Multi-Type New Energy Power System Stabilization and Control Method and Device Based on Frequency Response

Abstract

The present invention discloses a stability control method and device for multi-type new energy power systems based on frequency response. The stability control method specifically includes: respectively obtaining the frequency response modes of synchronous generators and wind-solar-storage devices, and constructing a frequency response model of a multi-machine system including wind-solar-storage, wherein the wind-solar-storage devices include electrochemical energy storage devices; based on the topological structure of the vertical matrix-type gravity energy storage grid connection, giving the frequency response mode of the gravity energy storage unit; according to the frequency response model of the multi-machine system including wind-solar-storage, combining the frequency response mode of the gravity energy storage unit, and based on the method of equivalent parameters, constructing a frequency response model of a new energy power system including gravity energy storage; based on the frequency response model of the new energy power system, performing stability control on multi-type new energy power systems. The present invention proposes a modeling scheme considering the participation of gravity energy storage in the power system frequency response link, accurately depicting the frequency response characteristics of the power system including gravity energy storage.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy power systems, and particularly relates to a stability control method and device for multi-type new energy power systems based on frequency response. Background Art

[0002] The large-scale centralized grid connection of renewable energy power systems such as wind power and photovoltaic power brings challenges to the safe and stable operation of the power grid system. For example, the output of renewable energy power systems is random, intermittent, and volatile, and renewable energy such as wind power, photovoltaic power, and energy storage devices are directly connected to the power grid system through electronic converters, resulting in a reduction in the inertia level within the power grid system, and the frequency stability problem becomes more prominent.

[0003] Currently, there have been frequency domain analyses on the frequency response of power systems containing wind power or photovoltaic power. For example, Patent CN103972912A provides a frequency domain analysis method for the frequency response of a power system containing wind power. This method simultaneously considers generator characteristics, governor characteristics, system network structure, load characteristics, and AGC control characteristics, takes into account the dynamic distribution characteristics of frequency in the power network, and solves the explicit expression of the frequency response of each node in the power system under the excitation of wind power. The frequency domain results are inverse-transformed into the time domain to evaluate the frequency deviation of the power system under the excitation of wind power fluctuations. The simulation results show that this model can quickly and accurately reflect the frequency deviation characteristics of each node under the excitation of wind power, and using this model to study the influence laws of the wind power access point, AGC, etc. on the system frequency deviation and its amplitude-frequency characteristics has important guiding significance for the selection of the wind farm access point, the planning of the wind farm access capacity, the filter design before wind power is connected to the grid, and the setting of AGC control parameters in the system, and has good promotion value and application prospects.

[0004] For example, Patent CN114123249A provides a load frequency control method for a wind power integrated power system based on the active response of battery energy storage. By means of droop control based on real-time state of charge adaptive regulation, an adaptive mode of the battery energy storage system is established, a fuzzy gain scheduling strategy is designed, and a particle swarm optimization algorithm is used to optimize the control parameters to verify whether the frequency after the response of the battery energy storage system can meet the allowable value requirements. This scheme can not only minimize the system frequency difference during load disturbances, but also well suppress the large-scale change of frequency deviation under high wind power fluctuations, and keep the frequency difference stable within the allowable deviation of 0.2 Hz, providing reliable frequency stability for the new energy power system.

[0005] However, there has been no research on the frequency response of multi-type and high-proportion new energy power systems simultaneously containing wind power, photovoltaic power, energy storage devices, etc.

[0006] In particular, for energy storage devices of the gravity energy storage type, the power output brought by the mechanical structure of gravity energy storage presents a discrete characteristic, and the input time between each heavy object block is relatively long, increasing the difficulty of characterizing the frequency response of the power system.

[0007] At present, the construction mechanism of the frequency response model of the power system involving gravity energy storage devices is not clear. Similarly, the lack of the frequency response model of the power system involving gravity energy storage devices also leads to the inability to accurately judge the frequency response characteristics of the system after gravity energy storage devices participate in the new energy power system.

[0008] Therefore, how to construct a frequency response model of a new energy power system with multiple types and high proportions such as wind power, photovoltaic power, and energy storage devices to accurately judge the frequency response characteristics of the system after gravity energy storage devices participate in the new energy power system is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0009] Aiming at the defects existing in the above-mentioned prior art, the present invention provides a stability control method and device for a multi-type new energy power system based on frequency response. The construction method specifically includes: respectively obtaining the frequency response modes of synchronous generators and wind-solar-storage devices, and constructing a frequency response model of a multi-machine system including wind-solar-storage, where the wind-solar-storage devices include electrochemical energy storage devices; based on the topological structure of vertical matrix-type gravity energy storage grid connection, giving the frequency response mode of the gravity energy storage unit; according to the frequency response model of the multi-machine system including wind-solar-storage, combining the frequency response mode of the gravity energy storage unit, and based on the method of equivalent parameters, constructing a frequency response model of a new energy power system including gravity energy storage; based on the frequency response model of the new energy power system, performing stability control on the multi-type new energy power system. The present invention proposes a modeling scheme considering the participation of gravity energy storage in the power system frequency response link, and accurately depicts the frequency response characteristics of the power system including gravity energy storage.

[0010] In the first aspect, the present invention provides a stability control method for a multi-type new energy power system based on frequency response, which specifically includes the following steps:

[0011] Respectively obtain the frequency response modes of synchronous generators and wind-solar-storage devices, and construct a frequency response model of a multi-machine system including wind-solar-storage, where the wind-solar-storage devices include electrochemical energy storage devices;

[0012] Based on the topological structure of vertical matrix-type gravity energy storage grid connection, give the frequency response mode of the gravity energy storage unit;

[0013] According to the frequency response model of the multi-machine system including wind-solar-storage, combine the frequency response mode of the gravity energy storage unit, and based on the method of equivalent parameters, construct a frequency response model of a new energy power system including gravity energy storage;

[0014] Based on the frequency response model of the new energy power system, the stability control is carried out for multiple types of new energy power systems.

[0015] Further, the synchronous generator includes a thermal power synchronous generator set. The method for obtaining the frequency response of the synchronous generator specifically includes:

[0016] Using a low-order power system frequency response model to simulate the frequency response of the synchronous generator, and giving the frequency response model of the synchronous generator. Among them, the frequency response model of the synchronous generator takes into account the transfer process of the turbine and the governor.

[0017] Further, the frequency response of the synchronous generator is specifically expressed as:

[0018]

[0019] Among them, is the primary frequency regulation power adjustment of the synchronous generator after Laplace transform, K m is the mechanical power gain factor, F H is the work coefficient of the high-pressure cylinder in the synchronous generator, T R is the reheat time constant, R is the primary frequency regulation droop coefficient of the governor, and s is the Laplace operator.

[0020] Further, the method for obtaining the frequency response of the wind-solar-storage device specifically includes:

[0021] Based on the direct-drive wind turbine generator set, photovoltaic generator set, and electrochemical energy storage device connected to the grid through converters respectively, combined with the frequency response method of additional control, the wind power frequency response method, photovoltaic frequency response method, and energy storage response method are given.

[0022] Further, the frequency response model of the multi-machine system containing wind-solar-storage is constructed, which is specifically expressed as:

[0023]

[0024] Among them, is the primary frequency regulation power adjustment of the wind turbine generator set after Laplace transform, K W is the frequency additional control proportional coefficient of the wind turbine generator set, T W is the frequency regulation time constant of the wind turbine generator set, is the primary frequency regulation power adjustment of the photovoltaic generator set after Laplace transform, K PV is the frequency additional control proportional coefficient of the photovoltaic generator set, T PV is the frequency regulation time constant of the photovoltaic generator set, is the primary frequency regulation power adjustment of the electrochemical energy storage device after Laplace transform, K E is the frequency additional control proportional coefficient of the electrochemical energy storage device, T Eis the frequency modulation time constant of the electrochemical energy storage device, is the frequency deviation of the power system after Laplace transform, and s is the Laplace operator.

[0025] Furthermore, based on the topological structure of the vertical matrix type gravity energy storage grid connection, the frequency response mode of the gravity energy storage unit is given, which specifically includes the following steps:

[0026] Considering the time scale, the gravity energy storage speed regulation system model corresponding to the topological structure of the vertical matrix type gravity energy storage grid connection is given, which is specifically expressed as:

[0027]

[0028] where, T m_gra is the input mechanical torque of the synchronous generator, k δ is the amplification factor of the governor, ω ref is the reference value of the electrical angular velocity of the synchronous generator, ω is the real-time electrical angular velocity of the synchronous generator, T gra is the frequency modulation time constant of the gravity energy storage unit, and s is the Laplace operator;

[0029] Based on the gravity energy storage speed regulation system mode, the frequency response mode of the gravity energy storage unit is given.

[0030] Furthermore, the frequency response mode of the gravity energy storage unit is specifically expressed as:

[0031]

[0032] where, is the primary frequency modulation power regulation amount of the gravity energy storage unit after Laplace transform, K gra_s is the proportional coefficient of the power response amount of the gravity energy storage, T gra is the frequency modulation time constant of the gravity energy storage unit, is the frequency deviation of the power system after Laplace transform, and s is the Laplace operator.

[0033] Furthermore, according to the frequency response model of the multi-machine system containing wind power, photovoltaics and energy storage, combined with the frequency response mode of the gravity energy storage unit, and based on the method of equivalent parameters, a frequency response model of the new energy power system containing gravity energy storage is constructed, which specifically includes the following steps:

[0034] Obtain the system inertia constant and system damping coefficient considering gravity energy storage;

[0035] Give the relationship between the grid power and frequency containing gravity energy storage, which is specifically expressed as:

[0036]

[0037] where, is the change in load after Laplace transform, is the primary frequency regulation power adjustment amount of the synchronous generator after Laplace transform, is the primary frequency regulation power adjustment amount of the gravity energy storage unit after Laplace transform, is the primary frequency regulation power adjustment amount of the wind turbine unit after Laplace transform, is the primary frequency regulation power adjustment amount of the photovoltaic unit after Laplace transform, is the primary frequency regulation power adjustment amount of the electrochemical energy storage device after Laplace transform, H sys is the system inertia constant considering gravity energy storage, s is the Laplace operator, D sys is the system damping coefficient considering gravity energy storage;

[0038] Based on the method of equivalent parameters, the frequency response mode of the wind-solar-storage device is processed, specifically expressed as:

[0039]

[0040] Among them, is the equivalent primary frequency regulation power adjustment amount of the wind-solar-storage device after Laplace transform, K U is the power gain of the wind-solar-storage device numbered U, V is the total number of wind-solar-storage devices, T V is the equivalent frequency regulation time constant of the wind-solar-storage device, s is the Laplace operator;

[0041] Construct a frequency response model of the new energy power system with gravity energy storage, specifically expressed as:

[0042] Give the relationship between the power and frequency of the power grid with gravity energy storage, specifically expressed as:

[0043]

[0044] Among them, is the equivalent primary frequency regulation power adjustment amount of the wind-solar-storage device after Laplace transform.

[0045] Furthermore, the system inertia constant considering gravity energy storage is specifically expressed as:

[0046]

[0047] Among them, E sys is the total kinetic energy of the system considering gravity energy storage, S G,i is the rated capacity of synchronous generator i, x G,i is the start-stop state value of synchronous generator i, n is the total number of synchronous generators, S Gra,j is the rated capacity of gravity energy storage unit j, x Gra,jis the start-stop status value of the gravity energy storage unit j, m is the total number of gravity energy storage units, S N,k is the rated capacity of the wind-solar-storage device k, x N,k is the start-stop status value of the wind-solar-storage device k, c is the total number of wind-solar-storage devices;

[0048] Considering the system damping coefficient of the gravity energy storage, it is specifically expressed as:

[0049]

[0050] Among them, is the damping coefficient of the load, is the damping coefficient of the synchronous generator i, is the damping coefficient of the gravity energy storage unit j.

[0051] Furthermore, considering the total kinetic energy of the system with gravity energy storage, it is specifically expressed as:

[0052]

[0053] Among them, H G,i is the inertia constant of the synchronous generator i, H Gra,j is the inertia constant of the gravity energy storage unit j;

[0054] Furthermore, based on the method of equivalent parameters, the frequency response mode of the wind-solar-storage devices is processed, which specifically includes the following steps:

[0055] Obtain the power gain of each wind-solar-storage device;

[0056] Based on the power gain of each wind-solar-storage device, give the power gain coefficient of each wind-solar-storage device;

[0057] Combined with the frequency modulation time constant of each wind-solar-storage device, complete the processing of the frequency response mode of the wind-solar-storage devices and give the equivalent frequency constant of the wind-solar-storage devices.

[0058] Furthermore, the power gain of each wind-solar-storage device is specifically expressed as:

[0059]

[0060] Among them, K U is the power gain of the wind-solar-storage device numbered U, is the maximum frequency modulation power of the wind-solar-storage device numbered U, S U is the rated capacity of the wind-solar-storage device numbered U, is the frequency modulation status of the wind-solar-storage device numbered U;

[0061] Furthermore, the power gain coefficient of each wind-solar-storage device is specifically expressed as:

[0062]

[0063] Among them, is the power gain coefficient of the wind-solar-storage device numbered U, and V is the total number of wind-solar-storage devices.

[0064] Furthermore, the equivalent frequency constant of the wind-solar-storage device is specifically expressed as:

[0065]

[0066] Among them, T V is the equivalent frequency modulation time constant of the wind-solar-storage device, and T U is the frequency modulation time constant of the wind-solar-storage device numbered U.

[0067] Furthermore, the equivalent frequency constant of the wind-solar-storage device can also be specifically expressed as:

[0068]

[0069] Among them, T V is the equivalent frequency modulation time constant of the wind-solar-storage device, V1 is the total number of direct-drive wind turbines, K U1 is the power gain of the direct-drive wind turbine numbered U1, T U1 is the frequency modulation time constant of the direct-drive wind turbine numbered U1, V2 is the total number of photovoltaic units, K U2 is the power gain of the photovoltaic unit numbered U2, T U2 is the frequency modulation time constant of the photovoltaic unit numbered U2, V3 is the total number of electrochemical energy storage devices, K U3 is the power gain of the electrochemical energy storage device numbered U3, T U3 is the frequency modulation time constant of the electrochemical energy storage device numbered U3.

[0070] In a second aspect, the present invention also provides a multi-type new energy power system stability control device based on frequency response, which adopts the above-mentioned multi-type new energy power system stability control method based on frequency response, and specifically includes:

[0071] An acquisition unit, configured to respectively obtain the frequency response modes of the synchronous generator and the wind-solar-storage device, and give the frequency response mode of the gravity energy storage unit based on the topological structure of the vertical matrix type gravity energy storage grid connection, wherein the wind-solar-storage device includes an electrochemical energy storage device;

[0072] A model construction unit, configured to construct a frequency response model of a multi-machine system including wind-solar-storage, and based on the frequency response model of the multi-machine system including wind-solar-storage, combine the frequency response mode of the gravity energy storage unit, and construct a frequency response model of a new energy power system including gravity energy storage based on the method of equivalent parameters;

[0073] A stability control operation unit is used to perform stability control on multiple types of new - energy power systems based on the frequency - response model of the new - energy power system.

[0074] Furthermore, the synchronous generator includes a thermal - power synchronous - generator set. The method for obtaining the frequency - response mode of the synchronous generator specifically includes:

[0075] Using a low - order power - system frequency - response model to simulate the frequency - response mode of the synchronous generator, and giving the frequency - response model of the synchronous generator, where the frequency - response model of the synchronous generator takes into account the transfer process of the turbine and the governor.

[0076] Furthermore, the frequency - response mode of the synchronous generator is specifically expressed as:

[0077]

[0078] Where, is the primary - frequency - regulation power adjustment amount of the synchronous generator after Laplace transform, K m is the mechanical - power gain factor, F H is the high - pressure cylinder work coefficient in the synchronous generator, T R is the reheat time constant, R is the primary - frequency - regulation droop coefficient of the governor, and s is the Laplace operator.

[0079] Furthermore, the method for obtaining the frequency - response mode of the wind - solar - storage device specifically includes:

[0080] Based on the direct - drive wind - turbine generator set, photovoltaic generator set, and electrochemical energy - storage device connected to the grid through converters respectively, and combining the frequency - response mode of additional control, the wind - power frequency - response mode, photovoltaic - power frequency - response mode, and energy - storage response mode are given.

[0081] Furthermore, the frequency - response model of the multi - machine system containing wind - solar - storage is constructed, which is specifically expressed as:

[0082]

[0083] Where, is the primary - frequency - regulation power adjustment amount of the wind - turbine generator set after Laplace transform, K W is the frequency - additional - control proportional coefficient of the wind - turbine generator set, T W is the frequency - regulation time constant of the wind - turbine generator set, is the primary - frequency - regulation power adjustment amount of the photovoltaic generator set after Laplace transform, K PV is the frequency - additional - control proportional coefficient of the photovoltaic generator set, T PV is the frequency - regulation time constant of the photovoltaic generator set, is the primary - frequency - regulation power adjustment amount of the electrochemical energy - storage device after Laplace transform, K Eis the frequency additional control proportionality coefficient of the electrochemical energy storage device, T E is the frequency modulation time constant of the electrochemical energy storage device is the frequency deviation of the power system after Laplace transform, and s is the Laplace operator

[0084] Furthermore, based on the topological structure of the vertical matrix type gravity energy storage grid connection, the frequency response mode of the gravity energy storage unit is given, specifically including

[0085] Considering the time scale, the gravity energy storage speed regulation system model corresponding to the topological structure of the vertical matrix type gravity energy storage grid connection is given, specifically expressed as

[0086]

[0087] where, T m_gra is the input mechanical torque of the synchronous generator, k δ is the amplification factor of the governor, ω ref is the electrical angular velocity reference value of the synchronous generator, ω is the real-time electrical angular velocity of the synchronous generator, T gra is the frequency modulation time constant of the gravity energy storage unit, and s is the Laplace operator

[0088] Based on the gravity energy storage speed regulation system mode, the frequency response mode of the gravity energy storage unit is given

[0089] Furthermore, the frequency response mode of the gravity energy storage unit is specifically expressed as

[0090]

[0091] where is the primary frequency modulation power regulation amount of the gravity energy storage unit after Laplace transform, K gra_s is the proportionality coefficient of the power response amount of the gravity energy storage, T gra is the frequency modulation time constant of the gravity energy storage unit is the frequency deviation of the power system after Laplace transform, and s is the Laplace operator

[0092] Furthermore, according to the frequency response model of the multi-machine system containing wind power, photovoltaics and energy storage, combined with the frequency response mode of the gravity energy storage unit, and based on the method of equivalent parameters, a frequency response model of the new energy power system containing gravity energy storage is constructed, specifically including

[0093] Obtain the system inertia constant and system damping coefficient considering gravity energy storage

[0094] Give the relationship between the grid power and frequency containing gravity energy storage, specifically expressed as

[0095]

[0096] Among them, is the change in load after Laplace transform, is the primary frequency regulation power adjustment amount of the synchronous generator after Laplace transform, is the primary frequency regulation power adjustment amount of the gravity energy storage unit after Laplace transform, is the primary frequency regulation power adjustment amount of the wind turbine unit after Laplace transform, is the primary frequency regulation power adjustment amount of the photovoltaic unit after Laplace transform, is the primary frequency regulation power adjustment amount of the electrochemical energy storage device after Laplace transform, H sys is the system inertia constant considering gravity energy storage, s is the Laplace operator, D sys is the system damping coefficient considering gravity energy storage;

[0097] Based on the method of equivalent parameters, the frequency response mode of the wind-solar-storage device is processed, specifically expressed as:

[0098]

[0099] Among them, is the equivalent primary frequency regulation power adjustment amount of the wind-solar-storage device after Laplace transform, K U is the power gain of the wind-solar-storage device numbered U, V is the total number of wind-solar-storage devices, T V is the equivalent frequency regulation time constant of the wind-solar-storage device, s is the Laplace operator;

[0100] Build a frequency response model of the new energy power system with gravity energy storage, specifically expressed as:

[0101] Give the relationship between the power and frequency of the power grid with gravity energy storage, specifically expressed as:

[0102]

[0103] Among them, is the equivalent primary frequency regulation power adjustment amount of the wind-solar-storage device after Laplace transform.

[0104] Furthermore, the system inertia constant considering gravity energy storage is specifically expressed as:

[0105]

[0106] Among them, E sys is the total kinetic energy of the system considering gravity energy storage, S G,i is the rated capacity of synchronous generator i, x G,i is the start-stop state value of synchronous generator i, n is the total number of synchronous generators, S Gra,jis the rated capacity of the gravity energy storage unit j, x Gra,j is the start-stop status value of the gravity energy storage unit j, m is the total number of gravity energy storage units, S N,k is the rated capacity of the wind-solar-storage device k, x N,k is the start-stop status value of the wind-solar-storage device k, c is the total number of wind-solar-storage devices;

[0107] Considering the system damping coefficient of the gravity energy storage, it is specifically expressed as:

[0108]

[0109] Among them, is the damping coefficient of the load, is the damping coefficient of the synchronous generator i, is the damping coefficient of the gravity energy storage unit j.

[0110] Furthermore, considering the total kinetic energy of the system with gravity energy storage, it is specifically expressed as:

[0111]

[0112] Among them, H G,i is the inertia constant of the synchronous generator i, H Gra,j is the inertia constant of the gravity energy storage unit j;

[0113] Furthermore, based on the method of equivalent parameters, the frequency response mode of the wind-solar-storage devices is processed, specifically including:

[0114] Obtain the power gain of each wind-solar-storage device;

[0115] Based on the power gain of each wind-solar-storage device, give the power gain coefficient of each wind-solar-storage device;

[0116] Combined with the frequency modulation time constant of each wind-solar-storage device, complete the processing of the frequency response mode of the wind-solar-storage devices and give the equivalent frequency constant of the wind-solar-storage devices.

[0117] Furthermore, the power gain of each wind-solar-storage device is specifically expressed as:

[0118]

[0119] Among them, K U is the power gain of the wind-solar-storage device numbered U, is the maximum frequency modulation power of the wind-solar-storage device numbered U, S U is the rated capacity of the wind-solar-storage device numbered U, is the frequency modulation status of the wind-solar-storage device numbered U;

[0120] Further, the power gain coefficient of each wind-solar-storage device is specifically expressed as:

[0121]

[0122] Among them, is the power gain coefficient of the wind-solar-storage device numbered U, and V is the total number of wind-solar-storage devices.

[0123] Further, the equivalent frequency constant of the wind-solar-storage device is specifically expressed as:

[0124]

[0125] Among them, T V is the equivalent frequency modulation time constant of the wind-solar-storage device, and T U is the frequency modulation time constant of the wind-solar-storage device numbered U.

[0126] Further, the equivalent frequency constant of the wind-solar-storage device can also be specifically expressed as:

[0127]

[0128] Among them, T V is the equivalent frequency modulation time constant of the wind-solar-storage device, V1 is the total number of direct-drive wind turbines, K U1 is the power gain of the direct-drive wind turbine numbered U1, T U1 is the frequency modulation time constant of the direct-drive wind turbine numbered U1, V2 is the total number of photovoltaic units, K U2 is the power gain of the photovoltaic unit numbered U2, T U2 is the frequency modulation time constant of the photovoltaic unit numbered U2, V3 is the total number of electrochemical energy storage devices, K U3 is the power gain of the electrochemical energy storage device numbered U3, T U3 is the frequency modulation time constant of the electrochemical energy storage device numbered U3.

[0129] A multi-type new energy power system stability control method and device based on frequency response provided by the present invention has at least the following beneficial effects:

[0130] (1) By proposing a modeling scheme that takes into account the participation of gravity energy storage in the power system frequency response link, based on the operating characteristics of gravity energy storage and the way of participating in the system frequency response, the present invention accurately depicts the frequency response characteristics of the power system containing gravity energy storage for the frequency response mode of a multi-machine system with wind, solar, and storage.

[0131] (2) Based on the frequency response model of a multi-machine system with wind, solar and storage, combined with the frequency response mode of gravity energy storage units, and based on the equivalent parameter method, a frequency response model of a new energy power system with gravity energy storage is constructed. By directly integrating the actual dynamic characteristics of the gravity energy storage unit into the frequency response model of a multi-machine system with wind, solar and storage, the frequency response behavior of the power system under various operating conditions can be more accurately simulated and predicted, effectively supporting the power system frequency, reducing the frequency deviation caused by fluctuations in renewable energy generation, and thus improving the frequency stability of the power system.

[0132] (3) For power systems that include multiple types of renewable energy such as wind power, photovoltaics, electrochemical energy storage, and gravity energy storage, different renewable energy power generation units have different operating characteristics, and the complexity of the power system increases dramatically. Equivalent aggregation processing is crucial for the construction of frequency response models. It can integrate the control strategies of different renewable energy power generation units and select the optimal strategy to improve the frequency stability of the power system and more accurately predict the dynamic behavior of the power system when it is disturbed. BRIEF DESCRIPTION OF THE DRAWINGS

[0133] Figure 1 A flow chart of a frequency response-based stabilization control method for a multi-type renewable energy power system provided by the present invention;

[0134] Figure 2 A schematic diagram of a flow chart of constructing a frequency response model of a new energy power system including gravity energy storage according to a certain embodiment of the present invention;

[0135] Figure 3 An equivalent frequency response model diagram of a new energy power system with gravity energy storage according to a certain embodiment of the present invention;

[0136] Figure 4 A schematic diagram of a frequency response-based stabilization control device for a multi-type renewable energy power system provided by the present invention. DETAILED DESCRIPTION

[0137] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0138] The terms used in the embodiments of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The singular forms "a", "the", and "said" used in the embodiments of the present invention and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. "Plural" generally includes at least two.

[0139] It should also be noted that the term "comprising", "including", or any other variant thereof is intended to cover a non-exclusive inclusion, such that a commodity or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such commodity or device. Without further limitation, an element defined by the statement "comprising one..." does not exclude the presence of additional identical elements in the commodity or device comprising said element.

[0140] Currently, the construction mechanism of the frequency response model of the power system involving gravity energy storage devices is not clear. Similarly, the lack of the frequency response model of the power system involving gravity energy storage devices also leads to the inability to accurately judge the frequency response characteristics of the system after gravity energy storage devices participate in the new energy power system.

[0141] Constructing the frequency response model of a new energy power system with multiple types and high proportions, such as wind power, photovoltaic, and energy storage devices, can realize the judgment of the frequency response characteristics of the system after gravity energy storage devices participate in the new energy power system. Thus, the stable control of multiple types of new energy power systems can be achieved.

[0142] Therefore, the solution for the stable control of multiple types of new energy power systems based on frequency response is to integrate the frequency response characteristics of gravity energy storage with the frequency response model of the power system including wind, light, and energy storage, construct the frequency response model of the new energy power system with vertical matrix-type gravity energy storage, and perform stable control operations for multiple types of new energy power systems based on this frequency response model of the new energy power system.

[0143] As Figure 1 shown, the present invention provides a method for stabilizing and controlling multiple types of new energy power systems based on frequency response, which specifically includes the following steps:

[0144] Respectively obtain the frequency response modes of synchronous generators and wind-light-energy storage devices, and construct a frequency response model of a multi-machine system including wind, light, and energy storage, where the wind-light-energy storage devices include electrochemical energy storage devices;

[0145] Based on the topological structure of the vertical matrix-type gravity energy storage grid connection, give the frequency response mode of the gravity energy storage unit;

[0146] According to the frequency response model of a multi-machine system with wind, light and energy storage, combined with the frequency response mode of a gravity energy storage unit, and based on the method of equivalent parameters, a frequency response model of a new energy power system with gravity energy storage is constructed;

[0147] Based on the frequency response model of the new energy power system, the stability control is carried out for multiple types of new energy power systems.

[0148] The present invention accurately depicts the frequency response characteristics of a power system with gravity energy storage by proposing a modeling scheme considering the participation of gravity energy storage in the frequency response link of the power system, based on the operating characteristics of gravity energy storage and the way of participating in the system frequency response, and aiming at the frequency response mode of a multi-machine system with wind, light and energy storage.

[0149] The synchronous generator includes a thermal power synchronous generator set. Obtaining the frequency response mode of the synchronous generator specifically includes:

[0150] Using a low-order frequency response model of the power system to simulate the frequency response mode of the synchronous generator, and giving the frequency response model of the synchronous generator, where the frequency response model of the synchronous generator takes into account the transfer process of the turbine and the governor.

[0151] Specifically, the frequency response mode of the synchronous generator is specifically expressed as:

[0152]

[0153] Among them, is the primary frequency modulation power regulation amount of the synchronous generator after Laplace transform, K m is the mechanical power gain factor, F H is the work coefficient of the high-pressure cylinder in the synchronous generator, T R is the reheat time constant, R is the primary frequency modulation droop coefficient of the governor, and s is the Laplace operator.

[0154] The wind-light-energy storage device can include any one of a direct-drive wind turbine generator set, a photovoltaic generator set, and an electrochemical energy storage device. Obtaining the frequency response mode of the wind-light-energy storage device specifically includes:

[0155] Based on the direct-drive wind turbine generator set, the photovoltaic generator set, and the electrochemical energy storage device connected to the grid through converters respectively, combined with the frequency response mode of additional control, the wind power frequency response mode, the photovoltaic frequency response mode, and the energy storage response mode are given.

[0156] That is, the direct-drive wind turbine generator set is connected to the grid through a converter, and frequency response support is realized through additional control; the photovoltaic generator set is also connected to the grid through a converter, and frequency response support is realized through additional control; the electrochemical energy storage device can include different types of electrochemical energy storage batteries, such as lithium batteries, etc., and is also connected to the grid through a converter, and frequency response support is realized through additional control.

[0157] Considering the types of wind-solar-storage devices and the grid connection methods, a frequency response model of a multi-machine system with wind-solar-storage is constructed, which is specifically expressed as:

[0158]

[0159] Among them, is the primary frequency regulation power adjustment amount of the wind turbine after Laplace transform, K W is the frequency additional control proportional coefficient of the wind turbine, T W is the frequency modulation time constant of the wind turbine, is the primary frequency regulation power adjustment amount of the photovoltaic unit after Laplace transform, K PV is the frequency additional control proportional coefficient of the photovoltaic unit, T PV is the frequency modulation time constant of the photovoltaic unit, is the primary frequency regulation power adjustment amount of the electrochemical energy storage device after Laplace transform, K E is the frequency additional control proportional coefficient of the electrochemical energy storage device, T E is the frequency modulation time constant of the electrochemical energy storage device, is the frequency deviation of the power system after Laplace transform, and s is the Laplace operator.

[0160] For a vertical matrix type gravity energy storage device, generally, an elevator car is dragged by a transmission device, heavy blocks are lifted or lowered by the elevator car, and a synchronous machine is driven by the discrete heavy blocks to realize the electro-mechanical energy conversion.

[0161] Considering the topological structure of the direct grid connection of the vertical matrix type gravity energy storage, based on the frequency response link corresponding to the gravity energy storage under the frequency response time scale of the new energy power system, a frequency modulation characteristic function containing gravity energy storage is constructed. When the power system frequency changes, the gravity energy storage unit gradually puts in heavy blocks. Within the time scale of the primary frequency modulation of the power system, the number of heavy blocks put in by the gravity energy storage unit can be two or multiple, and all the put-in heavy blocks participate in the primary frequency modulation control of the power system to realize the frequency response of the power system.

[0162] Therefore, based on the topological structure of the vertical matrix type gravity energy storage grid connection, the frequency response mode of the gravity energy storage unit is given, which specifically includes the following steps:

[0163] Considering the time scale, a gravity energy storage speed regulation system model corresponding to the topological structure of the vertical matrix type gravity energy storage grid connection is given, which is specifically expressed as:

[0164]

[0165] Among them, T m_gra is the input mechanical torque of the synchronous generator, k δis the amplification factor of the governor, ω ref is the reference value of the electrical angular velocity of the synchronous generator, ω is the real-time electrical angular velocity of the synchronous generator, T gra is the frequency modulation time constant of the gravity energy storage unit, s is the Laplace operator;

[0166] Based on the gravity energy storage speed regulation system mode, the frequency response mode of the gravity energy storage unit is given.

[0167] The frequency response mode of the gravity energy storage unit is specifically expressed as:

[0168]

[0169] Among them, is the primary frequency modulation power regulation amount of the gravity energy storage unit after Laplace transform, K gra_s is the proportional coefficient of the power response amount of the gravity energy storage, T gra is the frequency modulation time constant of the gravity energy storage unit, is the frequency deviation of the power system after Laplace transform, s is the Laplace operator.

[0170] Based on the above frequency response model of the multi-machine system containing wind power, photovoltaic power, and energy storage, and considering the vertical matrix-type gravity energy storage response mode, the transfer functions of the frequency response links of various types of new energy such as wind power, photovoltaic power, electrochemical energy storage, and gravity energy storage are attached to the traditional synchronous generator frequency response model.

[0171] Among them, the main forms of wind power, photovoltaic power, and electrochemical energy storage participating in frequency modulation are to indirectly respond to the frequency of the power system through the output of active power, that is, the form of participating in frequency modulation is to improve the unbalanced power in the power system and provide frequency support to the power system. Essentially, it is still a power source and does not increase the original inertia of the power system. On the premise of not increasing the inertia of the power system, the relationship between the power and frequency of the power grid containing gravity energy storage is formed.

[0172] Such as Figure 2 、 Figure 3 As shown, according to the frequency response model of the multi-machine system containing wind power, photovoltaic power, and energy storage, combined with the frequency response mode of the gravity energy storage unit, and based on the method of equivalent parameters, a frequency response model of the new energy power system containing gravity energy storage is constructed, which specifically includes the following steps:

[0173] Obtain the system inertia constant and system damping coefficient considering gravity energy storage;

[0174] Give the relationship between the power and frequency of the power grid containing gravity energy storage, which is specifically expressed as:

[0175]

[0176] Among them, is the change in load after Laplace transform, is the primary frequency regulation power adjustment of the synchronous generator after Laplace transform, is the primary frequency regulation power adjustment of the gravity energy storage unit after Laplace transform, is the primary frequency regulation power adjustment of the wind turbine unit after Laplace transform, is the primary frequency regulation power adjustment of the photovoltaic unit after Laplace transform, is the primary frequency regulation power adjustment of the electrochemical energy storage device after Laplace transform, H sys is the system inertia constant considering gravity energy storage, s is the Laplace operator, D sys is the system damping coefficient considering gravity energy storage;

[0177] Based on the method of equivalent parameters, the frequency response mode of the wind-solar-storage device is processed, specifically expressed as:

[0178]

[0179] where, is the equivalent primary frequency regulation power adjustment of the wind-solar-storage device after Laplace transform, K U is the power gain of the wind-solar-storage device numbered U, V is the total number of wind-solar-storage devices, T V is the equivalent frequency regulation time constant of the wind-solar-storage device, s is the Laplace operator;

[0180] Build a frequency response model of the new energy power system with gravity energy storage, specifically expressed as:

[0181] Give the relationship between the power and frequency of the power grid with gravity energy storage, specifically expressed as:

[0182]

[0183] where, is the equivalent primary frequency regulation power adjustment of the wind-solar-storage device after Laplace transform.

[0184] For the above relationship between the power and frequency of the power grid with gravity energy storage, the system inertia constant considering gravity energy storage is specifically expressed as:

[0185]

[0186] where, E sys is the total kinetic energy of the system considering gravity energy storage, S G,i is the rated capacity of synchronous generator i, x G,i is the start-stop state value of synchronous generator i, n is the total number of synchronous generators, S Gra,j is the rated capacity of gravity energy storage unit j, x Gra,jis the start / stop state value of gravity energy storage unit j, m is the total number of gravity energy storage units, S N,k is the rated capacity of wind, solar and storage device k, x N,k is the start / stop status value of wind / solar / storage device k, and c is the total number of wind / solar / storage devices;

[0187] For the above relationship between power and frequency of the power grid including gravity energy storage, the system damping coefficient taking into account gravity energy storage is specifically expressed as:

[0188]

[0189] in, is the damping coefficient of the load, is the damping coefficient of synchronous generator i, is the damping coefficient of gravity energy storage unit j.

[0190] For the above relationship between the inertia constant of the gravity energy storage system and the total kinetic energy of the gravity energy storage system, it can be specifically expressed as:

[0191]

[0192] Among them, H G,i is the inertia constant of synchronous generator i, H Gra,j is the inertia constant of gravity energy storage unit j;

[0193] For power systems that include multiple types of renewable energy such as wind power, photovoltaics, electrochemical energy storage, and gravity energy storage, different renewable energy power generation units have different operating characteristics, and the complexity of the power system increases dramatically. Equivalent aggregation processing is crucial for the construction of frequency response models. It can integrate the control strategies of different renewable energy power generation units and select the optimal strategy to improve the frequency stability of the power system and more accurately predict the dynamic behavior of the power system when disturbed.

[0194] Based on the equivalent parameter method, the frequency response mode of the wind, solar and storage equipment is processed, which specifically includes the following steps:

[0195] Obtain the power gain of each wind, solar and storage device;

[0196] Based on the power gain of each wind, solar and storage device, the power gain coefficient of each wind, solar and storage device is given;

[0197] Combined with the frequency modulation time constants of each wind, solar and storage device, the frequency response mode of the wind, solar and storage device is processed, and the equivalent frequency constant of the wind, solar and storage device is given.

[0198] As mentioned above, the wind-solar-storage device includes any one of a direct-drive wind turbine, a photovoltaic unit, and an electrochemical energy storage device. The power gain of each wind-solar-storage device is specifically expressed as:

[0199]

[0200] Among them, K U is the power gain of the wind-solar-storage device numbered U, is the maximum frequency regulation power of the wind-solar-storage device numbered U, S U is the rated capacity of the wind-solar-storage device numbered U, is the frequency regulation state of the wind-solar-storage device numbered U;

[0201] In a certain embodiment, the power gain of the wind-solar-storage device is the frequency additional control proportionality coefficient of the direct-drive wind turbine, photovoltaic unit or electrochemical energy storage device.

[0202] The power gain coefficients of each wind-solar-storage device are specifically expressed as:

[0203]

[0204] Among them, is the power gain coefficient of the wind-solar-storage device numbered U, and V is the total number of wind-solar-storage devices.

[0205] In addition, the power gain coefficients of each wind-solar-storage device can be normalized, that is, the sum of the power gain coefficients of all wind-solar-storage devices is 1.

[0206] The equivalent frequency constant of the wind-solar-storage device is specifically expressed as:

[0207]

[0208] Among them, T V is the equivalent frequency regulation time constant of the wind-solar-storage device, T U is the frequency regulation time constant of the wind-solar-storage device numbered U.

[0209] In addition, based on each wind-solar-storage device of different types, the equivalent frequency constant of the wind-solar-storage device can also be specifically expressed as:

[0210]

[0211] Among them, T V is the equivalent frequency regulation time constant of the wind-solar-storage device, V1 is the total number of direct-drive wind turbines, K U1 is the power gain of the direct-drive wind turbine numbered U1, T U1 is the frequency regulation time constant of the direct-drive wind turbine numbered U1, V2 is the total number of photovoltaic units, K U2 is the power gain of the photovoltaic unit numbered U2, T U2 is the frequency regulation time constant of the photovoltaic unit numbered U2, V3 is the total number of electrochemical energy storage devices, KU3 The power gain of the electrochemical energy storage device numbered U3, T U3 is the frequency modulation time constant of the electrochemical energy storage device numbered U3.

[0212] In a second aspect, as Figure 4 shown, the present invention also provides a multi-type new energy power system stability control device based on frequency response, which adopts the above-mentioned multi-type new energy power system stability control method based on frequency response, and specifically includes:

[0213] An acquisition unit, configured to respectively obtain the frequency response modes of the synchronous generator and the wind-solar-storage device, and based on the topological structure of the vertical matrix-type gravity energy storage grid connection, give the frequency response mode of the gravity energy storage unit, wherein the wind-solar-storage device includes an electrochemical energy storage device;

[0214] A model construction unit, configured to construct a frequency response model of a multi-machine system including wind-solar-storage, and according to the frequency response model of the multi-machine system including wind-solar-storage, combine the frequency response mode of the gravity energy storage unit, and based on the method of equivalent parameters, construct a frequency response model of a new energy power system including gravity energy storage;

[0215] A stability control operation unit, configured to perform stability control on a multi-type new energy power system based on the frequency response model of the new energy power system.

[0216] The synchronous generator includes a thermal power synchronous generator set. Obtaining the frequency response mode of the synchronous generator specifically includes:

[0217] Using a low-order power system frequency response model to simulate the frequency response mode of the synchronous generator, and giving the frequency response model of the synchronous generator, wherein the frequency response model of the synchronous generator takes into account the transfer process of the turbine and the governor.

[0218] The frequency response mode of the synchronous generator is specifically expressed as:

[0219]

[0220] wherein, is the primary frequency modulation power regulation amount of the synchronous generator after Laplace transform, K m is the mechanical power gain factor, F H is the work coefficient of the high-pressure cylinder in the synchronous generator, T R is the reheat time constant, R is the primary frequency modulation droop coefficient of the governor, and s is the Laplace operator.

[0221] Obtaining the frequency response mode of the wind-solar-storage device specifically includes:

[0222] Based on a direct-drive wind turbine generator set, a photovoltaic generator set, and an electrochemical energy storage device connected to the grid through an inverter, combined with the frequency response method of additional control, the wind power frequency response method, the photovoltaic frequency response method, and the energy storage response method are given.

[0223] Construct a frequency response model of a multi-machine system with wind, light, and storage, which is specifically expressed as:

[0224]

[0225] Among them, is the primary frequency regulation power adjustment amount of the wind turbine generator set after Laplace transform, and K W is the frequency additional control proportionality coefficient of the wind turbine generator set, and T W is the frequency modulation time constant of the wind turbine generator set, is the primary frequency regulation power adjustment amount of the photovoltaic generator set after Laplace transform, and K PV is the frequency additional control proportionality coefficient of the photovoltaic generator set, and T PV is the frequency modulation time constant of the photovoltaic generator set, is the primary frequency regulation power adjustment amount of the electrochemical energy storage device after Laplace transform, and K E is the frequency additional control proportionality coefficient of the electrochemical energy storage device, and T E is the frequency modulation time constant of the electrochemical energy storage device, is the frequency deviation of the power system after Laplace transform, and s is the Laplace operator.

[0226] Based on the topological structure of the vertical matrix type gravity energy storage connected to the grid, the frequency response method of the gravity energy storage unit is given, specifically including:

[0227] Considering the time scale, a gravity energy storage speed regulation system model corresponding to the topological structure of the vertical matrix type gravity energy storage connected to the grid is given, which is specifically expressed as:

[0228]

[0229] Among them, T m_gra is the input mechanical torque of the synchronous generator, and k δ is the amplification factor of the speed governor, ω ref is the electrical angular velocity reference value of the synchronous generator, ω is the real-time electrical angular velocity of the synchronous generator, and T gra is the frequency modulation time constant of the gravity energy storage unit, and s is the Laplace operator;

[0230] Based on the gravity energy storage speed regulation system mode, the frequency response method of the gravity energy storage unit is given.

[0231] The frequency response method of the gravity energy storage unit is specifically expressed as:

[0232]

[0233] Among them, is the primary frequency regulation power adjustment amount of the gravity energy storage unit after Laplace transform, and K gra_s is the proportional coefficient of the power response amount of gravity energy storage, and T gra is the frequency regulation time constant of the gravity energy storage unit, is the frequency deviation of the power system after Laplace transform, and s is the Laplace operator.

[0234] According to the frequency response model of a multi-machine system with wind, light and energy storage, combined with the frequency response mode of the gravity energy storage unit, and based on the method of equivalent parameters, a frequency response model of a new energy power system with gravity energy storage is constructed, which specifically includes:

[0235] Obtain the system inertia constant and system damping coefficient considering gravity energy storage;

[0236] Give the relationship between the grid power and frequency with gravity energy storage, which is specifically expressed as:

[0237]

[0238] Among them, is the load change amount after Laplace transform, is the primary frequency regulation power adjustment amount of the synchronous generator after Laplace transform, is the primary frequency regulation power adjustment amount of the gravity energy storage unit after Laplace transform, is the primary frequency regulation power adjustment amount of the wind turbine unit after Laplace transform, is the primary frequency regulation power adjustment amount of the photovoltaic unit after Laplace transform, is the primary frequency regulation power adjustment amount of the electrochemical energy storage device after Laplace transform, and H sys is the system inertia constant considering gravity energy storage, s is the Laplace operator, and D sys is the system damping coefficient considering gravity energy storage;

[0239] Based on the method of equivalent parameters, process the frequency response mode of the wind, light and energy storage equipment, which is specifically expressed as:

[0240]

[0241] Among them, is the equivalent primary frequency regulation power adjustment amount of the wind, light and energy storage equipment after Laplace transform, and K U is the power gain of the wind, light and energy storage equipment numbered U, V is the total number of wind, light and energy storage equipment, and T V is the equivalent frequency regulation time constant of the wind, light and energy storage equipment, and s is the Laplace operator;

[0242] Build a frequency response model of a new energy power system with gravity energy storage, specifically expressed as:

[0243] Give the relationship between the power and frequency of the power grid with gravity energy storage, specifically expressed as:

[0244]

[0245] Where, is the primary frequency regulation power adjustment amount equivalent to the wind-solar-storage equipment after Laplace transform.

[0246] The system inertia constant considering gravity energy storage is specifically expressed as:

[0247]

[0248] Where, E sys is the total kinetic energy of the system considering gravity energy storage, S G,i is the rated capacity of synchronous generator i, x G,i is the start-stop state value of synchronous generator i, n is the total number of synchronous generators, S Gra,j is the rated capacity of gravity energy storage unit j, x Gra,j is the start-stop state value of gravity energy storage unit j, m is the total number of gravity energy storage units, S N,k is the rated capacity of wind-solar-storage equipment k, x N,k is the start-stop state value of wind-solar-storage equipment k, c is the total number of wind-solar-storage equipment;

[0249] The system damping coefficient considering gravity energy storage is specifically expressed as:

[0250]

[0251] Where, is the damping coefficient of the load, is the damping coefficient of synchronous generator i, is the damping coefficient of gravity energy storage unit j.

[0252] The total kinetic energy of the system considering gravity energy storage is specifically expressed as:

[0253]

[0254] Where, H G,i is the inertia constant of synchronous generator i, H Gra,j is the inertia constant of gravity energy storage unit j;

[0255] Based on the equivalent parameter method, process the frequency response mode of the wind-solar-storage equipment, specifically including:

[0256] Obtain the power gain of each wind-solar-storage equipment;

[0257] Based on the power gain of each wind-solar-storage device, the power gain coefficient of each wind-solar-storage device is given;

[0258] Combined with the frequency modulation time constant of each wind-solar-storage device, the processing of the frequency response mode of the wind-solar-storage device is completed, and the equivalent frequency constant of the wind-solar-storage device is given.

[0259] The power gain of each wind-solar-storage device is specifically expressed as:

[0260]

[0261] where K U is the power gain of the wind-solar-storage device numbered U, is the maximum frequency modulation power of the wind-solar-storage device numbered U, S U is the rated capacity of the wind-solar-storage device numbered U, is the frequency modulation state of the wind-solar-storage device numbered U;

[0262] The power gain coefficient of each wind-solar-storage device is specifically expressed as:

[0263]

[0264] where, is the power gain coefficient of the wind-solar-storage device numbered U, and V is the total number of wind-solar-storage devices.

[0265] The equivalent frequency constant of the wind-solar-storage device is specifically expressed as:

[0266]

[0267] where T V is the equivalent frequency modulation time constant of the wind-solar-storage device, T U is the frequency modulation time constant of the wind-solar-storage device numbered U.

[0268] Furthermore, the equivalent frequency constant of the wind-solar-storage device can also be specifically expressed as:

[0269]

[0270] where T V is the equivalent frequency modulation time constant of the wind-solar-storage device, V1 is the total number of direct-drive wind turbines, K U1 is the power gain of the direct-drive wind turbine numbered U1, T U1 is the frequency modulation time constant of the direct-drive wind turbine numbered U1, V2 is the total number of photovoltaic units, K U2 is the power gain of the photovoltaic unit numbered U2, T U2is the frequency modulation time constant of the photovoltaic unit numbered U2, V3 is the total number of electrochemical energy storage devices, K U3 is the power gain of the electrochemical energy storage device numbered U3, T U3 is the frequency modulation time constant of the electrochemical energy storage device numbered U3.

[0271] A multi-type new energy power system stability control method and device based on frequency response provided by the present invention has at least the following beneficial effects:

[0272] (1) By proposing a modeling scheme considering the participation of gravity energy storage in the power system frequency response link, based on the operating characteristics of gravity energy storage and the way of participating in the system frequency response, and aiming at the frequency response mode of the multi-machine system with wind, light and storage, the frequency response characteristics of the power system with gravity energy storage are accurately depicted.

[0273] (2) According to the frequency response model of the multi-machine system with wind, light and storage, combined with the frequency response mode of the gravity energy storage unit, and based on the method of equivalent parameters, a frequency response model of the new energy power system with gravity energy storage is constructed. By directly integrating the actual dynamic characteristics of the gravity energy storage unit into the frequency response model of the multi-machine system with wind, light and storage, the frequency response behavior of the power system under various working conditions can be more accurately simulated and predicted, effectively supporting the power system frequency, reducing the frequency deviation caused by the fluctuation of new energy power generation, and thus improving the frequency stability of the power system.

[0274] (3) For a power system that simultaneously includes multiple types of new energy such as wind power, photovoltaic power, electrochemical energy storage, and gravity energy storage, different new energy power generation units have different operating characteristics, and the complexity of the power system suddenly increases. Equivalent aggregation processing is crucial for the construction of the frequency response model, which can integrate the control strategies of different new energy power generation units, select the optimal strategy to improve the frequency stability of the power system, and more accurately predict the dynamic behavior of the power system when it is disturbed.

[0275] The present invention also provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, it implements the multi-type new energy power system stability control method based on frequency response described in any one of the above.

[0276] Specifically, a computer device may include one or more processing devices, such as one or more central processing units (CPUs), and each processing unit may implement one or more hardware threads. The computer device may also include any storage resources for storing any kind of information such as code, settings, data, etc. Non-limiting examples include any one or a combination of the following: any type of RAM, any type of ROM, flash devices, hard disks, optical discs, etc. More generally, any storage resource may use any technology to store information.

[0277] Furthermore, any storage resource may provide volatile or non-volatile retention of information. Further, any storage resource may represent a fixed or removable component of the computer device. In one case, when the processing device executes the associated instructions stored in any storage resource or combination of storage resources, the computer device may perform any operation of the associated instructions. The computer device also includes one or more drive mechanisms for interacting with any storage resource, such as a hard disk drive mechanism, an optical disc drive mechanism, etc.

[0278] The computer device may also include an input / output module (I / O) for receiving various inputs (via input devices) and for providing various outputs (via output devices). A specific output mechanism may include a presentation device and an associated graphical user interface (GUI). In other embodiments, the input / output module (I / O), input devices, and output devices may not be included, and it may only act as a computer device in a network. The computer device may also include one or more network interfaces for exchanging data with other devices via one or more communication links. One or more communication buses couple the components described above together.

[0279] The communication link may be implemented in any way, for example, through a local area network, a wide area network (e.g., the Internet), a point-to-point connection, etc., or any combination thereof. The communication link may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc. governed by any protocol or combination of protocols.

[0280] The beneficial effects achieved by the above devices and apparatuses are consistent with those achieved by the above method, and are not elaborated in the embodiments of this specification.

[0281] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn the basic inventive concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A frequency response-based multi-type renewable energy power system stabilization method, characterized in that: The specific steps include: The frequency response modes of synchronous generators and wind, solar and storage devices are obtained respectively, and a frequency response model of a multi-machine system including wind, solar and storage is constructed, wherein the wind, solar and storage devices include electrochemical energy storage devices; Based on the topological structure of vertical matrix gravity energy storage grid-connected, the frequency response mode of gravity energy storage unit is given; The system inertia constant and system damping coefficient taking into account the gravity energy storage are obtained, wherein the system inertia constant taking into account the gravity energy storage is specifically expressed as: ； Among them, E sys is the total kinetic energy of the system taking into account the gravity energy storage, S G,i is the rated capacity of synchronous generator i, x G,i is the start / stop state value of synchronous generator i, n is the total number of synchronous generators, S Gra,j is the rated capacity of gravity energy storage unit j, x Gra,j is the start / stop state value of gravity energy storage unit j, m is the total number of gravity energy storage units, S N,k is the rated capacity of wind, solar and storage device k, x N,k is the start / stop status value of wind / solar / storage device k, and c is the total number of wind / solar / storage devices; The system damping coefficient taking into account gravity energy storage is specifically expressed as: ； in, is the damping coefficient of the load, is the damping coefficient of synchronous generator i, is the damping coefficient of gravity energy storage unit j; The relationship between the power and frequency of the power grid with gravity energy storage is given, which is specifically expressed as: ； in, is the load change after Laplace transformation, is the primary frequency modulation power regulation of the synchronous generator after Laplace transformation, is the primary frequency regulation power adjustment value of the gravity energy storage unit after Laplace transformation, is the primary frequency regulation power regulation of the wind turbine after Laplace transform, is the primary frequency modulation power regulation value of the photovoltaic unit after Laplace transformation, is the primary frequency modulation power regulation value of the electrochemical energy storage device after Laplace transformation, H sys is the system inertia constant taking into account the gravitational energy storage, s is the Laplace operator, and D sys is the system damping coefficient taking into account gravity energy storage; Based on the method of equivalent parameters, the frequency response mode of the wind, solar and storage devices is processed, which specifically includes the following steps: obtaining the power gain of each wind, solar and storage device; based on the power gain of each wind, solar and storage device, giving the power gain coefficient of each wind, solar and storage device; combining the frequency modulation time constant of each wind, solar and storage device, completing the processing of the frequency response mode of the wind, solar and storage device, and giving the equivalent frequency constant of the wind, solar and storage device; Construct a frequency response model of a new energy power system with gravity energy storage; Based on the frequency response model of renewable energy power system, stability control is carried out for various types of renewable energy power systems.

2. The multi-type new energy power system stabilization control method based on frequency response as claimed in claim 1 is characterized in that: The synchronous generator includes a thermal power synchronous generator set, and the frequency response mode of the synchronous generator is obtained, specifically including: The frequency response mode of the synchronous generator is simulated by a low-order power system frequency response model, and a frequency response model of the synchronous generator is given. The frequency response model of the synchronous generator takes into account the transmission process between the turbine and the speed regulator.

3. The multi-type new energy power system stabilization control method based on frequency response as claimed in claim 1 is characterized in that: Obtain the frequency response mode of wind, solar and storage equipment, including: Based on the direct-drive wind turbines, photovoltaic units and electrochemical energy storage devices connected to the grid via converters, combined with the frequency response method of additional control, wind power frequency response method, photovoltaic frequency response method and energy storage response method are given.

4. The multi-type new energy power system stabilization control method based on frequency response as claimed in claim 3 is characterized in that: The frequency response model of a multi-machine system including wind, solar and storage is constructed, which is specifically expressed as follows: ； in, is the primary frequency regulation power regulation of the wind turbine after Laplace transformation, K W is the additional control proportional coefficient of the frequency of the wind turbine, T W is the frequency modulation time constant of the wind turbine, is the primary frequency modulation power regulation of the photovoltaic unit after Laplace transformation, K PV is the additional control proportional coefficient of the frequency of the photovoltaic unit, T PV is the frequency modulation time constant of the photovoltaic unit, K is the primary frequency modulation power regulation of the electrochemical energy storage device after Laplace transformation, E is the frequency additional control proportional coefficient of the electrochemical energy storage device, T E is the frequency modulation time constant of the electrochemical energy storage device, is the frequency deviation of the power system after Laplace transformation, and s is the Laplace operator.

5. The multi-type new energy power system stabilization control method based on frequency response as claimed in claim 1, characterized in that: Based on the topological structure of vertical matrix gravity energy storage grid-connected, the frequency response mode of gravity energy storage unit is given, which specifically includes the following steps: Taking the time scale into account, the gravity energy storage speed regulation system model corresponding to the topological structure of vertical matrix gravity energy storage grid-connected is given, which is specifically expressed as: ； Among them, T m_gra is the input mechanical torque of the synchronous generator, k δ is the amplification factor of the speed regulator, ω ref is the reference value of the electrical angular velocity of the synchronous generator, ω is the real-time electrical angular velocity of the synchronous generator, T gra is the frequency modulation time constant of the gravity energy storage unit, s is the Laplace operator; Based on the gravity energy storage speed regulation system mode, the frequency response mode of the gravity energy storage unit is given.

6. The multi-type new energy power system stabilization control method based on frequency response as claimed in claim 5 is characterized in that: The frequency response mode of the gravity energy storage unit is specifically expressed as follows: ； in, is the primary frequency regulation power adjustment value of the gravity energy storage unit after Laplace transformation, K gra_s is the proportionality coefficient of the power response of gravity energy storage, T gra is the frequency modulation time constant of the gravity energy storage unit, is the frequency deviation of the power system after Laplace transformation, and s is the Laplace operator.

7. A multi-type new energy power system stabilization control device based on frequency response, characterized in that: The method for stabilizing a multi-type renewable energy power system based on frequency response as claimed in any one of claims 1 to 6 specifically comprises: The acquisition unit is used to obtain the frequency response modes of the synchronous generator and the wind, solar and storage devices respectively, and give the frequency response mode of the gravity energy storage unit based on the topological structure of the vertical matrix gravity energy storage grid connection, wherein the wind, solar and storage devices include electrochemical energy storage devices; A model building unit is used to build a frequency response model of a multi-machine system including wind, solar and storage. According to the frequency response model of the multi-machine system including wind, solar and storage, combined with the frequency response mode of the gravity energy storage unit, and based on the equivalent parameter method, a frequency response model of a new energy power system including gravity energy storage is built; The stabilization and control operation unit is used to perform stabilization and control on various types of renewable energy power systems based on the frequency response model of renewable energy power systems.

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