As can be seen from (a) in , as the control parameter K increases, the pole crosses to the right side of the imaginary axis and the system becomes unstable. As the K value decreases, the root locus deviates from the imaginary axis and the system stability increases. Figure 6 In (b), all system root trajectories are located on the left side of the imaginary axis, and the conjugate poles will not pass through the imaginary axis into the unstable region, that is, on the right side of the imaginary axis. By comparison, it can be seen that under reasonable parameter settings, the use of the frequency division coordinated control method of this application can significantly improve the operating stability of the hybrid pumped storage system and reduce the operating risks of each unit and the power grid.

[0160] Figure 7 is a schematic diagram of a spectral density distribution curve of frequency fluctuation of a hybrid pumped storage system provided in an embodiment of the present application, such as Figure 7 As shown in the figure, taking the wind power fluctuation scenario under the single-peak turbulence model KAI as an example, the variable-speed pumped-storage unit has a suppressive effect on the system frequency deviation in the entire frequency band, and its effect in the mid-frequency band is more significant: the power spectrum amplitude at the resonant frequency of 0.077Hz decreases from 1.77e-5 of the fixed-speed pumped-storage unit to 2.16e-6 of the variable-speed pumped-storage unit, and its response amplitude is maintained at the same level as the low-frequency band amplitude, which further confirms the regulation advantage of the variable-speed pumped-storage unit in the hybrid pumped-storage system and the frequency difference suppression effect within a specific load fluctuation range (0.02-0.12Hz).

[0161] Similarly, based on the scenario of wind turbine fluctuation, the dynamic performance of frequency fluctuation of hybrid pumped storage system under different control modes is compared and analyzed. The comparison time scale is 0-80s, and the frequency response time domain curve is obtained as follows: Figure 8 As shown, SC represents the frequency response time domain curve of the hybrid pumped storage system of the embodiment of the present application, SRC represents the frequency response time domain curve of the hybrid pumped storage system of the embodiment of the present application when the rate limit adjustment of the hydraulic mechanical speed governor system is taken into account; S1 represents the frequency response time domain curve of the traditional hybrid pumped storage system that does not adopt the frequency regulation control method of the present application, and SR1 represents the frequency response time domain curve of the traditional hybrid pumped storage system when the rate limit adjustment of the hydraulic mechanical speed governor system is taken into account.

[0162] It can be seen from the figure that under wind power disturbances with continuous time-frequency characteristics, the frequency regulation effects of SC and SRC are better than those of S1 and SR1, that is, the frequency regulation control method of the present application significantly improves the fluctuation of the system frequency deviation, which is consistent with the above discussion results.

[0163] From the perspective of the influencing mechanism, variable-speed pumped storage units can use their own huge rotational kinetic energy to participate in the system inertial response. Their flexibility and continuous power modulation capability make the grid frequency control more precise, so they can respond to load fluctuations more quickly than fixed-speed pumped storage units. In addition, by comparing Figure 8 It can be seen from the curves in (a) and (b) that when the regulation rate limiting effect in the hybrid pumped storage system is amplified, the frequency response effect of the hybrid pumped storage system will also improve, which shows that the regulation rate limiting and the frequency regulation control method of the present application have a positive synergistic effect in suppressing system frequency fluctuations.

[0164] Furthermore, it can be seen from the figure that the frequency error between SC and SRC is much smaller than that between S1 and SR1, indicating that by adopting the frequency division coordinated control method of the present application, the variable speed pumped storage unit quantitatively compensates for the high frequency regulation amount caused by the system wind power disturbance, resulting in the influence of the regulation rate limitation being significantly weakened. Specifically, at time t = 22s, in the case of SRC, the system frequency response error under the two control modes is reduced from △f1 = 1.01e-3 to △f c =1.14e-4.

[0165] In summary, for a hybrid pumped storage system with variable-speed pumped storage units participating in frequency regulation, when smoothing typical wind power load fluctuations, the frequency regulation control method of the present application can significantly improve system operation stability and frequency deviation.

[0166] The frequency regulation control device of the hybrid pumped storage system provided by the present invention is described below. The frequency regulation control device of the hybrid pumped storage system described below and the frequency regulation control method of the hybrid pumped storage system described above can be referred to each other.

[0167] Fig. 9 Schematic diagram of the structure of the frequency modulation control device of the hybrid pumped storage system provided by the present application. Fig. 9 As shown, it is applied to a hybrid pumped storage system, which includes a fixed-speed pumped storage unit, a variable-speed pumped storage unit and a frequency regulation system, including:

[0168] The acquisition module 100 is used to acquire the frequency regulation range output by the frequency regulation system when the frequency fluctuation occurs in the hybrid pumped storage system; the frequency regulation range is obtained by frequency regulation of the fixed speed pumped storage unit and the variable speed pumped storage unit;

[0169] The frequency division module 200 is used to perform frequency division processing on the frequency adjustment range based on the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit, and determine the frequency division result;

[0170] The frequency modulation module 300 is used to modulate the frequency of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit based on the frequency division result until the frequency fluctuation occurring in the hybrid pumped-storage system is eliminated.

[0171] It can be understood that the detailed functional implementation of each of the above-mentioned units / modules can be found in the introduction of the aforementioned method embodiment, and will not be repeated here.

[0172] It should be understood that the above-mentioned device is used to execute the method in the above-mentioned embodiment. The implementation principle and technical effect of the corresponding program module in the device are similar to those described in the above-mentioned method. The working process of the device can refer to the corresponding process in the above-mentioned method, which will not be repeated here.

[0173] The frequency regulation control device for a hybrid pumped-storage system provided in the embodiment of the present application considers the difference in amplitude-frequency response characteristics between the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit during the regulation process, obtains the frequency regulation range of the initial output of the frequency regulation system when frequency fluctuation occurs in the hybrid pumped-storage system, and then performs frequency division processing on the frequency regulation range in a targeted manner to divide the load fluctuation response frequency band, and uses the divided frequency division results to perform targeted regulation instruction allocation and frequency regulation control on the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit until the frequency fluctuation of the hybrid pumped-storage system is eliminated, thereby realizing joint frequency regulation control that takes into account the respective regulation advantages of the two types of units, and greatly improving the comprehensive regulation capability and operation stability of the hybrid pumped-storage system.

[0174] Based on the method in the above embodiment, the embodiment of the present application provides an electronic device, such as Fig.10 As shown, the electronic device may include: a processor (Processor) 1010, a communication interface (CommunicationsInterface) 1020, a memory (Memory) 1030 and a communication bus 1040, wherein the processor 1010, the communication interface 1020, and the memory 1030 communicate with each other through the communication bus 1040. The processor 1010 may call the logic instructions in the memory 1030 to execute the method in the above embodiment.

[0175] In addition, the logic instructions in the above-mentioned memory 1030 can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application.

[0176] Based on the method in the above embodiment, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program runs on a processor, the processor executes the method in the above embodiment.

[0177] Based on the method in the above embodiment, an embodiment of the present application provides a computer program product. When the computer program product runs on a processor, the processor executes the method in the above embodiment.

[0178] It is understandable that the processor in the embodiment of the present application may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0179] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, and the software modules can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can be located in an ASIC.

[0180] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions may be transmitted from a website site, a computer, a server or a data center to another website site, a computer, a server or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or a data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)), etc.

[0181] It should be understood that the various numerical numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0182] It should be understood that expressions such as "including" and "may include" that may be used in the present application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In the present application, terms such as "including" and / or "having" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0183] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A frequency modulation control method for a hybrid pumped storage system, applied to a hybrid pumped storage system, wherein the hybrid pumped storage system comprises a fixed-speed pumped storage unit, a variable-speed pumped storage unit and a frequency modulation system, and is characterized in that: include: When frequency fluctuation occurs in the hybrid pumped storage system, obtaining a frequency regulation range output by the frequency regulation system; Performing frequency division processing on the frequency adjustment range based on the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit, and determining a frequency division result; The fixed-speed pumped-storage unit and the variable-speed pumped-storage unit are frequency-adjusted based on the frequency division result until the frequency fluctuation of the hybrid pumped-storage system is eliminated.

2. The frequency modulation control method of the hybrid pumped storage system according to claim 1, characterized in that: The frequency adjustment range is subjected to frequency division processing based on the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit to determine the frequency division result, including: Analyzing the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit to determine the target operating frequency of the variable-speed pumped-storage unit at the resonance peak; Based on the target operating frequency of the variable-speed pumped-storage unit at the resonance peak, the frequency adjustment range is divided to determine a first frequency range component greater than the target operating frequency and a second frequency range component not greater than the target operating frequency; the frequency division result includes the first frequency range component and the second frequency range component.

3. The frequency modulation control method of the hybrid pumped storage system according to claim 2, characterized in that: The step of frequency-modulating the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit based on the frequency division result until the frequency fluctuation of the hybrid pumped-storage system is eliminated includes: Step S1, using the first frequency range component and the second frequency range component to perform frequency modulation on the variable speed pumped storage unit and the fixed speed pumped storage unit to determine an updated frequency adjustment range output by the frequency modulation system; Step S2, performing frequency division processing on the updated frequency adjustment range to determine an updated first frequency range component and an updated second frequency range component; Step S3, using the updated first frequency range component and the updated second frequency range component to perform frequency modulation on the variable speed pumped storage unit and the fixed speed pumped storage unit; When it is determined that the hybrid pumped storage system still has frequency fluctuations, an updated frequency adjustment range is determined, and steps S2 to S3 are repeated until the frequency fluctuations of the hybrid pumped storage system are eliminated.

4. The frequency modulation control method of the hybrid pumped storage system according to claim 3 is characterized in that: The step of frequency-modulating the variable-speed pumped-storage unit and the fixed-speed pumped-storage unit by using the first frequency range component and the second frequency range component comprises: Determine a first power deviation corresponding to the first frequency range component and a second power deviation corresponding to the second frequency range component; Performing power output limitation processing on the second power deviation to determine a second power adjustment amount and a corresponding second power adjustment margin of the constant-speed pumped-storage unit; Perform power output limitation processing based on the first power deviation and the second power adjustment margin to determine a first power adjustment amount and a corresponding first power adjustment margin of the variable-speed pumped-storage unit; the first power adjustment margin is used to iteratively update the frequency adjustment range; The variable-speed pumped-storage unit is frequency-regulated using the first power regulation amount, and the fixed-speed pumped-storage unit is frequency-regulated using the second power regulation amount.

5. The frequency modulation control method of the hybrid pumped storage system according to claim 4, characterized in that: After the variable-speed pumped-storage unit is frequency-regulated by using the first power regulation amount, and the fixed-speed pumped-storage unit is frequency-regulated by using the second power regulation amount, the method further includes: Acquire a first operating power of the variable-speed pumped-storage unit after frequency modulation and a second operating power of the fixed-speed pumped-storage unit after frequency modulation; Performing a primary frequency regulation calculation and a secondary frequency regulation calculation based on the current power fluctuation deviation of the external wind turbine generator set, the first operating power, and the second operating power, respectively, to determine a first frequency regulation range after the primary frequency regulation calculation and a second frequency regulation range after the secondary frequency regulation calculation; Determining a frequency adjustment amount corresponding to the first power adjustment margin; The first frequency adjustment range, the second frequency adjustment range and the frequency adjustment amount are superimposed to determine an updated frequency adjustment range output by the frequency modulation system.

6. The frequency modulation control method of a hybrid pumped storage system according to any one of claims 2 to 5, characterized in that: The analyzing the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit to determine the target operating frequency of the variable-speed pumped-storage unit at the resonance peak includes: Perform power spectrum density analysis on the historical power fluctuation time series data of external wind turbines to determine the target power fluctuation frequency range; An amplitude-frequency response characteristic difference analysis is performed on the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit within the target power fluctuation frequency range, and a target operating frequency of the variable-speed pumped-storage unit at a resonance peak is determined based on the analysis result.

7. The frequency modulation control method of the hybrid pumped storage system according to claim 6, characterized in that: The power spectrum density analysis of the historical power fluctuation time series data of the external wind turbine generator set is performed to determine the target power fluctuation frequency range, including: Acquire multiple types of wind power fluctuation time series data from the historical power fluctuation time series data of the external wind turbine generator set; Performing power spectrum density analysis on each type of wind power fluctuation time series data to determine a statistical average of wind power spectrum density corresponding to each type of wind power fluctuation time series data; The target power fluctuation frequency range is determined based on the frequency distribution of the statistical average values ​​of the power spectrum densities of various types of wind power.

8. A frequency modulation control device for a hybrid pumped storage system, applied to a hybrid pumped storage system, wherein the hybrid pumped storage system comprises a fixed-speed pumped storage unit, a variable-speed pumped storage unit and a frequency modulation system, characterized in that: include: An acquisition module, used for acquiring a frequency regulation range output by the frequency modulation system when frequency fluctuation occurs in the hybrid pumped storage system; A frequency division module, used to perform frequency division processing on the frequency adjustment range based on the amplitude-frequency response characteristics of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit, and determine a frequency division result; A frequency modulation module is used to modulate the frequency of the fixed-speed pumped-storage unit and the variable-speed pumped-storage unit based on the frequency division result until the frequency fluctuation of the hybrid pumped-storage system is eliminated.

9. An electronic device, characterized in that: include: at least one memory for storing a computer program; At least one processor is used to execute the program stored in the memory. When the program stored in the memory is executed, the processor is used to execute the method according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program runs on a processor, the processor is caused to execute the method according to any one of claims 1 to 7.

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