Frequency distribution analysis method and device for new energy unit based on comprehensive inertia control

Abstract

The application discloses a new energy unit frequency distribution analysis method and device based on comprehensive inertia control, which comprises the following steps: constructing a wind turbine comprehensive inertia control model according to the characteristics of a new energy unit; establishing a power system frequency response model considering comprehensive inertia control according to a traditional thermal power unit frequency response model and the wind turbine comprehensive inertia control model; constructing a power system frequency response space distribution characteristic model and obtaining power system frequency response space distribution characteristics according to the influence of wind turbine grid connection on the frequency space characteristics of a new power system and the obtained frequency deviation of the power system; and setting a dispersion degree coefficient to quantitatively evaluate the power system frequency response space distribution characteristics. The application analyzes the factors influencing the power grid frequency space distribution characteristics based on a system node frequency deviation expression and proposes a mathematical model of the frequency space distribution characteristics.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of frequency analysis technology of new energy power system, and particularly relates to a new energy unit frequency distribution analysis method and device based on comprehensive inertia control. BACKGROUND

[0002] The power system often causes power imbalance due to load changes, line faults, unit start-stop and other disturbance factors when running. In the active-frequency response process, the frequency will show obvious spatial distribution characteristics. The spatial distribution characteristics of the grid frequency refers to the difference in time and space of the frequency of each node of the power grid after being disturbed. With the access of new energy units and a large number of power electronic components to the power grid, the inertia level of some areas has decreased significantly, and as a result, the frequency spatial distribution characteristics are more and more obvious, which seriously affects the protection, control and analysis of the system frequency. The proportion of new energy units in the power grid is becoming higher and higher, and new energy units will become the main "frequency modulation role" of the power system, and it is feasible to improve the spatial distribution characteristics of the grid frequency through the virtual inertia control of new energy units. Traditional virtual inertia control is the commonly used method for new energy unit frequency modulation, but in actual application, the inertia support provided by the traditional virtual inertia control to the power system cannot guarantee the stability of the new power system frequency. Therefore, in order to ensure the safe and stable operation of the new power system, the inertia control method of the new energy unit needs to be further considered to improve the frequency spatial distribution characteristics of the new power system.

[0003] At present, domestic scholars have done a lot of research on the spatial distribution characteristics of power grid frequency. In the research of frequency dynamic spatial distribution characteristics and influence mechanism in large-scale power grid, the disturbance propagation in the power grid is regarded as the form of "frequency wave", and the transmission line is regarded as the propagation medium. With the help of wave theory, a spatial evolution model of power grid frequency dynamic considering spatial distribution characteristics is established, and the spatial distribution characteristics of frequency dynamic response are analyzed by empirical orthogonal function method. The research of high-order frequency response model and spatial dynamic distribution relationship of wide-area power system proposes a high-order frequency response model of power system based on the traditional SFR (System Frequency Response) model, which improves the accuracy of the system frequency response model to some extent, and quantitatively analyzes the influence of generator inertia distribution, shortest electrical distance, different disturbance locations and disturbance sizes on the spatial distribution characteristics of frequency. However, the above research objects are traditional power systems, and the influence of new energy units is not considered, which is difficult to apply to new power systems. The research of wide-area power grid frequency distribution characteristics based on data mining technology adopts time series data mining technology based on KNN (K-Nearest Neighbor Classification) classification algorithm and cross-correlation function analysis method to study the spatial distribution characteristics of power grid frequency. Although this method can directly characterize the spatial distribution characteristics of frequency with image representation, it does not analyze the reason why the power grid frequency has spatial distribution characteristics, and it is difficult to clearly understand the mechanism of influencing the spatial distribution characteristics of frequency, and it cannot improve the spatial distribution characteristics of frequency based on this research. The research of frequency spatial distribution characteristics of new energy power system combines the frequency response characteristics of each component in the new energy power system, and establishes a frequency dynamic analytical model considering spatial distribution characteristics to study and analyze the frequency spatial distribution characteristics of new energy power system with different structures. However, it does not consider that the virtual inertia control of new energy units brings certain frequency support to the power grid, and does not propose a corresponding method to solve the problem of obvious frequency spatial characteristics of new power system, which cannot guarantee the frequency stability of new power system.

[0004] Therefore, it is urgent to study the frequency stability control method suitable for new power system with high penetration rate. SUMMARY

[0005] To this end, the application provides a new energy unit frequency distribution analysis method and device based on comprehensive inertia control, aiming at the problem that the frequency space distribution characteristics of the new power system are increasingly obvious, a comprehensive inertia control method is proposed on the basis of the traditional single virtual inertia control method, a power system frequency response model containing new energy comprehensive inertia control is established in combination with the frequency response model of the traditional thermal power unit, factors affecting the frequency space distribution characteristics of the power grid are analyzed based on the system node frequency deviation expression, a mathematical model for describing the frequency space distribution characteristics is proposed, and an inertia evaluation index for analyzing the frequency space distribution characteristics is proposed for quantitative analysis of the system node frequency space distribution characteristics.

[0006] In order to achieve the above-mentioned purpose, the application provides the following technical scheme: a new energy unit frequency distribution analysis method based on comprehensive inertia control, comprising:

[0007] According to the characteristics of the new energy unit, a wind turbine comprehensive inertia control model is constructed; the wind turbine comprehensive inertia control model is used to relieve the frequency space characteristics of the power system;

[0008] According to the frequency response model of the thermal power unit, the wind turbine comprehensive inertia control model is combined to establish a power system frequency response model considering comprehensive inertia control; the frequency deviation of the power system is obtained through calculation and processing of the power system frequency response model considering comprehensive inertia control;

[0009] According to the influence of wind turbine grid connection on the frequency space characteristics of the power system, the frequency deviation of the power system is obtained, and a power system frequency response space distribution characteristic model is constructed; the power system frequency response space distribution characteristics are obtained through calculation and processing of the power system frequency response space distribution characteristic model;

[0010] A dispersion degree coefficient is set to quantitatively evaluate the power system frequency response space distribution characteristics through the dispersion degree coefficient.

[0011] As a preferred scheme of the new energy unit frequency distribution analysis method based on comprehensive inertia control, the inertia control power increment, torque control increment and active power increment provided to the system of the wind turbine are obtained through the wind turbine comprehensive inertia control model;

[0012] The calculation formula of the inertia control power increment, the torque control increment and the active power increment provided to the system of the wind turbine are respectively:

[0013]

[0014] P ref =P f -ΔP t

[0015] P is the inertia control power increment of the wind turbine generator; P is the torque control increment; P is the active power increment provided to the system; K is the virtual inertia control coefficient; K is the droop control coefficient; K is the torque control coefficient; s is a constant in the self-control theory; T is the filter time constant; Δf is the frequency deviation; Δω is the rotor speed deviation; ω is the initial rotor speed of the wind turbine generator. f t ref d p t d r ro

[0016] As the preferred scheme of the new energy unit frequency distribution analysis method based on comprehensive inertia control, in the process of obtaining the frequency deviation of the power system through the power system frequency response model considering comprehensive inertia control, the calculation expression of the frequency deviation is:

[0017]

[0018] Δf is the frequency deviation of the power system; ΔP is the power disturbance of the power system; H is the equivalent inertia of the power system; D is the damping coefficient of the thermal power unit; α is the new energy unit penetration rate, and satisfies 0<α<1; G(s) is the speed governor characteristic of the thermal power unit. sys sys sys i

[0019] As the preferred scheme of the new energy unit frequency distribution analysis method based on comprehensive inertia control, the mathematical expression of the power system frequency response space distribution characteristic model is:

[0020]

[0021] Δf is the frequency deviation of node i; η is the active power disturbance distribution coefficient; η is the inertia distribution coefficient; H is the inertia of node i; Δp is the active power injected by each node; ΔP is the power system disturbance. i P(i) H(i) i i sys

[0022] As the preferred scheme of the new energy unit frequency distribution analysis method based on comprehensive inertia control, the expression of the dispersion degree coefficient is:

[0023] ​​​​​​​​​​​​​​​​​​​

[0024] wherein Θ is a dispersion coefficient; Δf max,COI is a maximum deviation of the inertia center frequency; Δf max,i is a maximum frequency deviation of each node; m is the number of nodes in the system.

[0025] The application further provides a new energy unit frequency distribution analysis device based on comprehensive inertia control.

[0026] A wind turbine comprehensive inertia control model construction module is configured to construct a wind turbine comprehensive inertia control model according to the characteristics of the new energy unit, and the wind turbine comprehensive inertia control model is used to relieve the frequency space characteristics of the power system.

[0027] A power system frequency response model construction and processing module considering comprehensive inertia control is configured to establish a power system frequency response model considering comprehensive inertia control according to a thermal power unit frequency response model and in combination with the wind turbine comprehensive inertia control model, and the frequency deviation of the power system is obtained through calculation and processing of the power system frequency response model considering comprehensive inertia control.

[0028] A power system frequency response space distribution characteristic model construction and processing module is configured to construct a power system frequency response space distribution characteristic model according to the influence of wind power generator grid connection on the frequency space characteristics of the power system and in combination with the obtained frequency deviation of the power system, and the power system frequency response space distribution characteristics are obtained through calculation and processing of the power system frequency response space distribution characteristic model.

[0029] A power system frequency response space distribution characteristic quantitative evaluation module is configured to set a dispersion coefficient and quantitatively evaluate the power system frequency response space distribution characteristics through the dispersion coefficient.

[0030] As a preferred scheme of the new energy unit frequency distribution analysis device based on comprehensive inertia control, the wind turbine comprehensive inertia control model construction module is configured to obtain the inertia control power increment, the torque control increment and the active power increment provided to the system of the wind turbine through calculation of the wind turbine comprehensive inertia control model.

[0031] The calculation formulas of the inertia control power increment, the torque control increment and the active power increment provided to the system of the wind turbine are respectively as follows:

[0032]

[0033] P ref = P f - ΔP t

[0034] In the formula, P f , ΔP t , P ref are respectively an inertia control power increment, a torque control increment, and an active power increment provided to the system of the wind turbine generator; K d , K p , K t are respectively a virtual inertia control coefficient, a droop control coefficient, and a torque control coefficient; s is a constant in the self-control theory; T d is a filter time constant; Δf, Δω r are respectively a frequency deviation and a rotor speed deviation; ω ro is an initial rotor speed of the wind turbine generator.

[0035] As the preferred scheme of the new energy unit frequency distribution analysis device based on the comprehensive inertia control, in the process of obtaining the frequency deviation of the power system through the calculation and processing of the power system frequency response model considering the comprehensive inertia control, the calculation expression of the frequency deviation is:

[0036]

[0037] In the formula, Δf sys is the frequency deviation of the power system; ΔP sys is the power disturbance of the power system; H sys is the equivalent inertia of the power system; D is the damping coefficient of the thermal power unit; α is the penetration rate of the new energy unit, and satisfies 0 < α < 1; G i (s) is the governor characteristic of the thermal power unit.

[0038] As the preferred scheme of the new energy unit frequency distribution analysis device based on the comprehensive inertia control, in the power system frequency response space distribution characteristic model construction and processing module, the mathematical expression of the power system frequency response space distribution characteristic model is:

[0039]

[0040] In the formula, Δf i is the frequency deviation of node i; η P(i) , η H(i) are respectively an active power disturbance distribution coefficient and an inertia distribution coefficient; H i is the inertia of node i; Δp i is the active power injected by each node; ΔP sys is the disturbance of the power system.

[0041] As a preferred scheme of the new energy unit frequency distribution analysis device based on comprehensive inertia control, in the power system frequency response space distribution characteristic quantitative evaluation module, the expression of the dispersion degree coefficient is:

[0042]

[0043] In the formula, Θ is the dispersion degree coefficient, Δf max,COI is the maximum deviation of the inertia center frequency, Δf max,i is the maximum frequency deviation of each node, and m is the number of nodes in the system.

[0044] The application has the following advantages: according to the characteristics of the new energy unit, a wind turbine comprehensive inertia control model is constructed; the wind turbine comprehensive inertia control model is used to relieve the frequency space characteristics of the power system; according to the frequency response model of the thermal power unit, the wind turbine comprehensive inertia control model is combined to establish a power system frequency response model considering comprehensive inertia control; the frequency deviation of the power system is obtained through the calculation and processing of the power system frequency response model considering comprehensive inertia control; according to the influence of the wind turbine grid connection on the frequency space characteristics of the power system, the frequency deviation of the power system is obtained, and a power system frequency response space distribution characteristic model is constructed; the power system frequency response space distribution characteristics are obtained through the calculation and processing of the power system frequency response space distribution characteristic model; the dispersion degree coefficient is set, and the power system frequency response space distribution characteristics are quantitatively evaluated through the dispersion degree coefficient. The application proposes a power grid frequency space distribution characteristic quantitative index based on inertia center, maximum frequency deviation, frequency change rate and other indexes, describes the power grid frequency space distribution characteristics, and proposes an inertia control method to solve the problem that the frequency space distribution characteristics of some areas are obviously caused by the low inertia and low frequency modulation of new energy units in new power systems. The frequency space distribution characteristic model proposed for the new power system caused by the access of new energy units is more and more significant, and the power grid frequency space distribution characteristics are influenced by the size and position of the disturbance, the inertia response and primary frequency modulation capacity of the system, and the electrical distance between the disturbance node and other nodes in the power grid. The frequency space distribution characteristic model can describe the frequency space distribution characteristics of the system, and has high accuracy. The power grid frequency space distribution characteristic quantitative index proposed in the application can well reveal the frequency space distribution characteristics of the new power system, and is helpful to the research of power grid frequency stability. The inertia control method proposed in the application can improve the inertia level of each node of the system compared with single virtual inertia control, further improve the frequency stability of the power system, improve the power grid frequency space distribution characteristics, and the effectiveness of the proposed method is verified by simulation example system. BRIEF DESCRIPTION OF DRAWINGS

[0045] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0046] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0047] Figure 1 This is a schematic diagram of the frequency distribution analysis method for new energy generating units based on integrated inertia control provided in Embodiment 1 of the present invention;

[0048] Figure 2 This is a schematic diagram of the power system frequency response curve in the frequency distribution analysis method for new energy generating units based on integrated inertia control provided in Embodiment 1 of the present invention.

[0049] Figure 3 This is a simplified model of the frequency response of a traditional thermal power unit in the frequency distribution analysis method for new energy units based on integrated inertia control provided in Embodiment 1 of the present invention.

[0050] Figure 4 This is a schematic diagram of the DFIG wind turbine structure in the frequency distribution analysis method for new energy units based on integrated inertia control provided in Embodiment 1 of the present invention.

[0051] Figure 5 This is a schematic diagram of the wind power integrated inertia control block in the frequency distribution analysis method for new energy units based on integrated inertia control provided in Embodiment 1 of the present invention;

[0052] Figure 6 This is a schematic diagram of the power system frequency response model considering the comprehensive inertia control of new energy units in the frequency distribution analysis method of new energy units based on comprehensive inertia control provided in Embodiment 1 of the present invention.

[0053] Figure 7 This is a schematic diagram of an improved IEEE 10-machine 39-node system in one possible embodiment provided in Embodiment 1 of the present invention;

[0054] Figure 8This is a schematic diagram of the frequency response of each node under three models in one possible embodiment of the present invention, provided in Embodiment 1 of the present invention; wherein, (a) is the maximum frequency deviation of each node under the three models, and (b) is the frequency change rate of each node under the three models;

[0055] Figure 9 This is a schematic diagram of the node frequency dispersion under three modes in one possible embodiment of the present invention, provided in Embodiment 1 of the present invention; wherein, (a) is a heat map of the node frequency dispersion index under mode one, (b) is a heat map of the node frequency dispersion index under mode two, and (c) is a heat map of the node frequency dispersion index under mode three.

[0056] Figure 10 This is a schematic diagram of the equivalent inertia of each node under three modes in one possible embodiment of the present invention, provided in Embodiment 1 of the present invention; wherein, (a) is a schematic diagram of the equivalent inertia of each node under Mode 1, (b) is a schematic diagram of the equivalent inertia of each node under Mode 2, and (c) is a schematic diagram of the equivalent inertia of each node under Mode 3.

[0057] Figure 11 This is a schematic diagram comparing the mathematical model values ​​and simulated values ​​of frequency spatial distribution characteristics in one possible embodiment of Embodiment 1 of the present invention.

[0058] Figure 12 This is a schematic diagram of the architecture of the frequency distribution analysis device for new energy generating units based on integrated inertia control provided in Embodiment 2 of the present invention. Detailed Implementation

[0059] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] Example 1

[0061] See Figure 1 Embodiment 1 of the present invention provides a method for frequency distribution analysis of new energy generating units based on integrated inertia control, including the following steps:

[0062] S1. Based on the characteristics of new energy units, construct a comprehensive inertia control model for wind turbine units; the comprehensive inertia control model for wind turbine units is used to alleviate the frequency space characteristics of the power system.

[0063] S2. Based on the frequency response model of thermal power units and the comprehensive inertia control model of wind power units, establish a power system frequency response model considering comprehensive inertia control; obtain the frequency deviation of the power system through calculation and processing of the power system frequency response model considering comprehensive inertia control.

[0064] S3. Based on the impact of wind turbine grid connection on the frequency spatial characteristics of the power system, and combined with the obtained frequency deviation of the power system, construct a power system frequency response spatial distribution characteristic model; obtain the power system frequency response spatial distribution characteristics through calculation and processing of the power system frequency response spatial distribution characteristic model.

[0065] S4. Set a dispersion coefficient and use the dispersion coefficient to quantitatively evaluate the spatial distribution characteristics of the frequency response of the power system.

[0066] In this embodiment, in step S1, a comprehensive inertia control model for wind turbines is constructed based on the characteristics of new energy units; the comprehensive inertia control model for wind turbines is used to alleviate the frequency space characteristics of the power system.

[0067] Specifically, when a disturbance occurs in the power system, the grid frequency also fluctuates. During this fluctuation, the power system takes measures to suppress the fluctuation, such as... Figure 2 As shown. By Figure 2 It can be seen that the commonly used frequency regulation methods in power systems are: inertial response and primary frequency regulation.

[0068] Inertial response: When a disturbance causes a power drop in the system, the synchronous generator speed decreases, and the change in rotor kinetic energy is injected into the grid in the form of electrical power, slowing down the frequency drop and providing short-term frequency support for the system. The inertial time constant H is defined as:

[0069]

[0070] In the formula: E is the rotational kinetic energy of the unit; S n J is the rated capacity of the unit; J is the moment of inertia of the rotor; ω is the rated speed of the rotor.

[0071] Primary frequency regulation: When the grid frequency deviates from the rated value, the governor operates to increase the mechanical power input of the prime mover, and together with the load frequency effect, supports the frequency to reach a new equilibrium at a slightly lower level. Compared with the inertial response providing short-term frequency support, when frequency deviation exists, the primary frequency regulation response can provide the system with continuous active frequency support capability to prevent the frequency from falling continuously.

[0072] In this embodiment, when establishing a power system frequency response model that considers the inertia control of new energy sources, due to the low controllability of the load, only the inertia regulation and speed control system of the generator set are considered, and the impact of reactive power and part of the inertia in the load on the electromechanical transient frequency response is ignored.

[0073] Simplified frequency response model of traditional thermal power units, such as Figure 3 As shown. Figure 3 In this context, H represents the inertial time constant of the thermal power unit; D represents the damping coefficient of the thermal power unit; and K represents the damping coefficient of the thermal power unit. mi F is the mechanical power gain factor of the thermal power unit. Ri This represents the power ratio of the high-pressure cylinder in a thermal power unit; T Ri R is the time constant of the reheater of the steam turbine in the thermal power unit; R is the droop coefficient of the governor.

[0074] from Figure 3 From this, we can obtain:

[0075] ΔP G =G i (s)Δf (2)

[0076]

[0077] Where: ΔP G For mechanical power deviation of thermal power units; G i (s) represents the governor characteristic of the thermal power unit; Δf represents the frequency deviation of the thermal power unit.

[0078] Traditional renewable energy units lack frequency regulation capabilities, but GB38755—2019, the "Guidelines for the Safety and Stability of Power Systems," explicitly requires renewable energy power plants to possess a certain level of frequency support and regulation capabilities. Therefore, future grid-connected renewable energy units will need to provide a certain level of frequency support to the system. DFIG (Doubly Fed Induction Generator) units offer advantages such as low cost, high efficiency, and flexible control, making them the most widely used wind turbine generator sets. Therefore, taking a DFIG wind turbine generator set as an example, its simplified structural diagram is as follows: Figure 4 As shown, the unit structure mainly includes induction motors, converters, etc. The converter control mainly includes virtual inertia control, MPPT control, and pitch control.

[0079] New energy units, mainly wind turbines, have a significant amount of kinetic energy hidden in their turbine rotors. Their virtual inertia control generally uses the system frequency deviation as input and the active power provided to the system as output. This virtual inertia control method is simple and fixed. However, for wind turbines, the virtual inertia control method is poor in supporting the grid frequency in practical applications and it is difficult to ensure the frequency stability of the power system.

[0080] To address this problem, this invention proposes a comprehensive inertia control method to alleviate the frequency space characteristics of novel power systems. For example... Figure 5 As shown in the figure. (f) n f0 and f0 represent the system's rated frequency and current frequency, respectively; ω r ω ro These represent the rotor speed and its initial value of the wind turbine; Δf, Δω r These are the frequency deviation and the rotor speed deviation, respectively; T d K is the filter time constant; d K p K t These are the virtual inertia control coefficient, droop control coefficient, and torque control coefficient, respectively; K opt P is the MPPT control factor; e P f ΔP t P ref These are the electromagnetic power of the wind turbine, the power increment for inertia control, the power increment for torque control, and the power increment for active power supplied to the system.

[0081] from Figure 5 P was obtained from f ΔP t P ref The expressions are as follows:

[0082]

[0083] P ref =P f -ΔP t (6)

[0084] Assuming the wind speed remains constant during operation, the input mechanical power of a wind turbine is:

[0085] P m =0.5ρπR 2 C p (λ,β)v 3 (7)

[0086] In the formula, ρ is the air density; R is the radius of the fan blade; C p λ is the wind energy utilization coefficient; λ is the blade tip number ratio; β is the blade pitch angle; v is the wind speed.

[0087] When the wind speed exceeds the rated wind speed, due to limitations in its mechanical structure, the wind turbine typically adjusts its frequency by changing the blade pitch angle, rather than through inertial regulation. Therefore, we will only discuss the case where the wind speed is less than the rated wind speed, in which case the increase in mechanical input power is:

[0088]

[0089] In the formula: ΔC ω This is the mechanical power increment coefficient.

[0090] Since the damping coefficient of a wind turbine rotor is generally very small, we can ignore the damping coefficient here and obtain the motion equation of the wind turbine rotor:

[0091]

[0092] In the formula, H DFIG ΔP represents the virtual inertia time constant of the wind turbine. e This represents the increase in electromagnetic power of the wind turbine. Ignoring the effects of reactive power and voltage, the increase in electromagnetic power ΔP... e This can be equivalent to a first-order inertial element controlled by the inner loop of the quadrature-axis current of the converter related to electromagnetic torque, and its expression is:

[0093]

[0094] In the formula: This is the converter control time constant.

[0095] After normalizing equation (9) to unit values, the rotor frequency deviation of the low-frequency value can be expressed as the grid angular frequency increment, i.e.: Δf≈Δω e Simultaneously, performing a Laplace transform on equation (9) yields:

[0096]

[0097] The equivalent virtual inertia of a wind turbine generator can be defined as:

[0098]

[0099] In the formula: ω eo ω nom These are the initial value of the power grid angular frequency and the rated angular velocity of the wind turbine, respectively.

[0100] Furthermore, the converter has a fast response speed, and its dynamic process can be ignored, i.e., φ = 0. Therefore, the expression for the virtual inertia time constant of the wind turbine is obtained:

[0101]

[0102] Here H eq This indicates the frequency regulation capability of a wind turbine generator set; within a certain range, H... eq The larger the value, the stronger its frequency modulation capability, and vice versa.

[0103] In this embodiment, in step S2, a power system frequency response model considering comprehensive inertia control is established based on the thermal power unit frequency response model and the wind turbine unit comprehensive inertia control model; the frequency deviation of the power system is obtained through calculation and processing of the power system frequency response model considering comprehensive inertia control.

[0104] Specifically, to further study the frequency spatial distribution characteristics of the power system, based on the traditional frequency response model of thermal power units, and combined with the comprehensive inertia control model of wind turbine units proposed in this invention, a power system frequency response model considering comprehensive inertia control is established, such as... Figure 6 As shown.

[0105] Figure 6 In the middle, ΔP sys For the power disturbance of the power system, Δf sys For power system frequency deviation; ΔP G For the power increment of the thermal power unit speed governor; H sys The equivalent inertia of the power system is expressed as:

[0106] H sys =αH eq +(1-α)H (14)

[0107] In the formula: α is the penetration rate of new energy units, and satisfies 0 < α < 1.

[0108] Depend on Figure 6 The other expressions obtained are:

[0109]

[0110] The system frequency deviation expression Δf is obtained from equations (15) and (16). sys :

[0111]

[0112] Analysis of equation (17) shows that the magnitude of the system frequency deviation is mainly affected by factors such as the magnitude of the disturbance, the system inertial time constant, the damping coefficient, the permeability, and the characteristics of the thermal power unit governor.

[0113] In this embodiment, in step S3, based on the impact of wind turbine grid connection on the frequency spatial characteristics of the power system, and combined with the obtained frequency deviation of the power system, a power system frequency response spatial distribution characteristic model is constructed; through the calculation and processing of the power system frequency response spatial distribution characteristic model, the power system frequency response spatial distribution characteristics are obtained.

[0114] Specifically, in order to further analyze the impact of wind turbine grid connection on the frequency spatial characteristics of the new power system, a spatial distribution characteristic model of the frequency response of the new power system is established.

[0115] When a power system experiences a disturbance, the active power and frequency disturbance processes in the new power system differ from those in the traditional power system, expanding from three main stages to four: the disturbance power distribution stage, the voltage source inertia response stage, the current source virtual inertia and synchronous power source primary frequency regulation stage, and the power electronic equipment frequency regulation exit and energy recovery stage. Assume that node n has a value of ΔP. n In the initial stage of a disturbance, before the system's active power and frequency disturbance process reaches the frequency regulation stage, the active power injected into each node is:

[0116]

[0117] In the formula, P i Active power injected into each node; E i Let B be the potential of the i nodes; ij G ij The susceptance and conductance between nodes i and j are given by β; m is the number of nodes; β ij The phase difference between nodes i and j.

[0118] Assume that after node n is disturbed, the voltage phase angle becomes (β). n0 +Δβ n After linearizing equation (18), we get:

[0119]

[0120] In the formula, ΔP i β represents the active power imbalance at each node. ij0 Q represents the initial phase difference between nodes i and j; ij Q represents the synchronization power coefficient between nodes i and j; in Let be the synchronization power coefficient between node i and the disturbed node n.

[0121] Furthermore, the magnitude of the unbalanced power allocated to node i can be expressed as:

[0122]

[0123] Accordingly, following the expression for the system frequency deviation in equation (18), the expression for the frequency deviation of each node in the system is written as follows:

[0124]

[0125] In the formula, Δf i H represents the frequency deviation of node i; i Let be the magnitude of the inertia of node i.

[0126] Analysis of equation (21) reveals that the main factors affecting frequency are: 1) ΔPn 2) The magnitude of the disturbance; H i The primary frequency regulation capability of a system can be represented by the following factors: 1) the equivalent inertia level of a general node; 2) the magnitude of the damping coefficient D; 3) the magnitude of α-permeability; and 4) the governor characteristics of the thermal power unit. However, among these factors, the influence of the damping coefficient D on frequency is relatively small compared to the other factors and is generally a constant. Therefore, improving the inertia level H of the wind turbine unit on the power grid and its frequency support can enhance the overall system inertia and the inertia level of each node. i Improving the spatial distribution characteristics of the power grid frequency is an effective approach.

[0127] When a disturbance ΔP occurs at node n in the system n At this point, the disturbance at node n can be considered as the power disturbance of the power system, that is:

[0128] ΔP sys =ΔP n (twenty two)

[0129] Combining equations (21) and (17), based on the above analysis of the damping coefficient, we temporarily ignore the influence of the damping coefficient on the frequency spatial distribution characteristics. Simultaneously, based on the traditional power system with very low penetration, the system can be approximated as having only thermal power units as the power source. At this time, the system's frequency spatial distribution characteristics are extremely insignificant. Therefore, we can assume that the speed governor has a relatively small influence on the frequency spatial distribution characteristics. Thus, we temporarily ignore the influence of the damping coefficient and the thermal power unit speed governor, obtaining the mathematical model of the system's frequency spatial distribution characteristics:

[0130]

[0131] In the formula, η P(i) η H(i) These are the active power disturbance distribution coefficient and the inertia distribution coefficient, respectively; Δp i Active power injected into each node; ΔP sys This is a disturbance to the power system.

[0132] As can be seen from equation (13), due to the comprehensive inertia control of the wind turbine, the overall inertia level of the new power system is increased, and the adjustment of the inertia distribution coefficient η H(i) This improves the frequency spatial distribution characteristics of the system.

[0133] In this embodiment, in step S4, a dispersion coefficient is set, and the spatial distribution characteristics of the frequency response of the power system are quantitatively evaluated by the dispersion coefficient.

[0134] Specifically, the spatial distribution characteristics of power grid frequency are affected by multiple factors, and it is necessary to define evaluation indicators of frequency spatial distribution characteristics from multiple perspectives. Existing literature provides the following indicators: 1) Rate of change of frequency (ROCOF): the frequency fluctuation value per unit time after a disturbance occurs; 2) Maximum frequency deviation: the value at which the frequency fluctuation is at its maximum after a disturbance occurs.

[0135] To better analyze the spatial distribution characteristics of power grid frequency, the center of inertia (COI) is used as a reference for power grid frequency, and it is defined as follows:

[0136]

[0137] In the formula, f COI f is the inertial center frequency; i For thermal power unit i, the connection bus frequency is f; t The frequency of the bus for the new energy unit t.

[0138] The aforementioned indicators only reflect the differences in frequency response of each node to demonstrate the spatial distribution characteristics of frequency, and cannot intuitively reflect the frequency distribution characteristics of each node in the system. This invention proposes a dispersion coefficient Θ as a quantitative indicator of the spatial distribution characteristics of power grid frequency, and its expression is as follows:

[0139]

[0140] In the formula: Δf max,COI The maximum deviation of the inertial center frequency; Δf max,i Θ represents the maximum frequency deviation at each node; m represents the number of nodes in the system. The larger the index Θ is, the more pronounced the spatial distribution characteristics of the power grid frequency, and the worse the system stability.

[0141] In one possible embodiment, an example of frequency spatial distribution characteristic analysis of an improved IEEE 10-machine 39-node system built using Matlab / Simulink is provided below:

[0142] An improved IEEE 10-machine 39-node system was built using Matlab / Simulink, such as... Figure 7 As shown in the figure. The system consists of 10 power plants, 19 loads and 34 lines. Among them, G1-G8 are synchronous turbine units and W1-W2 are wind farms. Each wind farm consists of 80 wind turbine units (DFIG). The governor models of the 8 synchronous turbine units and the relevant parameters of the 2 wind farms are the same. The rated frequency of the system is 60Hz and the base capacity of the system is 100MVA. The relevant parameters of the synchronous turbine units and wind turbine units are shown in Tables 1 and 2, respectively.

[0143]

[0144] Table 1. Relevant parameters of synchronous generator units

[0145]

[0146] Table 2 Relevant parameters of wind turbine units

[0147] Assuming that at node 18 of an improved IEEE 10-machine 39-bus system, the load suddenly increases by 800MW at t=5s, to verify the feasibility of power system frequency space mathematics and the effectiveness of the proposed method in improving the frequency space distribution characteristics of the power grid, the following three modes are set:

[0148] Mode 1: Wind turbines do not participate in frequency regulation;

[0149] Mode 2: Single virtual inertia control mode;

[0150] Mode 3: The frequency integrated control mode proposed in this paper.

[0151] Under the above assumptions, the ROCOF and maximum frequency deviation of each node in the system under the above three modes are obtained as follows: Figure 8 As shown.

[0152] exist Figure 8 In (a), the maximum frequency deviation of all nodes in the improved IEEE 10-machine 39 system was compared under three models. In Mode 1, the maximum frequency deviation of the system was relatively large, with the maximum frequency deviation at node 39 reaching 0.43Hz. Moreover, the frequency deviations of each node differed significantly in value, showing a severe spatial distribution characteristic of the power grid frequency. In Mode 2, virtual inertia control was added to the wind turbines in the system. Although the maximum frequency deviation of each node in the system was smaller than that in Mode 1, the improvement was not very significant. In contrast, based on the frequency integrated control mode 3 proposed in this paper, the maximum frequency deviation of each node in the system was significantly smaller than that in Mode 1 and Mode 2. The maximum frequency deviations of each node were also relatively fixed in value, which fully demonstrates that the spatial distribution characteristic of the power grid frequency has been improved and the frequency stability of the system is relatively good.

[0153] exist Figure 8In (b), the frequency change rates of all nodes in the IEEE 10-machine-39 system were compared under three different modes. In Mode 1, because the wind turbines could not provide inertial support to the system, the frequency change rates of each node were large, especially at the wind turbine grid-connected nodes, resulting in poor overall system frequency regulation capability. In Mode 2, based on single virtual inertial control, the wind turbines provided weak inertial support to the system, and the frequency change of some nodes was slower than in Mode 1, but the problem of poor overall system frequency regulation capability was not solved. Compared with Modes 1 and 2, Mode 3 not only had a smaller overall system frequency change rate, but also a relatively consistent frequency change rate among the nodes, improving the spatial distribution characteristics of the grid frequency. At nodes 1, 9, 24, and 29 in the figure, the frequency change rates of the three models were not significantly different. The specific reason is that the inertial response of thermal power units has a much greater impact on these nodes than that of wind turbines.

[0154] After obtaining the frequency response of each node in the system, the maximum frequency deviation and frequency change rate of COI under the three modes are calculated by equation (24), as shown in Table 3.

[0155]

[0156] Table 3. Inertial center frequency response under three modes

[0157] As shown in Table 3, the maximum frequency deviation of COI and ROCOF in Mode 3 are lower than those in Mode 1 and Mode 2, indicating that the overall system frequency stability is higher in Mode 3.

[0158] To further verify the effectiveness of the inertia control model proposed in this invention in improving the frequency spatial distribution characteristics of the power grid, heat maps of the frequency dispersion of each node under three modes were obtained based on equation (24), as follows: Figure 9 As shown.

[0159] Figure 9 (a), (b), and (c) represent heatmaps showing the frequency dispersion of system nodes in modes one, two, and three, respectively. Each graph is divided into 40 sub-sections, where 1-39 represent the frequency dispersion of each of the 39 nodes in the system, and COI represents the dispersion of the system's center of inertia. The darker the color, the greater the dispersion, the more obvious the spatial distribution characteristics of the power grid frequency, and the worse the system stability.

[0160] Depend on Figure 9As shown in (a), (b), and (c), the dispersion index of most nodes in Mode 1 and Mode 2 is between 2 and 3, and some nodes have a higher dispersion index. Compared with Mode 1 and Mode 2, the dispersion of all nodes in Mode 3 decreases, the general dispersion index of nodes is between 0 and 1, and the maximum dispersion index of nodes does not exceed 2. This indicates that the spatial distribution characteristics of the power grid frequency have been significantly improved, and the power grid frequency stability is better under Mode 3.

[0161] Quantitative analysis of the frequency spatial distribution characteristics under the three models yielded the inertia distribution of each node in the improved 10-machine 39-node system under the three models, as follows: Figure 10 As shown.

[0162] pass Figure 10 (a), (b), and (c) allow direct observation of the spatial distribution of inertia at each node of the system under the three models. Among them, Figure 10 (a) is the inertia distribution diagram under mode 1. The inertia of nodes 1-39 does not change with time. The reason is that the wind turbines connected to the grid under this mode do not have virtual inertia control, only the fixed inertia provided by the thermal power units, and the overall inertia level is relatively low. Figure 10 (b) Due to the addition of a single virtual inertia control to the wind turbine, the inertia of the nodes changes with time, and the inertia of each node reaches its maximum value when the disturbance occurs (t=10s). Although the overall inertia level has increased compared with Mode 1, the increase is not enough to alleviate the frequency spatial distribution characteristics of the wind turbine under grid connection. Figure 10 (c) shows the inertia distribution of each node in Mode 3. The characteristics of the inertia of each node changing with time are similar to those in Mode 2, but the inertia level of each node is higher than that in Mode 1 and Mode 2. This explains why Mode 3 can alleviate the frequency spatial distribution characteristics and further illustrates the effectiveness of the present invention.

[0163] To reduce the randomness of experimental results, frequency deviation data of different nodes under three models were randomly obtained to verify the feasibility of the frequency spatial distribution mathematical model. The nodes selected for the three models are shown in Table 4, and the frequency spatial distribution characteristic model values ​​of the nodes corresponding to Mode 1, Mode 2, and Mode 3 are obtained as follows: Figure 11 As shown.

[0164]

[0165]

[0166] Table 4 shows the different node numbers used in the three modes.

[0167] Figure 11This is a comparison chart of the mathematical model values ​​and simulated values ​​for the frequency spatial distribution characteristics. Red, green, and blue represent the simulated values ​​of the corresponding nodes under the three modes, respectively. The dotted lines in the chart represent the values ​​calculated using the mathematical model of frequency spatial distribution characteristics according to equation (23). Figure 11 The results show that the values ​​calculated by the mathematical model of frequency spatial distribution characteristics are basically equal to the values ​​obtained by simulation, with very small errors. This indicates that the model can represent the frequency spatial distribution characteristics, which is beneficial for better analysis of frequency spatial distribution characteristics.

[0168] In summary, this invention constructs a comprehensive inertia control model for wind turbines based on the characteristics of new energy units. This comprehensive inertia control model is used to alleviate the frequency spatial characteristics of the power system. Based on the frequency response model of thermal power units and combined with the comprehensive inertia control model of wind turbines, a power system frequency response model considering comprehensive inertia control is established. The frequency deviation of the power system is obtained through calculation and processing using this comprehensive inertia control model. Based on the impact of wind turbine grid connection on the frequency spatial characteristics of the power system and combined with the obtained frequency deviation, a power system frequency response spatial distribution characteristic model is constructed. The spatial distribution characteristics of the power system frequency response are obtained through calculation and processing using this model. A dispersion coefficient is set, and the spatial distribution characteristics of the power system frequency response are quantitatively evaluated using this dispersion coefficient. This invention proposes quantitative indicators for the frequency spatial distribution characteristics of the power grid based on inertia center, maximum frequency deviation, and frequency change rate, characterizing the frequency spatial distribution characteristics of the power grid. It also proposes an inertia control method to address the problem of significant frequency spatial distribution characteristics in some areas of the new power system due to the "low inertia and low frequency" of new energy units. To address the increasingly pronounced frequency spatial distribution characteristics of new power systems due to the integration of renewable energy units, and considering that these characteristics are influenced by the magnitude and location of disturbances, the system's inertial response, primary frequency regulation capability, and electrical distance between disturbing nodes and other nodes, a proposed frequency spatial distribution characteristic model effectively characterizes these characteristics with high accuracy. The quantitative index for power grid frequency spatial distribution characteristics proposed in this invention effectively reveals the frequency spatial distribution characteristics of new power systems, contributing to research on power grid frequency stability. Furthermore, the inertial control method proposed in this invention improves the inertial levels of each node compared to single virtual inertial control, further enhancing power system frequency stability and improving the power grid frequency spatial distribution characteristics. Simulation examples validate the effectiveness of the proposed method.

[0169] It should be noted that the method of this disclosure embodiment can be executed by a single device, such as a computer or server. The method of this embodiment can also be applied to a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method of this disclosure embodiment, and the multiple devices will interact with each other to complete the method described.

[0170] It should be noted that the above description describes some embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0171] Example 2

[0172] See Figure 12 Embodiment 2 of the present invention also provides a frequency distribution analysis device for new energy generating units based on integrated inertia control, comprising:

[0173] The wind turbine integrated inertia control model construction module 001 is used to construct a wind turbine integrated inertia control model based on the characteristics of new energy units; the wind turbine integrated inertia control model is used to alleviate the frequency space characteristics of the power system.

[0174] The power system frequency response model construction and processing module 002, which considers comprehensive inertia control, is used to establish a power system frequency response model considering comprehensive inertia control based on the frequency response model of thermal power units and the comprehensive inertia control model of wind power units; and to obtain the frequency deviation of the power system through calculation and processing of the power system frequency response model considering comprehensive inertia control.

[0175] The power system frequency response spatial distribution characteristic model construction and processing module 003 is used to construct a power system frequency response spatial distribution characteristic model based on the impact of wind turbine grid connection on the power system frequency spatial characteristics and the obtained frequency deviation of the power system; and to obtain the power system frequency response spatial distribution characteristics through calculation and processing of the power system frequency response spatial distribution characteristic model.

[0176] The power system frequency response spatial distribution characteristic quantitative evaluation module 004 is used to set the dispersion degree coefficient and to quantitatively evaluate the power system frequency response spatial distribution characteristics through the dispersion degree coefficient.

[0177] In this embodiment, the wind turbine integrated inertia control model construction module 001 calculates the wind turbine's inertia control power increment, torque control increment, and active power increment provided to the system through the wind turbine integrated inertia control model.

[0178] The calculation formulas for the inertia control power increment, the torque control increment, and the active power increment provided to the system by the wind turbine are as follows:

[0179]

[0180] P ref =P f -ΔP t

[0181] In the formula, P f ΔP t P ref These represent the power increment for inertia control of the wind turbine, the torque control increment, and the active power increment supplied to the system, respectively; K d K p K t These are the virtual inertia control coefficient, droop control coefficient, and torque control coefficient, respectively; s is a constant in automatic control theory; T d Δf, Δω are the filter time constants; r These are the frequency deviation and the rotor speed deviation, respectively; ω ro This represents the initial rotational speed of the wind turbine rotor.

[0182] In this embodiment, in the power system frequency response model construction and processing module 002 considering integrated inertia control, during the process of obtaining the frequency deviation of the power system through the calculation and processing of the power system frequency response model considering integrated inertia control, the calculation expression of the frequency deviation is:

[0183]

[0184] In the formula, Δf sys For power system frequency deviation; ΔP sys For power disturbances in the power system; H sys Let G be the equivalent inertia of the power system; D be the damping coefficient of the thermal power unit; α be the penetration rate of new energy units, and satisfy 0 < α < 1; G i (s) represents the governor characteristics of the thermal power unit.

[0185] In this embodiment, in the power system frequency response spatial distribution characteristic model construction and processing module 003, the mathematical expression of the power system frequency response spatial distribution characteristic model is:

[0186]

[0187] In the formula, Δf i η is the frequency deviation of node i; P(i) η H(i) These are the active power disturbance distribution coefficient and the inertia distribution coefficient, respectively; H i Let Δp be the magnitude of the inertia of node i; i Active power injected into each node; ΔP sys This is a disturbance to the power system.

[0188] In this embodiment, the expression for the dispersion coefficient in the power system frequency response spatial distribution characteristic quantitative evaluation module 004 is as follows:

[0189]

[0190] In the formula, Θ is the dispersion coefficient; Δf max,COI The maximum deviation of the inertial center frequency; Δf max,i denoted as , where is the maximum frequency deviation of each node; m is the number of nodes in the system.

[0191] It should be noted that the information interaction and execution process between the modules of the above system are based on the same concept as the method embodiment in Embodiment 1 of this application, and the resulting technical effects are the same as those in the method embodiment of this application. For details, please refer to the description in the method embodiment shown above in this application, and it will not be repeated here.

[0192] Example 3

[0193] Embodiment 3 of the present invention provides a non-transitory computer-readable storage medium, wherein the computer-readable storage medium stores program code for a frequency distribution analysis method for new energy generating units based on integrated inertia control, the program code including instructions for executing the frequency distribution analysis method for new energy generating units based on integrated inertia control as described in Embodiment 1 or any possible implementation thereof.

[0194] Computer-readable storage media can be any available medium that a computer can access, or a data storage device such as a server or data center that integrates one or more available media. The available medium can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives, SSDs).

[0195] Example 4

[0196] Embodiment 4 of the present invention provides an electronic device, including: a memory and a processor;

[0197] The processor and the memory communicate with each other via a bus; the memory stores program instructions that can be executed by the processor, and the processor can call the program instructions to execute the frequency distribution analysis method of new energy units based on integrated inertia control in Embodiment 1 or any possible implementation thereof.

[0198] Specifically, a processor can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, an integrated circuit, etc. When implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. This memory can be integrated into the processor or located outside the processor and exist independently.

[0199] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as 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, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable system. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0200] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing systems. They can be centralized on a single computing system or distributed across a network of multiple computing systems. Optionally, they can be implemented using program code executable by a computing system, thereby storing them in a storage system for execution by the computing system. In some cases, the steps shown or described can be performed in a different order than those presented herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0201] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for analyzing the frequency distribution of new energy generating units based on integrated inertia control, characterized in that, include: Based on the characteristics of new energy units, a comprehensive inertia control model for wind turbine units is constructed. The integrated inertia control model for wind turbines is used to mitigate the frequency-space characteristics of the power system. Based on the frequency response model of thermal power units and the comprehensive inertia control model of wind power units, a frequency response model of the power system considering comprehensive inertia control is established; the frequency deviation of the power system is obtained through calculation and processing by the frequency response model of the power system considering comprehensive inertia control. Based on the impact of wind turbine grid connection on the frequency spatial characteristics of the power system, and combined with the obtained frequency deviation of the power system, a spatial distribution characteristic model of the power system frequency response is constructed; the spatial distribution characteristics of the power system frequency response are obtained through calculation and processing of the spatial distribution characteristic model of the power system frequency response. A dispersion coefficient is set, and the spatial distribution characteristics of the frequency response of the power system are quantitatively evaluated using the dispersion coefficient. The inertia control power increment, torque control increment, and active power increment supplied to the system of the wind turbine are calculated using the integrated inertia control model of the wind turbine. The calculation formulas for the inertia control power increment, the torque control increment, and the active power increment provided to the system by the wind turbine are as follows: P ref =P f -ΔP t In the formula, P f ΔP t P ref These represent the power increment for inertia control of the wind turbine, the torque control increment, and the active power increment supplied to the system, respectively; K d K p K t These are the virtual inertia control coefficient, droop control coefficient, and torque control coefficient, respectively; s is the complex variable in the Laplace transform; T d Δf, Δω are the filter time constants; r These are the frequency deviation and the rotor speed deviation, respectively; ω ro This refers to the initial rotational speed of the wind turbine rotor. In the process of calculating and processing the frequency deviation of the power system using the power system frequency response model that considers integrated inertia control, the expression for calculating the frequency deviation is as follows: In the formula, Δf sys For power system frequency deviation; ΔP sys For power disturbances in the power system; H sys Let G be the equivalent inertia of the power system; D be the damping coefficient of the thermal power unit; α be the penetration rate of new energy units, and satisfy 0 < α < 1; G i (s) represents the governor characteristics of the thermal power unit.

2. The method for frequency distribution analysis of new energy generating units based on integrated inertia control according to claim 1, characterized in that, The mathematical expression for the spatial distribution characteristic model of the power system frequency response is: In the formula, Δf i η is the frequency deviation of node i; P(i) η H(i) These are the active power disturbance distribution coefficient and the inertia distribution coefficient, respectively; H i Let Δp be the magnitude of the inertia of node i; i Active power injected into each node; ΔP sys This is a disturbance to the power system.

3. The frequency distribution analysis method for new energy generating units based on integrated inertia control according to claim 2, characterized in that, The expression for the dispersion coefficient is: In the formula, Θ is the dispersion coefficient; Δf max,COI The maximum deviation of the inertial center frequency; Δf max,i denoted as , where is the maximum frequency deviation of each node; m is the number of nodes in the system.

4. A frequency distribution analysis device for new energy generating units based on integrated inertia control, employing the frequency distribution analysis method for new energy generating units based on integrated inertia control as described in any one of claims 1-3, characterized in that, include: The wind turbine integrated inertia control model construction module is used to construct a wind turbine integrated inertia control model based on the characteristics of new energy units. The integrated inertia control model for wind turbines is used to mitigate the frequency-space characteristics of the power system. The module for constructing and processing a power system frequency response model considering integrated inertia control is used to establish a power system frequency response model considering integrated inertia control based on the frequency response model of thermal power units and the integrated inertia control model of wind power units; and to obtain the frequency deviation of the power system through calculation and processing of the power system frequency response model considering integrated inertia control. The module for constructing and processing the spatial distribution characteristic model of the power system frequency response is used to construct a spatial distribution characteristic model of the power system frequency response based on the impact of wind turbine grid connection on the spatial frequency characteristics of the power system and the obtained frequency deviation of the power system; and to obtain the spatial distribution characteristics of the power system frequency response through calculation and processing of the spatial distribution characteristic model of the power system frequency response. A quantitative evaluation module for the spatial distribution characteristics of the frequency response of a power system is used to set a dispersion coefficient and to quantitatively evaluate the spatial distribution characteristics of the frequency response of the power system using the dispersion coefficient. In the wind turbine integrated inertia control model construction module, the wind turbine integrated inertia control model is used to calculate the wind turbine inertia control power increment, torque control increment, and active power increment provided to the system. The calculation formulas for the inertia control power increment, the torque control increment, and the active power increment provided to the system by the wind turbine are as follows: P ref =P f -ΔP t In the formula, P f ΔP t P ref These represent the power increment for inertia control of the wind turbine, the torque control increment, and the active power increment supplied to the system, respectively; K d K p K t These are the virtual inertia control coefficient, droop control coefficient, and torque control coefficient, respectively; s is the complex variable in the Laplace transform; T d Δf, Δω are the filter time constants; r These are the frequency deviation and the rotor speed deviation, respectively; ω ro This refers to the initial rotational speed of the wind turbine rotor. In the power system frequency response model construction and processing module considering integrated inertia control, during the process of obtaining the frequency deviation of the power system through the calculation and processing of the power system frequency response model considering integrated inertia control, the calculation expression of the frequency deviation is: In the formula, Δf sys For power system frequency deviation; ΔP sys For power disturbances in the power system; H sys Let G be the equivalent inertia of the power system; D be the damping coefficient of the thermal power unit; α be the penetration rate of new energy units, and satisfy 0 < α < 1; G i (s) represents the governor characteristics of the thermal power unit.

5. The frequency distribution analysis device for new energy units based on integrated inertia control according to claim 4, characterized in that, In the module for constructing and processing the spatial distribution characteristic model of the power system frequency response, the mathematical expression of the spatial distribution characteristic model of the power system frequency response is: In the formula, Δf i η is the frequency deviation of node i; P(i) η H(i) These are the active power disturbance distribution coefficient and the inertia distribution coefficient, respectively; H i Let Δp be the magnitude of the inertia of node i; i Active power injected into each node; ΔP sys This is a disturbance to the power system.

6. The frequency distribution analysis device for new energy generating units based on integrated inertia control according to claim 5, characterized in that, In the quantitative evaluation module for the spatial distribution characteristics of the power system frequency response, the expression for the dispersion coefficient is: In the formula, Θ is the dispersion coefficient; Δf max,COI The maximum deviation of the inertial center frequency; Δf max,i denoted as , where is the maximum frequency deviation of each node; m is the number of nodes in the system.

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