Grid-type energy storage optimization configuration method and device for new energy transmission base

Abstract

The present application relates to the technical field of distribution network, and in particular to a method and device for optimizing the configuration of grid-type energy storage for a new energy delivery base, wherein the method includes: obtaining the node equivalent form of the new energy delivery base, establishing an equivalent matrix relationship between the power disturbance suffered by the external system in the new energy delivery base and the frequency change of each unit and obtaining the dominant eigenvalue, so as to analyze the frequency stability of the new energy delivery base to obtain the analysis result, thereby taking the eigenvalue of the equivalent matrix as the stability constraint condition and the minimum total planning cost of the energy storage power station as the optimization goal, and optimizing the configuration of the grid-type energy storage power station. Thus, the problem in the related technology that, since the new energy base is far away from the interaction point, it is difficult to fully exert its frequency regulation capacity by deploying frequency regulation resources such as grid-type energy storage near the collection station, it is difficult to achieve the balanced regulation of frequency and voltage, and it is impossible to effectively improve it, which increases the risk of instability in the operation of the power grid.

Description

Technical Field

[0001] The present application relates to the technical field of distribution network, and in particular to a method and device for optimizing the configuration of grid-type energy storage for a new energy transmission base. Background Art

[0002] With the rapid planning and construction of new energy systems, the construction proportion of new energy sites has gradually increased. Due to the uneven distribution of domestic new energy, areas rich in wind and solar resources are often geographically remote, resulting in large new energy capacity, large land area, and fewer interaction points with the transmission network. In related technologies, the frequency regulation resources are usually deployed near the aggregation station to achieve the frequency stability requirements on the transmission network side, mainly through the design of new energy delivery bases, and in order to ensure the reasonable scheduling and safe and reliable operation of the power grid. Among them, the GFM (Grid-forming) control strategy has stronger frequency support capabilities in high new energy penetration scenarios.

[0003] However, in the relevant technologies, since the new energy base occupies a large area and has fewer interaction points with the transmission network, and it is difficult to fully utilize the frequency regulation capabilities of frequency regulation resources such as grid-type energy storage when deployed near the collection station, it is easy to cause excessive load on the transmission line, resulting in the frequency regulation performance of each station in the new energy transmission base not being significantly improved, making it difficult to achieve balanced frequency and voltage regulation, and even failing to play an effective improvement role, affecting the stability of the power supply of the power grid, which urgently needs to be improved. Summary of the invention

[0004] The present application provides a method and device for optimizing the configuration of a grid-type energy storage for a new energy transmission base, in order to solve the problems in the related art that, since the new energy base is far away from the interaction point, it is difficult to fully utilize the frequency regulation capacity of frequency regulation resources such as grid-type energy storage when they are deployed near the collection station, which easily leads to excessive load on the transmission line, making it difficult to achieve balanced regulation of frequency and voltage, and even failing to play an effective improvement role, increasing the risk of instability in power grid operation, and the like.

[0005] The first aspect of the present application provides a method for optimizing the configuration of a grid-type energy storage system for a new energy transmission base, comprising the following steps: obtaining a node equivalent form of the new energy transmission base; establishing an equivalent matrix relationship between power disturbances suffered by an external system and frequency changes of each unit in the new energy transmission base based on the node equivalent form of the new energy transmission base; obtaining a dominant eigenvalue according to the equivalent matrix relationship, and analyzing the frequency stability of the new energy transmission base according to the dominant eigenvalue to obtain an analysis result; based on the analysis result, taking the eigenvalue of the equivalent matrix as a stability constraint condition, and minimizing the total planning cost of the energy storage power station as the optimization goal, optimizing the configuration of the grid-type energy storage power station.

[0006] Optionally, in one embodiment of the present application, obtaining the node equivalent form of the new energy transmission base includes: simplifying the active power-frequency relationship of the rotating elements and the new energy stations in the new energy base according to the rotor motion equation and the voltage source converter control principle, and obtaining the node equivalent form of the new energy transmission base.

[0007] Optionally, in one embodiment of the present application, the establishment of an equivalent matrix relationship between the power disturbance suffered by the external system in the new energy transmission base and the frequency change of each unit includes: establishing a frequency domain equivalent matrix describing the active power-frequency change of the transmission base according to the new energy transmission base construction structure corresponding to the node equivalent form of the new energy transmission base; determining the relationship between the active power change and the frequency change of each station in the system according to the frequency domain equivalent matrix to obtain the equivalent matrix relationship.

[0008] Optionally, in one embodiment of the present application, the relevant element expression of the frequency domain equivalent matrix is:

[0009]

[0010]

[0011] Among them, n is the total number of generator sets in the new energy transmission base, Δω i (s) and ΔP mi (s) is the change in angular velocity and mechanical power in the i-th new energy station, Δω pcc (s) and ΔP c (s) is the angular velocity change and power disturbance at the exit of the new energy transmission base, D mn is the element in the mth row and nth column of the equivalent matrix, where m and n are integers not exceeding (n+1), and Y r is the equivalent impedance of the transmission line, Y is the sum of the measured admittance of all units in the renewable energy transmission base, am and Y bm are the control admittance and measurement admittance coefficients of the mth VSC of the new energy station, K r is the synchronous torque coefficient, U r is the voltage at the outlet of each new energy unit, U pcc is the voltage of the collection station, δ r0 is the phase angle difference between the two voltage phases, X r is the transmission reactance between the new energy unit and the collection station, and s is the Laplace operator.

[0012] Optionally, in one embodiment of the present application, the dominant eigenvalue is obtained according to the equivalent matrix relationship to analyze the frequency stability of the new energy transmission base according to the dominant eigenvalue to obtain an analysis result, including: based on automatic control theory, performing eigenvalue analysis on the equivalent matrix to obtain the dominant eigenvalue; detecting whether the minimum eigenvalue of the dominant eigenvalue is located in the left half plane of the frequency domain to obtain the analysis result.

[0013] Optionally, in one embodiment of the present application, the expression of active power-frequency stability of the multi-machine parallel system of the analysis result is:

[0014]

[0015] Among them, A i is the transfer function expression between the output power change of the i-th new energy unit and its own mechanical or equivalent mechanical power change, B i,t is the transfer function expression between the output power change of the i-th new energy unit and the mechanical or equivalent mechanical power change of the t-th unit, C i is the transfer function expression between the output power change of the i-th renewable energy unit and the power change at the collection station side, ΔP i (s) is the output power change of the i-th renewable energy unit, ΔP mi (s) is the change in mechanical or equivalent mechanical power of the i-th unit, Δω pcc (s) is the change in angular velocity of the bus at the collection station.

[0016] Optionally, in one embodiment of the present application, based on the analysis results, taking the eigenvalue of the equivalent matrix as a stability constraint condition, and minimizing the total planning cost of the energy storage power station as the optimization goal, the grid-type energy storage power station is optimized, including: taking the siting of the energy storage power station and the capacity of the energy storage power station as constraints, wherein the siting of the energy storage power station takes into account system frequency safety constraints and equivalent eigenvalue constraints, and establishing an uncertainty model for new energy station units, taking the uncertainty of the output of the new energy units as a constraint condition, and performing power regulation to achieve the optimal configuration of the grid-type energy storage power station when the power balance constraint is met.

[0017] Optionally, in one embodiment of the present application, the model of the frequency safety constraint is:

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024] Among them, f RoCoF is the node frequency change rate, f0 is the rated frequency, is the maximum frequency change rate of the system, ΔP c is the angular velocity change and power disturbance at the exit of the new energy transmission base, H is the inertia coefficient of the new energy unit, K J is the total inertia of the system, and are the inertia time constants of the new energy unit and the energy storage power station, and The output of the new energy station unit and the rated output of the energy storage power station, is the unit operation status, BES(i) is the set of energy storage power station configuration node locations, Ge(i) is the location of the new energy station, is the position where the station inertia is the smallest, dis is the electrical distance between the two new energy stations, and the difference between the station position and the electrical distance will change the size of the control and measurement admittance in the equivalent matrix, γ n is a 0-1 variable related to the configuration of the energy storage power station, which can be understood as whether the nth energy storage power station is configured. is the maximum number of energy storage power stations. is the rated power of the energy storage station, is the configuration power of the energy storage power station, and The upper and lower limits of the energy storage power station capacity configuration, is the rated capacity of the energy storage power station.

[0025] Optionally, in one embodiment of the present application, the expression of the equivalent eigenvalue constraint is:

[0026]

[0027] Among them, Ei(n) is the set of energy storage power station configuration node locations considering the eigenvalue, Ge(m) is the set of new energy station configuration locations, and λ ci (n) are the eigenvalues ​​with the smallest modulus in the equivalent matrix C-type transfer function before and after the nth unit is connected to the energy storage, and The upper and lower limits of the characteristic values ​​for safe operation of the system are obtained based on the operation guidelines.

[0028] The second aspect of the present application provides a grid-type energy storage optimization configuration device for a new energy transmission base, including: an acquisition module, used to obtain the node equivalent form of the new energy transmission base; a construction module, used to establish an equivalent matrix relationship between the power disturbance suffered by the external system and the frequency change of each unit in the new energy transmission base based on the node equivalent form of the new energy transmission base; an analysis module, used to obtain the dominant eigenvalue according to the equivalent matrix relationship, so as to analyze the frequency stability of the new energy transmission base according to the dominant eigenvalue to obtain an analysis result; an optimization module, used to optimize the configuration of the grid-type energy storage power station based on the analysis result, with the eigenvalue of the equivalent matrix as the stability constraint condition and the minimum total planning cost of the energy storage power station as the optimization goal.

[0029] Optionally, in one embodiment of the present application, the acquisition module includes: a simplification unit, which is used to simplify the active power-frequency relationship of the rotating elements and the new energy stations in the new energy base according to the rotor motion equation and the voltage source converter control principle, and obtain the node equivalent form of the new energy transmission base.

[0030] Optionally, in one embodiment of the present application, the construction module includes: a construction unit, used to establish a frequency domain equivalent matrix describing the active power-frequency changes of the transmission base according to the new energy transmission base construction structure corresponding to the node equivalent form of the new energy transmission base; a determination unit, used to determine the relationship between the active power changes and frequency changes of each station in the system according to the frequency domain equivalent matrix to obtain the equivalent matrix relationship.

[0031] Optionally, in one embodiment of the present application, the relevant element expression of the frequency domain equivalent matrix is:

[0032]

[0033]

[0034] Among them, n is the total number of generator sets in the new energy transmission base, Δω i (s) and ΔP mi (s) is the change in angular velocity and mechanical power in the i-th new energy station, Δω pcc (s) and ΔP c (s) is the angular velocity change and power disturbance at the exit of the new energy transmission base, D mn is the element in the mth row and nth column of the equivalent matrix, where m and n are integers not exceeding (n+1), and Y r is the equivalent impedance of the transmission line, Y is the sum of the measured admittance of all units in the renewable energy transmission base, am and Y bmare the control admittance and measurement admittance coefficients of the mth VSC of the new energy station, K r is the synchronous torque coefficient, U r is the voltage at the outlet of each new energy unit, U pcc is the voltage of the collection station, δ r0 is the phase angle difference between the two voltage phases, X r is the transmission reactance between the new energy unit and the collection station, and s is the Laplace operator.

[0035] Optionally, in one embodiment of the present application, the analysis module includes: an analysis unit, used to perform eigenvalue analysis on the equivalent matrix based on automatic control theory to obtain the dominant eigenvalue; a detection unit, used to detect whether the minimum eigenvalue of the dominant eigenvalue is located in the left half plane of the frequency domain to obtain the analysis result.

[0036] Optionally, in one embodiment of the present application, the expression of active power-frequency stability of the multi-machine parallel system of the analysis result is:

[0037]

[0038] Among them, A i is the transfer function expression between the output power change of the i-th new energy unit and its own mechanical or equivalent mechanical power change, B i,t is the transfer function expression between the output power change of the i-th new energy unit and the mechanical or equivalent mechanical power change of the t-th unit, C i is the transfer function expression between the output power change of the i-th renewable energy unit and the power change at the collection station side, ΔP i (s) is the output power change of the i-th renewable energy unit, ΔP mi (s) is the change in mechanical or equivalent mechanical power of the i-th unit, Δω pcc (s) is the change in angular velocity of the bus at the collection station.

[0039] Optionally, in one embodiment of the present application, the optimization module includes: an optimization unit, which is used to use the siting of the energy storage power station and the capacity of the energy storage power station as constraints, wherein the siting of the energy storage power station takes into account the system frequency safety constraints and the equivalent eigenvalue constraints, and establishes an uncertainty model for the new energy station unit, and uses the uncertainty of the output of the new energy unit as a constraint condition to perform power regulation, so as to achieve the optimal configuration of the grid-type energy storage power station when the power balance constraint is met.

[0040] Optionally, in one embodiment of the present application, the model of the frequency safety constraint is:

[0041]

[0042]

[0043]

[0044]

[0045]

[0046]

[0047] Among them, f RoCoF is the node frequency change rate, f0 is the rated frequency, is the maximum frequency change rate of the system, ΔP c is the angular velocity change and power disturbance at the exit of the new energy transmission base, H is the inertia coefficient of the new energy unit, K J is the total inertia of the system, and are the inertia time constants of the new energy unit and the energy storage power station, and The output of the new energy station unit and the rated output of the energy storage power station, is the unit operation status, BES(i) is the set of energy storage power station configuration node locations, Ge(i) is the location of the new energy station, is the position where the station inertia is the smallest, dis is the electrical distance between the two new energy stations, and the difference between the station position and the electrical distance will change the size of the control and measurement admittance in the equivalent matrix, γ n is a 0-1 variable related to the configuration of the energy storage power station, which can be understood as whether the nth energy storage power station is configured. is the maximum number of energy storage power stations. is the rated power of the energy storage station, is the configuration power of the energy storage power station, and The upper and lower limits of the energy storage power station capacity configuration, is the rated capacity of the energy storage power station.

[0048] Optionally, in one embodiment of the present application, the expression of the equivalent eigenvalue constraint is:

[0049]

[0050] Among them, Ei(n) is the set of energy storage power station configuration node locations considering the eigenvalue, Ge(m) is the set of new energy station configuration locations, and λ ci (n) are the eigenvalues ​​with the smallest modulus in the equivalent matrix C-type transfer function before and after the nth unit is connected to the energy storage, and The upper and lower limits of the characteristic values ​​for safe operation of the system are obtained based on the operation guidelines.

[0051] The third aspect of the present application provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the grid-based energy storage optimization configuration method for the new energy transmission base as described in the above embodiment.

[0052] The fourth aspect of the present application provides a computer-readable storage medium, which stores a computer program. When the program is executed by a processor, it implements the above-mentioned grid-type energy storage optimization configuration method for the new energy transmission base.

[0053] The fifth aspect of the present application provides a computer program product, which, when executed, is used to implement the above-mentioned grid-type energy storage optimization configuration method for the new energy transmission base.

[0054] The embodiment of the present application can obtain the node equivalent form of the new energy delivery base, establish the equivalent matrix relationship between the power disturbance suffered by the external system in the new energy delivery base and the frequency change of each unit, and obtain the dominant eigenvalue to analyze the frequency stability of the new energy delivery base and obtain the analysis result. Based on the analysis result, the eigenvalue of the equivalent matrix is ​​used as the stability constraint condition, and the total planning cost of the energy storage power station is minimized as the optimization goal. The optimization configuration of the grid-type energy storage power station is carried out, which is helpful to improve the frequency regulation capability, effectively respond to the power disturbance occurring in the external system, and improve the overall frequency stability. Thus, the problem in the related technology that, because the new energy base is far away from the interaction point, it is difficult to fully exert its frequency regulation capability by deploying frequency regulation resources such as grid-type energy storage near the collection station, which easily leads to excessive load on the transmission line, and it is difficult to achieve balanced regulation of frequency and voltage, and even fails to play an effective improvement role, increasing the risk of instability in the operation of the power grid.

[0055] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0057] Figure 1 A schematic diagram of a typical structure of a new energy delivery base according to an embodiment of the present application;

[0058] Figure 2 A flowchart of a method for optimizing the configuration of a grid-type energy storage system for a new energy transmission base provided according to an embodiment of the present application;

[0059] Figure 3 is a simplified active power-frequency control model schematic diagram according to an embodiment of the present application;

[0060] Figure 4 Schematic diagram of the structure of an RLC circuit according to an embodiment of the present application;

[0061] Figure 5 A schematic diagram of a network-type control dynamics model according to an embodiment of the present application;

[0062] Figure 6 A schematic diagram of a network-following control dynamics model according to an embodiment of the present application;

[0063] Figure 7 A schematic diagram of the corresponding relationship between an active power-frequency control model and a first-order RLC circuit according to an embodiment of the present application;

[0064] Figure 8 A schematic diagram of a control admittance and a measurement admittance model according to an embodiment of the present application;

[0065] Fig. 9 This is a schematic diagram of the structure of a converter for a new energy transmission base station according to an embodiment of the present application;

[0066] Fig.10 This is a schematic diagram of an equivalent admittance structure of a new energy transmission base according to an embodiment of the present application;

[0067] Fig.11 A schematic diagram of the control and measurement admittance division of a grid-type energy storage according to an embodiment of the present application;

[0068] Fig.12 A schematic diagram of the structure of a grid-type energy storage optimization configuration device for a new energy delivery base provided according to an embodiment of the present application;

[0069] Fig.13 It is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0070] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0071] The following describes the grid-type energy storage optimization configuration method and device of the new energy delivery base in the embodiment of the present application with reference to the accompanying drawings.

[0072] Before introducing the grid-type energy storage optimization configuration method of the new energy transmission base in the embodiment of the present application, the following is a specific introduction to the relevant technology, wherein, in combination with Figure 1 As shown in the figure, the new energy transmission base is mainly composed of new energy stations and lower-level substations, and is equipped with rotating elements such as traditional synchronous units and phase-shifting units of a certain capacity. Among them, the new energy station is mainly composed of wind power or photovoltaic units as power generation units. Due to the power generation principle of wind and solar units, the new energy station units need to rely on the control unit to maintain their ability to stably transmit power. Therefore, the external characteristics of the new energy units are closely related to the control strategies used. Various generators, energy storage units and DC loads are connected to the AC power grid through VSC (Voltage-source Converter).

[0073] In addition, the control methods of VSC include PQ control, virtual inertia control, virtual synchronous control, etc. According to the characteristics of the AC interface, voltage source converters using these different control methods can be divided into grid forming converters and grid following converters. The external characteristics of the AC port of the grid forming converter are voltage sources, while the external characteristics of the grid following converter are current sources. These two control methods are currently widely used in the grid connection of new energy stations. In order to analyze the frequency stability problem after the interconnection of multiple groups of new energy units in the new energy transmission base, the commonly used analysis methods include eigenvalue analysis, frequency domain analysis, and small signal analysis. Both the eigenvalue analysis and the small signal analysis require detailed control structure parameters to determine the corresponding state variables and establish state space equations. When analyzing multi-machine systems, there will be too many state equations and it will be difficult to solve them.

[0074] With regard to the above-mentioned related technologies, since the new energy base is far away from the interaction point, it is difficult to fully exert the frequency regulation capacity of frequency regulation resources such as grid-type energy storage when deployed near the collection station, which can easily lead to excessive load on the transmission line, making it difficult to achieve balanced regulation of frequency and voltage, and even failing to play an effective improvement role, increasing the risk of instability in power grid operation. The present application provides a method for optimizing the configuration of grid-type energy storage for a new energy transmission base. In this method, the node equivalent form of the new energy transmission base can be obtained, and an equivalent matrix relationship between the power disturbance suffered by the external system and the frequency change of each unit in the new energy transmission base can be established, and the dominant eigenvalue is obtained to analyze the frequency stability of the new energy transmission base and obtain the analysis results. Based on the analysis results, the eigenvalue of the equivalent matrix is ​​used as the stability constraint condition, and the total planning cost of the energy storage power station is minimized as the optimization goal. The grid-type energy storage power station is optimized, which helps to improve the frequency regulation capability, effectively respond to the power disturbance occurring in the external system, and improve the overall frequency stability. This solves the problem in related technologies that, since the new energy base is far away from the interaction point, it is difficult to fully utilize the frequency regulation capacity of frequency regulation resources such as grid-type energy storage when deployed near the collection station, which can easily lead to overload of transmission lines, difficulty in achieving balanced regulation of frequency and voltage, and even failure to play an effective improvement role, increasing the risk of instability in grid operation, etc.

[0075] Specifically, Figure 2 A flow chart of a method for optimizing the configuration of a grid-type energy storage system for a new energy transmission base provided in an embodiment of the present application.

[0076] like Figure 2 As shown, the grid-type energy storage optimization configuration method of the new energy delivery base includes the following steps:

[0077] In step S101, the node equivalent form of the new energy delivery base is obtained.

[0078] It can be understood that the new energy transmission base refers to the place where the new energy power station transmits the generated electric energy to the power grid, connects it to the power supply system and supplies power to users, including but not limited to solar power stations, wind power stations, hydropower stations and other new clean energy power generation facilities. The node equivalent form includes but is not limited to the grid-connected control parameters of the new energy base, the power control link parameters of the grid-connected energy storage system, the rotating element parameters of the phase-shifting unit, etc.

[0079] Specifically, the embodiments of the present application can, but are not limited to, conduct field testing of new energy bases or software simulations by installing monitoring equipment to obtain grid-connected control parameters of new energy bases, power control link parameters of grid-connected energy storage systems, parameters of rotating elements of phase-shifting units, etc., wherein the grid-connected control parameters of new energy bases include voltage and frequency regulation strategies, active and reactive power control methods, etc., the power control link parameters of grid-connected energy storage systems include charging and discharging strategies, energy storage capacity, discharge rate, etc., and the rotating element parameters of phase-shifting units include inertia constants, rotor time constants, etc.

[0080] The embodiment of the present application helps with power system analysis and calculation by obtaining the node equivalent form of the new energy transmission base, and provides a data basis for the subsequent optimization configuration of grid-type energy storage of the new energy transmission base.

[0081] Optionally, in one embodiment of the present application, the node equivalent form of the new energy transmission base is obtained, including: simplifying the active power-frequency relationship of the rotating elements and the new energy stations in the new energy base according to the rotor motion equation and the voltage source converter control principle, to obtain the node equivalent form of the new energy transmission base.

[0082] In some embodiments, the embodiments of the present application are based on mathematical principles, adopt a reasonable VSC equivalent method, simplify the active power-frequency control part in the control structure, and then use the frequency domain analysis method, which can effectively avoid the problem of overly complex equations when analyzing multi-machine systems.

[0083] Specifically, for the rotating elements in the new energy transmission base, their inertia support capacity and synchronization characteristics are important factors affecting the frequency stability of the system. The rotor motion equation of the rotating elements can be used to express their synchronization characteristics. The specific equation can be as follows:

[0084]

[0085] Where J is the inertia time constant of the rotating element rotor, D is the damping coefficient, and D(ω-ω ref ) is the damping power, δ is the power angle of the synchronous unit, P e and P m are the electromagnetic power and mechanical power of the synchronous unit, ω ref is the rated angular velocity of the system, and ω is the mechanical angular velocity of the rotor.

[0086] Furthermore, since the active power of the rotating element is related to its frequency or frequency variation, when the rotating element is subjected to a certain disturbance, the embodiment of the present application can use the principle of small signal analysis to analogize the mechanical power, electromagnetic power and damping link in formula (1), which can be specifically as follows:

[0087]

[0088] Where J is the rotor inertia time constant, D is the damping coefficient, Δω=ω-ω ref is the rotor angular velocity change, E and V are the synchronous unit outlet voltage and the collection station bus voltage, respectively, X f is the transmission reactance, δ0 is the initial phase angle of the rotating element, is the synchronous torque coefficient, ω ref is the rated angular velocity of the system, ω is the mechanical angular velocity of the rotor, ΔP D is the damping power change, ΔP e is the change in electromagnetic power, ΔP m is the change in mechanical (or equivalent mechanical) power of the new energy unit, and Δδ is the change in rotor power angle.

[0089] It is worth noting that there is a differential relationship between the phase angle change and the speed change, so the transient process of the rotating element after being disturbed can be approximately regarded as follows: Figure 3 The first-order proportional-integral-differential control link shown. According to equation (2), the embodiment of the present application can clearly show that the rotor motion equation of the rotating element is similar to the first-order PID control, and the structure is similar to Figure 4 The circuit shown is an RLC parallel circuit. Therefore, when performing time domain and frequency domain analysis of the rotating elements, it satisfies the superposition and homogeneity. According to the superposition principle in the circuit, the circuit theory can be used to analyze the relationship between the active power change and the frequency change of each rotating element.

[0090] Furthermore, since the new energy station needs to pass through the VSC for power transmission, the active power-frequency characteristics of the station are determined by the VSC control strategy used. Among them, VSC can be divided into two categories: grid-following type and grid-forming type. The grid-forming type control strategy mainly uses VSG (virtual synchronous generator), which can analyze the frequency domain equivalent structure of the virtual synchronous machine control.

[0091] Combination Figure 5 As shown, the embodiment of the present application can construct a network control dynamics model, where K s is the synchronous torque coefficient, J is the virtual inertia coefficient, and D is the damping coefficient. The selection of J and D is affected by the capacity of the new energy station using grid-type control and the controller parameters. VSG control realizes the control of the output power of the new energy station by simulating the external characteristics of the synchronous generator. The principle of the control scheme is similar to that of formula (2), but the controller tracking principle is different from that of the synchronous generator.

[0092] However, in grid-following control, a phase-locked loop (PLL) or other measurement link is generally used to track the system frequency to adjust the active power of the station. Therefore, the PLL has a great influence on the active power-frequency control part. Figure 6 As shown, the embodiment of the present application can simplify its equivalent form into a network-following control dynamics model, where G pf (s) is the active power-frequency control link in the grid-following control, G m (s) is the offset generated by the phase-locked loop and other measurement links in the grid-following control. Similarly, the equivalent expression of adding the damping correction link can be derived.

[0093] After determining the expression of the active power-frequency control part of the new energy station and rotating elements, the mathematical relationship between the active power change and the angular velocity change of the new energy unit in the frequency domain can be obtained according to the analogy relationship between the element parameters and the coupling relationship of the elements. The ratio of the active power change to the frequency change is defined as the admittance coefficient, and the dynamic characteristics of the new energy transmission base are described by the admittance coefficient.

[0094] In the actual implementation process, the implicit differential equation relationship in the network-building and network-following control structures can be simplified to Figure 4 At the same time, in order to construct a unified admittance coefficient model, the control structure of the power control part in the converter can be defined as the control admittance coefficient Y a (s), the active power-frequency measurement deviation caused by the deviation caused by the measurement link delay and the power disturbance of the system as a whole is defined as the measurement admittance coefficient Y b (s).

[0095]

[0096] Among them, Y a (s) is the control admittance coefficient, Y b (s) is the measured admittance coefficient, Δω is the angular velocity change of the new energy unit, Δω c is the angular velocity change of the busbar at the collection station, ΔP m is the change in mechanical (or equivalent mechanical) power of the new energy unit, ΔP = ΔP D +ΔP e It is the change in the unit output power. The meaning of equivalent mechanical power is that the control scheme is designed according to the rotor motion equation of the synchronous machine in the VSC control strategy. The input power calculation method is consistent with the mechanical power calculation method in the synchronous machine.

[0097] Combination Figure 7 and Figure 8 As shown, the control admittance is Ya (s) = Js, the equivalent voltage on the admittance is Δω, and the measured admittance is Y b (s) = K s / s+D,ΔP=ΔP D +ΔP e This model can fully describe the relationship between the change in active power and the change in speed when the converter's own mechanical power changes, and the specific relationship can be solved based on the superposition principle. The specific relationship can be shown as follows:

[0098]

[0099] The embodiments of the present application can obtain the equivalent structure of the converter control link in the new energy station by performing circuit structure equivalence on the active power-frequency control part in the power control link of the converter based on the similarity between the mathematical relationship of the control link and the mathematical relationship of the circuit structure. The rotating elements in the new energy transmission base can also be used to obtain the equivalent structure using a similar idea. The equivalent admittance structure is used to describe the simplified active power-frequency relationship of each station in the new energy transmission base to obtain the node equivalent form of the new energy transmission base, thereby optimizing the control of the rotating elements, effectively improving the frequency regulation speed, improving the response capability to load changes, and effectively improving the stability and flexibility of the power system.

[0100] In step S102, based on the node equivalent form of the new energy transmission base, an equivalent matrix relationship between the power disturbance suffered by the external system and the frequency change of each unit in the new energy transmission base is established.

[0101] The embodiment of the present application can be based on the node equivalent form of the new energy transmission base, so as to establish an equivalent matrix relationship between the power disturbance suffered by the external system and the frequency change of each unit in the new energy transmission base, which is helpful to analyze the dynamic response behavior of the system, provide important reference for operation and regulation, and improve the stability and reliability of the system.

[0102] Optionally, in one embodiment of the present application, an equivalent matrix relationship between the power disturbance suffered by the external system and the frequency change of each unit in the new energy transmission base is established, including: establishing a frequency domain equivalent matrix describing the active power-frequency change of the transmission base according to the new energy transmission base construction structure corresponding to the node equivalent form of the new energy transmission base; determining the relationship between the active power change and the frequency change of each station in the system according to the frequency domain equivalent matrix to obtain an equivalent matrix relationship.

[0103] In the actual implementation process, the embodiments of the present application can be based on the following Figure 1The construction structure of the new energy transmission base shown in the figure is used to establish an equivalent form of describing the entire transmission base. Specifically, each new energy station in the new energy transmission base is connected to the transmission line in parallel, and the transmission lines are continuously gathered and gradually merged into the collection station, and then connected to the transmission network with a higher voltage level. Therefore, the embodiment of the present application can be used to make the new energy transmission base equivalent to a multi-machine parallel system, and any unit adopts the equivalent admittance analysis method to simplify the analysis process of the power-frequency characteristics of each new energy station. According to the control structure topology of multiple new energy stations or rotating elements, the multi-machine system is connected in sequence to obtain the following Fig. 9 and Fig.10 Models for the two admittance coefficients shown.

[0104] Furthermore, combined with Fig.10 As shown, according to the equivalent admittance structure of the new energy transmission base, the embodiment of the present application can establish an equivalent admittance matrix of a grid-connected system of multiple VSCs in parallel, wherein the details are as follows:

[0105]

[0106] Among them, n is the total number of generator sets in the new energy transmission base, Δω i (s) and ΔP mi (s) is the change in angular velocity and mechanical power in the i-th new energy station, Δω pcc (s) and ΔP c (s) is the angular velocity change and power disturbance occurring at the exit side of the new energy transmission base.

[0107] According to the circuit superposition principle and the parallel relationship of each unit, for the mth VSC structure in the system, the relevant elements in the equivalent admittance matrix can be expressed as:

[0108]

[0109] Among them, D mn is the element in the mth row and nth column of the equivalent matrix, where m and n are integers not exceeding (n+1), and Y r is the equivalent impedance of the transmission line, Y is the sum of the measured admittance of all units in the renewable energy transmission base, am and Y bm are the control admittance and measurement admittance coefficients of the mth VSC of the new energy station, K r is the synchronous torque coefficient, U r is the voltage at the outlet of each new energy unit, U pcc is the voltage of the collection station, δ r0 is the phase angle difference between the two voltage phases, X r is the transmission reactance between the new energy unit and the collection station, and s is the Laplace operator.

[0110] Through the equivalent matrix relationship, the embodiment of the present application can deeply understand the impact of external power disturbances on the frequency of each unit, effectively optimize the frequency stability adjustment strategy, improve the operating efficiency of the system, and help improve the reliability and stability of the optimized configuration.

[0111] Optionally, in one embodiment of the present application, the relevant elements of the frequency domain equivalent matrix are expressed as follows:

[0112]

[0113]

[0114] Among them, n is the total number of generator sets in the new energy transmission base, Δω i (s) and ΔP mi (s) is the change in angular velocity and mechanical power in the i-th new energy station, Δω pcc (s) and ΔP c (s) is the angular velocity change and power disturbance at the exit of the new energy transmission base, D mn is the element in the mth row and nth column of the equivalent matrix, where m and n are integers not exceeding (n+1), and Y r is the equivalent impedance of the transmission line, Y is the sum of the measured admittance of all units in the renewable energy transmission base, am and Y bm are the control admittance and measurement admittance coefficients of the mth VSC of the new energy station, K r is the synchronous torque coefficient, U r is the voltage at the outlet of each new energy unit, U pcc is the voltage of the collection station, δ r0 is the phase angle difference between the two voltage phase quantities, X r is the transmission reactance between the new energy unit and the collection station, and s is the Laplace operator.

[0115] The embodiment of the present application can obtain information on the frequency response characteristics and frequency stability of the power system through the relevant elements of the frequency domain equivalent matrix, which is conducive to evaluating the stability characteristics under different frequency changes, effectively optimizing the site response strategy, and improving the stability and reliability of the power system.

[0116] In step S103, the dominant eigenvalue is obtained according to the equivalent matrix relationship, so as to analyze the frequency stability of the new energy transmission base according to the dominant eigenvalue and obtain the analysis result.

[0117] The embodiment of the present application can effectively evaluate the frequency stability of the new energy transmission base under different working conditions through the eigenvalues ​​of the equivalent matrix, which helps to timely discover possible frequency stability risks and ensure the reliable operation of the system.

[0118] Optionally, in one embodiment of the present application, the dominant eigenvalue is obtained according to the equivalent matrix relationship to analyze the frequency stability of the new energy transmission base according to the dominant eigenvalue to obtain an analysis result, including: based on automatic control theory, performing eigenvalue analysis on the equivalent matrix to obtain the dominant eigenvalue; detecting whether the minimum eigenvalue of the dominant eigenvalue is located in the left half plane of the frequency domain to obtain the analysis result.

[0119] Specifically, combined Fig.10 As shown, the embodiment of the present application is to analyze the frequency stability of the new energy transmission base. By using the equivalent structure of the new energy base and the superposition principle, the expression form of the active power output by any new energy unit can be obtained, wherein the specific expression is as follows:

[0120]

[0121] Among them, ΔP i (s) is the output power change of the i-th unit, Δω i (s) is the output angular velocity change, Δω pcc (s) is the change in angular velocity of the busbar at the collection station, Y ai and Y bi are the control admittance coefficient and measurement admittance coefficient of the i-th unit, ΔP mi (s) is the change in mechanical (or equivalent mechanical) power of the i-th unit.

[0122] Furthermore, in combination with equations (5)-(7), the embodiment of the present application can simplify the relationship between the active power and the speed change of the i-th new energy station unit, which can be specifically expressed as follows:

[0123]

[0124]

[0125] Among them, || is the parallel calculation of two equivalent admittances, Y || =Y bi / (Y ai +Y bi ), A i , B i,t and C i They respectively represent the transfer function expression between the output power of the i-th renewable energy unit and the mechanical (or equivalent mechanical) power change of the i-th unit itself, the mechanical (or equivalent mechanical) power change of other units and the power change of the bus side of the collection station. They can be solved by the control admittance and measurement admittance coefficient of each unit after equivalent. r is the equivalent impedance of the transmission line, Y at and Ybt are the control admittance and measurement admittance coefficients of the tth renewable energy station VSC, ΔP c It is the power disturbance occurring at the export side of the new energy transmission base.

[0126] It can be seen from formula (8) that in the multi-machine parallel system equivalent to the renewable energy transmission base, the active power output capacity of each unit is determined by the active power input command of its own control link, the impact of other grid-connected units on itself, and the impact of external transmission network disturbance on itself. The equivalent admittance analysis method can be used to quantify the three types of influencing factors in the frequency domain. By analyzing A i ,B i,t ,C i The changing rules of these three types of transfer functions can be used to analyze the active power-frequency stability of the multi-machine parallel system, which can be specifically expressed as follows:

[0127]

[0128] Among them, A i is the transfer function expression between the output power change of the i-th new energy unit and its own mechanical or equivalent mechanical power change, B i,t is the transfer function expression between the output power change of the i-th new energy unit and the mechanical or equivalent mechanical power change of the t-th unit, C i is the transfer function expression between the output power change of the i-th renewable energy unit and the power change at the collection station side, ΔP i (s) is the output power change of the i-th renewable energy unit, ΔP mi (s) is the change in mechanical or equivalent mechanical power of the i-th unit, Δω pcc (s) is the change in angular velocity of the bus at the collection station.

[0129] It is worth noting that when analyzing the impact of external power transmission network disturbances on new energy units and performing stability analysis, the embodiment of the present application can use the corresponding relationship and specific expression form in formula (9)-(10) to perform stability analysis based on the stability criterion in automatic control theory. In automatic control theory, after establishing the relationship between the changes in two physical quantities, such as the relationship between active power and speed, the form of the characteristic equation in its transfer function can be analyzed. If all solutions of its characteristic equation are located in the left half plane of the polar axis, it can be determined that the new energy base system can still operate stably under certain disturbances, verifying that the frequency stability of the new energy transmission base is good.

[0130] In some cases, since the simplified relationship between active power and frequency of grid-type energy storage is similar to the equivalent structure of grid-type VSC, compared with new energy units, the energy storage carrier in grid-type energy storage is energy storage elements such as energy storage batteries, and its control characteristics of active power and frequency are reflected by power electronic devices, combined with Fig.11 As shown in the figure, according to the definition of active power control loop and equivalent admittance in network control, two expressions of mechanical admittance can be determined, which can be specifically expressed as follows:

[0131]

[0132] Among them, J and D are the virtual inertia coefficient and damping coefficient in the power control structure of the grid-type energy storage power station, K s is the synchronous torque coefficient, and the calculation process is the same as that in formula (2).

[0133] In addition, the equivalent form of the new energy stations in the new energy transmission base can also be solved equivalently through the above process, and then the equivalent form of each station in the frequency domain and the grid-type energy storage can be obtained.

[0134]

[0135] Among them, formula (12) shows the changes of the three types of transfer functions A, B, and C after adding a grid-connected energy storage power station at the i-th new energy station. The calculation process of the parameters of the transfer function with the subscript i+1 needs to refer to formula (9) and formula (11), and λ ci The calculation results also need to refer to the changes in formula (12) to obtain the characteristic value index that characterizes the stability of the unit.

[0136] When studying the impact of the external transmission network on the units of the renewable energy transmission base, we can focus on the transfer function of Class C, and determine the improvement effect of grid-type energy storage on the frequency stability of the renewable energy transmission base by obtaining the characteristic equation and analyzing the dominant eigenvalues. ci By analyzing the changes in frequency stability of the new energy transmission base before and after the grid-connected energy storage system is connected, we can analyze the improvement in frequency stability of the new energy transmission base before and after the grid-connected energy storage system is connected.

[0137] Optionally, in one embodiment of the present application, the expression of active power-frequency stability of the multi-machine parallel system of the analysis result is:

[0138]

[0139] Among them, A i is the transfer function expression between the output power change of the i-th new energy unit and its own mechanical or equivalent mechanical power change, B i,tis the transfer function expression between the output power change of the i-th new energy unit and the mechanical or equivalent mechanical power change of the t-th unit, C i is the transfer function expression between the output power change of the i-th renewable energy unit and the power change at the collection station side, ΔP i (s) is the output power change of the i-th renewable energy unit, ΔP mi (s) is the change in mechanical or equivalent mechanical power of the i-th unit, Δω pcc (s) is the change in angular velocity of the bus at the collection station.

[0140] The embodiment of the present application can effectively evaluate the stability of the system under different working conditions through the expression of active power-frequency stability, and can deeply understand the stability characteristics of the multi-machine parallel system, which is helpful to evaluate the stability performance of the system.

[0141] In step S104, based on the analysis results, the eigenvalue of the equivalent matrix is ​​used as a stability constraint condition, and the minimum total cost of the energy storage power station planning is used as the optimization goal to optimize the configuration of the grid-type energy storage power station.

[0142] It is understandable that the total planning cost of an energy storage power station includes the maintenance cost of the energy storage power station, daily operating cost, etc.

[0143] Specifically, the embodiment of the present application can set the optimization target of the grid-type energy storage to the energy storage power station configuration cost C required by the system planning device. t Minimum, the cost includes the investment cost of energy storage power station C in , Equipment maintenance cost C om , New energy base operating costs C op , where the operating cost includes the site power generation cost, wind abandonment penalty and solar abandonment penalty cost, and the specific expression is as follows:

[0144] minC t =C in +C om +C op (13)

[0145]

[0146]

[0147] C op =C G +C wt +C pv +C qt (16)

[0148] Among them, N GFM is the number of grid-type energy storage power stations, c B,GFMis the investment cost coefficient of the grid-type energy storage power station, is the capacity of the energy storage power station, μ is the discount rate of the energy storage power station, TL is the service life of the energy storage power station, c O,GFM is the maintenance cost of the energy storage power station, C mt is the annual maintenance cost coefficient of the energy storage power station, C G , C wt , C qt and C pv They are respectively the power generation cost of new energy stations, the penalty cost for wind power abandonment, the start-up and shutdown cost of conventional units, and the penalty cost for solar power abandonment.

[0149]

[0150] Among them, c re is the power generation cost coefficient of the new energy base unit, is the power generation of new energy units, c th and are the power generation cost coefficient of conventional units and the power generation of conventional units, and is the unit startup and shutdown cost, c wt and c pv are the penalty cost coefficients for wind and solar abandonment, and are the predicted wind turbine output and the actual wind turbine output, and They are the predicted output of photovoltaic generator sets and the actual output of photovoltaic generator sets respectively.

[0151] Optionally, in one embodiment of the present application, based on the analysis results, the eigenvalue of the equivalent matrix is ​​used as a stability constraint condition, and the minimum total planning cost of the energy storage power station is used as the optimization goal to optimize the configuration of the grid-type energy storage power station, including: taking the site selection of the energy storage power station and the capacity of the energy storage power station as constraints, wherein the site selection of the energy storage power station takes into account the system frequency safety constraints and the equivalent eigenvalue constraints, and establishes an uncertainty model for the new energy station unit, and uses the uncertainty of the output of the new energy unit as a constraint condition to perform power regulation, so as to achieve the optimal configuration of the grid-type energy storage power station when the power balance constraint is met.

[0152] In one embodiment of the present application, the model of frequency safety constraint is:

[0153]

[0154]

[0155]

[0156]

[0157]

[0158]

[0159] Among them, f RoCoF is the node frequency change rate, f0 is the rated frequency, is the maximum frequency change rate of the system, ΔP c is the angular velocity change and power disturbance at the exit of the new energy transmission base, H is the inertia coefficient of the new energy unit, K J is the total inertia of the system, and are the inertia time constants of the new energy unit and the energy storage power station, and The output of the new energy station unit and the rated output of the energy storage power station, is the unit operation status, BES(i) is the set of energy storage power station configuration node locations, Ge(i) is the location of the new energy station, is the position where the station inertia is the smallest, dis is the electrical distance between the two new energy stations, and the difference between the station position and the electrical distance will change the size of the control and measurement admittance in the equivalent matrix, γ n is a 0-1 variable related to the configuration of the energy storage power station, which can be understood as whether the nth energy storage power station is configured. is the maximum number of energy storage power stations. is the rated power of the energy storage station, is the configuration power of the energy storage power station, and The upper and lower limits of the energy storage power station capacity configuration, is the rated capacity of the energy storage power station.

[0160] In the actual implementation process, the embodiment of the present application can consider the site selection of the energy storage power station, the capacity of the energy storage power station, etc. as constraints. When selecting the site, it is necessary to additionally consider the stability constraints of the equivalent matrix eigenvalue analysis and the typical operation scenario constraints. The site selection constraints of the energy storage consider the system frequency security constraints and the equivalent eigenvalue constraints. The frequency security constraints consider the frequency change rate (RoCoF) indicator to provide stability constraints for the subsequent energy storage power station configuration, which can be specifically shown in equations (18)-(23).

[0161] In one embodiment of the present application, the expression of the equivalent eigenvalue constraint is:

[0162]

[0163] Among them, Ei(n) is the set of energy storage power station configuration node locations considering the eigenvalue, Ge(m) is the set of new energy station configuration locations, and λ ci (n) are the eigenvalues ​​with the smallest modulus in the equivalent matrix C-type transfer function before and after the nth unit is connected to the energy storage, and The upper and lower limits of the characteristic values ​​for safe operation of the system are obtained based on the operation guidelines.

[0164] Typical operation scenario constraints include node power balance constraints, unit output upper and lower limit constraints, unit start-up and shutdown time and cost constraints, as follows:

[0165]

[0166]

[0167]

[0168]

[0169]

[0170]

[0171]

[0172]

[0173] Among them, P re Provide power for new energy station units, and is the charging and discharging power of the energy storage station, P Le is the line loss power, The total output sent for the new energy base project, and are the upper and lower limits of the unit output, The unit is in operation state. and T is the time the unit has been started or stopped, on,i and T off,i To limit the startup and shutdown time of the unit, and is the unit startup and shutdown cost, qg i and tg i is the startup and shutdown cost of a unit, SP i and XP i It is the up and down climbing limit of the unit.

[0174] The operation constraints of energy storage power stations mainly consider the charging and discharging power constraints, power change extreme value constraints, power change constraints, etc. The specific forms are as follows:

[0175]

[0176]

[0177]

[0178]

[0179]

[0180]

[0181] in, is the rated power of the energy storage station, and It is the charging and discharging status of the energy storage power station (0 / 1). The transient power changes provided by the energy storage power station for frequency response, P t FR is the power regulation amount provided by the energy storage power station per unit time, Δt1, Δt2 and Δt3 are the times required for inertia response, primary frequency regulation response and secondary frequency regulation response in the frequency response, and the typical values ​​can be selected as 5, 20 and 360s respectively. is the amount of electricity stored in the energy storage station when restoring steady state, η c and η f It is the energy conversion efficiency of the energy storage power station during the charging and discharging process.

[0182] Since most of the generator sets in the new energy transmission base are wind power or photovoltaic units, the impact of the uncertainty of the output of the new energy units must be fully considered when designing the node power balance constraints. The embodiment of the present application adopts the opportunity constraint method to model the uncertainty of the new energy station units.

[0183]

[0184] Assuming that the maximum predicted output of the new energy station follows Gaussian distribution, equation (39) can be transformed into:

[0185]

[0186] Among them, Φ(P re ) is the probability distribution function of the maximum output of the new energy unit. By transforming this distribution function into a standard normal distribution, equation (40) can be transformed into:

[0187]

[0188] By rearranging formula (41), we can obtain the opportunity constraint of the output of new energy stations under the confidence level η.

[0189]

[0190] When considering the uncertainty constraints of the operation of new energy units, the node power balance constraint of formula (25) is:

[0191]

[0192] in, and They are the output of the new energy unit, the charging and discharging power of the energy storage power station, and the line loss power when considering operational uncertainty. The uncertain output of the new energy unit is considered through equations (39)-(42), and the power regulation constraints of the energy storage power station under uncertainty are shown below.

[0193]

[0194]

[0195]

[0196]

[0197] in, is the rated power of the energy storage station, and To describe the operating state variables of the energy storage power station in uncertain operating scenarios, and P is the charging and discharging power of the energy storage station considering the uncertainty of operation. t FR It is the power regulation amount provided by the energy storage power station per unit time.

[0198] After considering various constraints such as the operation constraints of the grid-type energy storage power station, the embodiment of the present application can use an inspirational algorithm such as a particle swarm algorithm to optimize and solve the above mathematical model, and finally obtain the optimal configuration plan of the grid-type energy storage power station to guide the configuration of the grid-type energy storage power station in the new energy base to maximize the active support effect of the energy storage power station.

[0199] According to the method for optimizing the configuration of the grid-type energy storage of the new energy delivery base proposed in the embodiment of the present application, the node equivalent form of the new energy delivery base can be obtained, the equivalent matrix relationship between the power disturbance suffered by the external system and the frequency change of each unit in the new energy delivery base can be established, and the dominant eigenvalue can be obtained to analyze the frequency stability of the new energy delivery base and obtain the analysis result. Based on the analysis result, the eigenvalue of the equivalent matrix is ​​used as the stability constraint condition, and the total planning cost of the energy storage power station is minimized as the optimization goal. The grid-type energy storage power station is optimized, which helps to improve the frequency regulation capability, effectively respond to the power disturbance occurring in the external system, and improve the overall frequency stability. Thus, the problem in the related technology that, because the new energy base is far away from the interaction point, it is difficult to fully exert its frequency regulation capability by deploying frequency regulation resources such as grid-type energy storage near the collection station, which easily leads to excessive load on the transmission line, and it is difficult to achieve balanced regulation of frequency and voltage, and even fails to play an effective improvement role, increasing the risk of instability in the operation of the power grid.

[0200] Next, a grid-type energy storage optimization configuration device for a new energy delivery base proposed in an embodiment of the present application will be described with reference to the accompanying drawings.

[0201] Fig.12 It is a structural schematic diagram of a grid-type energy storage optimization configuration device for a new energy delivery base according to an embodiment of the present application.

[0202] like Fig.12 As shown, the grid-type energy storage optimization configuration device 10 of the new energy delivery base includes: an acquisition module 100, a construction module 200, an analysis module 300 and an optimization module 400.

[0203] Specifically, the acquisition module 100 is used to obtain the node equivalent form of the new energy delivery base.

[0204] The construction module 200 is used to establish an equivalent matrix relationship between the power disturbance suffered by the external system and the frequency change of each unit in the new energy transmission base based on the node equivalent form of the new energy transmission base.

[0205] The analysis module 300 is used to obtain the dominant eigenvalue according to the equivalent matrix relationship, so as to analyze the frequency stability of the new energy transmission base according to the dominant eigenvalue and obtain the analysis result.

[0206] The optimization module 400 is used to optimize the configuration of the grid-type energy storage power station based on the analysis results, taking the eigenvalue of the equivalent matrix as the stability constraint condition and minimizing the total cost of the energy storage power station planning as the optimization goal.

[0207] Optionally, in one embodiment of the present application, the acquisition module 100 includes: a simplification unit.

[0208] Among them, the simplification unit is used to simplify the active power-frequency relationship of the rotating elements and the new energy stations in the new energy base according to the rotor motion equation and the control principle of the voltage source converter, and obtain the node equivalent form of the new energy transmission base.

[0209] Optionally, in one embodiment of the present application, the construction module 200 includes: a construction unit and a determination unit.

[0210] The construction unit is used to establish a frequency domain equivalent matrix describing the active power-frequency change of the transmission base according to the new energy transmission base construction structure corresponding to the node equivalent form of the new energy transmission base;

[0211] The determination unit is used to determine the relationship between the active power change and the frequency change of each station in the system according to the frequency domain equivalent matrix to obtain the equivalent matrix relationship.

[0212] Optionally, in one embodiment of the present application, the relevant elements of the frequency domain equivalent matrix are expressed as follows:

[0213]

[0214]

[0215] Among them, n is the total number of generator sets in the new energy transmission base, Δω i (s) and ΔP mi (s) is the change in angular velocity and mechanical power in the i-th new energy station, Δω pcc (s) and ΔP c (s) is the angular velocity change and power disturbance at the exit of the new energy transmission base, D mn is the element in the mth row and nth column of the equivalent matrix, where m and n are integers not exceeding (n+1), and Y r is the equivalent impedance of the transmission line, Y is the sum of the measured admittance of all units in the renewable energy transmission base, am and Y bm are the control admittance and measurement admittance coefficients of the mth VSC of the new energy station, K r is the synchronous torque coefficient, U r is the voltage at the outlet of each new energy unit, U pcc is the voltage of the collection station, δ r0 is the phase angle difference between the two voltage phase quantities, X r is the transmission reactance between the new energy unit and the collection station, and s is the Laplace operator.

[0216] Optionally, in one embodiment of the present application, the analysis module 300 includes: an analysis unit and a detection unit.

[0217] The analysis unit is used to perform eigenvalue analysis on the equivalent matrix based on automatic control theory to obtain the dominant eigenvalue;

[0218] The detection unit is used to detect whether the minimum eigenvalue of the dominant eigenvalue is located in the left half plane of the frequency domain to obtain the analysis result.

[0219] Optionally, in one embodiment of the present application, the expression of active power-frequency stability of the multi-machine parallel system of the analysis result is:

[0220]

[0221] Among them, A i is the transfer function expression between the output power change of the i-th new energy unit and its own mechanical or equivalent mechanical power change, B i,t is the transfer function expression between the output power change of the i-th new energy unit and the mechanical or equivalent mechanical power change of the t-th unit, C i is the transfer function expression between the output power change of the i-th renewable energy unit and the power change at the collection station side, ΔP i (s) is the output power change of the i-th renewable energy unit, ΔP mi (s) is the change in mechanical or equivalent mechanical power of the i-th unit, Δω pcc (s) is the change in angular velocity of the bus at the collection station.

[0222] Optionally, in one embodiment of the present application, the optimization module 400 includes: an optimization unit.

[0223] Among them, the optimization unit is used to use the site selection and capacity of the energy storage power station as constraints. The site selection of the energy storage power station takes into account the system frequency safety constraints and the equivalent eigenvalue constraints, and establishes an uncertainty model for the new energy station units. The power adjustment is carried out with the uncertainty of the output of the new energy units as a constraint condition, so as to achieve the optimal configuration of the grid-type energy storage power station when the power balance constraint is met.

[0224] Optionally, in one embodiment of the present application, the model of frequency safety constraint is:

[0225]

[0226]

[0227]

[0228]

[0229]

[0230]

[0231] Among them, f RoCoF is the node frequency change rate, f0 is the rated frequency, is the maximum frequency change rate of the system, ΔP c is the angular velocity change and power disturbance at the exit of the new energy transmission base, H is the inertia coefficient of the new energy unit, K J is the total inertia of the system, and are the inertia time constants of the new energy unit and the energy storage power station, and The output of the new energy station unit and the rated output of the energy storage power station, is the unit operation status, BES(i) is the set of energy storage power station configuration node locations, Ge(i) is the location of the new energy station, is the position where the station inertia is the smallest, dis is the electrical distance between the two new energy stations, and the difference between the station position and the electrical distance will change the size of the control and measurement admittance in the equivalent matrix, γ n is a 0-1 variable related to the configuration of the energy storage power station, which can be understood as whether the nth energy storage power station is configured. is the maximum number of energy storage power stations. is the rated power of the energy storage station, is the configuration power of the energy storage power station, and The upper and lower limits of the energy storage power station capacity configuration, is the rated capacity of the energy storage power station.

[0232] Optionally, in one embodiment of the present application, the expression of the equivalent eigenvalue constraint is:

[0233]

[0234] Among them, Ei(n) is the set of energy storage power station configuration node locations considering the eigenvalue, Ge(m) is the set of new energy station configuration locations, and λ ci (n) are the eigenvalues ​​with the smallest modulus in the equivalent matrix C-type transfer function before and after the nth unit is connected to the energy storage, and The upper and lower limits of the characteristic values ​​for safe operation of the system are obtained based on the operation guidelines.

[0235] It should be noted that the aforementioned explanation of the embodiment of the method for optimizing the configuration of a grid-type energy storage system for a new energy transmission base is also applicable to the device for optimizing the configuration of a grid-type energy storage system for a new energy transmission base of this embodiment, and will not be repeated here.

[0236] According to the grid-type energy storage optimization configuration device of the new energy delivery base proposed in the embodiment of the present application, the node equivalent form of the new energy delivery base can be obtained, the equivalent matrix relationship between the power disturbance suffered by the external system in the new energy delivery base and the frequency change of each unit can be established, and the dominant eigenvalue can be obtained to analyze the frequency stability of the new energy delivery base and obtain the analysis result. Based on the analysis result, the eigenvalue of the equivalent matrix is ​​used as the stability constraint condition, and the total planning cost of the energy storage power station is minimized as the optimization goal. The grid-type energy storage power station is optimized, which helps to improve the frequency regulation capability, effectively respond to the power disturbance occurring in the external system, and improve the overall frequency stability. Thus, the problem in the related technology that, because the new energy base is far away from the interaction point, it is difficult to fully exert its frequency regulation capability by deploying frequency regulation resources such as grid-type energy storage near the collection station, which easily leads to excessive load on the transmission line, and it is difficult to achieve balanced regulation of frequency and voltage, and even fails to play an effective improvement role, increasing the risk of instability in power grid operation, etc. is solved.

[0237] Fig.13 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device may include:

[0238] A memory 1301 , a processor 1302 , and a computer program stored in the memory 1301 and executable on the processor 1302 .

[0239] When the processor 1302 executes the program, the grid-type energy storage optimization configuration method for the new energy transmission base provided in the above embodiment is implemented.

[0240] Furthermore, the electronic device further comprises:

[0241] The communication interface 1303 is used for communication between the memory 1301 and the processor 1302 .

[0242] The memory 1301 is used to store computer programs that can be executed on the processor 1302 .

[0243] The memory 1301 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0244] If the memory 1301, the processor 1302 and the communication interface 1303 are implemented independently, the communication interface 1303, the memory 1301 and the processor 1302 can be connected to each other through a bus and communicate with each other. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig.13 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0245] Optionally, in a specific implementation, if the memory 1301, the processor 1302 and the communication interface 1303 are integrated on a chip, the memory 1301, the processor 1302 and the communication interface 1303 can communicate with each other through an internal interface.

[0246] The processor 1302 may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0247] An embodiment of the present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned grid-type energy storage optimization configuration method for a new energy transmission base.

[0248] The embodiment of the present application also provides a computer program product, which can run computer instructions, and when the computer instructions are executed by a processor, the above-mentioned grid-type energy storage optimization configuration method for the new energy transmission base is implemented.

[0249] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0250] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0251] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0252] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or N wirings (electronic devices), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways as necessary and then storing it in a computer memory.

[0253] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above embodiment, the N steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. If implemented by hardware, as in another embodiment, it can be implemented by any one or a combination of multiple of the following technologies known in the art: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0254] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0255] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0256] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for optimizing the configuration of grid-type energy storage for a new energy delivery base, characterized in that: The following steps are involved: Get the node equivalent form of the new energy delivery base; Based on the node equivalent form of the new energy transmission base, an equivalent matrix relationship between the power disturbance suffered by the external system and the frequency change of each unit in the new energy transmission base is established; Obtaining a dominant eigenvalue according to the equivalent matrix relationship, so as to analyze the frequency stability of the new energy transmission base according to the dominant eigenvalue and obtain an analysis result; Based on the analysis results, the eigenvalue of the equivalent matrix is ​​used as a stability constraint condition, and the minimum total cost of the energy storage power station planning is used as the optimization goal to optimize the configuration of the grid-type energy storage power station; The establishment of an equivalent matrix relationship between the power disturbance suffered by the external system in the new energy transmission base and the frequency change of each unit includes: establishing a frequency domain equivalent matrix describing the active power-frequency change of the transmission base according to the new energy transmission base construction structure corresponding to the node equivalent form of the new energy transmission base; determining the relationship between the active power change and the frequency change of each station in the system according to the frequency domain equivalent matrix to obtain the equivalent matrix relationship; Among them, the relevant elements of the frequency domain equivalent matrix are expressed as: Among them, n is the total number of generator sets in the new energy transmission base, Δω i (s) and ΔP mi (s) is the change in angular velocity and mechanical power in the i-th new energy station, Δω pcc (s) and ΔP c (s) is the angular velocity change and power disturbance at the exit of the new energy transmission base, D mn is the element in the mth row and nth column of the equivalent matrix, where m and n are integers not exceeding (n+1), and Y r is the equivalent impedance of the transmission line, Y is the sum of the measured admittance of all units in the renewable energy transmission base, am and Y bm are the control admittance and measurement admittance coefficients of the mth VSC of the new energy station, K r is the synchronous torque coefficient, U r is the voltage at the outlet of each new energy unit, U pcc is the voltage of the collection station, δ r0 is the phase angle difference between the two voltage phases, X r is the transmission reactance between the new energy unit and the collection station, and s is the Laplace operator.

2. The method for optimizing the configuration of grid-type energy storage for a new energy delivery base according to claim 1, characterized in that: The node equivalent form of obtaining the new energy delivery base includes: According to the rotor motion equation and the control principle of the voltage source converter, the active power-frequency simplified relationship of the rotating elements and the new energy station in the new energy base is respectively performed to obtain the node equivalent form of the new energy transmission base.

3. The method for optimizing the configuration of grid-type energy storage for a new energy delivery base according to claim 1, characterized in that: The method of obtaining the dominant eigenvalue according to the equivalent matrix relationship, and analyzing the frequency stability of the new energy transmission base according to the dominant eigenvalue to obtain the analysis result includes: Based on automatic control theory, an eigenvalue analysis is performed on the equivalent matrix to obtain the dominant eigenvalue; It is detected whether the minimum eigenvalue of the dominant eigenvalue is located in the left half plane of the frequency domain to obtain the analysis result.

4. The method for optimizing the configuration of grid-type energy storage for a new energy delivery base according to claim 1, characterized in that: The expression of active power-frequency stability of the multi-machine parallel system in the analysis result is: Among them, A i is the transfer function expression between the output power change of the i-th new energy unit and its own mechanical or equivalent mechanical power change, B i,t is the transfer function expression between the output power change of the i-th new energy unit and the mechanical or equivalent mechanical power change of the t-th unit, C i is the transfer function expression between the output power change of the i-th renewable energy unit and the power change at the collection station side, ΔP i (s) is the output power change of the i-th renewable energy unit, ΔP mi (s) is the change in mechanical or equivalent mechanical power of the i-th unit, Δω pcc (s) is the change in angular velocity of the bus at the collection station.

5. The method for optimizing the configuration of grid-type energy storage for a new energy delivery base according to claim 1, characterized in that: Based on the analysis results, the eigenvalue of the equivalent matrix is ​​used as a stability constraint condition, and the minimum total cost of energy storage power station planning is used as the optimization goal to optimize the configuration of the grid-type energy storage power station, including: The siting and capacity of the energy storage power station are taken as constraints, wherein the siting of the energy storage power station takes into account the system frequency safety constraints and the equivalent eigenvalue constraints, and an uncertainty model of the new energy station unit is established. The uncertainty of the output of the new energy unit is taken as a constraint condition to perform power regulation, so as to achieve the optimal configuration of the grid-type energy storage power station when the power balance constraint is met.

6. The method for optimizing the configuration of grid-type energy storage for a new energy delivery base according to claim 5, characterized in that: The model of the frequency safety constraint is: Among them, f RoCoF is the node frequency change rate, f0 is the rated frequency, is the maximum frequency change rate of the system, ΔP c is the angular velocity change and power disturbance at the exit of the new energy transmission base, H is the inertia coefficient of the new energy unit, K J is the total inertia of the system, and are the inertia time constants of the new energy unit and the energy storage power station, and The output of the new energy station unit and the rated output of the energy storage power station, is the unit operation status, BES(i) is the set of energy storage power station configuration node locations, Ge(i) is the location of the new energy station, is the position where the station inertia is the smallest, dis is the electrical distance between the two new energy stations, and the difference between the station position and the electrical distance will change the size of the control and measurement admittance in the equivalent matrix, γ n is a 0-1 variable related to the configuration of the energy storage power station, which can be understood as whether the nth energy storage power station is configured. is the maximum number of energy storage power stations to be configured, is the rated power of the energy storage station, is the configuration power of the energy storage power station, and The upper and lower limits of the energy storage power station capacity configuration, is the rated capacity of the energy storage power station.

7. The method for optimizing the configuration of grid-type energy storage for a new energy delivery base according to claim 5, characterized in that: The expression of the equivalent eigenvalue constraint is: Among them, Ei(n) is the set of energy storage power station configuration node locations considering the eigenvalue, Ge(m) is the set of new energy station configuration locations, and λ ci (n) are the eigenvalues ​​with the smallest modulus in the equivalent matrix C-type transfer function before and after the nth unit is connected to the energy storage, and The upper and lower limits of the characteristic values ​​for safe operation of the system are obtained based on the operation guidelines.

8. A grid-type energy storage optimization configuration device for a new energy delivery base, characterized in that: include: An acquisition module is used to obtain the node equivalent form of the new energy delivery base; A construction module is used to establish an equivalent matrix relationship between the power disturbance suffered by the external system and the frequency change of each unit in the new energy transmission base based on the node equivalent form of the new energy transmission base; An analysis module, used for obtaining a dominant eigenvalue according to the equivalent matrix relationship, so as to analyze the frequency stability of the new energy transmission base according to the dominant eigenvalue and obtain an analysis result; The optimization module is used to optimize the configuration of the grid-type energy storage power station based on the analysis results, taking the eigenvalue of the equivalent matrix as the stability constraint condition and minimizing the total cost of the energy storage power station planning as the optimization goal.

9. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the grid-type energy storage optimization configuration method for a new energy transmission base as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the grid-type energy storage optimization configuration method for a new energy transmission base as described in any one of claims 1 to 7.

11. A computer program product, characterized in that When the computer program is executed, it is used to implement the grid-type energy storage optimization configuration method for the new energy transmission base as described in any one of claims 1-7.

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